Subacute Administration Research Articles

Acute and sub-acute toxicity of ethanol leaf extract from Acrostichum aureum in rats

Acrostichum aureum L. (A.aureum) is a medicinal plant that has anti-cancer, anti-inflammatory, and anti-bacterial activities and has been widely used traditionally in the treatment of many diseases. However, there is a dearth of information on the plant's safety. The present investigation was carried out to evaluate the acute and sub-acute toxicity of ethanol leaf extract of A. aureum (ELAA) in female Sprague Dawley (SD) rats. Oral acute toxicity was studied in female SD rats administered a single dose of 5000 mg kg-1 body weight ELAA. The sub-acute toxicity evaluation was also conducted orally with 100, 200, 500, and 750 mg kg-1 body weight of ELAA for 28 days in female SD rats. The impact of sub-acute treatment on body weight, gross histology, relative organ weight, urinalysis, hematology, plasma biochemistry, and histopathology was assessed following treatment. The ELAA did not cause death or signs of toxicity after acute treatment. Similarly, all the parameters evaluated during acute and sub-acute administration of ELAA did not significantly differ from the control. Therefore, the median lethal dose (LD50) of the ethanol extract of Acrostichum aureum is greater than 5000 mg kg-1 body weight. Its oral sub-acute administration is also non-toxic and safe at the tested doses.

Lepidium meyenii (Maca) polysaccharides mitigate liver toxicity of aflatoxin B1 through activation of NRF-2/GPX and AhR/STAT3 signaling pathways

Aflatoxin B1 (AFB1) can induce serious liver toxicity in human. While completely avoiding AFB1 exposure is difficult, dietary intake of natural products may be leveraged to mitigate its adverse health effects. The roots of Lepidium meyenii (Maca) is rich in beneficial polysaccharides. Here we first evaluated dietary safety of MPs and then investigated MPs mitigating effects on the liver toxicity of AFB1. A 28-day sub-acute administration of Maca polysaccharides (MPs) demonstrated to be safe in mice at dose 0.2–1.2 g/kg.bw/day that significantly elevated mice stamina. Also, no toxicity was observed in human PC12 cells treated with MPs 25–100 μg/mL which successfully alleviated cobalt-caused cell apoptosis by ∼20%. In terms of anti-AFB1 hepatoxicity function, MPs 0.4–1.6 g/kg.bw/day significantly alleviated liver tissue damage, lipid accumulation, ROS damage, NF-κB p65, secretion of cytokines such as IL-6 and TNF-α in AFB1-treated mice. Flow cytometry found that MPs treatment recovered the elevation of F4/80 in the primary macrophages of AFB1-treated mice. At molecular level, MPs treatment activated liver NRF-2/GPX/SOD anti-oxidant system. In human macrophage model, MPs restored the inflammatory AhR/STAT3 pathway and mRNA expressions of Tnf-a, Inos, Arg-1 disrupted by AFB1. Our findings not only add to the current understanding on the toxicity mechanism of AFB1, but also provide references to the development of dietary intervention strategy using MPs.

Neurotransmitter Availability and Anti-Inflammatory and Antioxidant Effects of Subacute Administration of Aloysia gratissima (Gillies & Hook) Tronc. and Rutin in Female Wistar Rats

Neurotransmitter Availability and Anti-Inflammatory and Antioxidant Effects of Subacute Administration of Aloysia gratissima (Gillies & Hook) Tronc. and Rutin in Female Wistar Rats

Safety evaluation of Avicenna germinans leaf extracts in rats

BackgroundAvicenna germinans is one of Nigeria's dominant mangrove plants and has valuable pharmacological and therapeutic activity. It is widely employed in traditional medicine to treat many ailments and diseases, including cancer. However, little is known about the safety of the plant. Acute and sub-acute toxicity profiles of the plant extracts were assessed in this study. MethodsThe oral acute toxicity was determined with 5000 mg/kg body weight each of n-hexane, ethyl acetate, and ethanol extracts of Avicenna germinans leaf in rats. The rats were monitored for mortality, clinical manifestations, and weight changes over 14 days. During the sub-acute toxicity study, twenty-five female rats were fed with 0–1000 mg/kg ethanol extracts of Avicenna germinans for 21 days. The body weight was monitored during treatment, while changes in gross organ morphology, relative organ weights, hematology, serum biochemistry, and limited histological analysis were evaluated after treatment. ResultsAcute administration of the three extracts did not result in mortality or any obvious adverse effects. The gross pathology, relative organ weights, hematology, serum biochemistry, and histopathology were similar to the control, except for the 1000 mg/kg dose that evoked marked increases in relative heart, intestinal, thymus, and adrenal weights. In addition, foci of inflammatory cells in the interstitium and lymphoid hyperplasia were found in the heart and lungs, respectively, in the 1000 mg/kg group. ConclusionThe findings indicate that LD50 of the three extracts of Avicenna germinans were > 5000 mg/kg and sub-acute administration of the ethanol extract is relatively safe at least up to 750 mg/kg body weights.

Preclinical Safety Assessment of Lepidium sativum L. Seed Extract and its Nanoparticles via Acute and Subacute Oral Administration

Background: Lepidium sativum (LS) seed extract has various pharmacological properties, such as antioxidant, hepatoprotective, and anticancer activities. However, the translation of L. sativum seed extract to the clinical phase is still tedious due to its bioavailability and stability issues. This problem can be solved by encapsulating it in a nanodelivery system to improve its therapeutic potency. Methods: In this study, we have determined and compared the in vivo toxicity of ethanolic extracts of L. sativum seeds (EELS) and solid lipid nanoparticles (SLNs). To conduct toxicity (acute and subacute toxicity) assessments, EELS and SLNs were orally administered to Swiss albino mice. Animal survival, body weight, the weight of vital organs in relation to body weight, haematological profile, biochemistry profile, and histopathological alterations were examined. Results: Animals administered with 2000 mg/kg and 5000 mg/kg in an acute toxicity study exhibited no toxicological symptoms regarding behaviour, gross pathology, and body weight. As per a study on acute toxicity, the LD50 (lethal dose) for SLNs and EELS was over 400 mg/kg and over 5000 mg/kg, respectively. When animals were given SLNs (50 and 100 mg/kg, orally) and EELS (250, 500, and 1000 mg/kg, orally) for 28 days, subacute toxicity study did not exhibit any clinical changes. There were no differences in weight gain, haematological parameters, or biochemical parameters compared to the control groups (p > 0.05). The organs of the treated animals showed no abnormalities in the histological analysis (liver, heart, kidney, and spleen). Conclusion: The result confirms ethanolic extracts of L. sativum seeds and their SLNs to not have harmful effects following acute and subacute administration to mice. For further studies, patents available on Lepidium may be referred for its preclinical and clinical applications.

Tributyltin-induced visceral adiposity is associated with impaired redox balance in white adipose tissue of male rats

Tributyltin (TBT) is an organotin compound that has several adverse health effects, including the development of obesity. Although obesity is strongly associated with adipose redox imbalance, there is a lack of information on whether TBT promotes a pro-oxidative environment in WAT. Thus, adult male Wistar rats were randomly exposed to either vehicle (ethanol 0.4%) or TBT (1000 ng/kg) for 30 days. Body and fat pad masses, visceral fat morphology, lipid peroxidation, protein carbonylation, redox status markers, and catalase activity were evaluated. TBT promoted increased adiposity and visceral fat, with hypertrophic adipocytes, but did not alter body mass and subcutaneous fat. ROS production and lipid peroxidation were elevated in TBT group, as well as catalase protein expression and activity, although protein oxidation and glutathione peroxidase protein expression remained unchanged. In conclusion, this is the first study to demonstrate that subacute TBT administration leads to visceral adipose redox imbalance, with increased oxidative stress. This enlights the understanding of the metabolic toxic outcomes of continuous exposure to TBT in mammals.

Quantification of oxidative stress markers in the blood sera following subacute administration of different oximes in rats

Oxidative stress status, as a disruption of redox homeostasis, in the blood sera of Wistar rats caused by repeated application of selected acetylcholinesterase reactivators - asoxime, obidoxime, K027, K048, K074, and K075 were evaluated. Throughout this study, each oxime in a dose of 0.1 of LD50/kg im was given 2x/week for 4 weeks. Then, seven days after the last oximes' application, markers of lipid peroxidation (malondialdehyde, MDA), and protein oxidation (advanced oxidation protein products, AOPP), as well as the activity of antioxidant enzymes (catalase, CAT, superoxide dismutase, SOD, reduced glutathione, GSH, and oxidized glutathione, GSSG), were determined. Oxidative stress parameters, MDA and AOPP were significantly highest in the K048-, K074- and K075-treated groups (p < 0.001). The activity of CAT was significantly elevated in the obidoxime-treated group (p < 0.05), while treatment with K027, K048, and K074 induced high elevation in SOD levels (p < 0.01, p < 0.001). Interestingly, the activity of GSH in each oxime-treated group was significantly elevated. Unlike, treatment with obidoxime caused elevation in GSSG levels (p < 0.01). As a continuation of our previously published data, these results assure that applied oximes following subacute treatment ameliorated the oxidative status and further adverse systemic toxic effects in rats.

Standardized Extract from the Gotu Kola Leaves Improves Suicidal Behavior in Stressed Rats Subjected to Social Isolation

The leaves of Centella asiatica L. Urban (C. asiatica) and their bioactive compounds, triterpenoids asiaticoside (AS) and madecassoside (MA), are effective in reducing psychological stress and associated behavioral disorders in the conducted in vivo research. The present study evaluated AS+MA-based standardized C. asiatica leaves extract (INDCA) on SIS-induced suicidal behavior-related traits in laboratory rats. Male rats (n=6) were randomized, grouped, and individually caged for seven days for stress induction. For the next seven days (D7 to D14), rats were orally administered vehicle (stress control), positive control (fluoxetine, 30 mg/kg), and or INDCA (3, 10, 30 mg/kg) once a day. A separate group of rats without isolation stress (normal rats) was maintained. The scores for suicidal behavior-related traits, such as aggression, impulsivity, irritability, learned helplessness, and plasma cortisol, were measured after 14-day treatment. The stress control group showed a significant increase in aggression, irritability (total score), learned helplessness (escape latency, escape failure, and recovery attempts), and plasma cortisol levels, which confirmed suicidal behavior-related traits. The INDCA-treated rats showed a dose-dependent reduction in stress-induced behavioral traits and elevated plasma cortisol levels. In conclusion, subacute administration of INDCA showed amelioration of suicidal behavior in social-isolation-induced stress in laboratory rats and suggested a promising natural and safe option for the management of stress-induced behavioral disorders, including suicidal behavior.

Toxicological Characteristics of Bacterial Nanocellulose in an In Vivo Experiment-Part 1: The Systemic Effects.

This study aims to perform a toxicological and hygienic assessment of the safety of BNC in a subacute 8-week administration in rats. BNC was administered to male Wistar rats in doses of 0, 1.0, 10.0, and 100 mg/kg body weight for 8 weeks. Various parameters such as anxiety levels, cognitive function, organ masses, blood serum and liver biochemistry, oxidative stress markers, vitamin levels, antioxidant gene expression, and liver and kidney histology were evaluated. Low and medium doses of BNC increased anxiety levels and liver glutathione, while high doses led to elevated LDL cholesterol, creatinine, and uric acid levels. Liver tissue showed signs of degeneration at high doses. BNC did not significantly affect vitamin levels. The adverse effects of BNC are either not dose-dependent or fall within normal physiological ranges. Any effects on rats are likely due to micronutrient deficiencies or impacts on intestinal microbiota.

Sub-acute administration of metal-organic Framework-5 induces behavioral impairments and augments the levels of oxidative stress and inflammation in the brain of rats

Metal-organic frameworks (MOFs) are known as potential pharmaceutical carriers because of their structure. Here, we evaluated the sub-acute administrations of MOF-5 on behavioral parameters, oxidative stress, and inflammation levels in rats. Thirty-two male Wistar rats received four injections of saline or MOF-5 at different doses which were 1, 10, and 50 mg/kg via caudal vein. Y-Maze and Morris-Water Maze (MWM) tests were used to explore working memory and spatial learning and memory, respectively. The antioxidant capacity and oxidative stress level of brain samples were assessed by ferric reducing antioxidant power (FRAP) and thiobarbituric acid-reacting substance (TBARS) assay, respectively. The expression levels of GFAP, IL-1β, and TNF-α were also measured by quantitative real-time reverse-transcription PCR (qRT-PCR). Sub-acute administration of MOF-5 reduced the spatial learning and memory as well as working memory, dose-dependently. The levels of FRAP were significantly reduced in rats treated with MOF-5 at higher doses. The Malondialdehyde (MDA) levels increased at the dose of 50 mg/kg. Additionally, the expression levels of IL-1β and TNF-α were significantly elevated in the rats’ brains that were treated with MOF-5. Our findings indicate that sub-acute administration of MOF-5 induces cognitive impairment dose-dependently which might be partly mediated by increasing oxidative stress and inflammation.

Evaluation of the anodyne effect of Terminalia bellirica fruit pulp in mouse models of Swiss albino strain

Background: Terminalia bellirica has been extensively investigated and used since time immemorial as part of Ayurvedic practice entirely because of its curable properties. Their antioxidant, hepatoprotective, antibacterial, and immunemodulatory activities are mostly attributed to the presence of glucoside, gallic acid, and its esters, chebulinic acid, etc. Aims and Objectives: The aim of the study is to analyze the effects of sub-acute administration of T. bellirica fruit pulp aqueous extract (TBFPAE) in ameliorating pain in mouse models of the Swiss albino strain. Materials and Methods: Young mice of Swiss albino strain typically 3 months’ of age; Male gender and weighing approximately 20–30 g were used for the purpose of the study. The mice were investigated by grouping them into five sets of six each randomly as control, standard, and trial groups. Group I was allotted as vehicle and given 1% gum acacia (10 mL/kg) as control; Group II was given pentazocine (5 mg/kg) as standard for central anti-nociceptive activity, while the IIIrd, IVth, and Vth groups received the investigative product TBFPAE per oral in doses of 9, 18 and 36 mg/kg, respectively. Eddy’s hot plate technique was employed for assessing central anodyne activity. Results: All the test groups of TBFPAE were found to have an analgesic effect but doses 18 mg/kg and 36 mg/kg demonstrated greater effects, especially at 30 and 60 min. Maximum analgesic effect with TBFPAE was seen with 36 mg/kg dose at 60 min. Conclusion: Therefore, T. bellirica has some analgesic potential. However, further studies are required to confirm its dose and usage.

The role of HCN channels on the effects of T-type calcium channels and GABAA receptors in the absence epilepsy model of WAG/Rij rats.

In this study we used ivabradine (IVA), a hyperpolarization-activated cyclic nucleotide-gated (HCN) channel blocker, to identify its effect on spike-wave discharges (SWDs); and aimed to determine the role of IVA on the effects of T-type calcium channel blocker NNC 55-0396, GABAA receptor agonist muscimol and antagonist bicuculline in male WAG/Rij rats. After tripolar electrodes for electrocorticogram (ECoG) recordings were placed on the WAG/Rij rats' skulls, 5, 10, and 20 mg/kg IVA were intraperitoneally administered for 7 consecutive days and ECoG recordings were obtained on days 0th, 3rd, 6th, and 7th for threehours before and after injections. While acute injection of 5, 10, and 20 mg/kg IVA did not affect the total number and the mean duration of SWDs, subacute administration (7 days) of IVA decreased the SWDs parameters 24 hours after the 7th injection. Interestingly, when IVA was administered again 24 hours after the 6th IVA injection, it increased the SWDs parameters. Western-blot analyses showed that HCN1 and HCN2 expressions decreased and HCN4 increased in the 5-month-old WAG/Rij rats compared to the 1-month-old WAG/Rij and 5-month-old native Wistar rats, while subacute IVA administration increased the levels of HCN1 and HCN2 channels, except HCN4. Subacute administration of IVA reduced the antiepileptic activity of NNC, while the proepileptic activity of muscimol and the antiepileptic activity of bicuculline were abolished. It might be suggested that subacute IVA administration reduces absence seizures by changing the HCN channel expressions in WAG/Rij rats, and this affects the T-type calcium channels and GABAA receptors.

Immunohistochemical study on localized oestrogen receptors following subacute oral administration of 3-methylmorphine (codeine) in ovaries of albino Wistar rats

The immunohistochemistry of localized oestrogen receptors following subacute oral administration of dihydrocodeine in ovaries of albino Wistar rats was studied. The specific objectives were; to determine the distribution of oestrogen receptors in the ovaries using immunohistochemical expression method and to evaluate oestrogen staining intensity using Image J statistical software. The twenty 20 rats were divided into 4 groups of five rat each. The control (group A) rats received distilled water per body weight while group B-D received 30, 60 and 90 mg/kg dihydrocodeine orally for 28 days. Animals were anesthetized using ketamine injection and abdominopelvic incision was made. The ovaries were harvested and processed using histochemistry. Photomicrographs were obtained using light microscope and arm scope. Oestrogen staining intensity was analysed using analysis of variance (ANOVA), followed by Post Hoc test using Image J statistical software. The results obtained show that the ovarian follicles had high staining intensity with monoclonal oestrogen receptor antibodies in group I, while group II showed moderate-high staining intensity. Group III showed low intensity of staining of oestrogen in the ovaries of the rats, while group IV showed low staining intensity of oestrogen in the ovarian follicle of albino rats. Oestrogen receptor staining intensity decreased in the ovaries of the treatment groups, which was significant at p&lt;0.05. This study concludes that Dihydrocodeine caused significant decrease (p &lt;0.013) in localized estrogen receptor in the ovaries of albino rats.

Flaxseed Oil (Linum usitatissimum) Prevents Cognitive and Motor Damage in Rats with Hyperammonemia.

Hyperammonemia is characterized by the excessive accumulation of ammonia in the body as a result of the loss of liver detoxification, leading to the development of hepatic encephalopathy (HE). These metabolic alterations carry cognitive and motor deficits and cause neuronal damage, with no effective treatment at present. In this study, we aimed to evaluate the effect of two subacute oral administrations of flaxseed oil (0.26 and 0.52 mL/kg) on short- and long-term memory, visuospatial memory, locomotor activity, motor coordination, and the neuronal morphology of the prefrontal cortex (PFC) via tests on Wistar rats with hyperammonemia. The goal was to identify its role in the regulation of cerebral edema, without liver damage causing cerebral failure. In contrast with an ammonium-rich diet, flaxseed oil and normal foods did not cause cognitive impairment or motor alterations, as evidenced in the short-term and visuospatial memory tests. Furthermore, the flaxseed oil treatment maintained a regular neuronal morphology of the prefrontal cortex, which represents a neuroprotective effect. We conclude that the oral administration of flaxseed oil prevents cognitive and motor impairments as well as neuronal alterations in rats with hyperammonemia, which supports the potential use of this oil to ameliorate the changes that occur in hepatic encephalopathy.

Acute and sub-acute oral toxicity assessment of the methanol root extract of Olax subscorpioidea Oliv. (Olacaceae) in mice and rats

Olax subscorpioidea Oliv. is an important medicinal plant included in African traditional anticancer medicines. Little information about its safety and toxicity appears in the literature. This study thus aimed at evaluating the safety of its methanol root extract orally administered in laboratory animals. Fourier Transform Infrared (FTIR) spectrophotometric analysis of O. subscorpioidea extract was conducted. For acute toxicity, methods within the Organization for Economic Co-operation and Development (OECD) guidelines were used, with slight modifications. A single female mouse was orally administered a dose of 2,000 mg/kg body weight of O. subscorpioidea methanol root extract and was monitored for at least 24 h for any signs of toxicity or death. An additional four mice (n = 4, 2/sex) were similarly treated. Another female mouse was orally administered 5,000 mg/kg body weight and observed for at least 24 h. Additional four mice were similarly treated. For sub-acute toxicity, the extract was administered daily to Wistar rats for 21 days at 250 mg/kg, 500 mg/kg, and 1,000 mg/kg. General behaviours changes, haematological, biochemical, and histological examinations on rats’ organs were performed. The FTIR spectrum showed no peaks in the 2220–2260 cm−1 region, suggesting that no cyanide groups were present in the extract. A single oral dose at both 2000 mg/kg and 5000 mg/kg did not induce any signs of toxicity or mortality, indicating an oral median lethal dose (LD50) >5000 mg/kg. When compared to the controls, dose-dependent changes were observed in the red blood cells, haemoglobin and haematocrit levels at 500 mg/kg and 1000 mg/kg (p<0.05). Histopathological examinations showed severe vascular congestion in the liver, and interstitial congestion and haemorrhage with moderate glomerular damage in the kidney. This study showed O. subscorpioidea root's methanol extract as non-toxic in acute administration, but with potential for toxicity in sub-acute oral administration.

Phenolic profile, acute and subacute oral toxicity of the aqueous extract from Moroccan Mentha longifolia L. aerial part in Swiss Albino mice model

Ethnopharmacological relevanceMentha longifolia (L.) (Lamiaceae) is a native plant in Morocco, traditionally used in different countries to treat several disorders notably gastrointestinal illnesses, respiratory disorders, infectious diseases, inflammatory diseases, and menstrual problems. Robust scientific evidence has confirmed multiple pharmacological properties of M. longifolia including antihemolytic, anti-inflammatory, antibacterial, hepatoprotective, anti-cancer, antidiabetic, gastroprotective effect, and antispasmodic activity. Aim of the studyThe current study aimed to determine the phytochemical profile and assess the toxic effect of an aqueous extract of the arial parts of M. longifolia in male and female Swiss albino mice during acute and subacute oral toxicity. Materials and methodsHigh-performance Liquid Chromatography Diode Array Detector (HPLC-DAD) was used to provide qualitative and quantitative analyses of phenolic compounds of M. longifolia aqueous extract. In acute toxicity experiments, four distinct groups of mice (n = 5/group/sex) were administered Mentha longifolia aqueous extract at single oral dosages of 0.5; 1; 2; 4, and 8 g/kg BW given by gavage and intraperitoneal for up to 14 days. Regarding the subacute toxicity investigation, Swiss albino mice were given M. longifolia aqueous extract orally at dosages of 100; 500; and 1000 mg/kg BW daily for 28 days. Body weight is measured every 7 days and suggested biochemical and hematological parameters were quantified, at the finish of 28 days of daily administration, sections of the liver, kidney, and spleen were histologically evaluated for showing damage to organs. ResultsThe data of High-performance Liquid chromatography analysis revealed that M. longifolia aqueous extract was rich in interesting phytochemical compounds, mainly quercetin, and rutin, followed by a hydroxybenzoic acid-like syringic acid. Regarding the acute test in mice, no mortality or symptoms of toxicity were detected following oral administration with a single dose of M. longifolia aqueous extract at any dosage limit up to 4 g/kg, which was the no-observed side effect threshold (NOAEL). The mortality rate as well as acute toxicity of the M. longifolia aqueous extract delivered intraperitoneally, are increased progressively with increasing dosage. The non-observed adverse effect level (NOAEL) for the intraperitoneal dosage was 1 g/kg BW, and the lowest observed adverse effect level (LOAEL) was 2 g/kg BW, the estimated acute toxicity (LD50) of intraperitoneally given M. longifolia aqueous extract in mice was 4.800 g/kg BW. Concerning subacute examinations in mice, the M. longifolia aqueous extract did not induce substantial modifications in biochemical or hematological indicators, preserving a slight increase in creatinine and urea levels. At the end of the experiment, a histopathological examination of the kidneys, liver, and spleen revealed normal architecture, suggesting no morphological damage. ConclusionThe data we obtained indicate that acute or subacute administration of Mentha longifolia aqueous extract is relatively non-toxic in male and female Swiss albino mice.

Characterization and Preclinical Toxicity Assessment of Intranasal Administration of Standardized Extract of &lt;i&gt;Centella asiatica&lt;/i&gt; (L.) Urban Leaves (INDCA-NS) in Laboratory Rats

The objective of the present work was to characterize and assess the intranasal toxicity of a solution of total triterpenoids - based standardized extract of Centella asiatica (L.) Urban leaves (INDCA-NS). The acute and 28-day repeated-dose toxicity of intranasal administrated INDCA-NS in Wistar rats was evaluated. For the acute intranasal toxicity study, a single dose of 100 μg/rat/day was administered to five male and female rats and observed for mortality and signs of toxicity for 14 days. In the subacute toxicity study, the INDCA-NS (10, 30, and 100 μg/rat/day) were intranasally administered to a separate group of five male and female rats for 28 days, followed by a 14-day reversal period for behavioral, biochemical, and histological parameters. The effect of subacute administration of INDCA-NS on the ability to smell in rats was evaluated by a buried food test. Treatment with INDCA-NS did not result in mortality or treatment-related adverse signs during single or 28-day repeated-dose administration. In addition, intranasal INDCA-NS did not affect the sense of smell, as observed in the buried food test. Intranasal NDCA-NS was found safe in rats with a Maximum Tolerated Dose (MTD) of more than 100 μg/rat/day and No-Observed Adverse Effect Level (NOAEL) of more than 100 μg/rat/day in male and female rats during acute and subacute intranasal toxicity study respectively.

Subacute administration of cilostazol modulates PLC-γ/PKC-α/p38/NF-kB pathway and plays vascular protective effects through eNOS activation in early stages of atherosclerosis development

AimsHypercholesterolemia is an important risk factor for development of cardiovascular disturbances, such as atherosclerosis, and its treatment remains challenging in modern medicine. Cilostazol is a selective inhibitor of phosphodiesterase 3 clinically prescribed for intermittent claudication treatment. Due to its pleiotropic properties, such as lipid lowering, anti-inflammatory, and antioxidant effects, the therapeutic repurposing of cilostazol has become a strategic approach for atherosclerosis treatment. This study aimed to investigate the effects of subacute administration of cilostazol on the aortas of hypercholesterolemic rats, focusing on the signaling pathways involved in these actions. Main methodsA murine model of hypercholesterolemia was employed to mimic the early stages of atherosclerosis development. Vascular reactivity assays were performed on thoracic aorta rings to assess the vascular response, as well as the non-invasive blood pressure was evaluated by plethysmography method. Pro-inflammatory markers and malondialdehyde (MDA) levels were measured to investigate the anti-inflammatory and antioxidant effects of cilostazol. Western Blot analysis was performed in aortas homogenates to evaluate the role of cilostazol on PLC-γ/PKC-α/p38-MAPK/IκB-α/NF-кB and PKA/eNOS/PKG pathways. Key findingsThe hypercholesterolemic diet induced the production of pro-inflammatory mediators such as TNF-α, TXB2, VCAM, and worsened vascular function, marked by increased contractile response, decreased maximum relaxation, and elevated systolic and diastolic blood pressure. Cilostazol seems to counteract the deleterious effects promoted by hypercholesterolemic diet, showing important anti-inflammatory and vasculoprotective properties possibly through the inhibition of the PLC-γ/PKC-α/p38-MAPK/IκB-α/NF-кB pathway and activation of the PKA/eNOS/PKG pathway. SignificanceCilostazol suppressed hypercholesterolemia-induced vascular dysfunction and inflammation. Our data suggest the potential repurposing of cilostazol as a pharmacological treatment for atherosclerosis.

Effects of Sub-acute Administration of Onion Waste Quercetin on the Hippocampus of Mice: A Histological Approach

Quercetin is a flavonoid with a great capability of crossing the blood-brain barrier. It is reported to exert numerous beneficial effects on both animal and human health. The study evaluates the effects of onion waste quercetin (OWQ) on the histology of the hippocampus and dentate gyrus of mice. Twenty mice were assigned into four groups (n=5). The groups were given distilled water, and OWQ at 95mg/kg, 190mg/kg, and 380mg/kg respectively for 28 days. The brain of each mouse was harvested afterward, weighed, and processed for light microscopy. The normal and degenerating cells in the dentate gyrus and hippocampus Cornu Ammonis (CA1 &amp; CA3) were counted. The micrographs of the dentate gyrus showed normal molecular, granular, and polymorphic layers in the control mice, as well as the mice, treated with OWQ with few degenerating cells in the granular layer of OWQ-treated (190mg/kg) mice. The CA3 area of the hippocampus showed normal molecular and polymorphic layers in OWQ-treated mice. However, the granular layer of the mice that received OWQ at 190mg/kg showed numerous degenerating cells. OWQ especially at 95mg/kg was found to significantly increase the number of normal cells in the dentate gyrus and hippocampus (CA1 &amp; CA3) of the brain compared to the control at P&lt; .05. It also significantly decreased degenerating cells compared to the control (P&lt; .05). In conclusion, onion waste quercetin, especially at 95mg/kg was found to maintain the pool of normal cells within the dentate gyrus and hippocampus of mice brain.

Sub-acute oral toxicity of Hamo NK hard capsule in experimentalanimals

Background: Hamo NK hard capsule is composed of some dry extracts formulation of herbal medicine which had shown good properties effective treating dyslipidemia. However, there are no scientific reports of its toxicological properties which guarantee of the safety its usage as a potent treating dyslipidemia. Therefore, the present study was to investigate sub-acute toxicity of Hamo NK on rats through oral administration.Methods: The sub-acute administration Hamo NK was studied on Wistar rats. The animals were orally exposed to 0.25g/kg and 0.75 g/kg b.w/day of Hamo NK for 12 consecutive weeks. Physical observations and body weight were made during the study period. At the end of the experiment, blood samples were collected for hematology and clinical chemistry evaluations. Gross pathology and histopathology of livers and kidneys were assessed.Result: No major alteration was observed in the evaluated parameters at two doses of 0.25 g/kg per day and 0.75 g/kg per day. The histopathologic analysis of the livers and kidneys indicated architecture with normal aspect.Conclusion: Collectively, these data demonstrate that Hamo NK hard capsule has a high margin of safety.