Antihyperglycemic Activity of Aqueous Extract of Euphorbia guyoniana in Streptozotocin-Induced Diabetic Rats

Aims: This work assessed the antihyperglycemic effect of Euphorbia guyoniana. Background: Euphorbia guyoniana (Boss. and Reut.) is widely used in traditional medicine. Objective: This study was designed to confirm this traditional use by assessing its antihyperglycemic capacity in vivo. Methods: The effect of the aqueous extract of Euphorbia guyoniana (Boss. and Reut.) (60 mg/kg) on glycemia in both normal and diabetic rats was evaluated. The glycogen content in the liver and skeletal muscles (extensor digitorum longus and soleus) was measured. Furthermore, liver histopathological analysis was performed. Results: The findings showed that Euphorbia guyoniana (Boss. and Reut.) exhibited a significant decrease in glycaemia in diabetic rats (from 20±2 mmol/l to 5.5 mmol/l after 6 hours of oral administration; p<0.0001 and from 20±2 mmol/l to 4.5 mmol/l after 7 days of once-daily repeated oral administration of the aqueous Euphorbia guyoniana extract; p<0.0001). In addition, the extract increased the glycogen content in the liver (41±4 mg/g versus 70±5 mg/g in normal and diabetic rats respectively) and extensor digitorum longus (39±4 mg/g versus 60±1 mg/g in normal and diabetic rats, respectively), and partially restored corporal weight in diabetic rats. Furthermore, this aqueous extract has been shown to suppress hyperglycemia induced by glucose load in treated diabetic rats. Additionally, hepatic histology in diabetic rats has been improved. This plant revealed the presence of several phytochemical constituents and possessed antioxidant activity. Conclusion: The current study evidenced that Euphorbia guyoniana (Boss. and Reut.) has a beneficial effect on improving hyperglycemia and glycogen depletion in the diabetic state.

Serum Branched-Chain Amino Acid Metabolites Increase in Males When Aerobic Exercise Is Initiated with Low Muscle Glycogen

This study used global metabolomics to identify metabolic factors that might contribute to muscle anabolic resistance, which develops when aerobic exercise is initiated with low muscle glycogen using global metabolomics. Eleven men completed this randomized, crossover study, completing two cycle ergometry glycogen depletion trials, followed by 24 h of isocaloric refeeding to elicit low (LOW; 1.5 g/kg carbohydrate, 3.0 g/kg fat) or adequate (AD; 6.0 g/kg carbohydrate 1.0 g/kg fat) glycogen. Participants then performed 80 min of cycling (64 ± 3% VO2 peak) while ingesting 146 g carbohydrate. Serum was collected before glycogen depletion under resting and fasted conditions (BASELINE), and before (PRE) and after (POST) exercise. Changes in metabolite profiles were calculated by subtracting BASELINE from PRE and POST within LOW and AD. There were greater increases (p < 0.05, Q < 0.10) in 64% of branched-chain amino acids (BCAA) metabolites and 69% of acyl-carnitine metabolites in LOW compared to AD. Urea and 3-methylhistidine had greater increases (p < 0.05, Q < 0.10) in LOW compared to AD. Changes in metabolomics profiles indicate a greater reliance on BCAA catabolism for substrate oxidation when exercise is initiated with low glycogen stores. These findings provide a mechanistic explanation for anabolic resistance associated with low muscle glycogen, and suggest that exogenous BCAA requirements to optimize muscle recovery are likely greater than current recommendations.

Histological Effect of Allium sativum (Garlic) on the Liver of White Rabbits

Allium sativum commonly referred to as garlic has been known over the years for its medicinal and culinary purposes. It has also been reported to have several toxic effects when used excessively. However, the purpose of this study was to determine the histological effects of Allium sativum (garlic) powder on the liver of white rabbits at different dosages. Twenty rabbits were randomly divided int.o five groups with free access to food and water for a period of four weeks. Four groups B, C, D, and E were fed with garlic supplemented basal diet containing different concentrations of garlic powder i.e. 100mg, 200mg, 500mg, and 1000mg respectively. These groups were called the treated group. Group A was fed with basal diet only and was considered as the control group. The results obtained showed some histological changes such as the presence of cellular necrosis, vacuolations, lipofuscin pigments, pyknosis and nuclear hypertrophy which were as a result of liver glycogen depletion and hepatic cell damage which may be due to relatively high dosage of garlic used in some of the groups.

ZnT8 Deficiency Protects From APAP-Induced Acute Liver Injury by Reducing Oxidative Stress Through Upregulating Hepatic Zinc and Metallothioneins

Zinc transporter 8 (ZnT8) is an important zinc transporter highly expressed in pancreatic islets. Deficiency of ZnT8 leads to a marked decrease in islet zinc, which is thought to prevent liver diseases associated with oxidative stress. Herein, we aimed to investigate whether loss of islet zinc affects the antioxidant capacity of the liver and acute drug-induced liver injury. To address this question, we treated ZnT8 knockout (KO) or wild-type control mice with 300 mg/ kg acetaminophen (APAP) or phosphate-buffered saline (PBS). Unexpectedly, we found that loss of ZnT8 in mice ameliorated APAP-induced injury and was accompanied by inhibition of c-Jun N-terminal kinase (JNK) activation, reduced hepatocyte death, and decreased serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). An increase in hepatic glutathione (GSH) was observed, corresponding to a decrease in malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) levels. APAP-induced inflammation and glycogen depletion were alleviated. In contrast, no significant changes were observed in cytochrome P450 family 2 subfamily E member 1 (CYP2E1), the main enzyme responsible for drug metabolism. Elevated levels of hepatic zinc and metallothionein (MT) were also observed, which may contribute to the hepatoprotective effect in ZnT8 KO mice. Taken together, these results suggest that ZnT8 deficiency protects the liver from APAP toxicity by attenuating oxidative stress and promoting hepatocyte proliferation. This study provides new insights into the functions of ZnT8 and zinc as key mediators linking pancreatic and hepatic functions.

Initiating aerobic exercise with low glycogen content reduces markers of myogenesis but not mTORC1 signaling

Background The effects of low muscle glycogen on molecular markers of protein synthesis and myogenesis before and during aerobic exercise with carbohydrate ingestion is unclear. The purpose of this study was to determine the effects of initiating aerobic exercise with low muscle glycogen on mTORC1 signaling and markers of myogenesis. Methods Eleven men completed two cycle ergometry glycogen depletion trials separated by 7-d, followed by randomized isocaloric refeeding for 24-h to elicit low (LOW; 1.5 g/kg carbohydrate, 3.0 g/kg fat) or adequate (AD; 6.0 g/kg carbohydrate, 1.0 g/kg fat) glycogen. Participants then performed 80-min of cycle ergometry (64 ± 3% VO2peak) while ingesting 146 g carbohydrate. mTORC1 signaling (Western blotting) and gene transcription (RT-qPCR) were determined from vastus lateralis biopsies before glycogen depletion (baseline, BASE), and before (PRE) and after (POST) exercise. Results Regardless of treatment, p-mTORC1Ser2448, p-p70S6KSer424/421, and p-rpS6Ser235/236 were higher (P < 0.05) POST compared to PRE and BASE. PAX7 and MYOGENIN were lower (P < 0.05) in LOW compared to AD, regardless of time, while MYOD was lower (P < 0.05) in LOW compared to AD at PRE, but not different at POST. Conclusion Initiating aerobic exercise with low muscle glycogen does not affect mTORC1 signaling, yet reductions in gene expression of myogenic regulatory factors suggest that muscle recovery from exercise may be reduced.

Infection of Tilapia tilapinevirus in Mozambique Tilapia (Oreochromis mossambicus), a Globally Vulnerable Fish Species

Tilapia tilapinevirus, or tilapia lake virus (TiLV), is a highly contagious virus found in tilapia and its hybrid species that has been reported worldwide, including in Asia, the Americas, and Africa. In this study, we experimentally challenged Mozambique tilapia (Oreochromis mossambicus) with a virulent TiLV strain, VETKU-TV01, at both low (1 × 103 TCID50/mL) and high (1 × 105 TCID50/mL) concentration. After the challenge, the Mozambique tilapia showed pale skin with some hemorrhage and erosion, lethargy, abdominal swelling, congestion around the eye, and exophthalmos; there was a cumulative mortality rate at 48.89% and 77.78% in the groups that received the low and high concentration, respectively. Quantitative PCR and in situ hybridization confirmed the presence of TiLV in the internal organs of moribund fish. Notably, severe histopathological changes, including glycogen depletion, syncytial hepatic cells containing multiple nuclei and intracytoplasmic inclusion bodies, and infiltration of melanomacrophage into the spleen, were frequently found in the Mozambique tilapia challenged with high TiLV concentration. Comparatively, the infectivity and pathology of the TiLV infection in Mozambique tilapia and red hybrid tilapia (Oreochromis spp.) were found to be similar. Our results confirmed the susceptibility of Mozambique tilapia, which has recently been determined to be a vulnerable species, to TiLV infection, expanding knowledge that the virus can cause disease in this fish species.

Protective Effect of Emblica officinalis in Cyprinus carpio against Hepatotoxicity Induced by Malachite Green: Ultrastructural and Molecular Analysis

Malachite green (MG) dye, besides coloring is used as an effective aquaculture therapeutic. The present study assesses the mitigating ability of Emblica officinalis (EO) fruit extract against the dye induced chronic (60 days) cyto-toxicity in Cyprinus carpio. For this, four experimental groups were maintained: group I—control, group II—MG, group III—EO (positive control), group IV—MG + EO. The study was made at three tiers: detailing structural anomalies using a light microscope and transmission electron microscope (TEM), biochemical estimation of antioxidant enzymes, and lipid peroxidation and molecular analysis of expression patterns of HSP70, and CYP1A genes. MG intoxication resulted in necrosis, cytoplasmic vacuolation, glycogen depletion, abundant macrophages, loss of cell integrity and prominent nuclear alterations. Significant (p < 0.05) inhibition in the activities of catalase (CAT), superoxide dismutase (SOD), glutathione-S-transferase (GST) and reduced glutathione (GSH), along with an elevation in malondialdehyde (MDA) levels, occurred after 60 days of MG exposure. CYP1A and HSP70 genes presented a significant change in their expression in MG treated fish. Whereas oral supplementation with EO significantly restored the histo-architecture, normalized the altered enzymatic activity, reduced the oxidative stress level and regulated the expression of HSP70 and CYP1A genes. Thus, it can be concluded that EO acted as an effective ameliorant against malachite green induced cyto-toxicity in Cyprinus carpio.

A Correlative Study of Endometrial Glycogen Content in Female Infertility

Infertility is a global problem. It has been viewed as a discredit and social humiliation thrust upon healthy young adults. The present detects the glycogen content in the endometrial glands of infertile women in the age group of 18 -39 years. This study aimed to compare infertility and the glycogen content in the endometrial glands of fertile women of the same age group. The endometrium is the tissue of attention because it is the site for implantation of ovum. The current study was done to evaluate the glycogen content in the endometrium of infertile patients and compare it with that of fertile patients. This study was done on 60 cases and 20 controls. Our study showed that large masses of glycogen (++++) was seen in only 7 secretory endometria in infertile cases (14.9%) when compared to 14 secretory endometria infertile subjects (77.7%). Also, endometrial glycogen grading in the secretory phase in infertile patients showed glycogen depletion (Grade 0) in 13 cases (27.7%) whereas it was nil in the fertile group. Glycogen is an essential and straight source of nutrient for the primary concepts and also helps in the successful implantation of blastocyst and continuation of pregnancy.

In vivo study of silver nanomaterials’ toxicity with respect to size

Silver nanoparticles (Ag NPs) are widely used in nanomedicine, pharmaceutical products, industry and other consumer products owing to their unique physiochemical properties with probable potential risk to human health and the ecosystems. The aim of this work was to investigate the in-life morphological effects, biochemical, histological and histochemical alterations that might be induced by variable sizes of Ag NPs in hepatic, renal and testicular tissues with the hypothesis that variable sizes of nano-Ag could induce variable effects in the vital organs. Five groups of adult healthy male mice (BALB/C) were exposed to 35 intraperitoneal injections of Ag NPs (1 mg/kg bw) using five different particle sizes (10, 20, 40, 60 and 100 nm). All mice were subjected to in-life morphometric, biochemical, histological and histochemical analysis. The findings demonstrated that Ag NPs could induce alterations in the average body weight gain, food consumption, water intake and organ indices. In addition, these NPs significantly altered hepatic and renal biomarkers. Moreover, Ag NPs produced ground glass hepatocyte cytoplasm, with mitotic activity, nuclear alterations, degeneration, glycogen depletion and inflammatory cells infiltration in the liver. The kidneys of treated mice exhibited proximal renal tubules degeneration, distal renal tubules regeneration, glomerular shrinkage, Bowman’s capsule thickening and interstitial inflammation. The testicular tissues demonstrated spermatocyte sloughing and spermatid giant cell formation. The findings together indicated that Ag NPs could interact with the anatomical structures of the liver, kidney and testis in ways that could induce injury. In addition, the results indicated that smaller Ag NPs posed a greater potential risk than the larger ones, which might be associated with their behaviour, dissolution rate, bioavailability and their probable variable toxicokinetics.

Flight activity and glycogen depletion on a low-carbohydrate diet

ABSTRACTGlycogen is a critical store for locomotion. Depleted glycogen stores are associated with increased fatigue during exercise. The reduced effectiveness of low-carbohydrate diets for weight loss over longer time periods may arise because such diets reduce glycogen stores and thereby energy expenditure via physical activity. To explore the effect of a low-carbohydrate diet on activity and glycogen utilisation, we fed adult Drosophila melanogaster a standard or low-carbohydrate diet for 9 days and measured patterns of flight activity and rates of glycogen depletion. We hypothesised that flight activity and rates of glycogen depletion would be reduced on a low-carbohydrate diet. Flight activity was elevated in the low-carbohydrate group but glycogen depletion rates were unchanged. We conclude that increased activity is probably a foraging response to carbohydrate deficiency and speculate that the previously demonstrated metabolic depression that occurs on a low-carbohydrate diet in this species may allow for increased flight activity without increased glycogen depletion.