Laboratory Diet Research Articles

The effect of laboratory diet and feeding on growth parameters in juvenile zebrafish

Despite being one of the most used laboratory species in biomedical, behavioral and physiological research, the nutritional requirements of zebrafish (Danio rerio) are poorly understood, and no standardized laboratory diet exists. Diet and feeding regimen can substantially impact the welfare of the fish and, in turn, experimental reproducibility. Consequently, the establishment of a standardized diet and feeding protocol for laboratory zebrafish is imperative to enhance animal welfare, guarantee research reproducibility and advance the economic and environmental sustainability of laboratory dietary practices. Here the aim of this systematic review is to provide an overview of the parameters that need to be standardized in future nutritional studies to facilitate future meta-analyses for confirmation of an optimal juvenile diet for growth. A comprehensive search was conducted in PubMed and Scopus to identify relevant studies published up to August 2023, and the studies were selected on the basis of the predefined inclusion/exclusion criteria. The databases yielded a total of 1,065 articles, of which 14 were included in this review. We conducted data extraction and risk-of-bias analysis in the included studies. Statistical comparisons for specific growth rate, weight gain (%) and length gain (%) parameters were performed to determine the optimal feed for enhanced juvenile growth. We identified significant heterogeneity and caveats to our findings owing to a lack of standardization of experimental conditions in nutritional studies. Our findings highlight an urgent need for research on zebrafish nutrition. Therefore, the standardized parameters we have reported here represent a critical starting point for studies.

A long-term high-fat diet induces differential gene expression changes in spatially distinct adipose tissue of male mice.

The accumulation of visceral adipose tissue (VAT) is strongly associated with cardiovascular disease and diabetes. In contrast, individuals with increased subcutaneous adipose tissue (SAT) without corresponding increases in VAT are associated with a metabolic healthy obese phenotype. These observations implicate dysfunctional VAT as a driver of disease processes, warranting investigation into obesity-induced alterations of distinct adipose depots. To determine the effects of obesity on adipose gene expression, male mice (n = 4) were fed a high-fat diet to induce obesity or a normal laboratory diet (lean controls) for 12-14 mo. Mesenteric VAT and inguinal SAT were isolated for bulk RNA sequencing. AT from lean controls served as a reference to obesity-induced changes. The long-term high-fat diet induced the expression of 169 and 814 unique genes in SAT and VAT, respectively. SAT from obese mice exhibited 308 differentially expressed genes (164 upregulated and 144 downregulated). VAT from obese mice exhibited 690 differentially expressed genes (262 genes upregulated and 428 downregulated). KEGG pathway and GO analyses revealed that metabolic pathways were upregulated in SAT versus downregulated in VAT while inflammatory signaling was upregulated in VAT. We next determined common genes that were differentially regulated between SAT and VAT in response to obesity and identified four genes that exhibited this profile: elovl6 and kcnj15 were upregulated in SAT/downregulated in VAT while trdn and hspb7 were downregulated in SAT/upregulated in VAT. We propose that these genes in particular should be further pursued to determine their roles in SAT versus VAT with respect to obesity.NEW & NOTEWORTHY A long-term high-fat diet induced the expression of more than 980 unique genes across subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT). The high-fat diet also induced the differential expression of nearly 1,000 AT genes. We identified four genes that were oppositely expressed in SAT versus VAT in response to the high-fat diet and propose that these genes in particular may serve as promising targets aimed at resolving VAT dysfunction in obesity.

Evaluation of antidiabetic activities of linseed (linum usitatissimum l.) Sprout extracts in adult Streptozotocin-induced (a-stz) long-evan rats

The study investigates the anti-diabetic properties of linsseed (Linum usitatissimum L.) sprout extracts in adult streptozotocin (STZ)-induced Long-Evan rats, addressing the limitations of existing treatment strategies in Bangladesh. The diabetic rats were administered orally with 400 mg/kg body weight of methanolic extracts of linseed sprout with a lab diet and glibenclamide as a positive control. Blood sugar levels were measured before, after, and after STZ injection in Long- Evan rats. The lipid profiles and liver function tests were performed. Administration of extracts of linseed sprouts and a standard anti-diabetic drug reduced the glucose level from 9.1 mmol/l to 6.0 mmol/l and 10.5 mmol/l to 6.6 mmol/l , respectively. The study also showed a healthy level of liver function tests and lipid profiles. The in vivo analysis of the potential antidiabetic activity of linseed sprouts in the STZ-induced diabetic mouse model might be used to treat and manage diabetes. Bangladesh J. Bot. 53(3): 503-510, 2024 (September)

Renal Proximal Tubule Cell-specific Megalin Deletion Does Not Affect Atherosclerosis But Induces Tubulointerstitial Nephritis in Mice Fed Western Diet.

Pharmacological inhibition of megalin (also known as low-density lipoprotein receptor-related protein 2: LRP2) attenuates atherosclerosis in hypercholesterolemic mice. Since megalin is abundant in renal proximal tubule cells (PTCs), the purpose of this study was to determine whether PTC-specific deletion of megalin reduces hypercholesterolemia-induced atherosclerosis in mice. Female Lrp2 f/f mice were bred with male Ndrg1-Cre ERT2 +/0 mice to develop PTC-LRP2 +/+ and -/- littermates. To study atherosclerosis, all mice were bred to an LDL receptor -/- background and fed a Western diet to induce atherosclerosis. PTC-specific megalin deletion did not attenuate atherosclerosis in LDL receptor -/- mice in either sex. Serendipitously, we discovered that PTC-specific megalin deletion led to interstitial infiltration of CD68+ cells and tubular atrophy. The pathology was only evident in male PTC-LRP2 -/- mice fed the Western diet, but not in mice fed a normal laboratory diet. Renal pathologies were also observed in male PTC-LRP2 -/- mice in an LDL receptor +/+ background fed the same Western diet, demonstrating that the renal pathologies were dependent on diet and not hypercholesterolemia. In contrast, female PTC-LRP2 -/- mice had no apparent renal pathologies. In vivo multiphoton microscopy demonstrated that PTC-specific megalin deletion dramatically diminished albumin accumulation in PTCs within 10 days of Western diet feeding. RNA sequencing analyses demonstrated the upregulation of inflammation-related pathways in kidney. PTC-specific megalin deletion does not affect atherosclerosis, but leads to tubulointerstitial nephritis in mice fed Western diet, with severe pathologies in male mice.

Intake of Special Amino Acids Mixture Leads to Blunted Murine Colon Cancer Growth In Vitro and In Vivo.

Cancer cells require substantial amounts of energy and substrates for their metabolic hyperactivity, enabling the synthesis of new cells at the expense of healthy ones. Preliminary in vitro data suggest that a mix of free essential amino acids (EAA-mix) can promote cancer cell apoptosis by enhancing autophagy. This study aimed to confirm, both in vitro and in vivo, whether EAA intake could influence the development of colon cancer in mice. We investigated changes in cancer proliferation in CT26 cells treated with EAA-mix and in mice fed with EAA-rich modified diets (EAARD) as compared to those on a standard laboratory diet (StD). CT26 cells were injected subcutaneously (s.c.) or intraperitoneally (i.p.). After 21 days, tumors were removed and measured. In vitro data corroborated that EAA-mix impairs cancer growth by inducing apoptosis. In vivo data revealed that mice on StD developed significantly larger (s.c.) and more numerous (i.p.) cancers than those on EAARD. EAA administration appears to influence cancer cell survival with notable antiproliferative properties.

P-638 Paternal Consumption of Caloric and Non-Caloric Sweeteners is Associated with Sex-Specific Differences in Reproductive outcomes in offspring

Abstract Study question Does paternal pre-conception consumption of caloric or non-caloric sweeteners (NCS) coupled with high fat diets (HFD) predispose offspring to early puberty onset in mice? Summary answer Paternal prenatal consumption of the NCS Rebaudioside A(RebA) resulted in early puberty onset in female offspring only compared to water and caloric sweetener groups. What is known already A growing body of evidence suggests that the paternal diet also influences health and disease onset in offspring. Early puberty onset is associated with metabolic syndrome, type 2 diabetes, and cardiovascular disease later in adulthood. NCS are often promoted as heathier alternatives to caloric sweeteners. Evidence examining the impact of NCS on male reproductive function and offspring health outcomes, including pubertal timing are lacking. Few studies have shown maternal HFD can contribute to early puberty onset in female offspring however to our knowledge this is the first study to investigate paternal diet and offspring reproductive outcomes. Study design, size, duration 32 6-week-old C57/BL6 male mice were randomly assigned to receive a control diet (CD) or HF plus water (Con), fructose (Fr), Acesulfame K (Ak) or RebA). After 8 weeks, mice were mated. Litters were standardised to 2 males and 2 females per group and fed a standard laboratory diet. Participants/materials, setting, methods Puberty onset was measured in females by vaginal opening (from postnatal day (PN28) and in males by preputial separation (from PN35). Oral glucose tolerance tests were carried out at PN70. Mice were culled from PN80. Data were analysed by repeated measures or 2-way ANOVA. Main results and the role of chance There were no significant differences in birth weight, sex ratio or organ weights across groups. There was an overall effect of paternal NCS on male but not female offspring weight[CR1] at cull(p < 0.05), with male CDRebA offspring having increased BW (29.52g±1.5) compared with CDAk at PN80 (26.4g±3; p < 0.05). Females from paternal HF and CD RebA group [CR2] entered puberty significantly earlier (31.8d±1) than Fr (34d±1;p<0.01) and Con (34±1;p<0.05) groups. Male offspring from HFAk had lower glucose AUC (913±31) compared with CDCon (1289±48;p<0.001). Female offspring from CDRebA (1263±84) and CDFr (1273±67) groups had lower glucose AUC compared with CDCon group (1445±56;p<0.05). Limitations, reasons for caution This study was carried out on mice therefore direct translatability to humans is limited. examining the impact of paternal NCS intakes on molecular pathways in the ovary and testes to assess offspring reproductive health later in life and to evaluate pregnancy success following mating would essential for providing further insight. Wider implications of the findings The present study adds to the experimental evidence to date suggesting that NCS may not be beneficial alternatives to sugar-sweetened products consumed preconceptionally on the health of the offspring. This study also highlights the importance of including paternal diet in research when looking at transgenerational effects. Trial registration number not applicable

IL-1β Inhibition Partially Negates the Beneficial Effects of Diet-Induced Atherosclerosis Regression in Mice.

Thromboembolic events secondary to rupture or erosion of advanced atherosclerotic lesions is the global leading cause of death. The most common and effective means to reduce these major adverse cardiovascular events, including myocardial infarction and stroke, is aggressive lipid lowering via a combination of drugs and dietary modifications. However, we know little regarding the effects of reducing dietary lipids on the composition and stability of advanced atherosclerotic lesions, the mechanisms that regulate these processes, and what therapeutic approaches might augment the benefits of lipid lowering. Smooth muscle cell lineage-tracing Apoe-/- mice were fed a high-cholesterol Western diet for 18 weeks and then a zero-cholesterol standard laboratory diet for 12 weeks before treating them with an IL (interleukin)-1β or control antibody for 8 weeks. We assessed lesion size and remodeling indices, as well as the cellular composition of aortic and brachiocephalic artery lesions, indices of plaque stability, overall plaque burden, and phenotypic transitions of smooth muscle cell and other lesion cells by smooth muscle cell lineage tracing combined with single-cell RNA sequencing, cytometry by time-of-flight, and immunostaining plus high-resolution confocal microscopic z-stack analysis. Lipid lowering by switching Apoe-/- mice from a Western diet to a standard laboratory diet reduced LDL cholesterol levels by 70% and resulted in multiple beneficial effects including reduced overall aortic plaque burden, as well as reduced intraplaque hemorrhage and necrotic core area. However, contrary to expectations, IL-1β antibody treatment after diet-induced reductions in lipids resulted in multiple detrimental changes including increased plaque burden and brachiocephalic artery lesion size, as well as increasedintraplaque hemorrhage, necrotic core area, and senescence as compared with IgG control antibody-treated mice. Furthermore, IL-1β antibody treatment upregulated neutrophil degranulation pathways but downregulated smooth muscle cell extracellular matrix pathways likely important for the protective fibrous cap. Taken together, IL-1β appears to be required for the maintenance of standard laboratory diet-induced reductions in plaque burden and increases in multiple indices of plaque stability.

Diet Shifts Alter the Activity and Distribution of Digestive Enzymes in an Herbivorous Fish

The digestive tract is central to the function of an animal since it assimilates nutrients from the diet. Digestion itself is a chemical process and digestive enzymes are the digestive catalysts. Thus, we measured amylase, maltase, N-acetyl-b-d-glucosaminidase, lipase, trypsin, aminopeptidase, and alkaline phosphatase activities along the digestive tract of the marine herbivorous fish, Cebidichthys violaceus. We did this for wild-caught individuals of this species, and compared those to individuals fed carnivore, omnivore, and herbivore diets in the laboratory for six months. In laboratory fish, the enzymatic activities were generally lower compared to wild-caught fish. In wild caught fish, a strong anterior-to-posterior gradient of amylase activity was observed along the gut and this pattern largely disappeared in the lab-fed fish. N-acetyl-β-D-glucosaminidase (NAGase), which breaks down chitin products, showed an increase in activity in the distal intestines of the lab-fed fish, which is not observed in wild fish. The NAGase activity of the herbivorous fishes correlate with the bacterial species Paroccus sp., which is a known NAGase producer, and one of the dominant microbes in the distal intestines of the lab-fed fish. The role of this enzyme, however, remains unclear since the lab diets did not contain large amounts of chitin. These enzymatic differences tell us how much fish can modify their enzymatic activity to align with their diet. In summary, the findings show that C. violaceous can endure different degrees of protein and carbohydrate levels, within limits. Their digestive system clearly changed in response to more protein in the diet, along with a microbiome that had more potential pathogens. Live algal diets would may be the most suitable for this herbivorous fish based on the totality of gathered data from the lab. American Physiological Society Fellowship UCI Microbiome Initiative Grant. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Transgenic Overexpression of HDAC9 Promotes Adipocyte Hypertrophy, Insulin Resistance and Hepatic Steatosis in Aging Mice.

Histone deacetylase (HDAC) 9 is a negative regulator of adipogenic differentiation, which is required for maintenance of healthy adipose tissues. We reported that HDAC9 expression is upregulated in adipose tissues during obesity, in conjunction with impaired adipogenic differentiation, adipocyte hypertrophy, insulin resistance, and hepatic steatosis, all of which were alleviated by global genetic deletion of Hdac9. Here, we developed a novel transgenic (TG) mouse model to test whether overexpression of Hdac9 is sufficient to induce adipocyte hypertrophy, insulin resistance, and hepatic steatosis in the absence of obesity. HDAC9 TG mice gained less body weight than wild-type (WT) mice when fed a standard laboratory diet for up to 40 weeks, which was attributed to reduced fat mass (primarily inguinal adipose tissue). There was no difference in insulin sensitivity or glucose tolerance in 18-week-old WT and HDAC9 TG mice; however, at 40 weeks of age, HDAC9 TG mice exhibited impaired insulin sensitivity and glucose intolerance. Tissue histology demonstrated adipocyte hypertrophy, along with reduced numbers of mature adipocytes and stromovascular cells, in the HDAC9 TG mouse adipose tissue. Moreover, increased lipids were detected in the livers of aging HDAC9 TG mice, as evaluated by oil red O staining. In conclusion, the experimental aging HDAC9 TG mice developed adipocyte hypertrophy, insulin resistance, and hepatic steatosis, independent of obesity. This novel mouse model may be useful in the investigation of the impact of Hdac9 overexpression associated with metabolic and aging-related diseases.

Spirulina (Arthrospira platensis) supplementation: Impact on growth, metabolism, and antioxidant status in zebrafish

AbstractZebrafish (Danio rerio) is a valuable model for biomedical research because of its mammalian genetic similarities, rapid reproduction, and low maintenance costs. However, further investigation is required regarding their nutritional requirements and standardized laboratory diets. This study evaluated the metabolic and growth responses of zebrafish juveniles fed on diets supplemented with spirulina, Arthrospira platensis (SP) at different levels for 77 days. Six diets with SP inclusion levels of 0%, 2%, 4%, 6%, 8%, and 10% (SP0‐SP10) were formulated. A total of 300 zebrafish juveniles with an average initial weight of 0.113 ± 0.10 g (mean ± SD) were randomly distributed across six groups, with five replicates per group, each containing 10 animals. After 77 days, the SP6 group demonstrated significantly enhanced growth performance compared with the other supplementation levels. The condition factor was markedly higher in the SP6 and SP8 groups than in the SP0 group. No significant effects on total cholesterol levels were observed, but the SP4, SP6, and SP10 diets decreased triglyceride levels. Lipase activity was higher in the SP6 and SP8 groups than in the control group, whereas amylase activity showed no significant differences between treatments. Catalase and superoxide dismutase activities were significantly higher in the SP8 and SP10 groups than in the SP0 and SP2 groups. Glutathione S‐transferase activity was higher in the SP6, SP8, and SP10 groups than in the SP0 group. In addition, SP inclusion in zebrafish diets improved female gonadal development. In conclusion, this study indicates that SP supplementation has substantial potential as a growth promoter, positively influencing lipid metabolism and antioxidant enzyme activity without affecting zebrafish survival.

Dietary E. coli promotes age-dependent chemotaxis decline in C. elegans

An animal’s ability to sense odors declines during aging, and its olfactory drive is tuned by internal states such as satiety. However, whether internal states modulate an age-dependent decline in odor sensation is unknown. To address this issue, we utilized the nematode Caenorhabditis elegans and compared their chemotaxis abilities toward attractive odorants when aged under different dietary conditions. Feeding with the standard laboratory diet, Escherichia coli attenuated the chemotaxis ability toward diacetyl, isoamyl alcohol, and benzaldehyde when aged. On the other hand, feeding with either the lactic acid bacteria Lactobacillus reuteri or food deprivation selectively maintained the chemotaxis ability toward diacetyl. Our results suggest that ingestion of E. coli causes age-dependent chemotaxis decline. The changes in the chemotaxis behavior are attributed to the different expressions of diacetyl receptor odr-10, and the chemotaxis behavior of aged animals under food deprivation is shown to be dependent on daf-16. Our study demonstrates the molecular mechanism of how diet shapes the trajectory of age-dependent decline in chemosensory behaviors.

Impact of numerous larval diets on the biology of pink bollworm Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) under laboratory conditions

BackgroundPink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) has become a potential pest of cotton by causing substantial yield losses around the world including Pakistan. Keeping in view the facts like limited research investigations, unavailability, and high cost of artificial diet’s constituents and their premixes, the present research investigations on the dietary aspect of P. gossypiella were conducted. The larvae of P. gossypiella were reared on different diets that were prepared using indigenous elements. The standard/laboratory diet comprised of wheat germ meal 34.5 g, casein 30.0 g, agar–agar 20.0 g, sucrose 10.0 g, brewer’s yeast 5.0 g, α-cellulose 1.0 g, potassium-sorbate1.5 g, niplagin 0.5 g, decavitamin 0.01 g, choline-chloride 0.06 g, maize-oil 3.30 g, honey 2.0 g, and water 730.0 mL. Alternatives to cotton bolls and wheat germ meal were okra seed sprouts, okra fruit, cottonseed meal, and okra seed meals, which were included in the study to introduce an efficient and economic mass-rearing system.ResultsThe larval development completed in 19.68 d ± 0.05 d with a weight of 20.18 mg ± 0.20 mg at the fourth instar fed on the cottonseed meal-based diet instead of wheat germ meal based diet. On the same diet, 84.00% ± 4.00%, 17.24 mg ± 0.03 mg, and 7.76 d ± 0.06 d were recorded as pupae formation, pupal weight, and pupal duration, respectively. Adult emergence, 76.00% ± 1.00% was recorded from pupae collected from larvae raised on cottonseed meal-based diet. These male and female moths lived for 40.25 d ± 0.10 d, and 44.34 d ± 0.11 d, respectively. Females deposited 21.28 ± 0.04 eggs per day with the viability of 65.78% ± 0.14%. The larval mortality at the fourth instar was 37.20% ± 1.36% and malformed pupation of 12.00% ± 1.41% was recorded. Replacement of wheat germ meal with that of local meals (cottonseed and okra seed) in the standard laboratory diet has saved 463.80 to 467.10 PKR with 1.62 to 1.63 cost economic returns, respectively.ConclusionThis research is of novel nature as it provides a concise and workable system for the economic and successful rearing of P. gossypiella under laboratory conditions.

A biodynamic model predicting copper and cadmium bioaccumulation in caddisflies: Linkages between field studies and laboratory exposures.

Hydropsyche and Arctopsyche are filter-feeding caddisflies (Order: Trichoptera; Family: Hydropsychidae) that are commonly used to monitor metal exposures in rivers. While tissue residue concentrations provide important bioaccumulation data regarding metal bioavailability, they do not provide information regarding the mechanisms of uptake and loss, or exposure history. This study examined the physiological processes that control Cu and Cd uptake and loss using a biokinetic bioaccumulation model. Larvae of each taxon were experimentally exposed to either water or food enriched with stable isotopes (65Cu and 106Cd). Dissolved Cu uptake (ku) was similar between species (2.6-3.4 L-1g 1d-1), but Cd uptake was 3-fold higher in Hydropsyche than Arctopsyche (1.85 L-1g 1d-1 and 0.60 L-1g 1d-1, respectively). Cu and Cd efflux rates (ke) were relatively fast (0.14 d-1-0.24 d-1) in both species, and may explain, in part, their metal tolerance to mine-impacted rivers. Food ingestion rates (IR), assimilation efficiency (AE) of 65Cu and 106Cd from laboratory diets were also derived and used in a biodynamic model to quantify the relative contribution of dissolved and dietary exposure routes. Results from the biodynamic model were compared to tissue concentrations observed in a long-term field study and indicated that because dissolved Cu and Cd exposures accounted for less than 20% of body concentrations of either taxon, dietary exposure was the predominant metal pathway. An estimation of exposure history was determined using the model to predict steady state concentrations. Under constant exposure conditions (dissolved plus diet), steady state concentrations were reached in less than 30 days, an outcome largely influenced by rapid efflux (ke).

<i>In vivo</i> Antihyperlipidemic and Antioxidant Effect of Oil Extracted from <i>Sardinella maderensis </i>(Lowe, 1838) on Strain <i>Wistar</i> Rats

Cardiovascular diseases (CVD) are one of the leading causes of death and disability, the main cause of which is hyperlipidemia. This work aimed to evaluate the antihyperlipidemic and antioxidant <i>in vivo</i> potential of oil extracted from <i>Sardinella maderensis </i>on rats. The oil was extracted according to the method of Bligh and Dyer and underwent chemical analysis prior to in vivo assays. After studying <i>in vivo</i> the acute toxicity of <i>S. maderensis </i>oil, their antihyperlipidemic was assessed. Twenty-four male <i>Wistar</i> adult rats were randomly divided into four groups of 6 rats each. During a three-week experiment, group 1 was fed with standard laboratory diet (SLD); group 2 received SLD supplemented with boiled egg yolk (5 g/day/rat); group 3 was fed with SLD supplemented with <i>S. maderensis </i>oil (1 g/day/kg of body mass) and group 4 was fed with SLD supplemented with boiled egg yolk and <i>S. maderensis </i>oil. Liver, lung, kidney, adipose tissues and heart were later removed, weighted and analyzed. Some blood biochemical and oxidative stress parameters were also measured. Results showed that <i>S. maderensis</i> oil was siccative, good quality with a lethal dose greater than 5000 mg/Kg of CP and no signs of toxicity were observed. Hyperlipidemic diet increased significantly (p ˂ 0.05) lipid profil, glycemia, uremia, activity of transaminase and γGT, oxidative stress in group 2 compared to other groups. Supplementation with <i>S. maderensis</i> oil significantly (p˂0.05) reduced Lee's index, weight gain and BMI by 8.12%, 26.33% and 19.11% respectively in group 4 compared with group 2. Supplementation with <i>S. maderensis</i> oil decreased significantly (p ˂ 0.05) total-cholesterol, LDL-cholesterol, triglyceride, glycemia, proteinemia and increased levels of HDL-cholesterol in group 4 compared to group 2. Supplementation with <i>S. maderensis</i> oil significantly (p < 0.05) reduced TBARS levels by 54.36% and significantly (p < 0.05) increased GSH levels, SOD, CAT and PON-1 activity by 64.90%, 20.76%, 48.70% and 7.47 respectively in group 4 compared to group 2. This study shows that <i>S. maderensis</i> oil can be used in prevention of hyperlipidemia.

A high fat diet potentiates neonatal iron overload-induced memory impairments in rats.

The present study aimed at evaluating possible synergistic effects between two risk factors for cognitive decline and neurodegenerative disorders, i.e. iron overload and exposure to a hypercaloric/hyperlipidic diet, on cognition, insulin resistance, and hippocampal GLUT1, GLUT3, Insr mRNA expression, and AKT phosporylation. Male Wistar rats were treated with iron (30mg/kg carbonyl iron) or vehicle (5% sorbitol in water) from 12 to 14th post-natal days. Iron-treated rats received a standard laboratory diet or a high fat diet from weaning to adulthood (9months of age). Recognition and emotional memory, peripheral blood glucose and insulin levels were evaluated. Glucose transporters (GLUT 1 and GLUT3) and insulin signaling were analyzed in the hippocampus of rats. Both iron overload and exposure to a high fat diet induced memory deficits. Remarkably, the association of iron with the high fat diet induced more severe cognitive deficits. Iron overload in the neonatal period induced higher insulin levels associated with significantly higher HOMA-IR, an index of insulin resistance. Long-term exposure to a high fat diet resulted in higher fasting glucose levels. Iron treatment induced changes in Insr and GLUT1 expression in the hippocampus. At the level of intracellular signaling, both iron treatment and the high fat diet decreased AKT phosphorylation. The combination of iron overload with exposure to a high fat diet only led to synergistic deleterious effect on emotional memory, while the effects induced by iron and by the high fat diet on AKT phosphorylation were comparable. These findings indicate that there is, at least to some extent, an additive effect of iron combined with the diet. Further studies investigating the mechanisms associated to deleterious effects on cognition and susceptibility for the development of age-associated neurodegenerative disorders are warranted.

Differential effects of four laboratory animal control diets on gut microbiota in mice.

The gut microbiota is intricate and susceptible to multiple factors, with diet being a major contributor. The present study aimed to investigate the impact of four commonly used laboratory animal control diets, namely Keao Xieli's maintenance diet (KX), HFK's 1025 (HF), Research Diets' D12450B (RD), and Lab Diet's 5CC4 (LD), on the gut microbiota of mice. A total of 40 mice were randomly assigned to four groups, and each group was fed one of the four diets for a duration of 8 weeks. The assessment of gut microbiota was conducted using 16S rRNA sequencing both at the beginning of the study (week 0) and the end (week 8), which served as the baseline and endpoint samples, respectively. Following the 8-week feeding period, no significant differences were observed in physiological parameters, including body weight, visceral weight, and blood biochemical indices, across the four groups. Nonetheless, relative to the baseline, discernible alterations in the gut microbiota were observed in all groups, encompassing shifts in beta-diversity, hierarchical clustering, and key genera. Among the four diets, HF diet exhibited a significant influence on alpha-diversity, RD diet brought about notable changes in microbial composition at the phylum level, and LD diet demonstrated an interconnected co-occurrence network. Mantel analysis indicated no significant correlation between physiological parameters and gut microbiota in the four groups. Overall, our study demonstrated that the four control diets had a minimal impact on physiological parameters, while exerting a distinct influence on the gut microbiota after 8 weeks. © 2024 Society of Chemical Industry.

Exosomes From IgE-Stimulated Mast Cells Aggravate Asthma-Mediated Atherosclerosis Through circRNA CDR1as-Mediated Endothelial Cell Dysfunction in Mice.

IgE has been known for mediating endothelial cell dysfunction and mast cell (MC) activation to fuel asthma-aggravated high-fat diet-induced atherosclerosis. However, it remains unclear for the mechanism of asthma-mediated atherosclerosis, especially the potential involvement of IgE in the exacerbation of asthma-mediated atherosclerosis with a standard laboratory diet, and the cross talk between endothelial cells and MCs. Asthma-mediated atherosclerosis mice models under a standard laboratory diet and FcεR1 knock-out mice were used to determine the role of IgE-FcεR1 signaling in asthma-mediated atherosclerosis, which was assessed by Oil Red O staining and immunohistochemistry. Various in vitro assays including nanoparticle tracking analysis and transmission electron microscopy were used to evaluate exosome characteristics. Immunofluorescence and fluorescent in situ hybridization approaches were used to evaluate the effect and mechanism of MC-secreted exosomes encapsulated circular RNA CDR1as (cerebellar degeneration-related 1 antisense) on endothelial cells in vivo and in vitro. Finally, cohort studies examined the plasma CDR1as levels in patients with atherosclerosis with or without allergies. Asthma mice with a standard laboratory diet showed increased atherosclerotic lesions and inflammatory infiltration depending on IgE-FcεR1 signal. FcεR1 knockout mice and blockage of IgE-FcεR1 signaling with IgE monoclonal antibody, omalizumab, all significantly alleviated asthma-mediated atherosclerosis and vascular inflammatory remodeling. Anti-inflammation with dexamethasone and stabilization of MC with cromolyn partially alleviated atherosclerotic lesions and mitigated the inflammatory infiltration in arteries. Mechanistically, IgE stimulation upregulates MC CDR1as expression in exosomes and upregulates the endothelial cell adhesive factors VCAM-1 (vascular cell adhesion molecule-1) and ICAM-1 (intercellular adhesion molecule-1) via the CDR1as-FUS (fused in sarcoma)-phos-p65 axis. Knockdown of CDR1as in vivo significantly decreased the endothelial adhesion function and mitigated asthma-mediated atherosclerosis. Furthermore, a cohort study indicated higher plasma CDR1as levels in patients with atherosclerosis with allergies than in patients with atherosclerosis and healthy controls. Exosomes from IgE-stimulated MCs aggravated atherosclerosis through circular RNA CDR1as-mediated endothelial dysfunction, providing a novel insight into asthma-mediated atherosclerosis and potential diagnostic and therapeutic targets.

Effects of Estrogen on Histomorphology Steroid-Induced Avascular Necrosis of Head of Femur in Male Rats

Objectives: To study the effects of estrogen administration on histomorphology of avascular necrosis of the femoral head in male rats. Study Design: Lab-based experimental study. Place and Duration of Study: Department of Anatomy, Army Medical College, National University of Medical Sciences, Rawalpindi (NUMS), in collaboration with the National Institute of Health Islamabad, (NIH) Pakistan from Aug to Nov 2021. Methodology: Thirty male Sprague Dawley rats, three months of age, weighing 200-300 gm, were selected. Rats were equally divided into three groups. Group-A served as a control group in which no intervention was made, and the rats were fed on a standard lab diet. Groups B and C served as experimental groups. In Groups B and C, avascular necrosis was induced by steroids for the first week of the study. Group C along with steroids also received tab estrogen by oral gavage for eight weeks, starting from the fifth week of the study till the twelfth week of the study. All the rats were sacrificed after the completion of the experimental period. The microscopic parameters like cortical thickness and percentage of the empty lacunae were counted. Results: Histomorphological changes were observed when the comparison was made between Group B, Control Group A, and Experimental Groups B and C with statistically significant results (p-value 0.001). Conclusion: Estrogen helps in fracture healing and shows improvement in cortical and trabecular strength. It has shown improvement in the cortical thickness measurement after avascular necrosis causes a decrease in the thickness.

Tranexamic Acid Reduces Large Traumatic Bleeding and Mortality in Murine Iron Deficiency Anemia By Mechanisms Beyond Control of Fibrinolysis

Introduction Iron deficiency anemia (IDA) is common. Some clinical evidence suggests that IDA may aggravate traumatic hemorrhage and compromise outcomes. To study if IDA influences traumatic hemorrhage, coagulopathy, and mortality we developed a model of traumatic liver injury with and without tranexamic acid (TXA) in mice with dietary IDA and compared the results to control mice and mice after parenteral iron rescue. Materials and Methods Severe IDA was generated in C57BL/6J mice by starting an iron-deficient diet in 3-week-old mice for 8 weeks (+/- 1 mg intraperitoneal iron dextran 2 weeks before trauma). Control mice were fed a normal laboratory diet. IDA was confirmed by complete blood count, red cell indices, and liver iron. Mice (≈20 per group) were pre-treated with saline or TXA (10mg/kg) and subjected to liver laceration. Blood loss (weighing blood-soaked sponges from the abdomen), coagulopathy [APTT, Factor (F)II, FV, FVIII, FX, and fibrinogen), thrombin-antithrombin (TAT) and plasmin-antiplasmin (PAP) complexes] were analyzed at 60 minutes after trauma Cytokine levels (IL-1α, IL-1β, IL-2, IL-6, IL-10, MCP-1, RANTES, and TNFα) were measured at baseline, 60 minutes and 6 hours post-trauma. Data were expressed as median and compared by Mann-Whitney test. Seven-day survival was analyzed using Kaplan-Meier curves. Results IDA manifested as hypochromic/microcytic anemia with significantly lower hematocrits compared to normal controls (32% vs 48%, p=<0.0001) and hepatic iron content (20.04 µg/g vs. 72.41 µg/g, p=<0.0001), respectively. Parenteral iron repletion corrected anemia and hepatic iron stores (“iron replete” mice). IDA mice experienced significantly higher blood loss compared to control mice (24.5 vs. 20.6 µL/g p=<0.0001), and TXA prophylaxis reduced blood loss significantly in both groups to ~15 µL/g. Blood loss in iron replete mice was 15.8 µL/g, and TXA did not reduce bleeding beyond the ~15 µL/g threshold. Bleeding led to a similar degree of acute traumatic coagulopathy (ATC) in all groups, characterized by APTT prolongation, TAT-complex formation, and depletion of FV, FVIII, and fibrinogen. FII and FX were not affected, consistent with the presence of ATC, rather than disseminated intravascular coagulation. TXA promoted the correction of ATC by near-normalization of TAT-complexes, FV, FVIII, and fibrinogen in all groups. In contrast, the extent of fibrinolysis differed in that PAP complex formation was significantly higher in IDA mice compared to control mice (44 vs 28 ng/mL, p=0.0004). TXA corrected PAP-complex formation and APTT only in control mice, without affecting these parameters in IDA mice. Seven-day survival was high in control and iron replete mice (~75%) without additional improvement by TXA. However, 7-day survival was lower in IDA mice (50%) and rescued by TXA (80%, p=0.04). A post-traumatic cytokine response was observed for the pro-inflammatory cytokines IL-1α, IL-6, MCP-1, RANTES, and TNFα. TXA mitigated this response substantially, but mostly in IDA mice, with little effect in control and iron replete mice. Conclusion IDA resulted in enhanced bleeding and mortality, which was rescued by parenteral iron correction or TXA prophylaxis. Interestingly, exaggerated fibrinolysis provoked by IDA could not be corrected by TXA, while TXA suppressed the pro-inflammatory cytokine response. This suggests that bleed and mortality rescue in IDA were less dependent on the anti-fibrinolytic effects of TXA, and more dependent on anti-inflammatory effects, which are poorly understood. These observations open new avenues to study pharmacodynamic effects of TXA beyond fibrinolysis inhibition, which may be particularly impactful for trauma rescue in the setting of anemia.

Effects of Full-Spectrum Cannabis Oil with a Cannabidiol:Tetrahydrocannabinol 2:1 Ratio on the Mechanisms Involved in Hepatic Steatosis and Oxidative Stress in Rats Fed a Sucrose-Rich Diet

Introduction: This study aimed to analyze the effects of cannabis oil (cannabidiol:tetrahydrocannabinol [CBD:THC], 2:1 ratio) on the mechanisms involved in hepatic steatosis and oxidative stress in an experimental model of metabolic syndrome (MS) induced by a sucrose-rich diet (SRD). We hypothesized that noninvasive oral cannabis oil administration improves hepatic steatosis through a lower activity of lipogenic enzymes and an increase in carnitine palmitoyltransferase-1 (CPT-1) enzyme activity involved in the mitochondrial oxidation of fatty acids. Furthermore, cannabis oil ameliorates liver oxidative stress through the regulation of the main regulatory factors involved, nuclear factor erythroid 2 (NrF2) and nuclear factor-kB (NF-κB) p65. For testing this hypothesize, a relevant experimental model of MS was induced by feeding rats with a SRD for 3 weeks. Methods: Male Wistar rats were fed the following diets for 3 weeks: reference diet: standard commercial laboratory diet, SRD, and SRD + cannabis oil: noninvasive oral administration of 1 mg/kg body weight cannabis oil daily. The full-spectrum cannabis oil presents a total cannabinoid CBD:THC 2:1 ratio. Serum glucose, triglyceride, total cholesterol, HDL-cholesterol, LDL-cholesterol, uric acid, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase (AP), N-arachidonoylethanolamine or anandamide and 2-arachidonoylglycerol endocannabinoids levels, thiobarbituric acid reactive substance (TBARS) levels, and non-enzymatic antioxidant capacity (ferric ion-reducing antioxidant power [FRAP]) were evaluated. In the liver tissue: histology, nonalcoholic fatty liver disease activity score (NAS), triglycerides and cholesterol content, lipogenic enzyme activities (fatty acid synthase, acetyl-CoA carboxylase, malic enzyme, and glucose-6-phosphate dehydrogenase), enzyme related to mitochondrial fatty acid oxidation (CPT-1), reactive oxygen species, TBARS, FRAP, glutathione, catalase, glutathione peroxidase, and glutathione reductase enzyme activities. 4-hydroxynonenal, NrF2, and NF-κB p65 levels were analyzed by immunohistochemistry. Results: The results showed that SRD-fed rats developed dyslipidemia, liver damage, hepatic steatosis (increase of key enzymes related to the novo fatty acid synthesis and decrease of key enzyme related to mitochondrial fatty acid oxidation), lipid peroxidation, and oxidative stress. Hepatic NrF2 expression was significantly decreased and NF-κB p65 expression was increased. Cannabis oil administration improved dyslipidemia, liver damage, hepatic steatosis, lipid peroxidation (improving enzymes involved in lipid metabolism), and oxidative stress. In the liver tissue, NrF2 expression increased, and NF-κB p65 expression was reduced. Conclusion: The present study revealed new aspects of liver damage and steatosis, lipid peroxidation, and oxidative stress in dyslipidemic insulin-resistant SRD-fed rats. We demonstrated new properties and molecular mechanisms of cannabis oil (CBD:THC, 2:1 ratio) on lipotoxicity and hepatic oxidative stress in an experimental model of MS.