Effect of S-allylcysteine against diabetic nephropathy via inhibition of MEK1/2-ERK1/2-RSK2 signalling pathway in streptozotocin-nicotinamide-induced diabetic rats.

OBJECTIVE: In the current study, we evaluated the ameliorative effect of S-allylcysteine (SAC) against streptozotocin (STZ)-nicotinamide (NAD)-induced diabetic nephropathy (DN) in rats and also an attempt was made to establish the molecular mechanism of SAC. METHODS: DN rats were orally supplemented with SAC (150 mg/kg body weight) for a period of 45 days and the effect of SAC on urinary albumin excretion, metabolic parameters, and tubular injury biomarkers by ELISA, total levels and phosphorylation of MEK1/2, ERK1/2, and RSK2 by western blotting analysis in control and experimental rats were assessed. RESULTS: From this study, we observed that SAC considerably decreased polydipsia, poly urea, polyphagia, albuminuria and the levels of urinary N-acetyl-beta-D-glucosaminidase, neutrophil gelatinase-associated lipocalin, transforming growth factor-ß1 and SAC effectively altered the pathological changes in DN rats. SAC also reserved renal cortical phosphorylation of MEK1/2, ERK1/2 and RSK2. CONCLUSION: Hence this study recommended that SAC can successfully protect the DN through regulation of MEK1/2-ERK1/2-RSK2 signalling.

Antiobesity efficacy of asiatic acid: down-regulation of adipogenic and inflammatory processes in high fat diet induced obese rats.

In the current study, we evaluated the effects of Asiatic acid (AA) on lipid metabolic markers in HFD-induced obese Sprague-Dawley rat model. AA (20 mg/kg BW) was administered orally to HFD-fed rats for 42 days. Changes in body composition, glucose, insulin resistance (IR) and lipid profiles of tissues, plasma and the pattern of gene expression of peroxisome proliferator-activated receptor-γ (PPAR-γ) and its target genes fatty-acid synthase (FAS), adipocyte protein-2 (aP2) and uncoupling protein-2 (UCP-2) and pro-inflammatory factor tumor necrosis factor (TNF)-α were observed in experimental rats. Oral administration of AA exerts therapeutic effects similar to orlistat in attenuating body weight gain, glucose, IR, plasma and tissue lipids and mRNA levels of PPAR-γ, FAS, aP2 and inflammatory factor TNF-α and increasing UCP-2 expression in HFD-fed rats. Hence, these findings concluded that AA attenuate HFD-induced obesity by modulating PPAR-γ and its target genes and regulate lipid metabolism, suggesting their possible antiobesity effects.

Altered endocrine, cytokine signaling and oxidative stress: A plausible reason for differential changes in testicular cells in diet-induced and genetically-inherited - obesity in adult rats.

Obesity is emerging as a potential risk factor for male infertility. It is a multifactorial disorder with primarily genetic and/or environmental factors. Our earlier studies have shown differential effects of genetically inherited-and high fat diet induced-obesity on hormones, fertility and spermatogenesis in adult male rats. In the present study, we assessed the effect of high fat diet induced - and genetically inherited - obesity on the underlying molecular mechanisms affecting spermatogenesis. The expression of hormone receptors, cytokines and markers of oxidative stress as well as cell cycle mediators were affected in both the obese groups, however, the changes were different in the two groups. This could be due to difference in fat distribution between the two types of obese groups. Altered expression of hormone receptors, cytokines, cell cycle mediators and differential effects on oxidative stress could be the plausible reason for differential changes in germ cell population in both the groups.

Podophyllotoxin and Rutin Modulate M1 (iNOS+) Macrophages and Mitigate Lethal Radiation (LR) Induced Inflammatory Responses in Mice.

Accidental exposure to lethal doses of Gamma radiation leads to the systemic inflammatory syndrome which causes mortality. In view of this, management of hemopoietic syndrome by modulating pro-inflammatory response in clinically manageable time period seems to be the most appropriate strategy for encountering radiation induced damage and recovery. As both tissue and peripheral macrophages are critical for the management of radiation induced injuries, we have unraveled the immunomodulatory potential of radioprotective formulation (G-003M) on peripheral macrophages populations in this study. G-003M inhibited lethal radiation induced NO and Th1 effector cytokines in the exposed macrophages indicating its M1 dim polarizing capacity. In similar lines, conditioning of mice with G-003M before lethal irradiation (LR) inhibited LR induced titre of Th1 effector cytokines in both serums as well as in lung, small intestine, and spleen tissue confirming its immunomodulatory potential. G-003M potentially down modulated inflammatory response in LPS induced inflammatory model and enhanced M2 polarization of iNOS+ M1 effector macrophages providing a molecular hint on G-003M mechanism of action on macrophages. These observations revealed that G-003M potentially modulate pro-inflammatory programming of macrophages and mitigate radiation-induced inflammatory stress which is believed to contribute significantly to radioprotective attribute of G-003M. In this study, we demonstrate that Rutin and Podophyllotoxin drive M1dim/M2 polarization of LR primed macrophages apart from protecting DNA from radiation. These drugs have the capacity to programme innate immune cells like macrophages which may be involved in homeostasis during recovery.

Genetically Inherited Obesity and High-Fat Diet-Induced Obesity Differentially Alter Spermatogenesis in Adult Male Rats.

Obesity is a multifactorial disorder with predominantly genetic and/or environmental causes. Our aim was to delineate effects of genetically inherited and high-fat diet-induced obesity on fertility and spermatogenesis using two Wistar rat models: genetically inherited obese (GIO) WNIN/Ob rats and diet-induced obese (DIO) rats, which received a high-fat diet. The terminal body weights were similar in both groups, but there was a significant difference in metabolic and hormone profiles between the groups. Fertility assessment revealed a significant decrease in the litter size due to increased pre- and postimplantation loss in the DIO group, whereas the rats in the GIO group were infertile due to lack of libido. Significantly decreased sperm counts were observed in the GIO group compared with the DIO group. Enumeration of testicular cells on the basis of ploidy and cell type-specific expression markers, to study the effect of obesity on spermatogenesis, demonstrated that the GIO and DIO states affected mitosis: spermatogonia and S-phase population were increased. However, distinctive effects were observed on meiosis and spermiogenesis in both the groups. Differential effects of GIO and DIO on fertility and spermatogenesis could be due to the significant difference in white adipose tissue accumulation between the groups and not due to high body weights. The differential effects of obesity suggest male obesity-induced infertility observed in humans could be a combination of genetic and environmental factors.

Sphingosine-1-Phosphate (S-1P) Promotes Differentiation of Naive Macrophages and Enhances Protective Immunity Against Mycobacterium tuberculosis.

Sphingosine-1-phosphate (S-1P) is a key sphingolipid involved in the pathobiology of various respiratory diseases. We have previously demonstrated the significance of S-1P in controlling non-pathogenic mycobacterial infection in macrophages, and here we demonstrate the therapeutic potential of S-1P against pathogenic Mycobacterium tuberculosis (H37Rv) in the mouse model of infection. Our study revealed that S-1P is involved in the expression of iNOS proteins in macrophages, their polarization toward M1 phenotype, and secretion of interferon (IFN)-γ during the course of infection. S-1P is also capable of enhancing infiltration of pulmonary CD11b+ macrophages and expression of S-1P receptor-3 (S-1PR3) in the lungs during the course of infection. We further revealed the influence of S-1P on major signaling components of inflammatory signaling pathways during M. tuberculosis infection, thus highlighting antimycobacterial potential of S-1P in animals. Our data suggest that enhancing S-1P levels by sphingolipid mimetic compounds/drugs can be used as an immunoadjuvant for boosting immunity against pathogenic mycobacteria.

Ethanolic Fraction of Terminalia tomentosa Attenuates Biochemical and Physiological Derangements in Diet Induced Obese Rat Model by Regulating Key Lipid Metabolizing Enzymes and Adipokines.

The prevalence of overweight-obesity and associated comorbidities have reached alarming levels necessitating the need to explore effective therapeutics. In the present work, we demonstrated the promising antiobesity activity of ethanolic fraction of Terminalia tomentosa bark (EFTT) in diet induced obese rat model. High Fat Diet (HFD)-fed obese rats were orally administered with EFTT (50, 100 and 200 mg/kg body weight). Changes in body weight, body composition, bone mineral concentration, bone mineral density, plasma glucose, insulin, leptin, adiponectin, circulatory and tissue lipid profiles, and the activities of liver antioxidant enzymes, key lipid metabolic enzymes and mRNA expressions of fatty acid synthase (FAS), peroxisome proliferator-activated receptor gamma (PPAR-γ), leptin and tumor necrosis factor alpha (TNF-α) were assessed in experimental rats in the presence and absence of EFTT. At a dose of 200 mg/kg b.wt, EFTT has substantially attenuated body weight and related patho-physiological alterations in HFD-induced obese rats. These findings were correlated with histological observations of adipose tissue. The therapeutic activity of EFTT could be possibly through restoration of antioxidants status, regulation of key lipid metabolizing enzymes, expression of FAS, leptin, PPAR-γ and by synchronized control of energy metabolism in liver and adipose tissue.

Reversal of endothelial dysfunction in aorta of streptozotocin-nicotinamide-induced type-2 diabetic rats by S-Allylcysteine.

Dietary measures and plant-based therapies as prescribed by native systems of medicine have gained attraction among diabetics with claims of efficacy. The present study investigated the effects of S-Allylcysteine (SAC) on body weight gain, glucose, insulin, insulin resistance, and nitric oxide synthase in plasma and argininosuccinate synthase (AS) and argininosuccinate lyase (ASL), lipid peroxides and antioxidant enzymes in aorta of control and streptozotocin-nicotinamide (STZ-NA)-induced diabetic rats. Changes in body weight, glucose, insulin, insulin resistance, and antioxidant profiles of aorta and mRNA expressions of nitric oxide synthase, AS, and ASL were observed in experimental rats. SAC (150 mg/kg b.w) showed its therapeutic effects similar to gliclazide in decreasing glucose, insulin resistance, lipid peroxidation, and increasing body weight; insulin, antioxidant enzymes, and mRNA levels of nitric oxide synthase, argininosuccinate synthase, and argininosuccinate lyase genes in STZ-NA rats. Histopathologic studies also revealed the protective nature of SAC on aorta. In conclusion, garlic and its constituents mediate the anti-diabetic potential through mitigating hyperglycemic status, changing insulin resistance by alleviating endothelial dysregulation in both plasma and tissues.

Effects of S-Allylcysteine on Biomarkers of the Polyol Pathway in Rats with Type 2 Diabetes.

OBJECTIVES: We evaluated the effects of S-allylcysteine (SAC) on biomarkers of the polyol pathway in streptozotocin-nicotinamide (STZ-NA)-induced diabetes in rats. METHODS: Diabetes was induced in male albino Wistar rats by intraperitoneal administration of STZ (55 mg kg-1 bw-1) and NA (110 mg kg-1 bw-1). SAC (150 mg kg-1 bw-1) was orally administered to the rats with diabetes for 45 days to assess its effects on blood glucose, insulin, insulin resistance, glycated hemoglobin, aldose reductase (AR), sorbitol dehydrogenase (SDH), sorbitol, fructose, thiobarbituric acid-reactive substances (TBARS), hydroperoxide, hemoglobin and glutathione (GSH). RESULTS: On SAC administration in the rats with diabetes, the levels of blood glucose, insulin resistance, glycated hemoglobin, AR, SDH, sorbitol, fructose, TBARS and hydroperoxide increased significantly (p<0.05), whereas those of insulin, hemoglobin and GSH decreased. SAC showed therapeutic effects similar to those of gliclazide in decreasing blood glucose, AR, SDH, sorbitol, fructose, glycosylated hemoglobin, TBARS and hydroperoxides levels and significant increases in insulin, hemoglobin and GSH activity in rats with diabetes. Moreover, histopathologic studies also revealed the protective effect of SAC on pancreatic beta cells. CONCLUSIONS: The results indicate that SAC prevents complications of diabetes by reducing the influx of glucose in the polyol pathway, thereby elevating the GSH level and reducing the activities of AR and SDH. Therefore, SAC may have imperative implications for the deterrence and early treatment of type 2 diabetes.

Long-term functions of encapsulated islets grafted in nonhuman primates without immunosuppression.

BACKGROUND: Long-term survival and functions of encapsulated islet grafts need to be evaluated in the absence of immunosuppression. The present study aimed to assess the viability and functions of macroencapsulated islets grafted in nonhuman primates without immunosuppression for 1 year. METHODS: Islet transplantations were performed in partially pancreatectomized rhesus monkeys (two autologous and four allogenic) without immunosuppression using immunoisolatory devices. Macroencapsulated islets were implanted subcutaneously (5000-8000 IEQ/device) at two sites (left thigh and interscapular region) and were explanted at 2, 6, and 12 months after implantation. Staining for viability and apoptosis, in vivo and in vitro glucose-stimulated insulin release, expression of insulin and glucagon genes, and histopathologic examination of the device were used to assess engraftment potential, viability, and functions of islets. Animals were regularly monitored for dietary intake, body weight, and fasting blood glucose levels after islet transplantation. RESULTS: Devices explanted showed vascularization at the end of 2, 6, and 12 months with occasional lymphocytes and minimal fibrosis outside the device. Flow cytometric analysis revealed 97.9%±1.5% and 94.3%±5.71% viable ß cells in interscapular site and thigh in autologous recipients and 85.6%±4.01% (interscapular site) and 74.1%±12.05% (thigh) viable ß cells in allogenic islet recipients. In vivo glucose challenge test revealed significantly increased glucose-stimulated insulin release (P=0.028) in the left thigh with implant (17.58±3.13 mU/L) compared with the thigh without implant (9.86±1.063 mU/L). Insulin and glucagon gene expression was evident in islets recovered from explanted device. CONCLUSIONS: These results indicate that subcutaneous implantation of macroencapsulated islets is minimally invasive and has potential for transplantation without immunosuppression.

Studies on the molecular correlates of genomic stability in rat brain cells following Amalakirasayana therapy.

Adult Wistar NIN (WNIN) rats (6 months old) of both sexes were orally fed Amalakirasayana at a dose of 4.5 g per kg body weight, five days in a week. The Amalakirasayana was prepared by Arya Vaidya Sala, Kottakkal, Kerala, India, which is considered as gold standard. After 3, 9 and 15 months of such therapeutic regime, rats were sacrificed and various tissues including brain were removed. Isolated cell suspensions of neurons and astroglia were prepared from the cerebral cortex. DNA damage, as a prime indicator of the status of genomic stability was measured in terms of single (SSBs) and double strand breaks (DSBs) through (a). The "comet" assay and (b). The biochemical methods utilizing the unique properties of Escherichia coli DNA polymerase I (pol I) and calf thymus terminal transferase. The results convincingly indicate that while in control animals, there was a distinct increase in DNA damage with age in neurons and astrocytes, rasayana fed animals showed significantly less DNA damage in brain cells demonstrating beneficial effects of Rasayana therapy towards maintenance of genomic stability. DNA-damage may be the proximal cause of aging and strategies to reduce the rate of aging could be based on this fact.