Polyphenol-Rich Extract of Syzygium cumini Leaf Dually Improves Peripheral Insulin Sensitivity and Pancreatic Islet Function in Monosodium L-Glutamate-Induced Obese Rats

Exploring the Chemical and Biological Potential of Jamun (Syzygium cumini (L.) Skeels) Leaves: A Comprehensive Review

Leaves of jamun collected as agro by-produce during the cultivation of jamun is traditionally used as ayurvedic medicine to treat diabetes, gall bladder stones and other ailments. Most of the beneficial effects of jamun leaves are associated with phytochemicals found in jamun leaves such as gallic acid, tannins, mallic acid, flavonoids, essential oils, jambolin, ellagic acid, jambosine, antimellin and betulinic acid. Jamun possess curative activities like anticancer, antidiabetic, antifertility, anti-inflammatory, antidiarrheal, antimicrobial, antinociceptive, antioxidant, antiradiation, chemotherapeutic, and gastroprotective. The main goal of this review article is to provide information on the nutritional content, phytochemical composition and health promoting properties of jamun leaves. The review of literature based on the phytochemical composition and health promoting benefits of the jamun leaves, suggests that leaves can be used as potential constituent in the formulation of pharmacological drugs. From the review literature it is found that clinical, in-vivo, in-vitro studies are still required to check the health promoting effects of jamun leaves extracts on humans.

Astounding Health Benefits of Jamun (Syzygium cumini) toward Metabolic Syndrome

Syzygium cumini, also called Jamun, or black plum, is an excellent source of bioactive components such as flavonoids, polyphenols, antioxidants, iron, and vitamin C. The Jamun tree is a tropical evergreen blooming plant and is an important medicinal plant from the Myrtaceae family that has been used for a long time in Indian and other traditional medicines across the world. Jamun is mainly cultivated in Asian countries such as Pakistan, India, Sri Lanka, and Bangladesh. Since ancient medicine, it has been utilized to treat a variety of diseases and physiological conditions. Currently, it is mostly used as a medication to treat various metabolic issues, including diabetes, hyperlipidemia, hypertension, obesity, etc. Therefore, Jamun could serve a beneficial role against metabolic syndrome (MS). In this work, the latest available scientific literature on Jamun was collected and the clinical trials investigating its effect on diabetes, hypertension, obesity, and hyperlipidemia were analyzed to find out how Jamun could improve the symptoms and biomarkers of MS. Overall, the results of this study found a significant association of Jamun with the prevention and treatment of these biomarkers of MS. In many studies, Jamun showed pharmacological modifications not only in MS but in many other diseases as well. Currently, its utilization as a folk medicine for the treatment of patients with MS is widely acknowledged. Hence, the findings of a large number of clinical studies confirmed the ameliorating effects of Jamun against MS due to its antioxidation, antidiabetic, anti-inflammation anticarcinogenic, and hyperlipidemic effects. More research is still needed to determine and identify the Jamun compounds and to elucidate their mechanisms of action that are responsible for these astounding bioactive properties and health benefits.

Roles of Syzygium in Anti-Cholinesterase, Anti-Diabetic, Anti-Inflammatory, and Antioxidant: From Alzheimer's Perspective

Alzheimer's disease (AD) causes progressive memory loss and cognitive dysfunction. It is triggered by multifaceted burdens such as cholinergic toxicity, insulin resistance, neuroinflammation, and oxidative stress. Syzygium plants are ethnomedicinally used in treating inflammation, diabetes, as well as memory impairment. They are rich in antioxidant phenolic compounds, which can be multi-target neuroprotective agents against AD. This review attempts to review the pharmacological importance of the Syzygium genus in neuroprotection, focusing on anti-cholinesterase, anti-diabetic, anti-inflammatory, and antioxidant properties. Articles published in bibliographic databases within recent years relevant to neuroprotection were reviewed. About 10 species were examined for their anti-cholinesterase capacity. Most studies were conducted in the form of extracts rather than compounds. Syzygium aromaticum (particularly its essential oil and eugenol component) represents the most studied species owing to its economic significance in food and therapy. The molecular mechanisms of Syzygium species in neuroprotection include the inhibition of AChE to correct cholinergic transmission, suppression of pro-inflammatory mediators, oxidative stress markers, RIS production, enhancement of antioxidant enzymes, the restoration of brain ions homeostasis, the inhibition of microglial invasion, the modulation of ß-cell insulin release, the enhancement of lipid accumulation, glucose uptake, and adiponectin secretion via the activation of the insulin signaling pathway. Additional efforts are warranted to explore less studied species, including the Australian and Western Syzygium species. The effectiveness of the Syzygium genus in neuroprotective responses is markedly established, but further compound isolation, in silico, and clinical studies are demanded.

Role of Plant Derived Products Through Exhilarating Peroxisome Proliferator Activated Receptor-γ (ppar-γ) in the Amelioration of Obesity Induced Insulin Resistance

Abstract:

Insulin resistance is an elemental facet of the etiology of diabetes mellitus and the principal relating factor between obesity and diabetes. Oxidative stress, lipotoxicity, inflammation and receptor dysfunction are the underlying determinants of insulin resistance commencement in metabolic illnesses. ppar-γ is a nuclear transcription factor whose activation or inhibition directly influences insulin resistance and controls glucose and lipid homeostasis by modulating gene expression. Synthetic ligands of ppar-γ are therapeutically employed to counter the hyper-glycaemia associated with obesity and type 2 diabetes, but they possess severe side effects. In the modern era, bioactive phytochemicals have been employed in the drug development process and a considerable investigation has recently been initiated to analyze the ppar-γ activating ability of diverse phytochemicals. In this review, we outlined the role of phytochemicals in insulin resistance treatment through ppar-γ activation.

Molecular Determinants of the Cardiometabolic Improvements of Dietary Flavanols Identified by an Integrative Analysis of Nutrigenomic Data from a Systematic Review of Animal Studies

SCOPE

Flavanols are important polyphenols of the human diet with extensive demonstrations of their beneficial effects on cardiometabolic health. They contribute to preserve health acting on a large range of cellular processes. The underlying mechanisms of action of flavanols are not fully understood but involve a nutrigenomic regulation.

METHODS AND RESULTS

To further capture how the intake of dietary flavanols results in the modulation of gene expression, nutrigenomics data in response to dietary flavanols obtained from animal models of cardiometabolic diseases have been collected and submitted to a bioinformatics analysis. This systematic analysis shows that dietary flavanols modulate a large range of genes mainly involved in endocrine function, fatty acid metabolism, and inflammation. Several regulators of the gene expression have been predicted and include transcription factors, miRNAs and epigenetic factors.

CONCLUSION

This review highlights the complex and multilevel action of dietary flavanols contributing to their strong potential to preserve cardiometabolic health. The identification of the potential molecular mediators and of the flavanol metabolites driving the nutrigenomic response in the target organs is still a pending question which the answer will contribute to optimize the beneficial health effects of dietary bioactives.

Myricetin improves metabolic outcomes but not cognitive deficit associated to metabolic syndrome in male mice

Myricetin is a flavonol highly prevalent in edible vegetables and fruits, with recognized hypoglycemic and anti-obesity effects, besides great antioxidant capacity. Thus, this study sought to investigate whether myricetin is able to improve metabolic and behavioral outcomes found in monosodium l-glutamate (MSG) obese mice, a model of metabolic syndrome characterized by early hyperinsulinemia associated to obesity, dyslipidemia, hepatic steatosis, anxiety and cognitive deficit. Newborn male mice received MSG (4 mg kg-1 day-1, s.c.) on alternate days during the first 10 days of life for obesity induction, while control pups received equimolar saline solution. From postnatal day 90 to 135, MSG mice were orally treated with myricetin (50 mg kg-1 day-1) or distilled water, while control animals received vehicle. During the last week of treatment, all groups were submitted to behavioral tests: open field maze, elevated plus maze and Morris water maze. At the end of treatment, animals were euthanized for collection of liver, serum and adipose tissue fat pads. Myricetin treatment reduced the elevated serum levels of glucose and triglycerides, typically found in MSG mice, as well as restored peripheral insulin sensitivity and liver steatosis. Moreover, myricetin ameliorated the lack of thigmotaxis and exploratory behavior, but did not improve the cognitive deficit presented by MSG mice. Therefore, this study contributes to the pharmacological validation of myricetin as an affordable and healthy therapeutic adjuvant for the treatment of metabolic syndrome and most of its comorbidities.

Antidiabetic Potential of Syzygium sp.: An Overview

Diabetes, characterized by hyperglycemia, is one of the most significant metabolic diseases, reaching alarming pandemic proportions. It can be due to the defects in insulin action, or secretion, or both. The global prevalence of diabetes is estimated at 425 million people in 2017, and expected to rise to 629 million by 2045 due to an increasing trend of unhealthy lifestyles, physical inactivity, and obesity. Several treatment options are available to diabetics, however, some of the antidiabetic drugs result in adverse side effects such as hypoglycemia. Hence, there has been a proliferation of studies on natural products with antidiabetic effects, including plants from the Myrtaceae family, such as Psidium guajava, Eucalyptus globulus,Campomanesia xanthocarpa, and more significantly, Syzygium sp. Previous studies have shown that a number of Syzygium species had potent antidiabetic effects and were safe for consumption. This review aims to discuss the antidiabetic potential of Syzygium sp., based on in vitro and in vivo evidence.

Natural products as safeguards against monosodium glutamate-induced toxicity

Monosodium glutamate is a sodium salt of a nonessential amino acid, L-glutamic acid, which is widely used in food industry. Glutamate plays an important role in principal brain functions including formation and stabilization of synapses, memory, cognition, learning, as well as cellular metabolism. However, ingestion of foodstuffs rich in monosodium glutamate can result in the outbreak of several health disorders such as neurotoxicity, hepatotoxicity, obesity and diabetes. The usage of medicinal plants and their natural products as a therapy against MSG used in food industry has been suggested to be protective. Calendula officinalis, Curcuma longa, Green Tea, Ginkgo biloba and vitamins are some of the main natural products with protective effect against mentioned monosodium glutamate toxicity through different mechanisms. This review provides a summary on the toxicity of monosodium glutamate and the protective effects of natural products against monosodium glutamate -induced toxicity.

Ficus carica and Sizigium cumini Regulate Glucose and Lipid Parameters in High-Fat Diet and Streptozocin-Induced Rats

Obesity linked diabetes, popularly known as diabesity, has been viewed as a direct product of the modern lifestyle in both developed and developing countries, and its increased prevalence is seen as a major threat to public health globally. Ficus carica (FC) and Syzigium cumini (SC) are part of indigenous flora with traditional medicinal properties. Fresh seeds of SC fruit and fruit of FC were collected and macerated to obtain the final extract. Wistar rats were divided into seven groups fed either on a normal diet or high-fat diet (HFD) along with streptozocin (STZ) to induce diabesity. The crude extract of FC (FC.Cr.) and SC (SC.Cr.) were administered at 250 mg/kg/day and 500 mg/kg/day in induced diabesity state. Body weights, blood glucose level, complete blood count (CBC), cholesterol, triglycerides (TG), low-density lipoprotein (LDL), very-low-density lipoprotein (VLDL), and high-density lipoprotein (HDL) were recorded to analyze their effects on glucose and lipid metabolism. Further, superoxide dismutase (SOD) and malondialdehyde (MDA) were measured to examine their effects on lipid peroxidation and ant oxidative enzyme. Results showed that both FC.Cr. and SC.Cr. have the potential to control obesity-linked type 2 diabetes mellitus (T2DM) by lowering the body weights, serum glucose, cholesterol, TG, LDL, and VLDL, while increasing the protective effects of HDL dose-dependently. The crude extract of both plants showed significant activity to raise SOD and curb MDA under diabetic states. It was concluded that both FC.Cr. and SC.Cr. exhibited remarkable therapeutics potential in HFD-STZ-induced diabetic rats. However, we found that the effects of SC.Cr. are relatively more pronounced as compared to FC.Cr. in almost all parameters.

Advances in Research on the Protective Mechanisms of Traditional Chinese Medicine (TCM) in Islet β Cells

The dysfunction and decreased number of islet β cells are central to the main pathogenesis of diabetes. Improving islet β cell function and increasing the number of β cells are effective approaches to treat diabetes and constitute the main direction of diabetes drug development. The role of Chinese medicine in the treatment of diabetes began to be recognized. In recent years, Chinese medicine monomers have been found to increase insulin synthesis and secretion, reduce β cell-apoptosis, and protect the function of β cells. The results of in vivo animal experiments and in vitro studies on insulinoma cells also suggested TCMs could promote the proliferation of pancreatic islet β cells and induce other cells differentiation or transdifferentiation to islet β cells. Thereby, they may play a role in the treatment of diabetes. In this paper, we will review islet β cell protection with TCMs and the related mechanisms found in recent studies. An in-depth explanation of the role of TCM in islet β cell protection can provide a theoretical basis and research ideas for the development of TCM-based diabetes treatment drugs.

Syzygium cumini Leaf Extract Reverts Hypertriglyceridemia via Downregulation of the Hepatic XBP-1s/PDI/MTP Axis in Monosodium L-Glutamate-Induced Obese Rats

Syzygium cumini is used worldwide for the treatment of metabolic syndrome-associated outcomes. Previously, we described the antihypertriglyceridemic effect of the hydroethanolic extract of S. cumini leaf (HESc) in monosodium L-glutamate- (MSG-) induced obese rats. This study sought to investigate the molecular mechanisms underlying the antihypertriglyceridemic effect of HESc in MSG-obese rats. Newborn male Wistar rats were injected subcutaneously with MSG (4.0 g/kg/day, obese group) or saline 1.25% (1.0 mL/kg/day, lean group), from 2nd through 10th postnatal day. At 8 weeks old, obese rats started to be orally treated with HESc (0.5 or 1.0 g/kg/day, n = 7) or saline 0.9% (1 mL/kg/day, n = 7). Lean rats received saline solution (1 mL/kg/day, n = 7). Upon 8-week treatment, animals were euthanized for blood and tissue collection. Another set of adult nonobese Wistar rats was used for the assessment of HESc acute effects on Triton WR1339-induced hypertriglyceridemia. HESc reduced weight gain, as well as adipose tissue fat pads, without altering food intake of obese rats. HESc restored fasting serum glucose, triglycerides, total cholesterol, and free fatty acids, as well as insulin sensitivity, to levels similar to lean rats. Additionally, HESc halved the triglyceride content into very low-density lipoprotein particles, as well as healed liver steatosis, in obese rats. Hepatic protein expression of the endoplasmic reticulum chaperone GRP94 was decreased by HESc, which also downregulated the hepatic triglyceride secretion pathway by reducing the splicing of X-box binding protein 1 (XBP-1s), as well as protein disulfide isomerase (PDI) and microsomal triglyceride transfer protein (MTP) translational levels. This action was further corroborated by the acute inhibitory effect of HESc on triglyceride accumulation on Triton WR1339-treated rats. Our data support the downregulation of the XBP-1s/PDI/MTP axis in the liver of MSG-obese rats as a novel feasible mechanism for the antihypertriglyceridemic effect promoted by the polyphenolic phytocomplex present in S. cumini leaf.

Syzygium cumini (L.) Skeels improves metabolic and ovarian parameters in female obese rats with malfunctioning hypothalamus-pituitary-gonadal axis

Background

Obesity is a chronic and multifactorial disease characterized by increased adipose tissue. In females, obesity leads to reduced ovulation and lower chances of conception in diseases like polycystic ovary syndrome, making it important to characterize complementary medicine to attenuate such deleterious effects. Therefore, the aim of this study was to assess the effects of a hydroethanolic extract from Syzigium cumini leaves in female reproductive impairments present in the obesity model of neonatal L-monosodium glutamate injection.

Methods

Newborn Wistar rats received saline (CTRL) or L-monosodium glutamate 4 mg/g BW (MSG). At 90 days of age, CTRL and some MSG rats received saline, while others received hydroethanolic extract of S. cumini leaves (HESc 500 mg/kg/day, MSG-Syz group) for 30 consecutive days. Estrous cycle was determined by daily vaginal washes. On days 26 and 28 of treatment, oral glucose tolerance test and blood collection were performed for biochemical assessment. At the end, animals were euthanized during estrous phase; blood was collected to measure sex hormones and organs collected for weighing and histological evaluation.

Results

MSG-Syz showed reduced Lee Index, retroperitoneal fat pads and restored gluco-insulin axis. Moreover, HESc treatment reduced serum cholesterol levels when compared to MSG. Treatment with HESc did not restore the oligociclicity observed in obese animals, though MSG-Syz reestablished ovarian follicle health back to CTRL levels, with proliferating primordial follicles – these effects were followed by a decrease on periovarian adipocyte area.

Conclusions

This is the first report to show the reversibility of the reproductive dysfunctions seen in MSG female rats through ethnopharmacological treatment. Moreover, it expands the use of HESc as a prominent tool to treat metabolic and reproductive disorders. Finally, we provide novel evidence that, without a functioning hypothalamus-pituitary-gonads axis, metabolic improvement is ineffective for estrous cyclicity, but critical for ovarian follicle health.

Protective Effects of a Polyphenol-Rich Extract from Syzygium cumini (L.) Skeels Leaf on Oxidative Stress-Induced Diabetic Rats

Syzygium cumini (L.) Skeels has been reported to exert anti-inflammatory and cardiometabolic activities due to its high content of polyphenols. We characterized the chemical composition and assessed the antidiabetic effects of a novel polyphenol-rich extract (PESc) obtained from S. cumini leaf. Rats were injected with alloxan (150 mg/kg, ip, ALX group) and followed up for 7 days. Some were orally treated with PESc (50 mg/kg/day) for 7 days before and after diabetes induction (ALX-PP) or only for 7 days after alloxan injection (ALX-P). ALX-P and ALX-PP decreased fasting glycemia in 37 and 43%, respectively, as compared to ALX. Triglycerides and total cholesterol serum levels were also significantly reduced in comparison to ALX. PESc presented high polyphenol concentration (71.78 ± 8.57 GAE/100 g), with flavonoid content of 8.21 ± 0.42 QE/100 g. Upon HPLC-MS/MS and MS/MS studies, five main polyphenols-gallic acid, quercetin, myricetin, and its derivatives-were identified. Myricetin was predominant (192.70 ± 16.50 μg/mg PESc), followed by measurable amounts of gallic acid (11.15 ± 0.90 μg/mg PESc) and quercetin (4.72 ± 0.06 μg/mg PESc). Kinetic assessment of total antioxidant capacity revealed PESc high potency, since maximum response was reached within 5 min reaction time in a concentration-dependent manner. Specific antioxidant activity of PESc was assessed against both DPPH^• and ABTS^•+, showing strong activity (IC₅₀: 3.88 ± 1.09 and 5.98 ± 1.19 μg/mL, resp.). PESc also inhibited lipoxygenase activity (IC₅₀: 27.63 ± 8.47), confirming its antioxidant activity also on biologically relevant radicals. Finally, PESc induced insulin secretion by directly stimulating INS-1E β cells in the absence of any cytotoxic effect. Overall, our results support that PESc is a potent antioxidant phytocomplex with potential pharmacological use as a preventive antidiabetic natural product.

Supplementation of Syzygium cumini seed powder prevented obesity, glucose intolerance, hyperlipidemia and oxidative stress in high carbohydrate high fat diet induced obese rats

Background

Obesity and related complications have now became epidemic both in developed and developing countries. Cafeteria type diet mainly composed of high fat high carbohydrate components which plays a significant role in the development of obesity and metabolic syndrome.

This study investigated the effect of Syzygium cumini seed powder on fat accumulation and dyslipidemia in high carbohydrate high fat diet (HCHF) induced obese rats.

Method

Male Wistar rats were fed with HCHF diet ad libitum, and the rats on HCHF diet were supplemented with Syzygium cumini seed powder for 56 days (2.5% w/w of diet). Oral glucose tolerance test, lipid parameters, liver marker enzymes (AST, ALT and ALP) and lipid peroxidation products were analyzed at the end of 56 days. Moreover, antioxidant enzyme activities were also measured in all groups of rats.

Results

Supplementation with Syzygium cumini seed powder significantly reduced body weight gain, white adipose tissue (WAT) weights, blood glucose, serum insulin, and plasma lipids such as total cholesterol, triglyceride, LDL and HDL concentration. Syzygium cumini seed powder supplementation in HCHF rats improved serum aspartate amino transferase (AST), alanine amino transferase (ALT), and alkaline phosphatase (ALP) activities. Syzygium cumini seed powder supplementation also reduced the hepatic thiobarbituric acid reactive substances (TBARS) and elevated the antioxidant enzyme superoxide dismutase (SOD) and catalase (CAT) activities as well as increased glutathione (GSH) concentration. In addition, histological assessment showed that Syzygium cumini seed powder supplementation prevented inflammatory cell infiltration; fatty droplet deposition and fibrosis in liver of HCHFD fed rats.

Conclusion

Our investigation suggests that Syzygium cumini seed powder supplementation prevents oxidative stress and showed anti-inflammatory and antifibrotic activity in liver of HCHF diet fed rats. In addition, Syzygium cumini seed powder may be beneficial in ameliorating insulin resistance and dyslipidemia probably by increasing lipid metabolism in liver of HCHF diet fed rats.

Bioformulation of silver nanoparticles as berberine carrier cum anticancer agent against breast cancer

The present work focuses on the bioformulation of AgNPs as a carrier for berberine and tests whether biogenic AgNPs elicit anticancer activity against breast cancer.