[6]-Gingerol, from Zingiber officinale, potentiates GLP-1 mediated glucose-stimulated insulin secretion pathway in pancreatic β-cells and increases RAB8/RAB10-regulated membrane presentation of GLUT4 transporters in skeletal muscle to improve hyperglycemia in Leprdb/db type 2 diabetic mice

Renoprotective effect of a novel combination of 6-gingerol and metformin in high-fat diet/streptozotocin-induced diabetic nephropathy in rats via targeting miRNA-146a, miRNA-223, TLR4/TRAF6/NLRP3 inflammasome pathway and HIF-1α

BACKGROUND

MiRNA-146a and miRNA-223 are key epigenetic regulators of toll-like receptor 4 (TLR4)/tumor necrosis factor-receptor-associated factor 6 (TRAF6)/NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome pathway, which is involved in diabetic nephropathy (DN) pathogenesis. The currently available oral anti-diabetic treatments have been insufficient to halt DN development and progression. Therefore, this work aimed to assess the renoprotective effect of the natural compound 6-gingerol (GR) either alone or in combination with metformin (MET) in high-fat diet/streptozotocin-induced DN in rats. The proposed molecular mechanisms were also investigated.

METHODS

Oral gavage of 6-gingerol (100 mg/kg) and metformin (300 mg/kg) were administered to rats daily for eight weeks. MiRNA-146a, miRNA-223, TLR4, TRAF6, nuclear factor-kappa B (NF-κB) (p65), NLRP3, caspase-1, and hypoxia-inducible factor-1 alpha (HIF-1α) mRNA expressions were measured using real-time PCR. ELISA was used to measure TLR4, TRAF6, NLRP3, caspase-1, tumor necrosis factor-alpha (TNF-α), and interleukin-1-beta (IL-1β) renal tissue levels. Renal tissue histopathology and immunohistochemical examination of fibronectin and NF-κB (p65) were performed.

RESULTS

6-Gingerol treatment significantly reduced kidney tissue damage and fibrosis. 6-Gingerol up-regulated miRNA-146a and miRNA-223 and reduced TLR4, TRAF6, NF-κB (p65), NLRP3, caspase-1, TNF-α, IL-1β, HIF-1α and fibronectin renal expressions. 6-Gingerol improved lipid profile and renal functions, attenuated renal hypertrophy, increased reduced glutathione, and decreased blood glucose and malondialdehyde levels. 6-Gingerol and metformin combination showed superior renoprotective effects than either alone.

CONCLUSION

6-Gingerol demonstrated a key protective role in DN by induction of miRNA-146a and miRNA-223 expression and inhibition of TLR4/TRAF6/NLRP3 inflammasome signaling. 6-Gingerol, a safe, affordable, and abundant natural compound, holds promise for use as an adjuvant therapy with metformin in diabetic patients to attenuate renal damage and stop the progression of DN.

New labdane diterpenoids from Alpinia galanga: A new type of GLP-1 secretagogues targeting the PKA-CREB and PI3K-Akt signaling axes

Glucagon-like peptide-1 (GLP-1) secretagogues are fascinating pharmacotherapies to overcome the defects of GLP-1 analogs and dipeptidyl peptidase-4 (DPP-4) inhibitors in treating diabetes and obesity. To discover new GLP-1 secretagogues from natural sources, alpigalangols A-Q (1-17), 17 new labdane diterpenoids including four unusual nor-labdane and N-containing ones, were isolated from the fruits of Alpinia galanga. Most of the isolates showed GLP-1 promotive effects in NCl-H716 cells, of which compounds 3, 4, 12, and 14-17 were revealed with high promoting rates of 246.0%-413.8% at 50 µM. A mechanistic study manifested that the most effective compound 12 upregulated the mRNA expression of Gcg and Pcsk1, and the protein phosphorylation of PKA, CREB, and GSK3β, but was inactive on GPBAR and GPR119 receptors. Network pharmacology analysis indicated that the PI3K-Akt pathway was involved in the GLP-1 stimulation of 12, which was highly associated with AKT1, CASP3, PPARG, and ICAM1 proteins. This study suggests that A. galanga is rich in diverse labdane diterpenoids with GLP-1 promoting effects, representing a new type of antidiabetic candidates from natural sources.

Herbal Products as Complementary or Alternative Medicine for the Management of Hyperglycemia and Dyslipidemia in Patients with Type 2 Diabetes: Current Evidence Based on Findings of Interventional Studies

Type 2 diabetes (T2D) is known as a major public health problem with a noticeable adverse impact on quality of life and health expenditures worldwide. Despite using routine multiple pharmacological and nonpharmacological interventions, including diet therapy and increasing physical activity, controlling this chronic disease remains a challenging issue, and therapeutic goals are often not achieved. Therefore, recently, other therapeutic procedures, such as using herbal products and functional foods as complementary or alternative medicine (CAM), have received great attention as a new approach to managing T2D complications, according to the literature. We reviewed the existing evidence that supports using various fundamental medicinal herbs, including cinnamon, saffron, ginger, jujube, turmeric, and barberry, as CAM adjunctive therapeutic strategies for T2D patients. The current review addressed different aspects of the potential impact of the abovementioned herbal products in improving glycemic indices and lipid profiles, including the effect size reported in the studies, their effective dose, possible side effects, herbs-drug interactions, and their potential action mechanisms.

Anti-obesity and anti-diabetic bioactive peptides: A comprehensive review of their sources, properties, and techno-functional challenges

The scourge of obesity arising from obesogens and poor dieting still ravages our planet as half of the global population may be overweight and obese by 2035. This metabolic disorder is intertwined with type 2 diabetes (T2D), both of which warrant alternative therapeutic options other than clinically approved drugs like orlistat with their tendency of abuse and side effects. In this review, we comprehensively describe the global obesity problem and its connection to T2D. Obesity, overconsumption of fats, the mechanism of fat digestion, obesogenic gut microbiota, inhibition of fat digestion, and natural anti-obesity compounds are discussed. Similar discussions are made for diabetes with regard to glucose regulation, the diabetic gut microbiota, and insulinotropic compounds. The sources and production of anti-obesity bioactive peptides (AOBPs) and anti-diabetic bioactive peptides (ADBPs) are also described while explaining their structure-function relationships, gastrointestinal behaviors, and action mechanisms. Finally, the techno-functional applications of AOBPs and ADBPs are highlighted.

Potential Role of Phytochemicals as Glucagon-like Peptide 1 Receptor (GLP-1R) Agonists in the Treatment of Diabetes Mellitus

Currently, there is no known cure for diabetes. Different pharmaceutical therapies have been approved for the management of type 2 diabetes mellitus (T2DM), some are in clinical trials and they have been classified according to their route or mechanism of action. Insulin types, sulfonylureas, biguanides, alpha-glucosidase inhibitors, thiazolidinediones, meglitinides, sodium-glucose cotransporter type 2 inhibitors, and incretin-dependent therapies (glucagon-like peptide-1 receptor agonists: GLP-1R, and dipeptidyl peptidase 4 inhibitors: DPP-4). Although some of the currently available drugs are effective in the management of T2DM, the side effects resulting from prolonged use of these drugs remain a serious challenge. GLP-1R agonists are currently the preferred medications to include when oral metformin alone is insufficient to manage T2DM. Medicinal plants now play prominent roles in the management of various diseases globally because they are readily available and affordable as well as having limited and transient side effects. Recently, studies have reported the ability of phytochemicals to activate glucagon-like peptide-1 receptor (GLP-1R), acting as an agonist just like the GLP-1R agonist with beneficial effects in the management of T2DM. Consequently, we propose that careful exploration of phytochemicals for the development of novel therapeutic candidates as GLP-1R agonists will be a welcome breakthrough in the management of T2DM and the co-morbidities associated with T2DM.

Gut Microbiota Targeted Approach by Natural Products in Diabetes Management: An Overview

PURPOSE OF REVIEW

This review delves into the complex interplay between obesity-induced gut microbiota dysbiosis and the progression of type 2 diabetes mellitus (T2DM), highlighting the potential of natural products in mitigating these effects. By integrating recent epidemiological data, we aim to provide a nuanced understanding of how obesity exacerbates T2DM through gut flora alterations.

RECENT FINDINGS

Advances in research have underscored the significance of bioactive ingredients in natural foods, capable of restoring gut microbiota balance, thus offering a promising approach to manage diabetes in the context of obesity. These findings build upon the traditional use of medicinal plants in diabetes treatment, suggesting a deeper exploration of their mechanisms of action. This comprehensive manuscript underscores the critical role of targeting gut microbiota dysbiosis in obesity-related T2DM management and by bridging traditional knowledge with current scientific evidence; we highlighted the need for continued research into natural products as a complementary strategy for comprehensive diabetes care.

Ameliorative Effects of Zingiber officinale Rosc on Antibiotic-Associated Diarrhea and Improvement in Intestinal Function

The global increase in antibiotic consumption is related to increased adverse effects, such as antibiotic-associated diarrhea (AAD). This study investigated the chemical properties of Zingiber officinale Rosc (ZO) extract and its ameliorative effects using a lincomycin-induced AAD mouse model. Intestinal tissues were evaluated for the expression of lysozyme, claudin-1, and α-defensin-1, which are associated with intestinal homeostasis. The cecum was analyzed to assess the concentration of short-chain fatty acids (SCFAs). The chemical properties analysis of ZO extracts revealed the levels of total neutral sugars, acidic sugars, proteins, and polyphenols to be 86.4%, 8.8%, 4.0%, and 0.8%, respectively. Furthermore, the monosaccharide composition of ZO was determined to include glucose (97.3%) and galactose (2.7%). ZO extract administration ameliorated the impact of AAD and associated weight loss, and water intake also returned to normal. Moreover, treatment with ZO extract restored the expression levels of lysozyme, α-defensin-1, and claudin-1 to normal levels. The decreased SCFA levels due to induced AAD showed a return to normal levels. The results indicate that ZO extract improved AAD, strengthened the intestinal barrier, and normalized SCFA levels, showing that ZO extract possesses intestinal-function strengthening effects.

Can Polyherbal Medicine be used for the Treatment of Diabetes? - A Review of Historical Classics, Research Evidence and Current Prevention Programs

Diabetes mellitus (DM), a chronic medical condition, has attained a global pandemic status over the last few decades affecting millions of people. Despite a variety of synthetic drugs available in the market, the use of herbal medicines for managing diabetes is gaining importance because of being comparatively safer. This article reviews the result of a substantial literature search on polyherbal formulations (PHFs) developed and evaluated with potential for DM. The accumulated data in the literature allowed us to enlist 76PHFs consisting of different parts of 147 plant species belonging to 58 botanical families. The documented plant species are laden with bioactive components with anti-diabetic properties and thus draw attention. The most favoured ingredient for PHFs was leaves of Gymnema sylvestre and seeds of Trigonella foenum-graecum used in 27 and 22 formulations, respectively. Apart from herbs, shilajit (exudates from high mountain rocks) formed an important component of 9 PHFs, whereas calcined Mytilus margaritiferus and goat pancreas were used in Dolabi, the most commonly used tablet form of PHF in Indian markets. The healing properties of PHFs against diabetes have been examined in both pre-clinical studies and clinical trials. However, the mechanism(s) of action of PHFs are still unclear and considered the pitfalls inherent in understanding the benefits of PHFs. From the information available based on experimental systems, it could be concluded that plant-derived medicines will have a considerable role to play in the control of diabetes provided the challenges related to their bioavailability, bioefficacy, optimal dose, lack of characterization, ambiguous mechanism of action, and clinical efficiency are addressed.

Therapeutic application of natural compounds for skeletal muscle-associated metabolic disorders: A review on diabetes perspective

Skeletal muscle (SM) plays a vital role in energy and glucose metabolism by regulating insulin sensitivity, glucose uptake, and blood glucose homeostasis. Impaired SM metabolism is strongly linked to several diseases, particularly type 2 diabetes (T2D). Insulin resistance in SM may result from the impaired activities of insulin receptor tyrosine kinase, insulin receptor substrate 1, phosphoinositide 3-kinase, and AKT pathways. This review briefly discusses SM myogenesis and the critical roles that SM plays in insulin resistance and T2D. The pharmacological targets of T2D which are associated with SM metabolism, such as DPP4, PTB1B, SGLT, PPARγ, and GLP-1R, and their potential modulators/inhibitors, especially natural compounds, are discussed in detail. This review highlights the significance of SM in metabolic disorders and the therapeutic potential of natural compounds in targeting SM-associated T2D targets. It may provide novel insights for the future development of anti-diabetic drug therapies. We believe that scientists working on T2D therapies will benefit from this review by enhancing their knowledge and updating their understanding of the subject.

Ginger Bioactives: A Comprehensive Review of Health Benefits and Potential Food Applications

Ginger is an herbaceous and flowering plant renowned for its rhizome, which is widely employed as both a spice and an herb. Since ancient times, ginger has been consumed in folk medicine and traditional cuisines for its favorable health effects. Different in vitro and in vivo studies have disclosed the advantageous physiological aspects of ginger, primarily due to its antioxidant, anti-inflammatory, antimicrobial, and anti-carcinogenic properties. These health-promoting features are linked to the variety of bioactive compounds that are present in ginger. Following the advancement in consumer awareness and the industrial demand for organic antioxidants and functional ingredients, the application of ginger and its derivatives has been broadly investigated in a wide range of food products. The prominent features transmitted by ginger into different food areas are antioxidant and nutraceutical values (bakery); flavor, acceptability, and techno-functional characteristics (dairy); hedonic and antimicrobial properties (beverages); oxidative stability, tenderization, and sensorial attributes (meat); and shelf life and sensorial properties (film, coating, and packaging). This review is focused on providing a comprehensive overview of the tendencies in the application of ginger and its derivatives in the food industry and concurrently briefly discusses the beneficial aspects and processing of ginger.

6-Gingerol Ameliorates Adiposity and Inflammation in Adipose Tissue in High Fat Diet-Induced Obese Mice: Association with Regulating of Adipokines

We investigated the effects of 6-gingerol on adiposity and obesity-induced inflammation by focusing on the regulation of adipogenesis and adipokines in white adipose tissue (WAT) of diet-induced obese mice. C57BL/6 mice were fed a high-fat diet (HFD) containing 0.05% 6-gingerol for 8 weeks. 6-Gingerol supplementation significantly reduced body weight, WAT mass, serum triglyceride, leptin and insulin levels, and HOMA-IR in HFD-fed mice. Additionally, the size of adipocytes in epididymal fat pads was reduced in HFD-fed mice by 6-gingerol supplementation. 6-Gingerol reduced the mRNA and protein levels of adipogenesis-related transcription factors, such as SREBP-1, PPARγ, and C/EBPα in WAT. Furthermore, 6-gingerol suppressed the expression of lipogenesis-related genes, such as fatty acid synthase and CD36 in WAT. Adiponectin expression was significantly increased, whereas inflammatory adipokines (leptin, resistin, TNF-α, MCP-1, and PAI-1) and the macrophage marker F4/80 were significantly reduced in the WAT of HFD-fed mice by 6-gingerol supplementation. In conclusion, 6-gingerol effectively contributed to the alleviation of adiposity and inflammation in WAT, which is associated with the regulation of adipokines in diet-induced obese mice.

Protective Effects of Medicinal Plant-Based Foods against Diabetes: A Review on Pharmacology, Phytochemistry, and Molecular Mechanisms

Diabetes mellitus (DM) comprises a range of metabolic disorders characterized by high blood glucose levels caused by defects in insulin release, insulin action, or both. DM is a widespread condition that affects a substantial portion of the global population, causing high morbidity and mortality rates. The prevalence of this major public health crisis is predicted to increase in the forthcoming years. Although several drugs are available to manage DM, these are associated with adverse side effects, which limits their use. In underdeveloped countries, where such drugs are often costly and not widely available, many people continue to rely on alternative traditional medicine, including medicinal plants. The latter serves as a source of primary healthcare and plant-based foods in many low- and middle-income countries. Interestingly, many of the phytochemicals they contain have been demonstrated to possess antidiabetic activity such as lowering blood glucose levels, stimulating insulin secretion, and alleviating diabetic complications. Therefore, such plants may provide protective effects that could be used in the management of DM. The purpose of this article was to review the medicinal plant-based foods traditionally used for the management of DM, including their therapeutic effects, pharmacologically active phytoconstituents, and antidiabetic mode of action at the molecular level. It also presents future avenues for research in this field.

Mechanism exploration of 6-Gingerol in the treatment of atherosclerosis based on network pharmacology, molecular docking and experimental validation

BACKGROUND

The 6-Gingerol has significant anti-inflammatory, anti-oxidative and hypolipidemic activities and is widely used for treating cardiac-cerebral vascular diseases. However, the multi-target mechanism of 6-Gingerol in the treatment of atherosclerosis remains to be elucidated.

METHODS

Firstly, the therapeutic actions of 6-Gingerol anti-atherosclerosis were researched based on an atherosclerotic ApoE-deficient mice model induced by high-fat feed. Then, network pharmacology and molecular docking were employed to reveal the anti-atherogenic mechanism of 6-Gingerol. Finally, the target for these predictions was validated by target protein expression assay in vitro and in vivo experiments and further correlation analysis.

RESULTS

Firstly, 6-Gingerol possessed obvious anti-atherogenic activity, which was manifested by a significant reduction in the plaque area, decrease in the atherosclerosis index and vulnerability index. Secondly, based on network pharmacology, 14 predicted intersection target genes between the targets of 6-Gingerol and atherogenic-related targets were identified. The key core targets of 6-Gingerol anti-atherosclerosis were found to be TP53, RELA, BAX, BCL2, and CASP3. Lipid and atherosclerosis pathways might play a critical role in 6-Gingerol anti-atherosclerosis. Molecular docking results also further revealed that the 6-Gingerol bound well and stable to key core targets from network pharmacological predictions. Then, the experimental results in vivo and in vitro verified that the up-regulation of TP53, RELA, BAX, CASP3, and down-regulation of BCL2 from atherosclerotic ApoE-deficient mice model can be improved by 6-Gingerol intervention. Meanwhile, the correlation analysis further confirmed that 6-Gingerol anti-atherosclerosis was closely related to these targets.

CONCLUSION

The 6-Gingerol can markedly improve atherosclerosis by modulating key multi-targets TP53, RELA, BAX, CASP3, and BCL2 in lipid and atherosclerosis pathways. These novel findings shed light on the anti-atherosclerosis mechanism of 6-Gingerol from the perspective of multiple targets and pathways.

Revisiting the therapeutic potential of gingerols against different pharmacological activities

The rhizomes of ginger have been in use in many forms of traditional and alternative medicines. Besides being employed as condiment and flavoring agent, it is used in the treatment of nausea, osteoarthritis, muscle pain, menstrual pain, chronic indigestion, Alzheimer's disease, and cancer. Ginger rhizome contains volatile oils, phenolic compounds and resins, and characterization studies showed that [6]-gingerol, [6]-shogaol, and [6]-paradol are reported to be the pharmacologically active components. Gingerol is a major chemical constituent found as volatile oil in the rhizomes of ginger. It has several medicinal benefits and used for the treatment of rheumatoid arthritis, nausea, cancer, and diabetes. Many studies have been carried out in various parts of the world to isolate and standardize gingerol for their use as a complementary medicine. The present review summarizes wide range of research studies on gingerol and its pharmacological roles in various metabolic diseases.

Modulatory Effect of Medicinal Plants and Their Active Constituents on ATP-Sensitive Potassium Channels (KATP) in Diabetes

Hyperglycemia, which is a chronic metabolic condition caused by either a defect in insulin secretion or insulin resistance, is a hallmark of diabetes mellitus (DM). Sustained hyperglycemia leads to the onset and development of many health complications. Despite the number of available antidiabetic medications on the market, there is still a need for novel treatment agents with increased efficacy and fewer adverse effects. Many medicinal plants offer a rich supply of bioactive compounds that have remarkable pharmacological effects with less toxicity and side effects. According to published evidence, natural antidiabetic substances influence pancreatic β-cell development and proliferation, inhibit pancreatic β-cell death, and directly increase insulin output. Pancreatic ATP-sensitive potassium channels play an essential role in coupling glucose metabolism to the secretion of insulin. Although much of the literature is available on the antidiabetic effects of medicinal plants, very limited studies discuss their direct action on pancreatic KATP. The aim of this review is to focus on the modulatory effects of antidiabetic medicinal plants and their active constituents on pancreatic KATP. The KATP channel should be regarded as a key therapeutic milestone in the treatment of diabetes. Therefore, continuous research into the interaction of medicinal plants with the KATP channel is crucial.

The Effect of Ginger (Zingiber officinale Roscoe) Aqueous Extract on Postprandial Glycemia in Nondiabetic Adults: A Randomized Controlled Trial

Ginger has shown beneficial effects on blood glucose control due to its antioxidant and anti-inflammatory properties. The present study investigated the effect of ginger aqueous extract on postprandial glucose levels in nondiabetic adults and characterized its antioxidant activity. Twenty-four nondiabetic participants were randomly assigned into two groups (NCT05152745), the intervention group (n = 12) and the control group (n = 12). Both groups were administered 200 mL of an oral glucose tolerance test (OGTT), after which participants in the intervention group ingested 100 mL of ginger extract (0.2 g/100 mL). Postprandial blood glucose was measured while fasting and after 30, 60, 90, and 120 min. The total phenolic content, flavonoid content, and antioxidant activity of ginger extract were quantified. In the intervention group, the incremental area under the curve for glucose levels decreased significantly (p < 0.001) and the maximum glucose concentration significantly reduced (p < 0.001). The extract possessed a polyphenolic content of 13.85 mg gallic acid equivalent/L, a flavonoid content of 3.35 mg quercetin equivalent/L, and a high superoxide radical inhibitory capacity (45.73%). This study showed that ginger has a beneficial effect on glucose homeostasis under acute conditions and encourages the use of ginger extract as a promising source of natural antioxidants.

Peroxisomal KAT2 (3-ketoacyl-CoA thiolase 2) gene has a key role in gingerol biosynthesis in ginger (Zingiber officinale Rosc.)

Ginger is an important spice crop with medicinal values and gingerols are the most abundant pungent polyphenols present in ginger, responsible for most of its pharmacological properties. The present study focuses on the molecular mechanism of gingerol biosynthesis in ginger using transcriptome analysis. Suppression Subtractive Hybridization (SSH) was done in leaf and rhizome tissues using high gingerol-producing ginger somaclone B3 as the tester and parent cultivar Maran as the driver and generated high-quality leaf and rhizome Expressed Sequence Tags (ESTs). The Blast2GO annotations of the ESTs revealed the involvement of leaf ESTs in secondary metabolite production, identifying the peroxisomal KAT2 gene (Leaf EST 9) for the high gingerol production in ginger. Rhizome ESTs mostly coded for DNA metabolic processes and differential genes for high gingerol production were not observed in rhizomes. In the qRT-PCR analysis, somaclone B3 had shown high chalcone synthase (CHS: rate-limiting gene in gingerol biosynthetic pathway) activity (0.54 fold) in the leaves of rhizome sprouts. The presence of a high gingerol gene in leaf ESTs and high expression of CHS in leaves presumed that the site of synthesis of gingerols in ginger is the leaves. A modified pathway for gingerol/polyketide backbone formation has been constructed explaining the involvement of KAT gene isoforms KAT2 and KAT5 in gingerol/flavonoid biosynthesis, specifically the KAT2 gene which is otherwise thought to be involved mainly in β-oxidation. The results of the present investigations have the potential of utilizing KAT/thiolase superfamily enzymes for protein/metabolic pathway engineering in ginger for large-scale production of gingerols.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13562-022-00825-x.

6-gingerol ameliorates weight gain and insulin resistance in metabolic syndrome rats by regulating adipocytokines

Metabolic syndrome (MetS) can lead to increase of insulin resistance (IR) and visceral adipose tissue production of adipocytokines. 6-gingerol is known to have antioxidant and anti-inflammatory activities. Aim of this study is to investigate the effects of 6-gingerol on high-fat high-fructose (HFHF) diet-induced weight gain and IR in rats through modulation of adipocytokines. To induce MetS, male Sprague-Dawley rats were fed with a HFHF diet for 16 weeks and at Week 8, single-dose low-dose streptozotocin (22 mg/kg) were intraperitoneally injected. After 8 weeks of HFHF diet feeding, the rats were treated orally with 6-gingerol (50, 100, and 200 mg/kg/day) once daily for 8 weeks. At the end of the study, all animals were terminated, serum, liver, and visceral adipose tissues were harvested for biochemical analysis including the measurements of total cholesterol, triglycerides, HDL-cholesterol, fasting plasma glucose, insulin, leptin, adiponectin, proinflammatory cytokines (TNF-α and IL-6) and liver and adipose tissue histopathology. Biochemical parameters namely serum total cholesterol (243.7 ± 127.6 vs 72.6 ± 3 mg/dL), triglycerides (469.2 ± 164.9 vs 49.3 ± 6.3 mg/dL), fasting plasma glucose (334 ± 49.5 vs 121 ± 8.5 mg/dL), HOMA-IR (0.70 ± 0.24 vs 0.32 ± 0.06), and leptin (6.19 ± 1.24 vs 3.45 ± 0.33 ng/mL) were significantly enhanced, whereas HDL-cholesterol (26.2 ± 5.2 vs 27.9 ± 1.1 mg/dL) and adiponectin level (14.4 ± 5.5 vs 52.8 ± 10.7 ng/mL) were lowered in MetS vs normal control. Moreover, MetS were marked a significant increase in body weight and proinflammatory cytokines. Treatment with 6-gingerol dose-dependently restored all of those alterations towards normal values as well as the accumulation of lipid in liver and adipose tissues. These findings demonstrate that 6-gingerol, in a dose-dependent mode, showed capability of improving weight gain and IR in MetS rats through modulation of adipocytokines.

Potential of medicinal plants to ameliorate neovascularization activities in diabetes: A systematic review

Hyperglycemia in diabetes mediates the release of angiogenic factors, oxidative stress, hypoxia, and inflammation, which in turn stimulate angiogenesis. Excessive angiogenesis can cause diabetic retinopathy, diabetic neuropathy, and diabetic nephropathy. All of these complications are debilitating, which may lead to an increased susceptibility to lower-limb amputations due to ulcerations and infections. In addition, microvascular alterations, segmental demyelination, and endoneurial microangiopathy may cause progressive deterioration ultimately leading to kidney failure and permanent blindness. Some medicinal plants have potent anti-angiogenic, antioxidant or anti-inflammatory properties that can ameliorate angiogenesis in diabetes. The purpose of this systematic review is to demonstrate the potential of medicinal plants in ameliorating the neovascularization activities in diabetes. Manuscripts were searched from PubMed, Science Direct, and Scopus databases, and Google Scholar was used for searching additional papers. From 1862 manuscripts searched, 1854 were excluded based on inclusion and exclusion criteria and 8 were included into this systematic review, whereas the required information was extracted and summarized. All identified medicinal plants decreased the high blood glucose levels in diabetes, except the aqueous extract of Lonicerae japonicae flos (FJL) and Vasant Kusumakar Ras. They also increased the reduced body weight in diabetes, except the aqueous extract of FL and total lignans from Fructus arctii. However, methanolic extract of Tinospora cordifolia and Vasant Kusumakar Ras were not tested for their ability to affect the body weight. Besides, all medicinal plants identified in this systematic review decreased the vascular endothelial growth factor (VEGF) protein expression and vasculature activity demonstrated by histopathological examination indicating promising anti-angiogenic properties. All medicinal plants identified in this systematic review have a potential to ameliorate neovascularization activities in diabetes by targeting the mechanistic pathways related to oxidative stress, inflammation, and angiogenesis.

Gingerol, a Natural Antioxidant, Attenuates Hyperglycemia and Downstream Complications

Hyperglycemia is seen in approximately 68 percent of patients admitted to a medical intensive care unit (ICU). In many acute circumstances, such as myocardial infarction, brain, injury and stroke, it is an independent predictor of mortality. Hyperglycemia is induced by a mix of genetic, environmental, and immunologic variables in people with type 1 diabetes. These factors cause pancreatic beta cell death and insulin insufficiency. Insulin resistance and irregular insulin production cause hyperglycemia in type 2 diabetes patients. Hyperglycemia activates a number of complicated interconnected metabolic processes. Hyperglycemia is a major contributor to the onset and progression of diabetes' secondary complications such as neuropathy, nephropathy, retinopathy, cataracts, periodontitis, and bone and joint issues. Studies on the health benefits of ginger and its constituent's impact on hyperglycemia and related disorders have been conducted and gingerol proved to be a potential pharmaceutically active constituent of ginger (Zingiber officinale) that has been shown to lower blood sugar levels, because it possesses antioxidant properties and it functions as an antioxidant in the complicated biochemical process that causes hyperglycemia to be activated. Gingerol not only helps in treating hyperglycemia but also shows effectivity against diseases related to it, such as cardiopathy, kidney failure, vision impairments, bone and joint problems, and teeth and gum infections. Moreover, fresh ginger has various gingerol analogues, with 6-gingerol being the most abundant. However, it is necessary to investigate the efficacy of its other analogues against hyperglycemia and associated disorders at various concentrations in order to determine the appropriate dose for treating these conditions.

Ginger Could Improve Gestational Diabetes by Targeting Genes Involved in Nutrient Metabolism, Oxidative Stress, Inflammation, and the WNT/β-Catenin/GSK3β Signaling Pathway

This study aimed to evaluate the effect in female rats of 6 weeks of ginger consumption on gestational diabetes by assessing glucose and lipid metabolism, oxidative damage, inflammation, and the WNT/β-catenin/glycogen synthase kinase-3 beta (GSK3β) signaling pathway. In this study, 40 adult female rats were divided into 4 equal groups as follows: pregnant rats, pregnant rats with diabetes, pregnant rats consuming ginger, and pregnant rats with diabetes consuming ginger. Induction of diabetes on day 0 of pregnancy was induced by streptozotocin (STZ) injection. Insulin, glucose, and lipid profiles as metabolic factors were measured along with the hepatic expression of glucose transporter type 4 (GLUT4), mechanistic target of rapamycin complex 1 (mTORc1), sterol regulatory element-binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor α (PPAR-α), β-catenin, GSK3β, PPAR-g, nuclear factor-κB (NF-kB), and nuclear factor erythroid 2-related factor 2 (Nrf2). The levels of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and oxidative parameters were measured in the liver. The level of metabolic factors was significantly impaired in diabetic pregnant rats compared to the control group. However, ginger improved these parameters in the diabetic pregnant—ginger group compared to the diabetic pregnant group. The hepatic expression of genes involved in metabolism, oxidative stress, inflammation, and the wingless and int-1 (WNT) signaling pathway was significantly impaired in diabetic pregnant rats, while ginger improved them in the hepatic tissue of diabetic pregnant rats. It can be concluded that ginger could improve gestational diabetes by genes involved in metabolism, the WNT signaling pathway, oxidative stress, and inflammation. These results suggest that ginger can be an adjunct drug during pregnancy as a metabolic modulator.

Immunomodulatory and anti-inflammatory therapeutic potential of gingerols and their nanoformulations

Ginger (Zingiber officinale Roscoe), a member of the Zingiberaceae family, is one of the most popular spices worldwide, known since ancient times, and used both as a spice and a medicinal plant. The phenolic compounds found in ginger are predominantly gingerols, shogaols, and paradols. Gingerols are the major phenolic compounds found in fresh ginger and contain mainly 6-gingerol as well as 4-, 5-, 8-, 10-, and 12-gingerols. Gingerols possess a wide array of bioactivities, such as antioxidant and anticancer, among others. Regarding the different array of biological activities and published data on the mechanisms underlying its action, the complex interaction between three key events, including inflammation, oxidative stress, and immunity, appears to contribute to a plethora of pharmacological activities of this compound. Among these, the immunomodulatory properties of these compounds, which attract attention due to their effects on the immune system, have been the focus of many studies. Gingerols can alleviate inflammation given their ability to inhibit the activation of protein kinase B (Akt) and nuclear factor kappa B (NF-κB) signaling pathways, causing a decrease in proinflammatory and an increase in anti-inflammatory cytokines. However, given their low bioavailability, it is necessary to develop new and more effective strategies for treatment with gingerols. In order to overcome this problem, recent studies have addressed new drug delivery systems containing gingerols. In this review, the immunomodulatory activities of gingerol and its underlying mechanisms of action combined with the contributions of developed nanodrug delivery systems to this activity will be examined.

Promising influences of gingerols against metabolic syndrome: A mechanistic review

Metabolic syndrome is an inflammatory disorder characterized by diabetes, obesity, atherosclerosis, and hypertension. Globally, this disease is increasing, especially in developed countries. Supposedly, herbal treatments for this disease likely have fewer adverse effects than chemical medications. Thus, they can be suitable options among the available chemical treatments. Ginger has been used as a spice and medicinal plant in traditional medicine and cooking. This herbal compound and its derivatives, such as 6-gingerol, have shown promising effects on various molecular aspects of metabolic syndrome. In this study, we reviewed and discussed the significant impacts of gingerol, a derivative of ginger, on metabolic syndrome through various mechanisms. The benefits of 6-gingerol include its effects on AMP-activated protein kinase (AMPK), which prevent diabetes, lipid regulating effect (peroxisome proliferator-activated receptors, PPARs), as well as its effects on enzymes and proteins preventing hyperlipidemia caused by a high-fat diet. In addition, 6-gingerol has anti-atherosclerosis and anti-hypertension effects through several molecular mechanisms. The current review will discuss various effects of 6-gingerol on molecular pathways involved in diabetes, obesity, atherosclerosis, and hypertension as characterizing features of metabolic syndrome and suggests that 6-gingerol can be a potential treatment agent for metabolic syndrome and shed light on a higher requirement for more pre-clinical and clinical investigations.

Bioactive Compounds from the Zingiberaceae Family with Known Antioxidant Activities for Possible Therapeutic Uses

The Zingiberaceae family is a rich source of diverse bioactive phytochemicals. It comprises about 52 genera and 1300 species of aromatic flowering perennial herbs with characteristic creeping horizontal or tuberous rhizomes. Notable members of this family include ginger (Zingiber officinale Roscoe), turmeric (Curcuma longa L.), Javanese ginger (Curcuma zanthorrhiza Roxb.), and Thai ginger (Alpinia galanga L.). This review focuses on two main classes of bioactive compounds: the gingerols (and their derivatives) and the curcuminoids. These compounds are known for their antioxidant activity against several maladies. We highlight the centrality of their antioxidant activities with notable biological activities, including anti-inflammatory, antidiabetic, hepatoprotective, neuroprotective, antimicrobial, and anticancer effects. We also outline various strategies that have been applied to enhance these activities and make suggestions for research areas that require attention.

Xiaoyaosan Exerts Antidepressant-Like Effect by Regulating Autophagy Involves the Expression of GLUT4 in the Mice Hypothalamic Neurons

Many studies have proven that autophagy plays a pivotal role in the development of depression and it also affects the expression of GLUT4 in the hypothalamus. Xiaoyaosan has been shown to exert antidepressant effects in a variety of ways, but its underlying mechanism by which Xiaoyaosan regulates autophagy as well as GLUT4 in the hypothalamus remains unclear. Thus, in this study, we established a mouse model of depression induced by chronic unpredictable mild stress (CUMS), and set up autophagy blockade as a control to explore whether Xiaoyaosan exerts antidepressant effect by affecting autophagy. We examined the effects of Xiaoyaosan on behaviors exhibited during the open field test, tail suspension test and sucrose preference test, and the changes in autophagy in hypothalamic neurons as well as changes in GLUT4 and the related indicators of glucose metabolism in CUMS-induced depressive mouse model. We found that CUMS- and 3-MA-induced mice exhibited depressive-like behavioral changes, with decreased LC3 expression and increased p62 expression, suggesting decreased levels of autophagy in the mouse hypothalamus. The expression of GLUT4 was also decreased, and it was closely related to the level of autophagy through Rab8 and Rab10. Nevertheless, after the intervention of Xiaoyaosan, the above changes were effectively reversed. These results show that Xiaoyaosan can regulate the autophagy in hypothalamic neurons and the expression of GLUT4 in depressed mice.

OptNCMiner: a deep learning approach for the discovery of natural compounds modulating disease-specific multi-targets

Background

Due to their diverse bioactivity, natural product (NP)s have been developed as commercial products in the pharmaceutical, food and cosmetic sectors as natural compound (NC)s and in the form of extracts. Following administration, NCs typically interact with multiple target proteins to elicit their effects. Various machine learning models have been developed to predict multi-target modulating NCs with desired physiological effects. However, due to deficiencies with existing chemical-protein interaction datasets, which are mostly single-labeled and limited, the existing models struggle to predict new chemical-protein interactions. New techniques are needed to overcome these limitations.

Results

We propose a novel NC discovery model called OptNCMiner that offers various advantages. The model is trained via end-to-end learning with a feature extraction step implemented, and it predicts multi-target modulating NCs through multi-label learning. In addition, it offers a few-shot learning approach to predict NC-protein interactions using a small training dataset. OptNCMiner achieved better prediction performance in terms of recall than conventional classification models. It was tested for the prediction of NC-protein interactions using small datasets and for a use case scenario to identify multi-target modulating NCs for type 2 diabetes mellitus complications.

Conclusions

OptNCMiner identifies NCs that modulate multiple target proteins, which facilitates the discovery and the understanding of biological activity of novel NCs with desirable health benefits.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12859-022-04752-5.

The effects of ginger and its constituents in the prevention of metabolic syndrome: A review

Metabolic syndrome is a multifactorial disorder characterized by hyperglycemia, hyperlipidemia, obesity, and hypertension risk factors. Moreover, metabolic syndrome is the most ordinary risk factor for cardiovascular disease (CVD). Numerous chemical drugs are being synthesized to heal metabolic risk factors. Still, due to their abundant side effects, herbal medicines have a vital role in the treatment of these abnormalities. Ginger (Zingiber officinale Roscoe, Zingiberaceae) plant has been traditionally used in medicine to treat disorders, including CVD. The unique ginger properties are attributed to the presence of [6]-gingerol, [8]-gingerol, [10]-gingerol, and [6]-shogaol, which through different mechanisms can be beneficial in metabolic syndrome. Ginger has a beneficial role in metabolic syndrome treatment due to its hypotensive, anti-obesity, hypoglycemic, and hypolipidemic effects. It can significantly reduce atherosclerotic lesion areas, VLDL and LDL cholesterol levels, and elevate adenosine deaminase activity in platelet and lymphocytes. Also, it promotes ATP/ADP hydrolysis. In the current article review, the critical properties of ginger and its constituents' effects on the metabolic syndrome with a special focus on different molecular and cellular mechanisms have been discussed. This article also suggests that ginger may be introduced as a therapeutic or preventive agent against metabolic syndrome after randomized clinical trials.

Ginger for Healthy Ageing: A Systematic Review on Current Evidence of Its Antioxidant, Anti-Inflammatory, and Anticancer Properties

The world's population is ageing at an accelerated pace. Ageing is a natural, physiological but highly complex and multifactorial process that all species in the Tree of Life experience over time. Physical and mental disabilities, and age-related diseases, would increase along with the increasing life expectancy. Ginger (Zingiber officinale) is a plant that belongs to the Zingiberaceae family, native to Southeast Asia. For hundreds of years, ginger has been consumed in various ways by the natives of Asian countries, both as culinary and medicinal herb for the treatment of many diseases. Mounting evidence suggests that ginger can promote healthy ageing, reduce morbidity, and prolong healthy lifespan. Ginger, a well-known natural product, has been demonstrated to possess antioxidant, anti-inflammatory, anticancer, and antimicrobial properties, as well as an outstanding antiviral activity due to a high concentration of antiviral compounds. In this review, the current evidence on the potential role of ginger and its active compounds in the prevention of ageing is discussed.

Pharmacological Study: Synergistic Antidiabetic Activity of Cinnamon Bark and Zingiber Extract in Streptozotocin-Induced Diabetic Rats

Background: Cinnamon has been widely used by Indonesian people as a complementary therapy to treat hyperglycemia such as in diabetes mellitus patients. While ginger is also used as a mixture in traditional anti hyperglycemia herb. There is not known how much antidiabetic effect of cinnamon ethanolic extract when combined with ginger, and not many studies have analyzed the correlation of lowering blood glucose levels associated with increasing of insulin of this combination.   Objectives: This study aimed to investigates antidiabetic activity of cinnamon extract, zingiber extract, and mixture on streptozotocin-induced diabetic rats.   Methods: This pharmacological study used Wistar strain male rats under hyperglycemia condition induced by streptozotocin at a dose of 45mg/kg. Sample were grouped with 6 animals in each where there was a positive and negative control group and also an intervention group given ethanol extract for 14 days.  Results: The result showed that all intervention groups experienced an increase in insulin levels and a decrease in blood glucose levels after 14 days. The One Way Anova test showed that the increase of insulin levels treated with combination of ethanolic extract cinnamon bark at the dose 150mg/200gr and ginger ethanolic extract at the dose 100mg/200gr was comparable to Glibenclamide (p=0.355), but the decrease in blood glucose levels between groups showed a difference that was not statistically significant. There was a relationship between insulin levels and blood glucose levels linearity with the equation Y (insulin level) = -5.261 + (-0.060) blood glucose level.  Conclusions: The combination of cinnamon and ginger showed beneficial synergistic anti-diabetic activity. It can increase insulin levels, making it possible to control blood sugar levels in high blood glucose conditions.

Antidiabetic Phytochemicals From Medicinal Plants: Prospective Candidates for New Drug Discovery and Development

Diabetes, a chronic physiological dysfunction affecting people of different age groups and severely impairs the harmony of peoples' normal life worldwide. Despite the availability of insulin preparations and several synthetic oral antidiabetic drugs, there is a crucial need for the discovery and development of novel antidiabetic drugs because of the development of resistance and side effects of those drugs in long-term use. On the contrary, plants or herbal sources are getting popular day by day to the scientists, researchers, and pharmaceutical companies all over the world to search for potential bioactive compound(s) for the discovery and development of targeted novel antidiabetic drugs that may control diabetes with the least unwanted effects of conventional antidiabetic drugs. In this review, we have presented the prospective candidates comprised of either isolated phytochemical(s) and/or extract(s) containing bioactive phytoconstituents which have been reported in several in vitro, in vivo, and clinical studies possessing noteworthy antidiabetic potential. The mode of actions, attributed to antidiabetic activities of the reported phytochemicals and/or plant extracts have also been described to focus on the prospective phytochemicals and phytosources for further studies in the discovery and development of novel antidiabetic therapeutics.

Phytochemical profile and anti-oxidation activity changes during ginger (Zingiber officinale) harvest: Baby ginger attenuates lipid accumulation and ameliorates glucose uptake in HepG2 cells

We determined the phenolic content and anti-oxidation properties of ginger at different harvesting time and tested its effects on lipid droplet formation and glucose uptake in HepG2 cells. Ginger samples at different stages of maturity were harvested every two weeks starting from mid-October for 16 weeks. Our data indicate that ginger has the highest phenolic contents and superior anti-oxidation activity when harvested early (immature baby ginger); however, the concentration of phenolic contents and its anti-oxidation activity were progressively reduced up to 50% as ginger matures. Furthermore, the data indicate that baby ginger extract inhibits lipid accumulation and triglyceride content in oleic acid-induced HepG2 cells up to 20% in a dose-dependent manner. Baby ginger exhibited significant inhibition of α-amylase enzyme activity by 29.5% and ameliorated glucose uptake in HepG2 cell at similar level. Our results suggest that harvesting ginger at an appropriate (early) time may be beneficial for optimizing its biological active contents and qualitative properties. The data also suggest that a regular use of ginger can potentially lower incidences of obesity and diabetes.

Botanical Interventions to Improve Glucose Control and Options for Diabetes Therapy

Diabetes mellitus is a major public health problem worldwide. This endocrine disease is clustered into distinct subtypes based on the route of development, with the most common forms associated with either autoimmunity (T1DM) or obesity (T2DM). A shared hallmark of both major forms of diabetes is a reduction in function (insulin secretion) or mass (cell number) of the pancreatic islet beta-cell. Diminutions in both mass and function are often present. A wide assortment of plants have been used historically to reduce the pathological features associated with diabetes. In this review, we provide an organized viewpoint focused around the phytochemicals and herbal extracts investigated using various preclinical and clinical study designs. In some cases, crude extracts were examined directly, and in others, purified compounds were explored for their possible therapeutic efficacy. A subset of these studies compared the botanical product with standard of care prescribed drugs. Finally, we note that botanical formulations are likely suspects for future drug discovery and refinement into class(es) of compounds that have either direct or adjuvant therapeutic benefit.

Phytochemicals modulate pancreatic islet β cell function through glucagon-like peptide-1-related mechanisms

Glucagon-like peptide-1 (GLP-1) receptor-based therapies have been developed and extensively applied in clinical practice. GLP-1 plays an important role in improving glycemic homeostasis by stimulating insulin biosynthesis and secretion, suppressing glucagon activity, delaying gastric emptying, and reducing appetite and food ingestion. Furthermore, GLP-1 has positive effects on β-cell function by promoting β-cell proliferation and neogenesis while simultaneously reducing apoptosis. Here, we summarize possible mechanisms of action of GLP-1 upon pancreatic islets as well as describe phytochemicals that modulate pancreatic islet β cell function through glucagon-like peptide-1-related mechanisms. Together, this information provides potential lead compound candidates against diabetes that function as GLP-1 receptor-based pharmacotherapy.

Dietary Bioactive Ingredients Modulating the cAMP Signaling in Diabetes Treatment

As the prevalence of diabetes increases progressively, research to develop new therapeutic approaches and the search for more bioactive compounds are attracting more attention. Over the past decades, studies have suggested that cyclic adenosine monophosphate (cAMP), the important intracellular second messenger, is a key regulator of metabolism and glucose homeostasis in diverse physiopathological states in multiple organs including the pancreas, liver, gut, skeletal muscle, adipose tissues, brain, and kidney. The multiple characteristics of dietary compounds and their favorable influence on diabetes pathogenesis, as well as their intersections with the cAMP signaling pathway, indicate that these compounds have a beneficial effect on the regulation of glucose homeostasis. In this review, we outline the current understanding of the diverse functions of cAMP in different organs involved in glucose homeostasis and show that a diversity of bioactive ingredients from foods activate or inhibit cAMP signaling, resulting in the improvement of the diabetic pathophysiological process. It aims to highlight the diabetes-preventative or -therapeutic potential of dietary bioactive ingredients targeting cAMP signaling.

Role of Herbal Teas in Regulating Cellular Homeostasis and Autophagy and Their Implications in Regulating Overall Health

Tea is one of the most popular and widely consumed beverages worldwide, and possesses numerous potential health benefits. Herbal teas are well-known to contain an abundance of polyphenol antioxidants and other ingredients, thereby implicating protection and treatment against various ailments, and maintaining overall health in humans, although their mechanisms of action have not yet been fully identified. Autophagy is a conserved mechanism present in organisms that maintains basal cellular homeostasis and is essential in mediating the pathogenesis of several diseases, including cancer, type II diabetes, obesity, and Alzheimer’s disease. The increasing prevalence of these diseases, which could be attributed to the imbalance in the level of autophagy, presents a considerable challenge in the healthcare industry. Natural medicine stands as an effective, safe, and economical alternative in balancing autophagy and maintaining homeostasis. Tea is a part of the diet for many people, and it could mediate autophagy as well. Here, we aim to provide an updated overview of popular herbal teas’ health-promoting and disease healing properties and in-depth information on their relation to autophagy and its related signaling molecules. The present review sheds more light on the significance of herbal teas in regulating autophagy, thereby improving overall health.

Beneficial effect of Zingiber officinale on olanzapine-induced weight gain and metabolic changes

AIM

The present study aimed to investigate the effect of Zingiber officinale (ZO) extract on weight gain, food intake, locomotor activity, and lipid and glucose metabolism in olanzapine-treated rats.

METHODS

The hydroalcoholic extract of ZO was prepared by macerating the coarse dry powder in 70% v/v ethanol for 7 days, filtered, and concentrated under reduced pressure. Animals were divided into six groups containing six animals in each. Three doses of extract (100, 200, and 400 mg/kg, p.o.) were co-administered with olanzapine 2 mg/kg i.p for 21 days. Bodyweight and food intake were recorded at the interval of three days and locomotor activity once a week. At the end of the study oral glucose tolerance test was performed followed by the estimation of lipid profile.

RESULTS

Co-administration of hydroalcoholic extract of ZO with olanzapine ameliorated olanzapine-induced weight gain and hyperphagia. Similarly, ZO extract also improved pancreatic β-cell function and glucose and lipid metabolism.

CONCLUSIONS

ZO extract ameliorated olanzapine-induced weight gain and hyperphagia by improving pancreatic β-cell functions and lipid metabolism.

The Potential Role of Polyphenols in Modulating Mitochondrial Bioenergetics within the Skeletal Muscle: A Systematic Review of Preclinical Models

Polyphenols are naturally derived compounds that are increasingly being explored for their various health benefits. In fact, foods that are rich in polyphenols have become an attractive source of nutrition and a potential therapeutic strategy to alleviate the untoward effects of metabolic disorders. The last decade has seen a rapid increase in studies reporting on the bioactive properties of polyphenols against metabolic complications, especially in preclinical models. Various experimental models involving cell cultures exposed to lipid overload and rodents on high fat diet have been used to investigate the ameliorative effects of various polyphenols against metabolic anomalies. Here, we systematically searched and included literature reporting on the impact of polyphenols against metabolic function, particularly through the modulation of mitochondrial bioenergetics within the skeletal muscle. This is of interest since the skeletal muscle is rich in mitochondria and remains one of the main sites of energy homeostasis. Notably, increased substrate availability is consistent with impaired mitochondrial function and enhanced oxidative stress in preclinical models of metabolic disease. This explains the general interest in exploring the antioxidant properties of polyphenols and their ability to improve mitochondrial function. The current review aimed at understanding how these compounds modulate mitochondrial bioenergetics to improve metabolic function in preclinical models on metabolic disease.

Ginger (Zingiber officinale Roscoe) as a nutraceutical: Focus on the metabolic, analgesic, and antiinflammatory effects

Ginger (from the rizhome of Zingiber officinale Roscoe) has been widely used in ethnomedicine for the cure of several ailments. Main active ingredients include phenolic compounds named gingerols. In modern phytotherapy, ginger preparations are predominantly used to counteract nausea and vomiting in pregnant women. However, a number of other pharmacological actions of potential therapeutic interest, which might broaden the spectrum of its clinical use, have been reported. This focused review aims at giving a shot on the antinflammatory, analgesic, and metabolic actions of Zingiber officinale preparations, with a discussion on the clinical applications in knee osteoarthritis, dysmenorrhea, type‐2 diabetes, hyperlipidemia, overweight, and obesity.

CREB nuclear transcription activity as a targeting factor in the treatment of diabetes and diabetes complications

Diabetes mellitus is a metabolic disorder diagnosed by elevated blood glucose levels and a defect in insulin production. Blood glucose, an energy source in the body, is regenerated by two fundamental processes: glycolysis and gluconeogenesis. These two processes are the main mechanisms used by humans and many other animals to maintain blood glucose levels, thereby avoiding hypoglycaemia. The released insulin from pancreatic β-cells activates glycolysis. However, the glucagon released from the pancreatic α-cells activates gluconeogenesis in the liver, leading to pyruvate conversion to glucose-6-phosphate by different enzymes such as fructose 1,6-bisphosphatase and glucose 6-phosphatase. These enzymes' expression is controlled by the glucagon/ cyclic adenosine 3',5'-monophosphate (cAMP)/ proteinkinase A (PKA) pathway. This pathway phosphorylates cAMP-response element-binding protein (CREB) in the nucleus to bind it to these enzyme promoters and activate their expression. During fasting, this process is activated to supply the body with glucose; however, it is overactivated in diabetes. Thus, the inhibition of this process by blocking the expression of the enzymes via CREB is an alternative strategy for the treatment of diabetes. This review was designed to investigate the association between CREB activity and the treatment of diabetes and diabetes complications. The phosphorylation of CREB is a crucial step in regulating the gene expression of the enzymes of gluconeogenesis. Many studies have proven that CREB is over-activated by glucagon and many other factors contributing to the elevation of fasting glucose levels in people with diabetes. The physiological function of CREB should be regarded in developing a therapeutic strategy for the treatment of diabetes mellitus and its complications. However, the accessible laboratory findings for CREB activity of the previous research still not strong enough for continuing to the clinical trial yet.

6-Gingerol, a Bioactive Compound of Ginger Attenuates Renal Damage in Streptozotocin-Induced Diabetic Rats by Regulating the Oxidative Stress and Inflammation

The aim of present study is to investigate the role of 6-gingerol in ameliorating the renal injury in streptozotocin (STZ)-induced diabetic rats. The diabetes was induced by using a single dose of freshly prepared STZ (55 mg/kg body weight) intraperitoneally which causes the degeneration of pancreatic Langerhans islet β-cells. The diabetic rats were treated with oral gavage of 6-gingerol (10 mg/kg b.w.). The treatment plan was continued for 8 weeks successively and the body weight and fasting blood glucose levels were weekly checked. The biochemical parameters like lipid profile, kidney profile, antioxidant enzyme levels, lipid peroxidation and anti-inflammatory marker levels were investigated after the treatment plant. The pathological condition of kidneys was examined by haematoxylin-eosin (H&E) staining besides this analysis of NF-κB protein expression by immuno-histochemistry was performed. Some of the major parameters in diabetes control vs. normal control were reported as fasting blood glucose (234 ± 10 vs. 102 ± 8 mg/dL), serum creatinine (109.7 ± 7.2 vs. 78.9 ± 4.5 μmol/L) and urea (39.9 ± 1.8 vs. 18.6 mg/dL), lipid profile levels were significantly enhanced in diabetic rats. Moreover, diabetic rats were marked with decreased antioxidant enzyme levels and increased inflammatory markers. Treatment with 6-gingerol significantly restored the fasting blood glucose level, hyperlipidaemia, Malondialdehyde (MDA) and inflammatory marker levels, NF-κB protein expression and augmented the antioxidant enzyme levels in the kidneys of diabetic rats. The kidney damage was significantly normalized by the treatment of 6-gingerol and it provides an evidence that this novel compound plays a significant role in the protection of kidney damage. These findings demonstrate that 6-gingerol reduces lipid parameters, inflammation and oxidative stress in diabetic rats, thereby inhibiting the renal damage. Our results demonstrate that use of 6-gingerol could be a novel therapeutic approach to prevent the kidney damage associated with the diabetes mellitus.

A Song of Ice and Fire: Cold and Hot Properties of Traditional Chinese Medicines

The theory of cold and hot properties is the basic theory of traditional Chinese medicines (TCMs) and has been successfully applied to combat human diseases for thousands of years. Although the theory of cold and hot is very important to guide the clinical application of TCMs, this ancient theory remains an enigma for a long time. In recent years, more and more researchers have tried to uncover this ancient theory with the help of modern techniques, and the cold and hot properties of a myriad of TCMs have been studied. However, there is no review of cold and hot properties. In this review, we first briefly introduced the basic theories about cold and hot properties, including how to distinguish between the cold and hot properties of TCMs and the classification and treatment of cold and hot syndromes. Then, focusing on the application of cold and hot properties, we take several important TCMs with cold or hot property as examples to summarize their traditional usage, phytochemistry, and pharmacology. In addition, the mechanisms of thermogenesis and antipyretic effect of these important TCMs, which are related to the cold and hot properties, were summarized. At the end of this review, the perspectives on research strategies and research directions of hot and cold properties were also offered.

Nutritional implications of ginger: chemistry, biological activities and signaling pathways

Ginger (Zingiber officinale Roscoe) has been used as a food, spice, supplement and flavoring agent and in traditional medicines due to its beneficial characteristics such as pungency, aroma, nutrients and pharmacological activity. Ginger and ginger extracts were reported to have numerous effects, such as those on diabetes and metabolic syndrome, cholesterol levels and lipid metabolism, and inflammation, revealed by epidemiological studies. To understand the beneficial characteristics of ginger, especially its physiological and pharmacological activities at the molecular level, the biological effects of ginger constituents, such as monoterpenes (cineole, citral, limonene and α/β-pinenes), sesquiterpenes (β-elemene, farnesene and zerumbone), phenolics (gingerols, [6]-shogaol, [6]-paradol and zingerone) and diarylheptanoids (curcumin), and the associated signaling pathways are summarized. Ginger constituents are involved in biological activities, such as apoptosis, cell cycle/DNA damage, chromatin/epigenetic regulation, cytoskeletal regulation and adhesion, immunology and inflammation, and neuroscience, and exert their effects through specific signaling pathways associated with cell functions/mechanisms such as autophagy, cellular metabolism, mitogen-activated protein kinase and other signaling, and development/differentiation. Estrogens, such as phytoestrogens, are one of the most important bioactive materials in nature, and the molecular mechanisms of estrogen actions and the assays to detect them have been discussed. The molecular mechanisms of estrogen actions induced by ginger constituents and related applications, such as the chemoprevention of cancers, and the improvement of menopausal syndromes, osteoporosis, endometriosis, prostatic hyperplasia, polycystic ovary syndrome and Alzheimer's disease, were summarized by a comprehensive search of references to understand more about their health benefits and associated health risks.

Olive Leaf Polyphenols (OLPs) Stimulate GLUT4 Expression and Translocation in the Skeletal Muscle of Diabetic Rats

Skeletal muscles are high-insulin tissues responsible for disposing of glucose via the highly regulated process of facilitated glucose transporter 4 (GLUT4). Impaired insulin action in diabetes, as well as disorders of GLUT4 vesicle trafficking in the muscle, are involved in defects in insulin-stimulated GLUT4 translocation. Since the Rab GTPases are the main regulators of vesicular membrane transport in exo- and endo-cytosis, in the present work, we studied the effect of olive leaf polyphenols (OLPs) on Rab8A, Rab13, and Rab14 proteins of the rat soleus muscle in a model of streptozotocin (SZT)-induced diabetes (DM) in a dose-dependent manner. Glucose, cholesterol, and triglyceride levels were determined in the blood, morphological changes of the muscle tissue were captured by hematoxylin and eosin histological staining, and expression of GLUT4, Rab8A, Rab13, and Rab14 proteins were analyzed in the rat soleus muscle by the immunofluorescence staining and immunoblotting. OLPs significantly reduced blood glucose level in all treated groups. Furthermore, significantly reduced blood triglycerides were found in the groups with the lowest and highest OLPs treatment. The dynamics of activation of Rab8A, Rab13, and Rab14 was OLPs dose-dependent and more effective at higher OLP doses. Thus, these results indicate a beneficial role of phenolic compounds from the olive leaf in the regulation of glucose homeostasis in the skeletal muscle.

Ginger Extract Increases GLUT-4 Expression Preferentially Through AMPK Than PI3K Signalling Pathways in C2C12 Muscle Cells

PURPOSE

There are two signal transduction pathways related to glucose metabolism in C2C12 mouse myoblast cells; one through AMP-activated protein kinase (AMPK), and the other through phosphoinositide 3-kinase (PI3K). Ginger is reported to have hypoglycemic effects. The aim of this study was to determine the exact mechanism of action of ginger in those pathways.

METHODS

C2C12 cells were seeded to four separate experimental groups; Control: treated with 50 μg/mL DMSO in the absence of any inhibitor; Treatment 1: treated with 50 μg/mL ethyl acetate ginger extract without any inhibitor; Treatment 2: treated with 50 μg/mL extract in the presence of 20 μM AMPK inhibitor; Treatment 3: treated with 50 μg/mL extract in the presence of 25 μM PI3K inhibitor. The amount of GLUT-4 protein (an important glucose transporter) was determined in cytosolic and membrane fractions using sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blotting.

RESULTS

GLUT-4 concentration was significantly higher in the membrane fraction of cells treated with ethyl acetate ginger extract in the absence of any inhibitor in comparison with cells treated with this extract in the presence of each of the inhibitors (P-value < 0.05). GLUT-4 quantity in the membrane fractions in all groups was more than cytosolic fractions. The amount of GLUT-4 in membrane fraction of treated cells in the presence of PI3K inhibitor was higher than in the cells treated with this extract in the presence of AMPK inhibitor (P-value < 0.05).

CONCLUSION

Ethyl acetate ginger extract affects the amount of GLUT-4 protein in membrane and cytosolic fractions of C2C12 myoblast cells mostly through AMPK pathway but less via PI3K.

Diabetes and plant-derived natural products: From ethnopharmacological approaches to their potential for modern drug discovery and development

Diabetes is a disease of serious concern faced by the health care industry today. Primary diabetes mellitus and its complications are still costly to manage with modern drugs. Extensive research on the screening of anti-diabetic agents in past decades established natural products as one of the major potential sources of drug discovery. However, only a few drugs of plant origin have been scientifically validated. Therefore, the development of new anti-diabetic drugs is of great demand. Hence, natural products could be explored as potential anti-diabetic drugs. Natural plants derived extracts and molecules like berberine, ginsenosides, curcumin, stevioside, gingerols, capsaicin, catechins, simple phenolic compounds, anthocyanins, resveratrol, genistein and hesperidin obtained from different species are used for curing diabetes and found to possess different action mechanisms. In this review, the importance of medicinal plants and their active constituents for anti-diabetic agents are described. The present study also emphasized the importance of diabetes control, reduction in its complications and use of the anti-diabetic agents. The detailed action mechanism of these extracts/compounds for their activities are also described. However, the anti-diabetic drugs from plant origin require scientific validation through animal and clinical studies to exploit in terms of modern commercial medicines.

Steamed Ginger May Enhance Insulin Secretion through KATP Channel Closure in Pancreatic β-Cells Potentially by Increasing 1-Dehydro-6-Gingerdione Content

Ginger (Zingiber officinale Roscoe) and its active compounds (gingerols, shogaols and paradols) have been reported as having beneficial functions for several diseases, including diabetes. In this study, we revealed that the steaming process could enhance the anti-diabetic potential of ginger. To confirm the anti-diabetic effect of steamed ginger extract (GG03), we assessed pancreatic islets impaired by alloxan in zebrafish and demonstrated anti-hyperglycemic efficacy in a mouse model. The EC50 values of ginger extract (GE) and GG03 showed that the efficacy of GG03 was greater than that of GE. In addition, LC50 values demonstrated that GG03 had lower toxicity than GE, and the comparison of the Therapeutic Index (TI) proved that GG03 is a safer functional food. Furthermore, our data showed that GG03 significantly lowered hyperglycemia in a diabetic mouse model. HPLC was performed to confirm the change in the composition of steamed ginger. Interestingly, GG03 showed a 375% increase in 1-dehydro-6-gingerdione (GD) compared with GE. GD has not yet been studied much pharmacologically. Thus, we identified the protective effects of GD in the damaged pancreatic islets of diabetic zebrafish. We further assessed whether the anti-diabetic mechanism of action of GG03 and GD involves insulin secretion. Our results suggest that GG03 and GD might stimulate insulin secretion by the closure of KATP channels in pancreatic β-cells.