Rat Feces Research Articles

Effects of continuous intravenous infusion with propofol on intestinal metabolites in rats.

Microbial metabolites play an important role in regulating intestinal homeostasis and immune responses. Propofol is a common anesthetic in clinic, but it is not clear whether it affects intestinal metabolites in rats. Tail vein puncture was performed after adaptive feeding for 1 month in eight 2-month-old rats and they were given continuous intravenous infusion of propofol for 3 h. The feces of rats were divided into different groups based on time periods, with before and after anesthesia with propofol on days 1, 3 and 7 labeled as groups P, A1, A3 and A7, respectively. The effect of continuous intravenous infusion with propofol on rat fecal metabolites was determined using the non-targeted metabolomics technique gas chromatography coupled with a time-of-flight mass spectrometer analysis. The types and contents of metabolites in rat feces were changed after continuous intravenous infusion with propofol, but the changes were not statistically significant. The contents of the metabolites 3-hydroxyphenylacetic acid and palmitic acid increased from day 3 to 7, and it was shown that the two metabolites were positively correlated at a statistically significant level. Linoleic acid decreased to its lowest level on day 3, and it returned to pre-anesthesia level on day 7. At the same time, linoleic acid metabolism was a metabolic pathway that was co-enriched 7 days after infusion with propofol. Spearman correlation analysis showed that there was significant correlation between some differential metabolites and differential microorganisms. It was observed that zymosterol 1, cytosin and elaidic acid were negatively correlated with Alloprevotella in the A3 vs. P group. In the A7 vs. P group, cortexolone 3 and coprostan-3-one were positively correlated with Faecalibacterium, whilst aconitic acid was negatively correlated with it. In conclusion, the present study revealed statistically insignificant effects of continuous intravenous propofol on the intestinal metabolites in rats.

Potential effects of sodium hyaluronate on constipation-predominant irritable bowel syndrome

Treatment strategies for constipation-predominant irritable bowel syndrome (IBS-C) continue to improve. However, effective drugs are still lacking. Herein, we explored whether sodium hyaluronate (SH) could be used to treat IBS-C. The effects of SH with different molecular weights were compared in a rat model of IBS-C. Low-molecular-weight SH (LMW-SH, 5 ∼ 10 kDa), medium-molecular-weight SH (MMW-SH, 200 ∼ 400 kDa), and high-molecular-weight SH (HMW-SH, 1300 ∼ 1500 kDa) were screened for efficacy in IBS-C using the following indicators: body weight, number of fecal pellets, fecal moisture, visceral hypersensitivity, and gastrointestinal transit rate. H-HMW-SH was the most effective in improving IBS-C symptoms. The ELISA kits indicated that H-HMW-SH reduced the levels of pro-inflammatory cytokines IL-1β, IL-18, and TNF-α in IBS-C rats. In addition, both western blot and immunofluorescence analyses showed that H-HMW-SH increased the protein expressions of claudin-1, occludin and zonula occludens-1. Furthermore, H-HMW-SH restored the balance of intestinal flora in different intestinal contents (duodenum, jejunum, ileum, and colon) and feces of rats with IBS-C. Overall, our study illustrates the therapeutic potential of H-HMW-SH in the treatment of IBS-C.

Characterization of the metabolites of Eucommiae Cortex in rats provides a further insight into its estrogen-like effective substances

Eucommiae Cortex is one of important traditional Chinese medicines (TCMs) used in Asia for preventing and treating osteoporosis induced by estrogen deficiency. However, the low exposure of prototype components in Eucommiae Cortex in vivo is difficult to interpret its efficacy. Under the guidance of UPLC-Q/TOF-MS, 42 metabolites including 32 lignans and 10 phenolics, 21 of which were new compounds, were isolated from rat urine and feces after oral administration of aqueous extract of E. ulmoides Oliv. by various chromatographic techniques. Their structures were determined based on extensive physicochemical analyses and spectral data. Their absolute configurations were determined by experimental and calculated ECD spectra, along with the calculated NMR with DP4 evaluation. Additionally, all isolated metabolites were evaluated for their estrogen-like activities, and there are 15 metabolites having estrogen-like effects after assessing influences in MCF-7 cells. Further, Dual Luciferase Reporter Gene Assay was used to determine their activation with estrogen receptor, M10 and M11 mixtures, M14, M19, M33, M27, M31, M38-M41 could activate ERα, and M19 and M41 could activate ERβ. These results not only clarify the pharmacological substances of Eucommiae Cortex, but also provide a basis for guiding its clinical application.

The study on the impact of sex on the structure of gut microbiota of bamboo rats in China.

Bamboo rats are rodents that eat bamboo, and their robust capacity for bamboo digestion is directly correlated with their gut flora. Chinese bamboo rat (Rhizomys sinensis) is a common bamboo rat in Chinese central and southern regions. As a single-stomach mammal, bamboo rats are a famous specificity bamboo-eating animal and their intestinal microbial composition may also play a key role in the digestion of cellulose and lignin. So, the gut microbiota of bamboo rat may play an important role in the adaptation of bamboo rats for digesting lignocellulose-based diet. To study the microbiome differences of bamboo rats from different sexes, the microbial genomic DNA was extracted from each fecal sample and the V4 region of 16S rRNA genes was amplified and sequencing on an IlluminaHiSeq6000 platform. The operational taxonomic units (OTUs) were classified, the OTUs in different sexes was identified and compared at phylum and genus levels. For isolation and screening of cellulose degradation bacteria from bamboo rats, fresh feces from randomly selected bamboo rats were collected and used for the isolation and screening of cellulose degradation bacteria using Luria Bertani (LB) Agar medium containing Carboxymethyl cellulose. The cellulase activity, biochemical characterization and phylogenetic analysis of the purified bacteria strains were characterized. A total of 3,833 OTUs were classified. The total microbial diversity detected in the female and male rats was 3,049 OTUs and 3,452 OTUs, respectively. The Shannon index revealed significant differences between the two groups (p < 0.05), though they were all captive and had the same feeding conditions. At the phylum level, Firmicutes, Bacteroidota, and Proteobacteria were prominent in the microbial community. At the genus level, the microbial community was dominated by Lachnospiraceae, Lactobacillus, Bacteroides, and Prevotella, but there was a significant difference between the two groups of bamboo rats; ~90 bacteria genus in the female group was significantly higher than the male group. Among them, Bacteroides, Colidextribacter, and Oscillibacter were significantly higher genera, and the genera of Lachnoclostridium, Oscillibacter, and Papillibacter had the highest FC value among the male and female bamboo rats. The KEGG function annotation and different pathways analysis revealed that membrane transport, carbohydrate metabolism, and amino acid metabolism were the most enriched metabolic pathways in the two groups, and multiple sugar transport system permease protein (K02025 and K02026), RNA polymerase sigma-70 factor (K03088), and ATP-binding cassette (K06147) were the three different KEGG pathways (p < 0.05). Two cellulose degradation bacteria strains-Bacillus subtilis and Enterococcus faecalis-were isolated and characterized from the feces of bamboo rats.

Absorption, Distribution, Metabolism, and Excretion of [14C]BS1801, a Selenium-Containing Drug Candidate, in Rats.

BS1801 is a selenium-containing drug candidate with potential for treating liver and lung fibrosis. To fully elucidate the biotransformation of BS1801 in animals and provide sufficient preclinical drug metabolism data for human mass balance study, the metabolism of BS1801 in rats was investigated. We used radiolabeling techniques to investigate the mass balance, tissue distribution, and metabolite identification of BS1801 in Sprague-Dawley/Long-Evans rats after a single oral dose of 100 mg/kg (100 μCi/kg) [14C]BS1801: 1. The mean recovery of radioactive substances in urine and feces was 93.39% within 168 h postdose, and feces were the main excretion route. 2. Additionally, less than 1.00% of the dose was recovered from either urine or bile. 3. BS1801-related components were widely distributed throughout the body. 4. Fifteen metabolites were identified in rat plasma, urine, feces, and bile, and BS1801 was detected only in feces. 5. BS1801-M484, the methylation product obtained via a N-Se bond reduction in BS1801, was the most abundant drug-related component in plasma. The main metabolic pathways of BS1801 were reduction, amide hydrolysis, oxidation, and methylation. Overall, BS1801 was distributed throughout the body, and excreted mainly as an intact BS1801 form through feces. No differences were observed between male and female rats in distribution, metabolism, and excretion of BS1801.

Classical famous prescription of Jichuan decoction improved loperamide-induced slow transit constipation in rats through the cAMP/PKA/AQPs signaling pathway and maintained inflammatory/intestinal flora homeostasis

IntroductionJichuan decoction (JCD) is a well-known traditional Chinese medicinal formula that moistens the intestines and is widely used for the treatment of constipation in China. However, its effects and mechanisms in alleviating slow transit constipation (STC) in vivo remain unclear. We attempted to demonstrate the effect of JCD, with and without essential oil (VO), on intestinal transit and its underlying molecular mechanisms in rats with loperamide-induced STC. Materials and methodsWater consumption, body weight, fecal water content, time to first melena excretion, and intestinal transit ratio of the animals were measured. 5-Hydroxytryptamine (5-HT), substance P (SP), vasoactive intestinal peptide (VIP), and interleukin-6 (IL-6) levels in the sera of rats were evaluated using ELISA. Hematoxylin and eosin and Periodic Acid–Schiff staining were used to determine intestinal tissue histology, while quantitative real-time PCR, western blotting, and immunohistochemical analysis were used to assess the relative expression levels of cAMP/PKA/AQPs pathway- and inflammation-related proteins. 16 S rDNA sequence analysis of rat feces was used to determine the diversity and abundance of the intestinal flora. ResultsThe JCD groups showed reduced time to first melena excretion and expression of VIP and IL-6. The JCD groups, specifically JCD + VO groups, showed increased fecal water content, intestinal transit rate, and SP expression. Further, these groups showed improved histological characteristics of the colon, with no significant change in the index of immune organs or morphological characteristics of other organs. In addition, a significant decrease in the activation of the cAMP/PKA/AQPs signaling pathway in the colon tissue was observed in these groups, specifically the JCD + VO groups. Moreover, treatment with JCD, with or without VO, downregulated the expression of inflammatory factors and enriched the diversity of intestinal flora as evidenced by polymorphism analysis and the contents of Bacteroides, Lactobacillus, and Erysipelas, with the JCD + VO groups showing better therapeutic outcomes. ConclusionJCD improved loperamide-induced STC, and co-administration with VO exhibited better activity than sole JCD therapy. JCD may improve STC by inhibiting the cAMP/PKA/AQPs signaling pathway and maintaining inflammatory/intestinal flora homeostasis.

Synergistic effect of Euphorbia kansui stir-fried with vinegar and bile acids on malignant ascites effusion through modulation of gut microbiota.

Background: Toxic Euphorbia kansui (EK) is employed to treat malignant ascites effusion (MAE). EK stir-fried with vinegar (VEK) has been demonstrated to reduce toxicity due to its preserved water-expelling effect. This was demonstrated to be correlated with gut microbiota. Therein, bile acids (BAs) have a bidirectional relationship with the gut microbiota. Therefore, the aim of this study is to explore whether BA-mediated gut microbiota influences the water-expelling effect of VEK against MAE. Methods: The MAE rat model was established by intraperitoneal injection of Walker-256 tumor cells. A reliable simultaneous method for the determination of 15 bile acids in rat feces using ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was established and applied to analyze the fecal BAs in rats treated with VEK. The screened BA was then administered to VEK-treated MAE rats. The water-expelling effect was evaluated using histopathological analysis, biochemical examination, inflammatory factors in ascites, urine volume, ascites amount, and intestinal aquaporin expression. The microbial composition was determined using 16S rRNA sequencing, and the contents of bile acids were finally measured. Results: VEK decreased the content of fecal deoxycholic acid (DCA), lithocholic acid (LCA), and taurocholic acid (TCA) while increasing the content of ursodeoxycholic acid (UDCA). VEK alleviated liver, stomach, and intestinal injuries; oxidative damage; and inflammation, which were further ameliorated with UDCA intervention. VEK alleviated MAE by increasing the fecal water content, urine volume, and AQP3 protein expression and decreasing the urine levels of Na+, K+, and Cl-. This was retained with the intervention of UDCA. UDCA and VEK regulated the BA metabolism disorder to a certain extent. Analysis of gut microbiota showed that VEK increased the abundance of Lactobacillus and decreased that of Prevotella_9 in MAE rats. The combined administration of UDCA and VEK showed a better modulation of the microbiota structure than that of VEK alone, and the effect of this administration reached closer to the reference state. Conclusion: The water-expelling effect of VEK did not directly depend on the BA-mediated gut microbiota. However, VEK and BAs had a synergistic effect on malignant ascites effusion through the regulation of the gut microbiota. These results provided a scientific basis for the reasonable usage of VEK and the novel combination treatment strategy of VEK and UDCA.

Lead speciation in body tissues, gastrointestinal contents, and feces of lead-exposed wild rats (Rattus rattus)

The toxic effects of lead (Pb) are an ongoing concern for which research continues to seek a solution. In Pb-contaminated areas, Pb concentrations in the environment and organisms are quantified to assess the degree of contamination. Understanding organismal uptake of Pb and its behavior in the body requires distinguishing Pb chemical species. We used Pb L3-edge X-ray absorption near-edge structure (XANES) to study the distribution of Pb species in body tissues, digestive tract contents, and feces of wild rats (Rattus rattus) collected from a heavily Pb-contaminated mining area in Zambia. Freeze-drying improved the XANES spectrum quality by approximately 10 μg-Pb/g-dry through concentrating the Pb without changing its chemical state from its wet state. We successfully identified and analyzed the Pb species in seven different tissues (bone, muscle, liver, kidney, spleen, lung, and brain), three different digestive-tract contents (stomach, small intestine, and colon), and feces from three wild rats. We described chemical-form-based details of Pb uptake and distribution that are common among rats, such as the increased Pb binding with thiol groups through the digestive system, distribution of mobile Pb to hematopoietic organs and vascular-related tissues, and Pb binding to thiol groups, especially in the liver and brain.

Roseburia intestinalis relieves intrahepatic cholestasis of pregnancy through bile acid/FXR-FGF15 in rats

Previous research has demonstrated significant differences in intestinal flora between pregnant women with intrahepatic cholestasis of pregnancy (ICP) and healthy pregnant women. The objective of our study is to identify the key bacteria involved in ICP rats and explore the underlying mechanism. We established an ICP rat model and collected rat feces for metagenomic sequencing and found that Roseburia intestinalis (R.I) is the key bacteria in ICP. Transplantation of R.I improved phenotypes associated with ICP through the bile acid/farnesoid X receptor-fibroblast growth factor 15 (FXR-FGF15) signaling pathway. We used the FXR antagonist Z-Guggulsterone (Z-Gu) to verify the key role of FXR in ICP and found that Z-Gu reversed the benefits of R.I on ICP rats. Our research highlights the important role of intestinal flora in the pathogenesis of ICP and provides a novel approach for its treatment.

Mercury species analysis and tissue distribution in rats after continuous administration of Cinnabaris

Cinnabaris is a traditional Chinese medicine(TCM) commonly used for sedation and tranquilization in clinics, and its safety has always been a concern. This study intends to investigate the species and tissue distribution of mercury in rats after continuous administration of Cinnabaris. In the experiment, 30 rats were randomly divided into the control group(equivalent to 0.5% carboxy-methyl cellulose sodium), low-dose Cinnabaris group(0.2 g·kg~(-1)), high-dose Cinnabaris group(2 g·kg~(-1)), pseudogerm-free control group(equivalent to 0.5% sodium carboxymethyl cellulose), and pseudogerm-free Cinnabaris group(2 g·kg~(-1)). They were orally administered for 30 consecutive days. Ultrasound-assisted acid extraction method combined with high performance liquid chromatography and inductively coupled plasma-mass spectrometry(HPLC-ICP-MS) was adopted to determine inorganic mercury [Hg(Ⅱ)], methylmercury(MeHg), and ethylmercury(EtHg) in different tissue, plasma, urine, and feces of rats. The optimal detection conditions and extraction methods were optimized, and the linearity(R~2&gt;0.999 3), precision(RSD&lt;7.0%), and accuracy(spike recoveries ranged from 73.05% to 109.5%) of all the mercury species were satisfied, meeting the requirements of analysis. The results of mercury species detection showed that Hg(Ⅱ) was detected in all the tissue of the five experimental groups, and the main accumulating organs were the intestinal tract, stomach, and kidney. MeHg existed at a low concentration in most tissue, and EtHg was not detected in all groups. In addition, pathological examination results showed that hepatocyte vacuolar degeneration, loose cytoplasm, light staining, and mononuclear cell infiltration were observed in the high-dose Cinnabaris group, low-dose Cinnabaris group, and pseudogerm-free Cinnabaris group, with slightly milder lesions in the low-dose Cinnabaris group. Hydrous degeneration of renal tubular epithelium could be seen in the high-dose Cinnabaris group and pseudogerm-free Cinnabaris group, but there was no significant difference between the other groups and the control group. No abnormal changes were found in the brain tissue of rats in each group. This paper studied the different mercury species and tissue distribution in normal and pseudogerm-free rats after continuous administration of Cinnabaris for 30 days and clarified its effects on the tissue structure of the liver, kidney, and brain, which provided supporting evidence for the safety evaluation of Cinnabaris.

Pharmacokinetics, Mass Balance, Tissue Distribution and Metabolism of [14C]101BHG-D01, a Novel Muscarinic Receptor Antagonist, in Rats.

101BHG-D01, a novel long-acting and selective muscarinic receptor antagonist for the treatment of chronic obstructive pulmonary disease (COPD), is undergoing Phase Ib clinical trial in patients and has shown its potential efficacy. Its preparation method and medical use thereof have been patented in the United States (Patent No.US9751875B2). In this study, the pharmacokinetics, mass balance, tissue distribution and metabolism of radioactive 101BHG-D01 were investigated in rats after an intravenous dose of 1 mg/kg [14C]101BHG-D01 (100 μCi/kg). Radioactivity in rat plasma, urine, feces, and tissues was measured by liquid scintillation counting (LSC), and metabolite profiling and identification were conducted by UHPLC-β-RAM and UHPLC-Q-Exactive Plus MS. The total radioactivity of the study drug in rat plasma rapidly declined with an average terminal elimination half-life of 0.35 h. The radioactivity in most tissues reached the maximum concentration at 0.25 h post-- dosing. The radioactivity mainly concentrated in the kidney and pancreas. The drug-related substances tended to be distributed into the blood cells in the circulation. At 168 h post dosing, the mean recovery of the total radioactivity in urine and feces was 78.82%. Fecal excretion was the major excretion route, accounting for approximately 61% of the radioactive dose. The study drug was metabolized extensively, and a total of 17 metabolites were identified in rat plasma, urine, and feces. The major metabolic pathways involved oxidation, oxidation and dehydrogenation, and O-dephenylation. In conclusion, the study results are useful for better understanding the pharmacokinetic profiles of 101BHG-D01 and provide a robust foundation for subsequent clinical studies.

Comprehensive identification of metabolites and metabolic characteristics of luteolin and kaempferol in Simiao Yong'an Decoction in rats by UHPLC-LTQ-Orbitrap MS/MS

Simiao Yong'an Decoction is a classic prescription for treating gangrene. Modern medical evidence has proven that Si-miao Yong'an Decoction has therapeutic effects on atherosclerosis(AS), vascular occlusion angeitides, and hypertension, while its pharmacodynamic mechanism remains unclear. The evidence of network pharmacology, molecular docking, literature review, and our previous study suggests that luteolin and kaempferol are two major flavonoids in Simiao Yong'an Decoction and can inhibit macrophage inflammation and exert anti-AS effects. However, due to lack of the metabolism studies in vivo, little is known about the metabolic characteristics of luteolin and kaempferol. This study employed ultra-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry(UHPLC-LTQ-Orbitrap MS/MS) and relevant software to identify the metabolites and metabolic pathways of luteolin and kaempferol in rat plasma, urine, and feces, after oral administration of luteolin and kaempferol, respectively. After the administration of luteolin, 10, 11, and 3 metabolites of luteolin were detected in the plasma, urine, and feces, respectively. After the administration of kaempferol, 9, 3, and 1 metabolites of kaempferol were detected in the plasma, urine, and feces, respectively. The metabolic pathways mainly involved methylation, glucuronidation, and sulfation. This study enriches the knowledge about the pharmacological mechanism of luteolin and kaempferol and supplies a reference for revealing the metabolic process of other flavonoids in Simiao Yong'an Decoction, which is of great significance for elucidating the pharmacological effects and effective substances of this decoction in vivo.

Identification and Characterization of Chemical Constituents from Ammopiptanthus nanus Stem and Their Metabolites in Rats by UHPLC-Q-TOF-MS/MS.

Ammopiptanthus nanus as a Kirgiz medicine is widely used for the treatment of frostbite and chronic rheumatoid arthritis. However, due to a lack of systematic research on the chemical components of A.nanus and their metabolites, the bioactive components in it remain unclear. Herein, a reliable strategy based on UHPLC-Q-TOF-MS/MS was established to comprehensively analyze the chemical components and their metabolites in vivo. In total, 59 compounds were identified from A.nanus stem extract, among which 14 isoflavones, 10 isoprenylated isoflavones, 4 polyhydroxy flavonoids, 9 alkaloids and 1 polyol were characterized for the first time. After oral administration of A.nanus stem extract, 30 prototype constituents and 28 metabolites (12 phase I and 16 phase II metabolites) were speculated on and identified in rat serum, urine and feces. Furthermore, the metabolic pathways of the chemical components were systematically analyzed and proposed. In conclusion, the chemical components from A.nanus stem and their metabolites in vivo were first studied, which may provide useful chemical information for further study on the effective material basis and pharmacological mechanism of A.nanus.

Biotransformation of se-methylselenocysteine into volatile selenocompounds by bacteria isolated from rat gut microflora

Selenium (Se) is an essential micronutrient that exists in various chemical forms in nature. Because of this property, animals must metabolize diverse Se species to utilize them as selenoproteins. Although gut microflora is suggested to play a role in Se metabolism in host animal, the biotransformation of Se by gut microflora in animal gut is not fully understood. In this study, we isolated Morganella morganii from rat feces under the condition that Se-methylseleno-L-cysteine (MeSeCys), one of the major Se sources in vegetables, was present in excess. Then, we examined the biotransformation of MeSeCys by M. morganii. Two volatile selenocompounds, dimethyldiselenide (DMDSe) and dimethylselenide (DMSe), were detected by GC–MS in the headspace of M. morganii culture. We speculate that M. morganii cleaved off the methylselenyl group from MeSeCys. Taken together, we conclude that gut microflora plays a role in the biotransformation of MeSeCys, and seems to support efficient metabolism in animals.

Analytical toxicology of the semi-synthetic cannabinoid hexahydrocannabinol studied in human samples, pooled human liver S9 fraction, rat samples, and drug product using HPLC-HRMS/MS.

Hexahydrocannabinol (HHC) is an emerging semi-synthetic cannabinoid, that is obtained from cyclization of cannabidiol and subsequent hydrogenation. As a potentially legal alternative of Δ9-tetrahydrocannabinol (Δ9-THC), it is increasingly seized in the United States and Europe. The aims of this study were to investigate the metabolism of HHC in pooled human liver S9 fraction (pHLS9), in rat, and human samples. Additionally, a locally obtained low-THC cannabis product was investigated that was advertised with elevated concentration of HHC. Overall, HHC formed an 11-HO metabolite, as well as a carboxy metabolite. While only the parent compound was detected in rat urine and feces, the hydroxy metabolite was additionally detected in pHLS9 and human plasma. The carboxy metabolite was only detectable in human plasma. The metabolism corresponded well to that of Δ9-THC, although glucuronidation and the formation of an 8-HO metabolite was not observed. Detectability of HHC and its carboxy metabolite in rat urine was investigated using GC-MS, but neither the parent compound, nor the metabolite were detectable. The investigated low-THC cannabis product appeared to be an actual cannabis product, since in addition to HHC, cannabinol, cannabidiol, and Δ9-THC were detected after qualitative analysis. Estimation of its content revealed 30.6 % HHC but also 4 % of Δ9-THC.

Validated LC-MS/MS method for quantitation of solasodine in rat urine and feces: Blocking nonspecific adsorption

AbstractSolasodine, a steroidal alkaloid, is distributed extensively in Solanaceae plants with multiple biological activities such as neuroprotection, antineoplastic and anticonvulsant activities. However, there is little information about the excretion of intact solasodine in vivo. To investigate its excretion, a reliable LC-MS/MS method for quantitation solasodine in rat urine and feces was established and validated. Sample preparation was carried out by liquid-liquid extraction using MTBE as extractant. Moreover, rat urine was preconditioned with BSA, an anti-adsorptive additive, to prevent the nonspecific binding of solasodine to containers and tubes. The method was validated over the range of 4–2000 ng mL−1. The correlation coefficient (r2) were all above 0.999. The intra- and inter-day precision and accuracy were within 16.9% and between −11.0 and 8.9%, respectively. The recovery of solasodine in urine and feces was in the range of 72.5–80.3 and 75.7–80.2%, respectively. IS-normalized matrix factor ranged from 0.94 to 1.12 with RSD% ≤4.02%. This method was successfully applied to the excretion study of solasodine following oral and intravenous administration.

Metabolic characteristics of ginsenosides from Panax ginseng in rat feces mediated by gut microbiota

Ginsenosides in Panax ginseng are regarded to be functional ingredients for diverse pharmacological effects and orally administrated with very low absorption in the gastrointestinal tract to be metabolized by gut microbiota. However, in vivo metabolic characteristics of ginsenosides mediated by gut microbiota are not well-known. This study aimed to explore the metabolic profiles of ginsenosides in rat feces mediated by gut microbiota. Ginsenosides and metabolites were identified and relatively quantified by ultra-performance liquid chromatography tandem/quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS). As a result, eighty-four metabolites were identified in the normal control rat feces, while only thirty intermediates were found with very low yields in the pseudo-germ-free (GF) group. Similarly, the main bioconversion pathways of ginsenosides in vivo were the same deglycosylation reaction mediated by gut microbiota in vitro. The findings demonstrated significant differences in metabolic profiles between the normal control and pseudo-GF rats, which implied gut microbiota played an important role in the metabolism of ginsenosides.

Metabolic profiling of Qi-Yu-San-Long decoction in rat feces by ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry combined with a post-targeted screening strategy.

Research into traditional Chinese medicine metabolism in feces is one of the key avenues to understanding the fate of traditional Chinese medicines in vivo. In this study, we used ultraperformance liquid chromatography-quadrupole time-of-flight MS in combination with a post-targeted screening strategy to identify the prototype components and metabolites in rat feces after oral administration. Based on our group's previous research, the component database of Qi-Yu-San-Long decoction (QYSLD) was established. Prototype components were screened from the fecal samples based on summarized chromatographic and MS behaviors. According to the chemical structure characteristics of related compounds, the possible metabolic pathways were inferred, and the metabolites related to QYSLD were predicted. We extracted ion chromatograms by predicting the m/z values of metabolite excimer ions and identified related metabolites based on their retention time and fragmentation behavior. A total of 93 QYSLD-related xenobiotics were confirmed or tentatively identified in rat fecal samples, and the results indicated that the main metabolic pathways of QYSLD were hydrolysis, deglycosylation, oxidation, reduction, decarboxylation, methylation and acetylation. This study presents a rapid method for identifying the prototype components and metabolites, and offers valuable insights into the biotransformation profiling of QYSLD in rat feces.

In vivo metabolism combined network pharmacology to identify anti-constipation constituents in Aloe barbadensis Mill

Ethnopharmacological relevanceAloe barbadensis Mill. (Aloe vera), is a homology of medicine and food plant, widely applied in functional food, cosmetics, and medicine. Aloe vera whole leaf extract, one of the most popular traditional Chinese medicines (TCMs), is mainly used in China to treat functional constipation. Aim of the studyTo elucidate the active constituents of Aloe vera for treating functional constipation. Materials and methodsPrototype constituents and metabolites in rat plasma and excreta after oral administration of Aloe vera whole leaf extract were identified by UPLC-Q-TOF/MS, and the pharmacokinetics (PK) properties of its key anti-constipation constituents speculated by network pharmacology were investigated via the established UFLC-MS/MS method. ResultsA total of 13 prototype constituents and 56 metabolites were identified in rat plasma, urine, and feces after oral administration of Aloe vera. Among them, aloesin, aloenin, aloin B, aloin A, and aloe-emodin were intimately connected to the core targets of constipation in network pharmacology analysis, and recognized as major anti-constipation constituents in Aloe vera. The validated quantitative method of the six active constituents in rat plasma exhibited good linearity, and lower limits of quantification (0.64–1.95 ng/mL). Aloin A, aloin B, aloeresin D and aloe-emodin exhibited better absorption and slower elimination rate, whereas the others, including aloesin and aloenin showed fast absorption and elimination in rat plasma after oral administration of Aloe vera. Aloin A and its isomer aloin B present similar Tmax and t1/2 but different AUC and Cmax values, indicating different relative bioavailability. The results suggested that aloin A, aloin B and aloe-emodin may be key constituents of Aloe vera for the treatment of constipation, and the other constituents including aloeresin D also contribute to its anti-constipation. ConclusionsThis study will benefit understanding the contributions of those constituents for the anti-constipation effect of Aloe vera and also provide valuable information for its application in functional food development and clinics.

Fatal neural angiostrongyliasis in the Bolivian squirrel monkey (Saimiri boliviensis boliviensis) leading to defining Angiostrongylus cantonensis risk map at a zoo in Australia

Neural angiostrongyliasis (NA) is a parasitic disease caused by Angiostrongylus cantonensis (rat lungworm). This study presents a case of NA in a captive Bolivian squirrel monkey from a zoo in western Sydney, Australia. The objective was to identify the A. cantonensis cox1 haplotype responsible for the infection and compare its mitochondrial DNA (mtDNA) to known Australian mtDNA. An epidemiological investigation was conducted to assess the risk of infection, focusing on the resident rat population in the zoo. Methods involved trapping rats and collecting rat faeces for Angiostrongylus detection, speciation, and cox1 haplotype confirmation. Various techniques were employed, including necropsy, morphological examination, and molecular methods such as ITS-2 qPCR, cox1 sequencing, and ITS-2 metabarcoding. Cluster analysis of rat faeces distribution and Angiostrongylus detection utilised an equal sampling effort (ESE) approach. Gastropods were collected throughout the study for Angiostrongylus surveillance using a hypersensitive qPCR assay. Results revealed significant clustering of rat faeces near exhibits with fresh food provision and absence of predators. Angiostrongylus-positive faeces were uniformly distributed across the zoo property. Mitochondrial DNA analysis confirmed the presence of the Ac13 haplotype of A. cantonensis in the monkey. Morphology, ITS-2 metabarcoding and partial cox1 sequencing detected only A. cantonensis, with the Ac13 cox1 haplotype predominating. A high prevalence of infection (64%, 9/14) was found in brown rats, with quantification of larvae indicating high shedding rates. Co-infections with both Ac13 and local SYD.1 A. cantonensis cox1 haplotypes were observed. Only three gastropods (all of which were Angiostrongylus-negative) were found in the survey. To minimise the risk of exposure for susceptible species, targeted rodent control was implemented in areas with higher exposure risk. A potential strategy (which requires further exploration) to consider for future zoo design was suggested. This study provides insights into the epidemiology and genetic diversity of A. cantonensis in Australia, emphasising the importance of control measures to prevent future outbreaks.