Ravirajsinh N. Jadeja

Natural Products for the Treatment of Obesity, Metabolic Syndrome, and Type 2 Diabetes

Globally, the incidence of obesity, metabolic syndrome, and diabetes (OMD) are continuously on the rise because of rapid changes in human life-style and dietary habits. Herbal extracts are of special interest in treating combination of these diseases because of their multipronged mode of action. The list of potential herbals to control metabolic diseases is ever-expanding. However, because of poor characterization and safety issues, these herbs face limitations for their clinical usage. This special issue is a collection of research and review articles on preclinical and clinical benefits of herbals in controlling OMD. This special issue contains 24 articles accepted from a total of 37 submissions consisting of 20 research articles, 3 review articles, and 1 clinical study. The research articles in this issue can be broadly divided into three disease categories—nonalcoholic steatohepatitis (NASH), obesity, and diabetic complications. Four articles of this special issue focus on evaluating the protective role of herbal extracts on NASH. The studies by X. R. Yang et al. “Effect of dietary cocoa tea (Camellia ptilophylla) supplementation on high-fat diet-induced obesity, hepatic Steatosis, and hyperlipidemia in mice” and H.-Y. Jung et al. “The Korean mistletoe (Viscum album coloratum) extract has an antiobesity effect and protects against hepatic steatosis in mice with high-fat diet-induced obesity” report the potential benefits of Camellia ptilophylla and Viscum album coloratum extracts against HFD-induced NASH. Another two articles evaluated protective effects of biherbal combination (S. miltiorrhiza, G. jasminoides and Grape Pomace, Omija Fruit) in ameliorating experimental NASH. This special issue also contains five articles that focus on antiobesity potential of herbal extracts. These detailed studies evaluated the benefits of 10 herbs and their potential mechanisms responsible in controlling obesity using experimental HFD-fed mice/rat in vivo and 3T3L1 preadipocyte in vitro models. Modulation of PPARγ was a key antiobesity mechanism of Artemisia iwayomogi, Codonopsis lanceolata, Populus balsamifera and its active component (salicortin), and beta-glucan-rich extract from Pleurotus sajor-caju (Fr.) Singer. H.-Y. Shin et al. reported an activation of AMP-activated protein kinase by extract of six herbal medicines (OB-1). In this special issue, 11 articles focus on the potential benefits of various herbal extracts/phytocompounds on diabetes-induced insulin resistance, nephropathy, retinopathy, cardiomyopathy, and inflammation. A. l. Al-Malki showed oat extract to be beneficial for diabetic nephropathy and retinopathy by modulating nuclear factor kappa B (NF-kB). Inhibition of aldose reductase activity by scopoletin ameliorated cataractogenesis in galactose-fed rats (J. Kim et al.). Boehmeria nivea extract (S. H. Kim et al.) and swertiamarin (T. P. Patel et al.) regulated experimental insulin resistance by modulating PPARγ. In another report, S. Kadan et al. evaluated effect of eight antidiabetic medicinal plants extracts on GLUT 4 translocation. The benefits of fisetin and an ayurvedic herbal formulation (Kal-1) on diabetes-induced inflammation was also reported. Further, quercetin was shown to preserve β-cell mass and function in fructose-fed hyperinsulinemic rats via modulating pancreatic akt/foxo1 activation. Berberine ameliorated glucose- and insulin-induced cardiomyocyte hypertrophy by modulating PPARα/NO. In an interesting article by S. E. Martinez et al. pharmacometrics of an antidiabetic compound, 3-methoxypterostilbene was reported. 3-Methoxypterostilbene inhibited α-glucosidase and α-amylase activity and exhibited approximately 50% bioavailability. Three review articles were also incorporated in this special issue. A review by Y. Liu et al. (recent updates on beneficial role of berberine in controlling NASH) provides detailed account on molecular regulation of lipid metabolism and NASH by berberine. In another review by C. D. Lorenzo et al. the use of in vitro and clinical approaches to assess the benefits of plant food supplements is critically discussed. The potential benefits of Kampo, a Japanese traditional medicine, in treating obesity was reviewed by J.-i Yamakawa et al. based on basic and clinical evidence. The only clinical study as a part of this special issue focuses on evaluating body weight lowering effects of herbal extract-THI (target herbal ingredient) on exercising healthy overweight humans following a two-month randomized double-blind, placebo-controlled trial. The study reports a significant reduction in body weight indicating its potential antiobesity effect. We envisage that this special issue will attract broad interest in the fields of obesity, metabolic syndrome, and type 2 diabetes and encourage the perusal of in-depth molecular and cellular mechanistic investigations into the use of natural products, in particular the herbal therapies for metabolic disorders and their complications.

Withaferin-A Reduces Acetaminophen-Induced Liver Injury in Mice

Withaferin-A (WA) has anti-oxidant activities however, its therapeutic potential in acetaminophen (APAP) hepatotoxicity is unknown. We performed a proof-of-concept study to assess the therapeutic potential of WA in a mouse model that mimics APAP-induced liver injury (AILI) in humans. Overnight fasted C57BL/6NTac (5-6 wk. old) male mice received 200 mg/kg APAP intraperitoneally (i.p.). After 1 h mice were treated with 40 mg/kg WA or vehicle i.p., and euthanized 4 and 16 h later; their livers were harvested and serum collected for analysis. At 4 h, compared to vehicle-treated mice, WA-treated mice had reduced serum ALT levels, hepatocyte necrosis and intrahepatic hemorrhage. All APAP-treated mice had reduced hepatic glutathione (GSH) levels however, reduction in GSH was lower in WA-treated when compared to vehicle-treated mice. Compared to vehicle-treated mice, livers from WA-treated mice had reduced APAP-induced JNK activation, mitochondrial Bax translocation, and nitrotyrosine generation. Compared to vehicle-treated mice, WA-treated mice had increased hepatic up-regulation of Nrf2, Gclc and Nqo1, and down-regulation of Il-6 and Il-1β. The hepatoprotective effect of WA persisted at 16 h. Compared to vehicle-treated mice, WA-treated mice had reduced hepatocyte necrosis and hepatic expression of Il-6, Tnf-α and Il-1β, increased hepatic Gclc and Nqo1 expression and GSH levels, and reduced lipid peroxidation. Finally, in AML12 hepatocytes, WA reduced H₂O₂-induced oxidative stress and necrosis by preventing GSH depletion. Collectively, these data show mechanisms whereby WA reduces necrotic hepatocyte injury, and demonstrate that WA has therapeutic potential in AILI.

Naturally Occurring Nrf2 Activators: Potential in Treatment of Liver Injury

Oxidative stress plays a major role in acute and chronic liver injury. In hepatocytes, oxidative stress frequently triggers antioxidant response by activating nuclear erythroid 2-related factor 2 (Nrf2), a transcription factor, which upregulates various cytoprotective genes. Thus, Nrf2 is considered a potential therapeutic target to halt liver injury. Several studies indicate that activation of Nrf2 signaling pathway ameliorates liver injury. The hepatoprotective potential of naturally occurring compounds has been investigated in various models of liver injuries. In this review, we comprehensively appraise various phytochemicals that have been assessed for their potential to halt acute and chronic liver injury by enhancing the activation of Nrf2 and have the potential for use in humans.

Phytochemical Constituents and Free Radical Scavenging Activity of Clerodendron glandulosum.Coleb Methanolic Extract

Objective: The present study was undertaken to evaluate the phytochemical constituents and antioxidant and free radical scavenging properties of Clerodendron glandulosum.Coleb.Methods: - Methanolic extract of C.glandulosum.Coleb (MECG) was studied for its qualitative and quantitative phytochemical constituents and free radical scavenging potential using different in vitro assays for hydrogen peroxide, hydroxyl, superoxide, DPPH, nitric oxide, peroxynitrite, singlet oxygen and hypochlorous acid radicals scavenging assays. Its lipid peroxidation inhibitory activity, metal chelating activity and reducing power were also assayed.Results: Qualitative phytochemical screening of MECG showed presence of polyphenols, steroids, flavanoids and saponins. Quantitative phytochemical analysis revealed 34.3±0.89 mg/ml gallic acid equivalent-polyphenols, 46.1±1.00 mg/ml quercetin equivalent-flavanoids and 53.36±0.93 mg/ml ascorbic acid per 100 mg MECG. The MECG scavenges hydrogen peroxide (IC50 120.23± 1.53 ?g/ml), hydroxyl (IC50 70.23±1.36 ?g/ml) superoxide (IC50 80.36±1.36 ?g/ml), DPPH (IC50 50.11±1.36 ?g/ml) and nitric oxide (IC50 90.11±1.55 ?g/ml) radicals in a dose dependent manner. The IC50 values for peroxynitrite, singlet oxygen and hypochlorous acid were 48.41±1.72, 62.15±1.69 and 136.69±2.01?g/ml, respectively. MECG also inhibited lipid peroxidation (IC50 150.56±3.02 ?g/ml) and promoted metal chelation (IC50 50.29±2.00 ?g/ml) in a dose-dependent manner. Assay of reducing capacity of MECG showed a dose-dependent response.Conclusion: The results suggest that a methanolic extract of Clerodendron glandulosum.Coleb possesses a strong antioxidant activity against all known radicals and can be considered as a natural antioxidant.

Gender-specific differential expression of exosomal miRNA in synovial fluid of patients with osteoarthritis

The pathogenesis of osteoarthritis (OA) is poorly understood, and therapeutic approaches are limited to preventing progression of the disease. Recent studies have shown that exosomes play a vital role in cell-to-cell communication, and pathogenesis of many age-related diseases. Molecular profiling of synovial fluid derived exosomal miRNAs may increase our understanding of OA progression and may lead to the discovery of novel biomarkers and therapeutic targets. In this article we report the first characterization of exosomes miRNAs from human synovial fluid. The synovial fluid exosomes share similar characteristics (size, surface marker, miRNA content) with previously described exosomes in other body fluids. MiRNA microarray analysis showed OA specific exosomal miRNA of male and female OA. Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis identified gender-specific target genes/signaling pathways. These pathway analyses showed that female OA specific miRNAs are estrogen responsive and target TLR (toll-like receptor) signaling pathways. Furthermore, articular chondrocytes treated with OA derived extracellular vesicles had decreased expression of anabolic genes and elevated expression of catabolic and inflammatory genes. In conclusion, synovial fluid exosomal miRNA content is altered in patients with OA and these changes are gender specific.

Herbal Medicines for the Treatment of Nonalcoholic Steatohepatitis: Current Scenario and Future Prospects

Nonalcoholic steatohepatitis (NASH) is a multifactorial disease and has close correlations with other metabolic disorders. This makes its treatment difficult using a single pharmacological drug. Use of plant extract/decoction or polyherbal formulation to treat various liver diseases is very well mentioned in various traditional systems of medicine (Ayurveda, Japanese or traditional Chinese Medicine, and Kampo medicine). Medicinal herbs are known for their multifaceted implications and thus can form an effective treatment schedule against NASH. Till date, several plant extracts, polyherbal formulations, and phytochemicals have been evaluated for their possible therapeutic potential in preventing onset and progression of NASH in experimental models, but clinical studies using the same are sparse. Herbal extracts with antioxidants, antidiabetic, and antihyperlipidemic properties have been shown to ameliorate symptoms of NASH. This review article is a meticulous compilation of our current knowledge on the role of natural products in alleviating NASH and possible lacunae in research that needs to be addressed.

M1 Muscarinic Receptors Modify Oxidative Stress Response to Acetaminophen-Induced Acute Liver Injury

The role of muscarinic receptor subtypes in modulating acute liver injury is unknown. We detected M1 muscarinic receptor (M1R) expression in human and murine hepatocytes, and investigated the consequences of M1R deficiency on acute liver injury in vivo and inhibiting M1R activation on hepatocyte injury in vitro. Age-matched wild-type (WT) and M1R-deficient (Chrm1(-/-)) male mice were injected intraperitoneally with 200mg/kg acetaminophen (APAP) and euthanized 0, 2, 4, 16, 24, and 36h later. Biochemical and histological parameters indicated that liver injury peaked within 16h after APAP treatment and resolved by 24h. Compared to WT, M1R-deficient mice had reduced intrahepatic hemorrhage and hepatocyte necrosis, reflected by an attenuated rise in serum alanine aminotransferase levels. Livers of M1R-deficient mice showed reduced hepatocyte DNA fragmentation and attenuated expression of injury cytokines (Il-1α, Il-1β, Il-6, and Fasl). In all mice hepatic glutathione levels decreased after APAP injection, but they recovered more quickly in M1R-deficient mice. During the course of APAP-induced liver injury in M1R-deficient compared to WT mice, hepatic Nrf-2, Gclc, and Nqo1 expressions increased and nitrotyrosine generation decreased. APAP metabolic pathways were not altered by M1R deficiency; expression of hepatic Cyp2e1, Cyp1a2, Cyp3a11, Cyp3a13, Car, and Pxr was similar in Chrm1(-/-) and WT mice. Finally, treatment of murine AML12 hepatocytes with a novel M1R antagonist, VU0255035, attenuated H2O2-induced oxidative stress, prevented GSH depletion, and enhanced viability. We conclude that M1R modify hepatocyte responses to oxidative stress and that targeting M1R has therapeutic potential for toxic liver injury.

Sida rhomboidea. Roxb Leaf Extract Down-Regulates Expression of PPARγ2 and Leptin Genes in High Fat Diet Fed C57BL/6J Mice and Retards in Vitro 3T3L1 Pre-Adipocyte Differentiation

Sida rhomboidea. Roxb leaf extract (SRLE) is being used by the populace of North-East India to alleviate symptoms of diabetes and obesity. We have previously reported its hypolipidemic and anti-diabetic properties. In this study, we report the effect of SRLE on (i) in vivo modulation of genes controlling high fat diet (HFD) induced obesity and (ii) in vitro 3T3L1 pre-adipocyte differentiation and leptin release. Supplementation with SRLE significantly prevented HFD induced increment in bodyweight, plasma lipids and leptin, visceral adiposity and adipocyte hypertrophy. Also, SRLE supplementation reduced food intake, down regulated PPARγ2, SREBP1c, FAS and LEP expressions and up-regulated CPT-1 in epididymal adipose tissue compared to obese mice. In vitro adipogenesis of 3T3L1 pre-adipocytes was significantly retarded in the presence of SRLE extract. Also decreased triglyceride accumulation, leptin release and glyceraldehyde-3-Phosphate dehydrogenase activity along with higher glycerol release without significant alteration of viability of 3T3L1 pre-adipocytes, was recorded. Our findings suggest that prevention of HFD induced visceral adiposity is primarily by down regulation of PPARγ2 and leptin gene expression coupled with attenuation of food intake in C57BL/6J mice. SRLE induced prevention of pre-adipocytes differentiation, and leptin release further substantiated these findings and scientifically validates the potential application of SRLE as a therapeutic agent against obesity.

Effects of modulating M3 muscarinic receptor activity on azoxymethane-induced liver injury in mice

Previously, we reported that azoxymethane (AOM)-induced liver injury is robustly exacerbated in M3 muscarinic receptor (M3R)-deficient mice. We used the same mouse model to test the hypothesis that selective pharmacological modulation of M3R activity regulates the liver injury response. Initial experiments confirmed that giving a selective M3R antagonist, darifenacin, to AOM-treated mice mimicked M3R gene ablation. Compared to vehicle controls, mice treated with the M3R antagonist had reduced survival and increased liver nodularity and fibrosis. We next assessed AOM-induced liver injury in mice treated with a selective M3R agonist, pilocarpine. After pilocarpine treatment, stimulation of post-M3R signaling in the liver was evidenced by ERK and AKT activation. In contrast to the damaging effects of the M3R antagonist, administering pilocarpine to AOM-treated mice significantly attenuated hepatic stellate cell activation, collagen deposition, bile ductule proliferation, and liver fibrosis and nodularity. As anticipated from these findings, livers from pilocarpine-treated mice exhibited reduced expression of key players in fibrosis (α1 collagen, α-smooth muscle actin, TGF-β1, PGDF, TGF-β1R, PGDFR) and decreased mRNA levels for molecules that regulate extracellular matrix formation (TIMP-1, TIMP-2, MMP-2, MMP-13). Cleaved caspase-3, nitrotyrosine and BrdU immunostaining provided evidence that pilocarpine treatment reduced hepatocyte apoptosis and oxidative stress, while increasing hepatocyte proliferation. Collectively, these findings identify several downstream mechanisms whereby M3R activation ameliorates toxic liver injury. These novel observations provide a proof-of-principle that selectively stimulating M3R activation to prevent or diminish liver injury is a therapeutic strategy worthy of further investigation.

Acute and Sub Chronic Oral Toxicity of Sida rhomboidea .Roxb Leaf Extract

Acute and sub chronic oral administration of Sida rhomboidea.Roxb (SR) aqueous leaf extract did not register any adverse behavioral alterations or significant toxic manifestations. However, significant decrement in food intake and body weight gain along with higher plasma AST and ALT levels were recorded with a dose of 3000 mg/kg body weight. It is inferred that SR extract is non-toxic, therefore, safe for consumption.