Age-related decline in the expression of BRG1, ATM and ATR are partially reversed by dietary restriction in the livers of female mice.

BRG1 (Brahma-related gene 1) is a member of the SWI/SNF (switch/sucrose nonfermentable) chromatin remodeling complex which utilizes the energy from ATP hydrolysis for its activity. In addition to its role of regulating the expression of a vast array of genes, BRG1 mediates DNA repair upon genotoxic stress and regulates senescence. During organismal ageing, there is accumulation of unrepaired/unrepairable DNA damage due to progressive breakdown of the DNA repair machinery. The present study investigates the expression level of BRG1 as a function of age in the liver of 5- and 21-month-old female mice. It also explores the impact of dietary restriction on BRG1 expression in the old (21-month) mice. Salient findings of the study are: Real-time PCR and Western blot analyses reveal that BRG1 levels are higher in 5-month-old mice but decrease significantly with age. Dietary restriction increases BRG1 expression in the 21-month-old mice, nearly restoring it to the level observed in the younger group. Similar expression patterns are observed for DNA damage response genes ATM (Ataxia Telangiectasia Mutated) and ATR (Ataxia Telangiectasia and Rad3-related) with the advancement in age and which appears to be modulated by dietary restriction. BRG1 transcriptionally regulates ATM as a function of age and dietary restriction. These results suggest that BRG1, ATM and ATR are downregulated as mice age, and dietary restriction can restore their expression. This implies that dietary restriction may play a crucial role in regulating BRG1 and related gene expression, potentially maintaining liver repair and metabolic processes as mice age.

Therapeutic Potential of Dillenia indica L. in Attenuating Hyperglycemia-Induced Oxidative Stress and Apoptosis in Alloxan-Administered Diabetic Mice.

BACKGROUND: Hyperglycemia-induced oxidative stress accelerates the process of apoptosis in tissues. Dilleniaindica (DI) is a medicinal plant, and its fruit contains many therapeutic properties. The therapeutic activity of the Methanolic Fruit Extract (MFE) of DI in attenuating oxidative stress and apoptosis in the liver and kidney tissues of alloxan-induced diabetic mice was analyzed in the present study. METHODS: High-Performance Thin Layer Chromatography (HPTLC) profiling of MFE was conducted. GLUT4 protein expression analysis and lipid peroxidation assays were conducted to check for MFE effect by administering in diabetic mice. An ultrastructural study was conducted for both the tissues. In apoptotic studies, the TUNEL assay and apoptotic protein expression analysis was conducted. RESULTS: High-Performance Thin Layer Chromatography (HPTLC) profiling of MFE showed the presence of two crucial antioxidants, ascorbic acid, and naringenin. In GLUT-4 protein expression analysis, MFE suppresses hyperglycemia by upregulating GLUT4 protein expression. Lipid peroxidation assay showed a decrease in malondialdehyde (MDA) upon MFE administration in diabetic mice. An ultrastructural study was conducted, and MFE was found to restore cellular alterations in diabetic tissues. In apoptotic studies, the TUNEL assay shows that MFE treatment showed fewer apoptotic cells than the diabetic group. The study also observed decreased caspase 3 protein expression and increased Bcl-2 protein expression. CONCLUSIONS: Therefore, it is inferred from the study that MFE can exert a protective effect by suppressing hyperglycemia and modulating oxidative stress and apoptosis in alloxan-administered diabetic mice.

Potentilla fulgens upregulate GLUT4, AMPK, AKT and insulin in alloxan-induced diabetic mice: an in vivo and in silico study.

OBJECTIVE: This study was designed to investigate whether the glucose lowering effects of Potentilla fulgens acts by modulating GLUT4, AKT2 and AMPK expression in the skeletal muscle and liver tissues. METHODOLOGY: Alloxan-induced diabetic mice treated with Potentilla fulgens was assessed for their blood glucose and insulin level, mRNA and protein expression using distinguished methods. Additionally, GLUT4, AKT2 and AMPK were docked with catechin, epicatechin, kaempferol, metformin, quercetin and ursolic acid reportedly present in Potentilla fulgens. RESULTS: Potentilla fulgens ameliorates hyperglycaemia and insulin sensitivity via activation of AKT2 and AMPK, increases the expression of GLUT4, AKT2, AMPKα1 and AMPKα2 whose levels are reduced under diabetic condition. Molecular docking revealed interacting residues and their binding affinities (-4.56 to -8.95 Kcal/mol). CONCLUSIONS: These findings provide more clarity vis-avis the mechanism of action of the phytoceuticals present in Potentilla fulgens extract which function through their action on GLUT4, PKB and AMPK.

Effect of 5-HT2C receptor agonist and antagonist on chronic unpredictable stress (CUS) - Mediated anxiety and depression in adolescent Wistar albino rat: Implicating serotonin and mitochondrial ETC-I function in serotonergic neurotransmission.

Anxiety and depression are among the major neuropsychiatric disorders worldwide, and yet the etiologies of these disorders remain unclear to date. Chronic unpredictable stress (CUS) procedure mimics several behavioral characteristics such as anxiety and depression in rodents. Using this animal model, we have attempted to understand the serotonergic system in the hippocampus and prefrontal cortex, while using the 5-HT2CR agonist and antagonist in evaluating 5-HT2C receptor neurotransmission. A decrease in serotonin (5-HT) level, tryptophan hydroxylase-2 activity and, 5-HT2CR receptor protein down-regulation in the CUS exposed group, explains the involvement of 5-HT and 5-HT2CR neurotransmission in the genesis of anxiety and depression. Besides, the oxidative stress - attenuated electrolyte imbalance via decrease ATPase pump activity, and compromised oxidative phosphorylation via decrease ETC-I activity are some of the underlying factors affecting neuronal cell survival and serotonergic neurotransmission. To complement our finding, altered behavioral performance scored in the open field test, elevated plus maze test, and the forced swim test, when exposed to CUS is indicative or consistent with anxiety, depression, emotional and locomotor status of the animals. Keeping these findings in mind, treatment with 5-HT2CR agonist (1-Methylpsilocin at 0.7 mg/kg), and 5-HT2CR antagonist (RS-102221 hydrochloride at 1 mg/kg) displayed varying results. One prominent finding was the anxiolytic ability of the 5-HT2CR agonist and the anti-depressive ability of the 5-HT2CR antagonist on the 7th-day treatment. Though the exact mechanism of action is not clear, their ability to equilibrate brain redox status, restoring Ca2+ level via Ca2+ATPase pump activity, and sustaining the mitochondrial bioenergetics can all be accounted for facilitating neurogenesis and the serotonergic system.

Culture-dependent and metagenomic analysis of lesser horseshoe bats' gut microbiome revealing unique bacterial diversity and signatures of potential human pathogens.

Bats are highly diverse and ecologically important mammals. They harbor various bacteria, viruses, and fungal communities that are either beneficial or potentially pathogenic. Extensive metagenomic studies in bats are limited, particularly for the gut, and to date, there are no reports on the bacterial diversity of Rhinolophus monoceros from Meghalaya, India. There are limited studies on the isolation of potential harmful or beneficial bacteria and their interactions with the environment through culture-dependent approaches. Therefore, high-throughput screening was used to understand the population structure, genetic diversity, and ecological role of the microorganisms. High-throughput sequencing of the 16S rRNA marker for gene mapping showed that the gut samples constitute a diverse group of bacteria that is dominated by Proteobacteria, followed by Firmicutes. The bacterial genera Corynebacterium and Mycobacterium were also observed in the Illumina dataset. Illumina sequencing revealed eight bacterial phyla composed of 112 genera. The metagenomic analysis of the OTUs from the gut revealed diverse bacterial communities as well as zoonotic and human pathogens. There were differences in the bacterial communities between the two methods used in this study, which could be related to host specificity, diet, and habitat. The culture-dependent technique resulted in the isolation of 35 bacterial isolates, of which Bacillus cereus and B. anthracis are well-known bacterial pathogens that show virulent traits including hemolytic and proteolytic activities. Pseudomonas stutzeri is an opportunistic human pathogen that was also isolated and showed similar traits. Antibiotic sensitivity tests were performed on all 35 isolates, and different antibiotics were used for Gram-positive and -negative bacteria. The result showed that some isolates are resistant to antibiotics such as penicillin G and Cefoxitin. This report on gut bacterial communities could attract interest in the possibility of isolating and characterizing bacteria for the production of antibiotics, enzymes, plant growth promoters, and probiotics. However, the presence of potential pathogenic bacteria that may impose health hazards cannot be ignored and needs to be studied further.

Chlorophyllin supplementation modulates hyperglycemia-induced oxidative stress and apoptosis in liver of streptozotocin-administered mice.

Chlorophyllin is a water-soluble mixture of sodium-copper salts of chlorophyll with antioxidant and antimutagen properties. In this study, an attempt has been made to evaluate the effect of chlorophyllin on hyperglycemia-induced oxidative stress and apoptosis in liver of streptozotocin (STZ)-administered mice. In STZ-induced diabetes, two causative factors for pancreatic ß-cell deaths are DNA alkylation and profound reactive oxygen species (ROS) generation. In this study, chlorophyllin treatment was found to be able to modulate oxidative stress and apoptosis in liver of diabetic mice. Diabetic mice exhibited a significant reduction of ROS, malondialdehyde (MDA), and protein carbonyl levels upon treatment with the chlorophyllin. However, antioxidant enzymes, such as copper-zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD), and catalase (CAT) showed enhanced activity as well as expression in chlorophyllin-administered diabetic mice. The hepatoprotective effect of chlorophyllin was confirmed from the decreased activity of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). The histological and ultrastructural studies revealed the ability of chlorophyllin to restore morphological and cellular alterations as observed in STZ-induced diabetic mice. The effect of chlorophyllin on apoptosis showed the downregulation of cysteine-dependent aspartate-specific protease (caspase) 3 and caspase 9, whereas upregulation of B-cell lymphoma-2 (Bcl-2) protein, and the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) assay demonstrated a few apoptotic cells. In conclusion, it can be stated that chlorophyllin treatment can exert hepatoprotective effect via modulating hyperglycemia-induced oxidative stress and apoptosis in STZ-administered diabetic mice. © 2018 BioFactors, 44(5):418-430, 2018.

Evaluation of the antidiabetic property of aqueous leaves extract of Zanthoxylum armatum DC. using in vivo and in vitro approaches.

The present study was designed to evaluate the antidiabetic potential of the aqueous leaves extract of Zanthoxylum armatum DC. leaves using in vivo and in vitro approaches. For in vivo studies, blood glucose level was monitored at different intervals after administration of varying doses of the extract for its hypoglycemic (100-6000 mg/kg b.w.) and antihyperglycemic (250 mg/kg b.w.) effect in normoglycemic and diabetic mice. In vitro enzymatic inhibition activity was tested against α-amylase, α- and ß-glucosidase and lipase. Additionally hydroxyl radical, hydrogen peroxide scavenging assay and phytochemical screening were also performed. Element analysis of the plant was studied by Atomic Absorption Spectrometry (AAS) and Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES). The plant extract showed significant hypoglycemic and antihyperglycemic effect in normoglycemic and diabetic mice. The IC50 values of extract for α-amylase, ß-glucosidase, lipase, hydroxyl radical scavenging activity, hydrogen peroxide scavenging activity were 7.40 mg/ml, 0.30 mg/ml, 8.35 mg/ml, 3.25 mg/ml, 9.62 mg/ml respectively and the percentage of inhibition for α-glucosidase was 79.82% at 0.8 mg/ml. In vitro studies were compared with their respective standards. Elemental analysis revealed the presence of essential elements such as Mg, V, Fe, Cr, Zn, Cu, Mo, Mn, K, Ca, P and Sr which are all known to play a role in regulating blood glucose. The results demonstrate that Z. armatum aqueous leaves extract possess antidiabetic property in both in vivo and in vitro condition.

Genistein represses PEPCK-C expression in an insulin-independent manner in HepG2 cells and in alloxan-induced diabetic mice.

Genistein has been reported to exert beneficial effects on type 2 diabetes mellitus (T2DM); however, the underlying molecular mechanisms involved therein have not been clearly elucidated. To address this question, the effect of genistein on the expression of phosphoenolpyruvate carboxykinase (PEPCK), and glucose production in HepG2 cells and in alloxan-induced diabetic mice was investigated. HepG2 cells were exposed to different concentration of genistein in presence or absence of modulators, and the expression of cytosolic PEPCK (PEPCK-C) and the signaling pathways was studied. Further, the biological relevance of the in vitro study was tested in alloxan-induced diabetic mice. Genistein lowered PEPCK-C expression and glucose production in HepG2 cells accompanied with increased in phosphorylation states of AMPK, MEK½, ERK½, and CRTC2. Treatment with the AMPK inhibitor (compound C) enhanced genistein-induced MEK½ and ERK½ activity indicating a potential cross-talk between the two signaling pathways. In vivo, genistein also reduced fasting glucose levels accompanied with reduced PEPCK-C expression and increased in AMPK and ERK½ phosphorylation states in the liver of genistein-treated alloxan-induced diabetic mice. Genistein fulfills the criteria of a suitable anti-diabetic agent by reducing glucose production and inhibiting PEPCK-C expression in HepG2 cells and also in alloxan-induced diabetic mice. These results indicate that genistein is an effective candidate for preventing T2DM through the modulation of AMPK-CRTC2 and MEK/ERK signaling pathways, which may allow a novel approach to modulate dysfunction in hepatic gluconeogenesis in T2DM.

Amelioration of age-dependent increase in oxidative stress markers in male mice by extract of Potentilla fulgens.

OBJECTIVE: To investigate the effect of Potentilla fulgens extract on lipid peroxidation and antioxidant status in male mice as a function of age. METHODS: Eighteen-month-old Swiss albino male mice were administered the dichloromethane-methanol extract of P. fulgens (250 mg/kg b.w.) on alternate days via intraperitoneal route for a period of 14 days. Lipid peroxidation and activities of catalase (CAT) and glutathione peroxidase (GPx1) in liver and kidney were measured and serum oxygen radical absorbance capacity (ORAC) assay was estimated. Phytochemical analysis of P. fulgens extract using high performance thin layer chromatography (HPTLC) was carried out with gallic acid, quercetin, catechin, and epicatechin as markers. RESULTS: Significant increase in level of thiobarbituric acid-reactive substances (TBARS), decreased GPx1, and CAT activities as well as reduction in ORAC were observed in 18-month-old mice as compared to that of 2-month-old mice. Treatment with P. fulgens extract significantly lowered TBARS level, ameliorated CAT, and GPx1 activities in liver and kidney and improved serum ORAC in aging mice. HPTLC studies revealed well resolved bands of P. fulgens extract containing epicatechin and catechin. DISCUSSION: This study showed that P. fulgens is a potent antioxidative agent, which can emerge as a promising candidate in alleviating the age-associated oxidative stress and related diseases.

Antidiabetic, antioxidant, and TNF-α lowering properties of extract of the traditionally used plant Ixeris gracilis in alloxan-induced diabetic mice.

CONTEXT: Ixeris gracilis DC. Stebbins (Asteraceae) is a plant considered to be medicinal by local communities of Meghalaya, India. OBJECTIVE: To evaluate the antidiabetic potential, antioxidant activity, and effect of the 80% methanolic extract of the leaves of Ixeris gracilis on tumor necrosis factor-α (TNF-α) expression. MATERIALS AND METHODS: Varying doses (250-1000 mg/kg body weight) were administered intraperitoneally to normoglycemic mice and their hypoglycemic properties noted for 24 h; the optimum dose observed was used to evaluate its antihyperglycemic activity and effect on glucose tolerance. In vitro antioxidant activity was analyzed by assessing the DPPH radicals scavenging ability of the extract and the total polyphenols, flavonoid, carbohydrate, and protein contents were determined. Diabetic mice were then subjected to daily intraperitoneal injections of the extract for 12 days after which the antioxidant enzyme activities in the tissues were assayed and serum TNF-α was evaluated by ELISA. RESULTS: The extract displayed varying hypoglycemic activity. The dose of 250 mg/kg body weight exhibited potent antihyperglycemic activity and improved glucose tolerance. The extract was able to scavenge free radicals (IC50 57.544 µg/ml) and contained polyphenol (76.269 ± 0.204 mg GAE/g dry wt), flavonoid (70.070 ± 0.626 mg rutin equivalent/g dry wt), protein (4.368 ± 8.916 mg/g dry wt), and carbohydrate (558.189 ± 0.002 mg/g dry wt). TNF-α level and overall activity of glutathione peroxidase and superoxide dismutase in the liver, kidney, and brain of extract-treated diabetic mice were improved. CONCLUSION: The study supports the inclusion of Ixeris gracilis in the list of plants with antidiabetic potential.

Effect of Potentilla fulgens on lipid peroxidation and antioxidant status in alloxan-induced diabetic mice.

Potentilla fulgens (Rosaceae) root traditionally used as a folk remedy by local health practitioners of Khasi Hills, Meghalaya was investigated for its effects on lipid peroxidation and antioxidant status in alloxan-induced diabetic mice. Significant increase in levels of thiobarbituric acid reactive substances (TBARS) and decrease in activities of glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) were observed under diabetic condition. Intraperitoneal administration of methanol extract of P. fulgens roots at a dose of 250 mg/kg body weight to male swiss albino diabetic mice for 14 days caused significant reduction in the elevated TBARS level, while increasing the activities of the antioxidant enzymes in diabetic mice. Maximum reduction in TBARS level was observed in liver tissue (75%, p<0.001). Kidney exhibited the highest elevation in the activity for catalase (68%, p<0.001) and superoxide dismutase (29%, p<0.001) while maximum increase in glutathione peroxidase activity was seen in brain (50%, p<0.001). The effects of P. fulgens was compared against known antioxidant, vitamin C. Results indicate that Potentilla fulgens methanolic root extract can reduce free radical mediated oxidative stress in experimental diabetes mellitus.