Free radical scavenging polyphenols isolated from Phyllanthus niruri L. ameliorates hyperglycemia via SIRT1 induction and GLUT4 translocation in in vitro and in vivo models.

Type 2 diabetes milletus (T2DM) is a complex multifaceted disorder characterized by insulin resistance in skeletal muscle. Phyllanthus niruri L. is well reported sub-tropical therapeutically beneficial ayurvedic medicinal plant from Euphorbiaceae family used in various body ailments such as metabolic disorder including diabetes. The present study emphasizes on the therapeutic potential of Phyllanthus niruri L. and its phytochemical(s) against insulin resistance conditions and impaired antioxidant activity thereby aiding as an anti-hyperglycemic agent in targeting T2DM. Three compounds were isolated from the most active ethyl acetate fraction namely compound 1 as 1-O-galloyl-6-O-luteoyl-ß-D-glucoside, compound 2 as brevifolincarboxylic acid and compound 3 as ricinoleic acid. Compounds 1 and 2, the two polyphenols enhanced the uptake of glucose and inhibited ROS levels in palmitate induced C2C12 myotubes. PNEAF showed the potent enhancement of glucose uptake in palmitate-induced insulin resistance condition in C2C12 myotubes and significant ROS inhibition was observed in skeletal muscle cell line. PNEAF treated IR C2C12 myotubes and STZ induced Wistar rats elevated SIRT1, PGC1-α signaling cascade through phosphorylation of AMPK and GLUT4 translocation resulting in insulin sensitization. Our study revealed an insight into the efficacy of marker compounds isolated from P. niruri and its enriched ethyl acetate fraction as ROS scavenging agent and helps in attenuating insulin resistance condition in C2C12 myotubes as well as in STZ induced Wistar rat by restoring glucose metabolism. Overall, this study can provide prospects for the marker-assisted development of P. niruri as a phytopharmaceutical drug for the insulin resistance related diabetic complications.

Untargeted metabolomics and phenotype data indicate the therapeutic and prophylactic potential of Lysimachia candida Lindl. towards high-fat high-fructose-induced metabolic syndrome in rats.

The present study evaluated the therapeutic potential of the medicinal plant Lysimachia candida Lindl. against metabolic syndrome in male SD rats fed with a high-fat high-fructose (HFHF) diet. Methanolic extract of Lysimachia candida Lindl. (250 mg kg-1 body weight p.o.) was administrated to the HFHF-fed rats daily for 20 weeks. Blood samples were collected, and blood glucose levels and relevant biochemical parameters were analysed and used for the assessment of metabolic disease phenotypes. In this study, Lysimachia candida decreased HFHF diet-induced phenotypes of metabolic syndrome, i.e., obesity, blood glucose level, hepatic triglycerides, free fatty acids, and insulin resistance. Liquid chromatography-mass spectrometry-based metabolomics was done to study the dynamics of metabolic changes in the serum during disease progression in the presence and absence of the treatment. Furthermore, multivariate data analysis approaches have been employed to identify metabolites responsible for disease progression. Lysimachia candida Lindl. plant extract restored the metabolites that are involved in the biosynthesis and degradation of amino acids, fatty acid metabolism and vitamin metabolism. Interestingly, the results depicted that the treatment with the plant extract restored the levels of acetylated amino acids and their derivatives, which are involved in the regulation of beta cell function, glucose homeostasis, insulin secretion, and metabolic syndrome phenotypes. Furthermore, we observed restoration in the levels of indole derivatives and N-acetylgalactosamine with the treatment, which indicates a cross-talk between the gut microbiome and the metabolic syndrome. Therefore, the present study revealed the potential mechanism of Lysimachia candida Lindl. extract to prevent metabolic syndrome in rats.

Kaempferol 3-O-rutinoside from Antidesma acidum Retz. Stimulates glucose uptake through SIRT1 induction followed by GLUT4 translocation in skeletal muscle L6 cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Antidesma acidum Retz, a perennial herb is known for its anti-diabetic potential among the traditional health care providers of the tribal communities of Manipur, India. Scientific validation of the ancient knowledge on traditional use of this plant with the help of modern tools and techniques can promote further research and its use in health care. AIM OF THE STUDY: Type 2 Diabetes (T2D) is a complex metabolic disorder and linked with hyperglycemia occurring from insufficiency in insulin secretion, action, or both. The aim of this study was to scientifically validate the traditional myth behind the uses of this plant material against diabetes. More specifically, it was aimed to determine the effect of methanolic extract of A. acidum leaves and/or any of its bioactive phytochemical(s), in enhancing insulin sensitization and subsequently stimulating the insulin signaling cascade of glucose metabolism. MATERIALS AND METHODS: Methanol was used for extraction from the leaf powder of A. acidum followed by bioactivity guided fractionation and isolation of most active component. Biological evaluation was performed to determine the glucose uptake ability against insulin resistance in skeletal muscle (L6) cells. To understand the detailed mechanism of actions of the purified compound, several molecular biology and structural biology experiments such as Western blot, siRNA transfection assay and molecular docking study were performed. RESULTS AND DISCUSSION: Bioactivity guided isolation of pure compound and spectral data analysis led us to identify the active component as Kaempferol 3-O-rutinoside (KOR) for the first time from the leaf of A. acidum. Over expression of NAD-dependent histone deacetylase, Sirtuin 1 (SIRT1) was observed following KOR treatment. SIRT1 plays an important role in the metabolic pathway and over expression of SIRT implies that it involves in insulin signaling directly or indirectly. Molecular docking and simulation study showed the strong involvement between KOR and SIRT1.Treatment with KOR resulted in significant over expression of SIRT1followed by upregulation of insulin-dependent p-IRS, AKT and AMPK signaling molecules, and stimulation of the GLUT4 translocation, which ultimately enhanced the glucose uptake in sodium palmitate-treated insulin resistant L6 myotubes. Further, the effect of KOR on IRS1, AKT and AMPK phosphorylation, GLUT4 translocation, and glucose uptake was attenuated in SIRT1-knockdown myotubes. CONCLUSION: Overall, the results of this study suggest that Kaempferol 3-O-rutinoside is the active component presents in the leaf of A. acidum which increases glucose consumption by inducing SIRT1 activation and consequently improves insulin sensitization. These results may find future applications in drug discovery research against T2DM.

Astragalin mediates the pharmacological effects of Lysimachia candida Lindl on adipogenesis via downregulating PPARG and FKBP51 signaling cascade.

Metabolic disturbances in different tissue cells and obesity are caused by excessive calorie intake, and medicinal plants are potential sources of phytochemicals for combating these health problems. This study investigated the role of methanolic extract of the folklore medicinal plant Lysimachia candida (LCM) and its phytochemical, astragalin, in managing obesity in vivo and in vitro. Administration of LCM (200 mg/kg/body weight) daily for 140 days significantly decreased both the body weight gain (15.66%) and blood triglyceride and free fatty acid levels in high-fat-diet-fed male Wistar rats but caused no substantial change in leptin and adiponectin levels. The protein expression of adipogenic transcription factors in visceral adipose tissue was significantly reduced. Further, the 3T3-L1 cell-based assay revealed that the butanol fraction of LCM and its isolated compound, astragalin, exhibited antiadipogenic activity through downregulating adipogenic transcription factors and regulatory proteins. Molecular docking studies were performed to depict the possible binding patterns of astragalin to adipogenesis proteins. Overall, we show the potential antiobesity effects of L. candida and its bioactive compound, astragalin, and suggest clinical studies with LCM and astragalin.

Evaluation of therapeutic effect of Premna herbacea in diabetic rat and isoverbascoside against insulin resistance in L6 muscle cells through bioenergetics and stimulation of JNK and AKT/mTOR signaling cascade.

BACKGROUND: Premna herbacea Roxb., a perennial herb is well documented for its therapeutic uses among the traditional health care-givers of Assam, India. Scientific validation on the traditional use of the medicinal plant using modern technology may promote further research in health care. PURPOSE: This study evaluates the therapeutic potential of methanolic extract of P. herbacea (MEPH) against type 2 diabetes mellitus (T2DM) and its phytochemical(s) in ameliorating insulin resistance (IR), thereby endorsing the plant bioactives as effective anti-hyperglycemic agents. METHODS: The anti-diabetic potential of the plant extract was explored both in L6 muscle cells and high fructose high fat diet (HF-HFD) fed male Sprague Dawley (SD) rats. Bioactivity guided fractionation and isolation procedure yielded Verbascoside and Isoverbascoside (ISOVER) as bioactive and major phytochemicals in P. herbacea. The bioenergetics profile of bioactive ISOVER and its anti-hyperglycemic potential was validated in vitro by XFe24 analyzer, glucose uptake assay and intracellular ROS generation by flourometer, FACS and confocal microscopy. The potential of ISOVER was also checked by screening various protein markers via immunoblotting. RESULTS: MEPH enhanced glucose uptake in FFA-induced insulin resistant (IR) L6 muscle cells and decreased elevated blood glucose levels in HF-HFD fed rats. Isoverbascoside (ISOVER) was identified as most bioactive phytochemical for the first time from the plant in the Premna genus. ISOVER activated the protein kinase B/AMP-activated protein kinase signaling cascades and enhanced glucose uptake in IR-L6 muscle cells. ISOVER decreased the phosphorylation of p38 mitogen-activated protein kinase (p38MAPK) and c-Jun N-terminal kinase (JNK) and increased that of mammalian target of rapamycin (mTOR), thereby attenuating IR. However, molecular docking revealed that ISOVER increases insulin sensitivity by targeting the JNK1 kinase as a competitive inhibitor rather than mTOR. These findings were further supported by the bioenergetics profile of ISOVER. CONCLUSION: This study for the first time depicts the functional properties of ISOVER, derived from Premna herbacea, in ameliorating IR. The phytochemical significantly altered IR with enhanced glucose uptake and inhibition of ROS through JNK-AKT/mTOR signaling which may pave the way for further research in T2DM therapeutics.

Beneficial effect of the methanolic leaf extract of Allium hookeri on stimulating glutathione biosynthesis and preventing impaired glucose metabolism in type 2 diabetes.

Oxidative stress resulting from the depletion of glutathione (GSH) level plays a vital role in generating various degenerative diseases, including type 2 diabetes (T2D). We tested the hypothesis that depleted glutathione levels can be enhanced and the impaired glucose metabolism can be prevented by supplementing Allium hookeri, a herb rich in organosulfur compounds, in a High Fat (HF) diet-induced T2D Male Sprague Dawley rat model. The experimental rats were divided into three groups (n = 6), namely normal diet, high-fat diet, and high-fat diet treated with A.hookeri methanolic leaf extract (250 mg/kg). Consumption of HF diet along with the plant extract resulted in significant reduction of the body weight (7.08%-14.89%) and blood glucose level (6.5%-16.4%) from the 13th week onward. There was a significant decrease in reactive oxygen species, oxidized glutathione (GSSG) levels, and an increase in GSH level in skeletal muscle tissues supplemented with the plant extract. The protein expressions of the signaling molecules such as GCLC and GR involved in GSH synthesis and of GLUT4 in glucose transport were also upregulated in the skeletal muscle tissues of the plant extract-treated group. Results of in vitro studies with muscle cell line (L6) further demonstrated the beneficial effect of the plant extract in increasing glucose uptake and maintaining the GSH/GSSH equilibrium via regulation of protein expression of GCLC/GR/GLUT4 signaling molecules in sodium palmitate (0.75 mM) treated cells. Overall this study suggests that dietary supplementation with Allium hookeri, can restore the glutathione level and regulate the blood glucose level in T2D.

Methanolic Extract of Lysimachia Candida Lindl. Prevents High-Fat High-Fructose-Induced Fatty Liver in Rats: Understanding the Molecular Mechanism Through Untargeted Metabolomics Study.

Fatty liver is one of the most common metabolic syndrome affecting the global population. Presently, limited treatment modalities with symptomatic approach are available for alleviating fatty liver. Traditional and herbal treatment modalities have shown evidence to improve the disease pathology. In the present research work, evaluation of a selected medicinal plant Lysimachia candida Lindl. was carried out to investigate its beneficial effects on fatty liver disease in rats. Male Sprague Dawley (SD) rats were fed with high-fat high-fructose diet to induce fatty liver phenotypes. After induction for 15 weeks, methanolic extract of Lysimachia candida Lindl. (250 mg/kg b. w. p. o.) was administrated to the rats daily for the next 17 weeks. Blood samples were collected at different time points to analyze fasting blood glucose levels and relevant biochemical parameters important for the assessment of metabolic disease phenotypes. Liquid chromatography-mass spectrometry (LC-MS) based metabolomics was done to study the dynamics of metabolic changes in the serum during disease progression and how the medicinally important plant extract treatment reversed the metabolic diseases. Multivariate data analysis approaches have been employed to understand the metabolome changes and disease pathology. This study has identified the interplay of some metabolic pathways that alter the disease progression and their reversal after administration of the plant extract. Different group of metabolites mainly bile acids, fatty acids, carnitines, and their derivatives were found to be altered in the diseased rats. However, all the metabolites identified between control and disease groups are mainly related to lipid metabolism. The results depict that the treatment with the above-mentioned plant extract improves the regulation of aberrant lipid metabolism, and reverses the metabolic syndrome phenotype. Therefore, the present study reveals the potential mechanism of the herbal extract to prevent metabolic syndrome in rats.