Mechanisms for antidiabetic effect of gingerol in cultured cells and obese diabetic model mice

Ginger Supplementation Attenuated Mitochondrial Fusion and Improved Skeletal Muscle Size in Type 2 Diabetic Rats

BACKGROUND/AIM

Oxidative stress, regulated by SOD2 and mitochondrial dynamics, contributes to muscle atrophy in diabetes. Ginger root extract (GRE) reduces oxidative stress. However, its effect on oxidative stress, mitochondrial dynamics, and muscle atrophy is not known in the diabetic muscle. This study examined the effect of GRE on intramuscular oxidative stress, mitochondrial dynamics, and muscle size in diabetic rats.

MATERIALS AND METHODS

Twenty-six male Sprague-Dawley rats were randomly divided into control diet (CON; n=10), high-fat diet with one dose of 35 mg/kg streptozotocin (HFD; n=9), and high-fat diet with one dose of 35 mg/kg streptozotocin and 0.75% w/w GRE (GRE; n=7) fed for seven weeks. Subsequently, the muscle was analyzed for cross-sectional area (CSA), H2O2 concentration, and DRP-1, MFN2, Parkin, PINK1, SOD2 mRNA. Additionally, the protein levels of SOD2, DRP-1, DRP-1ser616, LC3AB, MFN2, OPA1, Parkin, and PINK1 were analyzed. CSA, H2O2 concentration, and gene and protein expression levels were analyzed using a one-way ANOVA. Correlations among intramuscular H2O2, CSA, and SOD2 protein were assessed using Pearson's bivariate correlation test.

RESULTS

In the soleus, the GRE group had a greater CSA and lower intramuscular H2O2 concentration compared to the HFD group. Compared to the HFD group, the GRE group had higher SOD2 and DRP-1 mRNA levels and lower MFN2 and total OPA1 protein levels. H2O2 concentration was negatively correlated with CSA and positively correlated with SOD2.

CONCLUSION

GRE attenuated intramuscular H2O2, mitochondrial fusion, and muscle size loss. These findings suggest that GRE supplementation in diabetic rats reduces oxidative stress, which may contribute to muscle size preservation.

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.

Plant-Derived Nutraceuticals Involved in Body Weight Control by Modulating Gene Expression

Obesity is the most prevalent health problem in the Western world, with pathological body weight gain associated with numerous co-morbidities that can be the main cause of death. There are several factors that can contribute to the development of obesity, such as diet, sedentary lifestyle, and genetic make-up. Genetic predispositions play an important role in obesity, but genetic variations alone cannot fully explain the explosion of obesity, which is why studies have turned to epigenetics. The latest scientific evidence suggests that both genetics and environmental factors contribute to the rise in obesity. Certain variables, such as diet and exercise, have the ability to alter gene expression without affecting the DNA sequence, a phenomenon known as epigenetics. Epigenetic changes are reversible, and reversibility makes these changes attractive targets for therapeutic interventions. While anti-obesity drugs have been proposed to this end in recent decades, their numerous side effects make them not very attractive. On the other hand, the use of nutraceuticals for weight loss is increasing, and studies have shown that some of these products, such as resveratrol, curcumin, epigallocatechin-3-gallate, ginger, capsaicin, and caffeine, can alter gene expression, restoring the normal epigenetic profile and aiding weight loss.

Molecular structures, chemical descriptors, and pancreatic lipase (1LPB) inhibition by natural products: a DFT investigation and molecular docking prediction

Density functional theory (DFT) calculations and molecular docking have been carried out on natural products containing eugenol, gingerol, ascorbic acid, oleurpoein, piperine, hesperidin, quercetin, Luteolin, and curcumin in order to predict their biological activities and to analyze their pancreatic lipase inhibition. The biological activity predictions are based on the global and local chemical descriptors, namely, HOMO-LUMO gaps, chemical hardness, chemical potential, electrophilicity, dipole moment, and Fukui functions. Our findings show that the studied compounds can be divided into two groups based on the chemical descriptors; the first group is composed of eugenol, gingerol, ascorbic acid, and oleuropein and the second one is composed of piperine, hesperidin, quercetin, Luteolin, and curcumin depending on the HOMO-LUMO gaps and electrophilicity values predicting best reactivity for the second group than the first one. The frontier orbitals offer a deeper insight concerning the electron donor and electron acceptor capabilities, whereas the local descriptors resulting from Fukui functions put emphasis on the active sites of different candidate ligands. The molecular docking was performed in order to compare and identify the inhibition activity of the natural candidate ligands against pancreatic lipase which were compared to that of synthesized ones. The molecular docking results revealed that the Luteolin compound has the best binding affinity of -8.56 kcal/mol due to their unique molecular structure and the position of -OH aromatic substituents.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11224-023-02176-2.

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.

A systematic analysis of anti-diabetic medicinal plants from cells to clinical trials

Background

Diabetes is one of the fastest-growing health emergencies of the 21st century, placing a severe economic burden on many countries. Current management approaches have improved diabetic care, but several limitations still exist, such as decreased efficacy, adverse effects, and the high cost of treatment, particularly for developing nations. There is, therefore, a need for more cost-effective therapies for diabetes management. The evidence-based application of phytochemicals from plants in the management of diseases is gaining traction.

Methodology

Various plants and plant parts have been investigated as antidiabetic agents. This review sought to collate and discuss published data on the cellular and molecular effects of medicinal plants and phytochemicals on insulin signaling pathways to better understand the current trend in using plant products in the management of diabetes. Furthermore, we explored available information on medicinal plants that consistently produced hypoglycemic effects from isolated cells to animal studies and clinical trials.

Results

There is substantial literature describing the effects of a range of plant extracts on insulin action and insulin signaling, revealing a depth in knowledge of molecular detail. Our exploration also reveals effective antidiabetic actions in animal studies, and clear translational potential evidenced by clinical trials.

Conclusion

We suggest that this area of research should be further exploited in the search for novel therapeutics for diabetes.

Renoprotective effects of the ginger (Zingiber officinale) on Diabetic kidney disease, current knowledge and future direction: a systematic review of animal studies

OBJECTIVE

Diabetic kidney disease affects approximately 40% of diabetic patients and is the leading cause of chronic kidney disease (CKD) worldwide. As a result, preventing renal complications in diabetic patients is critical. Ginger (Zingiber Officinale Rosco) is a popular spice and natral medicine. The present study was a systematic review focused on the existing evidence of the renoprotective effect of ginger extract on some features of diabetic kidney disease.

METHODS

The literature was searched in online databases such as PubMed, Scopus, EMBASE, ProQuest databases, and Google Scholar from inception to July 2022.

RESULTS

This review included 41 articles that met the eligibility criteria. Ginger supplementation was found to be associated with a significant decrease in blood glucose in 28 studies. Nine studies showed a significant reduction in malondialdehyde (MDA) after supplementation. Also, seventeen studies showed decreased serum levels of creatinine. Fifteen studies reported a decrease in total cholesterol (TC) and fourteen studies showed a lowered triglycerides (TG) concentrations. In twenty-six studies, ginger reduced renal injuries due to diabetes.

CONCLUSION

Ginger may improve blood sugar indices, lipid profile, some inflammatory markers, oxidative stress, and pathologic injuries in diabetic kidney disease. However, future well-designed clinical trials and meta-analyses are required for a solid consensus.

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.

Pharmacologically Active Phytomolecules Isolated from Traditional Antidiabetic Plants and Their Therapeutic Role for the Management of Diabetes Mellitus

Diabetes mellitus is a chronic complication that affects people of all ages. The increased prevalence of diabetes worldwide has led to the development of several synthetic drugs to tackle this health problem. Such drugs, although effective as antihyperglycemic agents, are accompanied by various side effects, costly, and inaccessible to the majority of people living in underdeveloped countries. Medicinal plants have been used traditionally throughout the ages to treat various ailments due to their availability and safe nature. Medicinal plants are a rich source of phytochemicals that possess several health benefits. As diabetes continues to become prevalent, health care practitioners are considering plant-based medicines as a potential source of antidiabetic drugs due to their high potency and fewer side effects. To better understand the mechanism of action of medicinal plants, their active phytoconstituents are being isolated and investigated thoroughly. In this review article, we have focused on pharmacologically active phytomolecules isolated from medicinal plants presenting antidiabetic activity and the role they play in the treatment and management of diabetes. These natural compounds may represent as good candidates for a novel therapeutic approach and/or effective and alternative therapies for diabetes.

Serum untargeted metabolomics analysis of the mechanisms of evodiamine on type 2 diabetes mellitus model rats

Evodiamine (EVO) is an alkaloid extracted from Evodia rutaecarpa and has various pharmacological activities, including hypolipidemic, anti-inflammatory, anti-infective, and antitumor effects. However, the therapeutic effects of EVO on type 2 diabetes mellitus (T2DM) and the possible mechanisms remain unknown. In this study, we used a T2DM rat model using a high-fat diet (HFD) combined with streptozotocin (STZ) injections followed by treatment with EVO. First, we evaluated the therapeutic effects of EVO on T2DM rats, following which we evaluated the anti-inflammatory and anti-oxidative effects of EVO on T2DM rats. Finally, we analyzed the metabolic regulatory mechanism of EVO in T2DM rats using an untargeted metabolomics approach. The results showed that EVO treatment alleviated the hyperglycemia, hyperlipidemia, insulin resistance (IR), and pathological changes of the liver, pancreas and kidneys in T2DM rats. Moreover, EVO treatment ameliorated the oxidative stress and decreased the serum levels of pro-inflammatory cytokines in T2DM model rats. Serum untargeted metabolomics analysis indicated that the EVO treatment affected the levels of 26 metabolites, such as methionine, citric acid, cholesterol, taurocholic acid, pilocarpine, adrenic acid, and other metabolites. These metabolites were mainly related to the amino sugar and nucleotide sugar metabolism, arginine biosynthesis, arginine and proline metabolism, glutathione metabolism, and tryptophan metabolism pathways. In conclusion, EVO can reduce blood glucose and improve oxidative stress and inflammatory response in T2DM rats. These functions are related to the regulation of amino sugar and nucleotide sugar metabolism, arginine biosynthesis, arginine and proline metabolism, glutathione metabolism, and tryptophan metabolism pathways.

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.

In vitro and in vivo therapeutic potentials of 6-gingerol in combination with amphotericin B for treatment of Leishmania major infection: Powerful synergistic and multifunctional effects

The ongoing conventional drugs for leishmaniasis treatment are insufficient. The present study aimed to assess 6-gingerol alone and in combination with amphotericin B on Leishmania major stages using experimental and in vivo murine models. Here, arrays of experimental approaches were designed to monitor and evaluate the 6-gingerol potential therapeutic outcomes. The binding affinity of 6-gingerol and IFN-γ was the basis for docking conformations. 6-Gingerol combined with amphotericin B represented a safe mixture, extremely leishmanicidal, a potent antioxidant, induced a remarkable apoptotic index, significantly increased the expression of the Th1-related cytokines (IL-12p40, IFN-γ, and TNF- α), iNOS, and transcription factors (STAT1, c-Fos, and Elk-1). In contrast, the expression of the Th2-related cytokines was significantly downregulated (p < 0.001). This combination was also potent when the lesion appearance was evaluated following three weeks of treatment. The histopathological and immunohistochemical patterns of the murine model represented clusters of CD4+ and CD8+ T lymphocytes which compressed and deteriorated the macrophages harboring Leishman bodies. The primary mode of action of 6-gingerol and amphotericin B involved broad mechanistic insights providing a coherent basis for further clinical study as a potential drug candidate for CL. In conclusion, 6-gingerol with amphotericin B synergistically exerted anti-leishmanial activity in vitro and in vivo and potentiated macrophages' leishmanicidal activity, modulated Th1- and Th2-related phenotypes improved the histopathological changes in the BALB/c mice infected with L. major. They elevated the leukocyte infiltration into the lesions. Therefore, this combination should be considered for treating volunteer patients with CL in clinical studies.

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.

Hyperglycemia-induced oxidative stress in isolated proximal tubules of mouse: the in vitro effects of myricitrin and its solid lipid nanoparticle

CONTEXT

The hyperglycemia (Hyper) induces oxidative stress in kidney tubular cells. Myricitrin (Myr) has an antioxidant effect along with low bioavailability.

OBJECTIVE

The present research investigated the effects of Myr and its solid lipid nanoparticles (SLN) on isolated proximal tubules exposed to the hyperglycemic condition.

MATERIALS AND METHODS

In this experimental study, the proximal tubules of mice were dissected by the microdissection method and the tubules were prepared for experimental or Real Time-PCR measurement.

RESULTS

The malondialdehyde level, transforming growth factor-β, nuclear factor kappa B and Bax genes expression increased in Hyper and decreased in Hyper + Myr and its SLN-treated groups compared to Hyper. Superoxide dismutase, total antioxidant capacity, the viability of proximal tubules and Bcl-2 gene expression decreased in untreated Hyper and increased in all treatment groups compared to Hyper.

CONCLUSION

The hyperglycemia-induced oxidative disorder, inflammation and apoptosis in proximal tubules and that administrating Myr and its SLN improved them.

Effect of traditional Chinese medicine on gut microbiota in adults with type 2 diabetes: A systematic review and meta-analysis

BACKGROUND

Despite advances in research on type 2 diabetes mellitus (T2DM) with the development of science and technology, the pathogenesis and treatment response of T2DM remain unclear. Recent studies have revealed a significant role of the microbiomein the development of T2DM, and studies have found that the gut microbiota may explain the therapeutic effect of traditional Chinese medicine (TCM), a primary branch of alternative and complementary medicine, in the treatment of T2DM. The aim of this study was to systematically review all randomized controlled trials (RCTs) on TCM for gut microbiota to assess the effectiveness and safety of TCM in T2DM patients.

METHODS

All RCTs investigating the effects of TCM interventions on modulating gut microbiota and improving glucose metabolism in the treatment of T2DM adults were included. Meta-analyses were conducted when sufficient data were available, other results were reported narratively. The study protocol was pre-specified, documented, and published in PROSPERO (registration no. CRD42020188043).

RESULTS

Five studies met the eligibility criteria ofthe systematic review. All five studies reported the effects of TCM interventions on the gut microbiota modulation and blood glucose control. There were statistically significant improvements in HbA1c (mean difference [MD]: -0.69%; [95% CI -0.24, -0.14]; p = 0.01, I² = 86%), fasting blood glucose (MD: -0.87 mmol/l; [95% CI -1.26, -0.49]; p < 0.00001, I² = 75%) and 2-h postprandial blood glucose(MD: -0.83mmol/l; [95% CI: -1.01, -0.65]; p < 0.00001, I² = 0%). In addition, there were also statistically significant improvements in homeostasis model assessment of insulin resistance (HOMA-IR) (standardized mean difference [SMD]: -0.99, [95% CI -1.25 to -0.73]; p < 0.00001, I² = 0%) and homeostasis model assessment of β-cell function (HOMA-β) (SMD: 0.54, [95% CI 0.21 to 0.87]; p = 0.001, I² = 0%).There was a significant change in the relative abundance of bacteria in the genera Bacteroides (standardized mean difference [SMD] 0.87%; [95% CI 0.58, 1.16], however, the change in Enterococcus abundance was not statistically significant (SMD: -1.71%; [95% CI: -3.64, 0.23]; p = 0.08) when comparing TCM supplementaltreatment with comparator groups. Other changes in the gut microbiota, including changes in the relative abundances of some probiotics and opportunistic pathogens at various taxon levels, and changes in diversity matrices (α and β), were significant by narrative analysis. However, insufficient evidences were found to support that TCM intervention had an effect on inflammation.

CONCLUSION

TCM had the effect of modulating gut microbiota and improving glucose metabolisms in T2DM patients. Although the results of the included studies are encouraging, further well-conducted studies on TCM interventions targeting the gut microbiota are needed.

14-Deoxy-11,12-Didehydroandrographolide Ameliorates Glucose Intolerance Enhancing the LKB1/AMPK[Formula: see text]/TBC1D1/GLUT4 Signaling Pathway and Inducing GLUT4 Expression in Myotubes and Skeletal Muscle of Obese Mice

14-Deoxy-11,12-didehydroandrographolide (deAND), a bioactive component of Andrographis paniculata, has antidiabetic activity. AMP-activated protein kinase (AMPK) regulates glucose transport and ameliorates insulin resistance. The aim of the present study was to investigate whether activation of AMPK is involved in the mechanism by which deAND ameliorates insulin resistance in muscles. deAND amounts up to 40 [Formula: see text]M dose-dependently activated phosphorylation of AMPK[Formula: see text] and TBC1D1 in C2C12 myotubes. In addition, deAND significantly activated phosphorylation of LKB1 at 6 h after treatment, and this activation was maintained up to 48 h. deAND increased glucose uptake at 18 h after treatment, and this increase was time dependent up to 72 h. Compound C, an inhibitor of AMPK, suppressed deAND-induced phosphorylation of AMPK[Formula: see text] and TBC1D1 and reversed the effect on glucose uptake. In addition, the expression of GLUT4 mRNA and protein in C2C12 myotubes was up-regulated by deAND in a time-dependent manner. Promotion of GLUT4 gene transcription was verified by a pGL3-GLUT4 (837 bp) reporter assay. deAND also increased the nuclear translocation of MEF-2A and PPAR[Formula: see text]. After 16 weeks of feeding, the high-fat diet (HFD) inhibited phosphorylation of AMPK[Formula: see text] and TBC1D1 in skeletal muscle of obese C57BL/6JNarl mice, and deactivation of AMPK[Formula: see text] and TBC1D1 by the HFD was abolished by deAND supplementation. Supplementation with deAND significantly promoted membrane translocation of GLUT4 compared with the HFD group. Supplementation also significantly increased GLUT4 mRNA and protein expression in skeletal muscle compared with the HFD group. The hypoglycemic effects of deAND are likely associated with activation of the LKB1/AMPK[Formula: see text]/TBC1D1/GLUT4 signaling pathway and stimulation of MEF-2A- and PPAR[Formula: see text]-dependent GLUT4 gene expression, which account for the glucose uptake into skeletal muscle and lower blood glucose levels.

The protective effects of steamed ginger on adipogenesis in 3T3-L1 cells and adiposity in diet-induced obese mice

BACKGROUND/OBJECTIVES

The steamed ginger has been shown to have antioxidative effects and a protective effect against obesity. In the present study, we investigated the effects of ethanolic extract of steamed ginger (SGE) on adipogenesis in 3T3-L1 preadipocytes and diet-induced obesity (DIO) mouse model.

MATERIALS/METHODS

The protective effects of SGE on adipogenesis were examined in 3T3-L1 adipocytes by measuring lipid accumulations and genes involved in adipogenesis. Male C57BL/6J mice were fed a normal diet (ND, 10% fat w/w), a high-fat diet (HFD, 60% fat w/w), and HFD supplemented with either 40 mg/kg or 80 mg/kg of SGE for 12 weeks. Serum chemistry was measured, and the expression of genes involved in lipid metabolism was determined in the adipose tissue. Histological analysis and micro-computed tomography were performed to identify lipid accumulations in epididymal fat pads.

RESULTS

In 3T3-L1 cells, SGE significantly decreased lipid accumulation, with concomitant decreases in the expression of adipogenesis-related genes. SGE significantly attenuated the increase in body, liver, and epididymal adipose tissue weights by HFD. Serum total cholesterol and triglyceride levels were significantly lower in SGE fed groups compared to HFD. In adipose tissue, SGE significantly decreased adipocyte size than that of HFD and altered adipogenesis-related genes.

CONCLUSIONS

In conclusion, steamed ginger exerted anti-obesity effects by regulating genes involved in adipogenesis and lipogenesis in 3T3-L1 cell and epididymal adipose tissue of DIO mice.

Qualitative analysis on chemical constituents from different polarity extracted fractions of the pulp and peel of ginger rhizomes by ultra-high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry

RATIONALE

Ginger pulp is the dried rhizome scraped off the skin which originates from Zingiber officinale Rosc., a Zingiberaceae plant. Ginger peel is the dried rhizome skin of Zingiber officinale Rosc. (Zingiberaceae). The present work aims to investigate the different chemical constituents that are related to the medicinal properties of the ginger pulp and ginger peel.

METHODS

A rapid ultra-high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC/ESI-QTOF/MS) method was developed for qualitative analysis of the constituents in different polarity extracted fractions of the pulp and peel of ginger rhizomes.

RESULTS

A total of 83 compounds were identified from the pulp and peel of ginger rhizomes, including 36 diarylheptanoids, 25 gingerols and 22 other compounds. Nine of these were new compounds. In total, 46, 27, 65 and 51 compounds were identified from the crude extract, petroleum ether, ethyl acetate, and n-butanol fractions of the ginger pulp, respectively, and 60, 30, 70 and 62 compounds were identified from the crude extract, petroleum ether, ethyl acetate, n-butanol fractions of the ginger peel, respectively. Each identified compound is marked on the corresponding chromatogram.

CONCLUSIONS

The integrated method is sensitive and reliable for searching the different chemical constituents from different polarity extracted fractions of the ginger pulp and ginger peel. This work may provide a significant contribution to research into the medicinal properties of the ginger pulp and ginger peel.

A recent update on the multifaceted health benefits associated with ginger and its bioactive components

Due to recent lifestyle shifts and health discernments among consumers, synthetic drugs are facing the challenge of controlling disease development and progression. Various medicinal plants and their constituents are recognized for their imminent role in disease management via modulation of biological activities. At present, research scholars have diverted their attention on natural bioactive entities with health-boosting perception to combat the lifestyle-related disarrays. In particular, Zingiber officinale is a medicinal herb that has been commonly used in food and pharmaceutical products. Its detailed chemical composition and high value-added active components have been extensively studied. In this review, we have summarized the pharmacological potential of this well-endowed chemo preventive agent. It was revealed that its functionalities are attributed to several inherent chemical constituents, including 6-gingerol, 8-gingerol, 10-gingerol, 6-shogaol, 6-hydroshogaol, and oleoresin, which were established through many studies (in vitro, in vivo, and cell lines). In this review, we also focused on the therapeutic effects of ginger and its constituents for their effective antioxidant properties. Their consumption may reduce or delay the progression of related diseases, such as cancer, diabetes, and obesity, via modulation of genetic and metabolic activities. The updated data could elucidate the relationship of the extraction processes with the constituents and biological manifestations. We have collated the current knowledge (including the latest clinical data) about the bioactive compounds and bioactivities of ginger. Their detailed mechanisms, which can lay foundation for their food and medical applications are also discussed.

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.

Ginger and avocado as nutraceuticals for obesity and its comorbidities

Obesity is a worldwide epidemic and is one of the factors involved in the etiology of type 2 diabetes mellitus. Obesity induces low-grade inflammation and oxidative stress. The treatment for obesity involves changes in diet, physical activity, and even medication and surgery. Currently, the use of nutraceutical compounds is associated with health benefits. Ginger and avocado are used for many people all around the world; however, its effect as a nutraceutical compound is less known by the general population. For this reason, we searched information of the literature to point its effects on distinct mechanisms of defense against the obesity its comorbidities. The present review aimed showing that these nutraceuticals may be useful in obesity treatment. Reports have shown that ginger and avocado induce antioxidant and anti-inflammatory effects by improving enzymatic activity and modulating obesity-related impairments in the anti-inflammatory system in different tissues, without side effects. Furthermore, ginger and avocado were found to be effective in reversing the harmful effects of obesity on blood lipids. In conclusion, on the basis of the positive effects of ginger and avocado in in vitro, animal, and human studies, these nutraceuticals may be useful in obesity treatment.

Evaluation of the Anti-Diabetic Activity of Some Common Herbs and Spices: Providing New Insights with Inverse Virtual Screening

Culinary herbs and spices are widely used as a traditional medicine in the treatment of diabetes and its complications, and there are several scientific studies in the literature supporting the use of these medicinal plants. However, there is often a lack of knowledge on the bioactive compounds of these herbs and spices and their mechanisms of action. The aim of this study was to use inverse virtual screening to provide insights into the bioactive compounds of common herbs and spices, and their potential molecular mechanisms of action in the treatment of diabetes. In this study, a library of over 2300 compounds derived from 30 common herbs and spices were screened in silico with the DIA-DB web server against 18 known diabetes drug targets. Over 900 compounds from the herbs and spices library were observed to have potential anti-diabetic activity and liquorice, hops, fennel, rosemary, and fenugreek were observed to be particularly enriched with potential anti-diabetic compounds. A large percentage of the compounds were observed to be potential polypharmacological agents regulating three or more anti-diabetic drug targets and included compounds such as achillin B from yarrow, asparasaponin I from fenugreek, bisdemethoxycurcumin from turmeric, carlinoside from lemongrass, cinnamtannin B1 from cinnamon, crocin from saffron and glabridin from liquorice. The major targets identified for the herbs and spices compounds were dipeptidyl peptidase-4 (DPP4), intestinal maltase-glucoamylase (MGAM), liver receptor homolog-1 (NR5A2), pancreatic alpha-amylase (AM2A), peroxisome proliferator-activated receptor alpha (PPARA), protein tyrosine phosphatase non-receptor type 9 (PTPN9), and retinol binding protein-4 (RBP4) with over 250 compounds observed to be potential inhibitors of these particular protein targets. Only bay leaves, liquorice and thyme were found to contain compounds that could potentially regulate all 18 protein targets followed by black pepper, cumin, dill, hops and marjoram with 17 protein targets. In most cases more than one compound within a given plant could potentially regulate a particular protein target. It was observed that through this multi-compound-multi target regulation of these specific protein targets that the major anti-diabetic effects of reduced hyperglycemia and hyperlipidemia of the herbs and spices could be explained. The results of this study, taken together with the known scientific literature, indicated that the anti-diabetic potential of common culinary herbs and spices was the result of the collective action of more than one bioactive compound regulating and restoring several dysregulated and interconnected diabetic biological processes.

Polyphenols targeting diabetes via the AMP-activated protein kinase pathway; future approach to drug discovery

Regarding the widespread progression of diabetes, its related complications and detrimental effects on human health, investigations on this subject seems compulsory. AMP-activated protein kinase (AMPK) is a serine/threonine kinase and a key player in energy metabolism regulation. AMPK is also considered as a prime target for pharmaceutical and therapeutic studies on disorders such as diabetes, metabolic syndrome and obesity, where the body energy homeostasis is imbalanced. Following the activation of AMPK (physiological or pharmacological), a cascade of metabolic events that improve metabolic health is triggered. While there are several publications on this subject, this is the first report that has focused solely on polyphenols targeting diabetes via AMPK pathway. The multiple characteristics of polyphenolic compounds and their favorable influence on diabetes pathogenesis, as well as their intersections with the AMPK signaling pathway, indicate that these compounds have a beneficial effect on the regulation of glucose homeostasis. PPs could potentially occupy a significant position in the future anti-diabetic drug market.

Molecular Changes in Diabetic Wound Healing following Administration of Vitamin D and Ginger Supplements: Biochemical and Molecular Experimental Study

BACKGROUND

Circulating micro-RNAs are differentially expressed in various tissues and could be considered as potential regulatory biomarkers for T2DM and related complications, such as chronic wounds.

AIM

In the current study, we investigated whether ginger extract enriched with [6]-gingerol-fractions either alone or in combination with vitamin D accelerates diabetic wound healing and explores underlying molecular changes in the expression of miRNA and their predicted role in diabetic wound healing.

METHODS

Diabetic wounded mice were treated with [6]-gingerol-fractions (GF) (25 mg/kg of body weight) either alone or in combination with vitamin D (100 ng/kg per day) for two weeks. Circulating miRNA profile, fibrogenesis markers, hydroxyproline (HPX), fibronectin (FN), and collagen deposition, diabetic control variables, FBS, HbA1c, C-peptide, and insulin, and wound closure rate and histomorphometric analyses were, respectively, measured at days 3, 6, 9, and 15 by RT-PCR and immunoassay analysis.

RESULTS

Treatment of diabetic wounds with GF and vitamin D showed significant improvement in wound healing as measured by higher expression levels of HPX, FN, collagen, accelerated wound closure, complete epithelialization, and scar formation in short periods (11-13 days, (P < 0.01). On a molecular level, three circulating miRNAs, miR-155, miR-146a, and miR-15a, were identified in diabetic and nondiabetic skin wounds by PCR analysis. Lower expression in miR-155 levels and higher expression of miR-146a and miR-15a levels were observed in diabetic skin wounds following treatment with gingerols fractions and vitamin D for 15 days. The data showed that miRNAs, miR-146a, miR-155, and miR-15a, correlated positively with the expression levels of HPX, FN, and collagen and negatively with FBS, HbA1c, C-peptide, and insulin in diabetic wounds following treatment with GF and /or vitamin D, respectively.

CONCLUSION

Treatment with gingerols fractions (GF) and vitamin D for two weeks significantly improves delayed diabetic wound healing. The data showed that vitamin D and gingerol activate vascularization, fibrin deposition (HPX, FN, and collagen), and myofibroblasts in such manner to synthesize new tissues and help in the scar formation. Accordingly, three miRNAs, miR-155, miR-146a, and miR-15, as molecular targets, were identified and significantly evaluated in wound healing process. It showed significant association with fibrin deposition, vascularization, and reepithelialization process following treatment with GF and vitamin D. It proposed having anti-inflammatory action and promoting new tissue formation via vascularization process during the wound healing. Therefore, it is very interesting to consider miRNAs as molecular targets for evaluating the efficiency of nondrug therapy in the regulation of wound healing process.

Phytomedicines Used for Diabetes Mellitus in Ghana: A Systematic Search and Review of Preclinical and Clinical Evidence

Background

Available data indicate that diabetes mellitus leads to elevated cost of healthcare. This imposes a huge economic burden on households, societies, and nations. As a result many Ghanaians, especially rural folks, resort to the use of phytomedicine, which is relatively less expensive. This paper aims at obtaining information on plants used in Ghana to treat diabetes mellitus, gather and present evidence-based data available to support their uses and their mechanisms of action, and identify areas for future research.

Method

A catalogue of published textbooks, monographs, theses, and peer-reviewed articles of plants used in Ghanaian traditional medicine between 1987 and July 2018 for managing diabetes mellitus was obtained and used.

Results

The review identified 76 plant species belonging to 45 families that are used to manage diabetes mellitus. Leaves were the part of the plants frequently used for most preparation (63.8%) and were mostly used as decoctions. Majority of the plants belonged to the Euphorbiaceae, Lamiaceae, Asteraceae, and Apocynaceae families. Pharmacological data were available on 23 species that have undergone in vitro studies. Forty species have been studied using in vivo animal models. Only twelve plants and their bioactive compounds were found with data on both preclinical and clinical studies. The records further indicate that medicinal plants showing antidiabetic effects did so via biochemical mechanisms such as restitution of pancreatic β-cell function, improvement in insulin sensitivity by receptors, stimulating rate of insulin secretion, inhibition of liver gluconeogenesis, enhanced glucose absorption, and inhibition of G-6-Pase, α-amylase, and α-glucosidase activities.

Conclusion

This review contains information on medicinal plants used to manage diabetes mellitus, including their pharmacological properties and mechanisms of action as well as models used to investigate them. It also provides gaps that can form the basis for further investigations and development into useful medications for effective treatment of diabetes mellitus.

Oil tea improves glucose and lipid levels and alters gut microbiota in type 2 diabetic mice

Oil tea has traditionally been used in minority populations in China for treating various ailments in traditional Chinese medicine. Individually, green tea and ginger, which are the main ingredients of oil tea, have demonstrated antidiabetic effects; however, whether oil tea exerts antidiabetic effects remains unknown. In addition, aberrant gut microbiota structure is associated with diabetic status, and research indicates that there may be beneficial effects of tea on gut microbiota. Therefore, we hypothesized that oil tea exerts antidiabetic effects and induces alteration in gut microbiota. To test our hypothesis, we first examined the nutrition composition of oil tea. Then, db/db mice were randomly divided into 3 groups and orally gavaged with saline, metformin, and oil tea for 8 weeks. Fasting blood glucose (FBG), oral glucose tolerance test (OGTT), and lipid levels were tested during the experiment. 16S rRNA genes were sequenced and changes in gut microbiota in response pre/post treatment were examined. Our experiments showed that oil tea contains high concentrations of tea polyphenols (246.35 mg/100 g) and [6]-gingerol (2.98 mg/100 g). It appeared that oil tea treatment significantly suppressed the postprandial blood glucose elevation and lowered the levels of FBG, total cholesterol, triglycerides, and LDL-cholesterol (P < .05). The composition of gut microbiota changed significantly in response to oil tea treatment, Lachnospiraceae were significantly enriched (q < 0.05, LDA score> 3.5). Redundancy analysis identified 155 oil tea-modulating family level phylotypes, where Lachnospiraceae significantly correlated with FBG, total cholesterol, and LDL-cholesterol (P < .05). Our findings demonstrate that oil tea improved glucose and lipid levels and modulated gut microbiota in db/db mice.

Spice-Derived Bioactive Ingredients: Potential Agents or Food Adjuvant in the Management of Diabetes Mellitus

Spices possess tremendous therapeutic potential including hypoglycemic action, attributed to their bioactive ingredients. However, there is no study that critically reviewed the hypoglycemic potency, safety and the bioavailability of the spice-derived bioactive ingredients (SDBI). Therefore, the aim of the study was to comprehensively review all published studies regarding the hypoglycemic action of SDBI with the purpose to assess whether the ingredients are potential hypoglycemic agents or adjuvant. Factors considered were concentration/dosages used, the extent of blood glucose reduction, the IC50 values, and the safety concern of the SDBI. From the results, cinnamaldehyde, curcumin, diosgenin, thymoquinone (TQ), and trigonelline were showed the most promising effects and hold future potential as hypoglycemic agents. Conclusively, future studies should focus on improving the tissue and cellular bioavailability of the promising SDBI to achieve greater potency. Additionally, clinical trials and toxicity studies are with these SDBI are warranted.

Probing the interaction of the phytochemical 6-gingerol from the spice ginger with DNA

6-Gingerol [5-hydroxy-1-(4-hydroxy-3-methoxyphenyl) decan-3-one], the bio-active ingredient of the popular Indian spice ginger (Zingiber officinale Roscoe), is well-known for its pharmacological and physiological actions. The potent antioxidant, antiemetic, antiulcer, antimicrobial, analgesic, hypoglycemic, antihypertensive, antihyperlipidemic, immunostimulant, anti-inflammatory, cardiotonic, and cancer prevention activities of 6-Gingerol has been investigated and explored. 6-Gingerol is a good candidate for the treatment of various cancers including prostrate, pancreatic, breast, skin, gastrointestinal, pulmonary, and renal cancer. In this study we report for the first time the molecular recognition of 6-Gingerol with calf thymus DNA (ctDNA) through experimental and molecular modeling techniques confirming a minor groove binding mode of 6-Gingerol with ctDNA. Fluorescence and UV-vis spectroscopic studies confirm the complex formation of 6-gingerol with ctDNA. The energetics and thermodynamics of the interaction of 6-Gingerol with ctDNA was explored by Isothermal Titration Calorimetry (ITC) and Differential Scanning Calorimetry (DSC). The ctDNA helix melting upon 6-Gingerol binding was examined by melting temperature Tm analysis. Further the electrophoretic mobility shift assay confirms a possible groove binding of 6-Gingerol with ctDNA. Molecular docking and Molecular dynamics (MD) studies provide a detailed understanding on the interaction of 6-Gingerol binding in the minor groove of DNA which supports experimental results.

Antioxidant effect of myricitrin on hyperglycemia-induced oxidative stress in C2C12 cell

Hyperglycemia induced oxidative stress inside the cells. Myricitrin, as an antioxidant plant-derived component, may be useful in hyperglycemia. Hence, the aim of this study was conducted to evaluate the antioxidant effects of myricitrin on hyperglycemia-induced oxidative damage in myotubes (C2C12 cells). In this experimental study, mouse myoblast cell line (C2C12) was obtained and divided into five groups: control, hyperglycemia, hyperglycemia + myricitrin 1, 3, and 10 μM. After treatment period for 48 h, cells were collected, homogenized, and centrifuged at 2000 rpm for 10 min. All samples were kept at - 80 °C until experimental and real-time PCR assessments were performed. Hyperglycemia increased malondialdehyde (MDA) (p < 0.05), total antioxidant capacity (TAC) (p < 0.001), and cellular apoptosis, and decreased levels of superoxide dismutase (SOD), catalase (CAT) (p < 0.01), myotube glycogen content (p < 0.05), glucose transporter type 4 (Glut-4), and cellular viability (p < 0.001). Myricitrin administration improved SOD (p < 0.05), CAT (p < 0.01), muscle cell's glycogen content (p < 0.01), Glut-4 gene expression (p < 0.001), Thiazolyl blue tetrazolium bromide (MTT) (p < 0.05), and Bax to Bcl-2 ratio (p < 0.001), and reduced MDA (p < 0.05) compared to hyperglycemia group. In conclusion, hyperglycemic condition induced oxidative stress along with cellular apoptosis, and myricitrin improved these disorders. Also, low and moderate doses of myricitrin are more efficient on skeletal muscle cells exposed to hyperglycemic statues than a high concentration of this antioxidant agent.

Curculigoside and polyphenol-rich ethyl acetate fraction of Molineria latifolia rhizome improved glucose uptake via potential mTOR/AKT activated GLUT4 translocation

Adipose tissue is one of the major organs responsible for rapid restoration of postprandial glucose fluxes. Being the major isoform of glucose transporter in adipose tissue, regulations of insulin-dependent GLUT4 trafficking have always been of research interest. The present study aimed to examine the molecular mechanisms underlying the efficacy of curculigoside and polyphenol-rich ethyl acetate fraction (EAF) of Molineria latifolia rhizome in triggering glucose uptake. We assessed the adipogenic potential and glucose uptake stimulatory activity of curculigoside and EAF by employing a murine 3T3-L1 adipocyte model. The transcriptional and translational expressions of selected intermediates in the insulin signalling pathway were evaluated. While curculigoside neither promoted adipogenesis nor activated peroxisome proliferator activated receptor gamma, treatment with polyphenol-rich EAF resulted otherwise. However, both treatments enhanced insulin-stimulated uptake of glucose. This was coupled with increased availability of GLUT4 at the plasma membrane of the differentiated adipocytes although the total GLUT4 protein level was unaffected. In addition, the treatment increased the phosphorylation of both AKT and mTOR, which have been reported to be associated with GLUT4 translocation. The present findings proposed that curculigoside and EAF increased glucose transport activity of 3T3-L1 adipocytes via GLUT4 translocation as a result of potential mTOR/AKT activation. The more potent efficacy observed with EAF suggested potential synergistic and multi-targeted action.

Targeted and untargeted-metabolite profiling to track the compositional integrity of ginger during processing using digitally-enhanced HPTLC pattern recognition analysis

Tracking the impact of commonly applied post-harvesting and industrial processing practices on the compositional integrity of ginger rhizome was implemented in this work. Untargeted metabolite profiling was performed using digitally-enhanced HPTLC method where the chromatographic fingerprints were extracted using ImageJ software then analysed with multivariate Principal Component Analysis (PCA) for pattern recognition. A targeted approach was applied using a new, validated, simple and fast HPTLC image analysis method for simultaneous quantification of the officially recognized markers 6-, 8-, 10-gingerol and 6-shogaol in conjunction with chemometric Hierarchical Clustering Analysis (HCA). The results of both targeted and untargeted metabolite profiling revealed that peeling, drying in addition to storage employed during processing have a great influence on ginger chemo-profile, the different forms of processed ginger shouldn't be used interchangeably. Moreover, it deemed necessary to consider the holistic metabolic profile for comprehensive evaluation of ginger during processing.

The effects of ginger intake on weight loss and metabolic profiles among overweight and obese subjects: A systematic review and meta-analysis of randomized controlled trials

This systematic review and meta-analysis of randomized controlled trials (RCTs) was performed to summarize the effect of ginger intake on weight loss, glycemic control and lipid profiles among overweight and obese subjects. We searched the following databases through November 2017: MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials. The relevant data were extracted and assessed for quality of the studies according to the Cochrane risk of bias tool. Data were pooled using the inverse variance method and expressed as Standardized Mean Difference (SMD) with 95% Confidence Intervals (95% CI). Heterogeneity between studies was assessed by the Cochran Q statistic and I-squared tests (I2). Overall, 14 studies were included in the meta-analyses. Fourteen RCTs with 473 subjects were included in our meta-analysis. The results indicated that the supplementation with ginger significantly decreased body weight (BW) (SMD -0.66; 95% CI, -1.31, -0.01; P = 0.04), waist-to-hip ratio (WHR) (SMD -0.49; 95% CI, -0.82, -0.17; P = 0.003), hip ratio (HR) (SMD -0.42; 95% CI, -0.77, -0.08; P = 0.01), fasting glucose (SMD -0.68; 95% CI, -1.23, -0.05; P = 0.03) and insulin resistance index (HOMA-IR) (SMD -1.67; 95% CI, -2.86, -0.48; P = 0.006), and significantly increased HDL-cholesterol levels (SMD 0.40; 95% CI, 0.10, 0.70; P = 0.009). We found no detrimental effect of ginger on body mass index (BMI) (SMD -0.65; 95% CI, -1.36, 0.06; P = 0.074), insulin (SMD -0.54; 95% CI, -1.43, 0.35; P = 0.23), triglycerides (SMD -0.27; 95% CI, -0.71, 0.18; P = 0.24), total- (SMD -0.20; 95% CI, -0.58, 0.18; P = 0.30) and LDL-cholesterol (SMD -0.13; 95% CI, -0.51, 0.24; P = 0.48). Overall, the current meta-analysis demonstrated that ginger intake reduced BW, WHR, HR, fasting glucose and HOMA-IR, and increased HDL-cholesterol, but did not affect insulin, BMI, triglycerides, total- and LDL-cholesterol levels.

Solid Lipid Nanoparticles of Myricitrin Have Antioxidant and Antidiabetic Effects on Streptozotocin-Nicotinamide-Induced Diabetic Model and Myotube Cell of Male Mouse

Type 2 diabetes mellitus (T2DM) may occur via oxidative stress. Myricitrin is a plant-derived antioxidant, and its solid lipid nanoparticle (SLN) may be more potent. Hence, the present study was conducted to evaluate the effects of myricitrin SLN on streptozotocin-nicotinamide- (STZ-NA-) induced T2DM of the mouse and hyperglycemic myotube. In this experimental study, cold homogenization method was used to prepare SLN. Then, 120 adult male NMRI mice were divided into 7 groups: control, vehicle, diabetes (received STZ 65 mg/kg 15 min after injected NA 120 mg/kg), diabetes + SLN containing myricitrin 1, 3, and 10 mg/kg, and diabetes + metformin. For in vitro study, myoblast (C2C12) cell line was cultured and divided into 6 groups (n = 3): control, hyperglycemia, hyperglycemia + SLN containing myricitrin 1, 3, and, 10 μM, and hyperglycemia + metformin. After the last nanoparticle treatment, plasma samples, pancreas and muscle tissues, and myotubes were taken for experimental assessments. Diabetes increased lipid peroxidation and reduced antioxidant defense along with the hyperglycemia, insulin resistance, and pancreas apoptosis. Hyperglycemia induced oxidative stress, antioxidant impairment, and cellular apoptosis. Myricitrin SLN improved diabetes and hyperglycemia complications in the in vivo and in vitro studies. Therefore, SLN of myricitrin showed antioxidant, antidiabetic, and antiapoptotic effects in the mouse and myotube cells.

Banxia-houpu decoction restores glucose intolerance in CUMS rats through improvement of insulin signaling and suppression of NLRP3 inflammasome activation in liver and brain

ETHNOPHARMACOLOGICAL RELEVANCE

Banxia-houpu decoction is a famous formula in traditional Chinese medicine (TCM) with the powerful anti-depressant activity.

AIM OF THE STUDY

This study aimed to investigate the effect of Banxia-houpu decoction on glucose intolerance associated with anhedonia in chronic unpredictable mild stress (CUMS) rats, then to explore its underlying pharmacological mechanisms.

MATERIALS AND METHODS

After 6-week CUMS procedure, male Wistar rats were given Banxia-houpu decoction (3.29 and 6.58g/kg, intragastrically) for 6 weeks. Sucrose solution consumption test was employed to evaluate the anhedonia behavior. Oral glucose tolerance test (OGTT) was used to determine glucose tolerance. Serum levels of corticosterone, corticotropin-releasing factor (CRF), insulin and interleukin-1 beta (IL-1β) were measured by commercial enzyme-linked immunosorbent assay kits, respectively. Furthermore, the key proteins for insulin signaling, as well as nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, were analyzed by Western blot in periphery liver and brain regions hypothalamus, hippocampus and prefrontal cortex, respectively.

RESULTS

Banxia-houpu decoction significantly increased sucrose solution consumption and decreased serum corticosterone and CRF levels in CUMS rats, further demonstrating its antidepressant activity. More importantly, Banxia-houpu decoction improved glucose tolerance in OGTT in this animal model. Furthermore, it protected against CUMS-induced insulin signaling impairment in the liver, as well as hypothalamus and prefrontal cortex in rats. Although without significant effect on serum IL-1β levels, Banxia-houpu decoction inhibited NLRP3 inflammasome activation in the liver, hypothalamus, hippocampus and prefrontal cortex of CUMS rats, respectively.

CONCLUSIONS

The present study demonstrates that Banxia-houpu decoction suppresses NLRP3 inflammasome activation and improves insulin signaling impairment in both periphery liver and brain regions in CUMS rats, possibly contributing to its anti-depressive effect with glucose tolerance improvement. These results may provide the evidence that Banxia-houpu decoction is a potential antidepressant with the advantage to reduce the risk of comorbid depression with type 2 diabetes mellitus.

Phenethyl isothiocyanate protects against H2O2-induced insulin resistance in 3T3-L1 adipocytes

Obesity is associated with systemic oxidative stress and leads to insulin resistance. Phenethyl isothiocyanate (PEITC), a natural dietary isothiocyanate, has been shown to have beneficial effects in improving cellular defense activities against oxidative stress through activation of nuclear factor erythroid-2 related factor 2 (Nrf2) pathway. However, little evidence exists if the antioxidative activity has beneficial effects on glucose metabolism. Here, we tested the preventive potential of PEITC for impaired insulin-induced glucose uptake by oxidative stress in 3T3-L1 adipocytes. Treatment with PEITC increased the expression of antioxidative enzymes regulated by Nrf2 such as γ-glutamylcysteine-synthetase, heme oxygenase 1, NAD(P)H:quinone oxidoreductase 1 and glutathione S-transferase, and reduced oxidative stress induced by H₂O₂. Furthermore, PEITC restored impaired insulin-stimulated glucose uptake, translocation of glucose transporter 4 and insulin signaling by H₂O₂. These results indicate that PEITC protected insulin-regulated glucose metabolism impaired by oxidative stress through the antioxidative activity in 3T3-L1 adipocytes.

[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

BACKGROUND

[6]-Gingerol, a major component of Zingiber officinale, was previously reported to ameliorate hyperglycemia in type 2 diabetic mice. Endocrine signaling is involved in insulin secretion and is perturbed in db/db Type-2 diabetic mice. [6]-Gingerol was reported to restore the disrupted endocrine signaling in rodents. In this current study on Leprdb/db diabetic mice, we investigated the involvement of endocrine pathway in the insulin secretagogue activity of [6]-Gingerol and the mechanism(s) through which [6]-Gingerol ameliorates hyperglycemia.

METHODS

Leprdb/db type 2 diabetic mice were orally administered a daily dose of [6]-Gingerol (200 mg/kg) for 28 days. We measured the plasma levels of different endocrine hormones in fasting and fed conditions. GLP-1 levels were modulated using pharmacological approaches, and cAMP/PKA pathway for insulin secretion was assessed by qRT-PCR and ELISA in isolated pancreatic islets. Total skeletal muscle and its membrane fractions were used to measure glycogen synthase 1 level and Glut4 expression and protein levels.

RESULTS

4-weeks treatment of [6]-Gingerol dramatically increased glucose-stimulated insulin secretion and improved glucose tolerance. Plasma GLP-1 was found to be significantly elevated in the treated mice. Pharmacological intervention of GLP-1 levels regulated the effect of [6]-Gingerol on insulin secretion. Mechanistically, [6]-Gingerol treatment upregulated and activated cAMP, PKA, and CREB in the pancreatic islets, which are critical components of GLP-1-mediated insulin secretion pathway. [6]-Gingerol upregulated both Rab27a GTPase and its effector protein Slp4-a expression in isolated islets, which regulates the exocytosis of insulin-containing dense-core granules. [6]-Gingerol treatment improved skeletal glycogen storage by increased glycogen synthase 1 activity. Additionally, GLUT4 transporters were highly abundant in the membrane of the skeletal myocytes, which could be explained by the increased expression of Rab8 and Rab10 GTPases that are responsible for GLUT4 vesicle fusion to the membrane.

CONCLUSIONS

Collectively, our study reports that GLP-1 mediates the insulinotropic activity of [6]-Gingerol, and [6]-Gingerol treatment facilitates glucose disposal in skeletal muscles through increased activity of glycogen synthase 1 and enhanced cell surface presentation of GLUT4 transporters.

Methylglyoxal and Advanced Glycation End products: Insight of the regulatory machinery affecting the myogenic program and of its modulation by natural compounds

Methylglyoxal (MG) is a reactive dicarbonyl intermediate and a precursor of advanced glycation end products (AGEs). The authors investigated the role played by AGEs in muscle myopathy and the amelioration of its effects by curcumin and gingerol. In addition to producing phenotypical changes, MG increased oxidative stress and reduced myotube formation in C2C12 cells. RAGE (receptor for AGEs) expression was up-regulated and MYOD and myogenin (MYOG) expressions were concomitantly down-regulated in MG-treated cells. Interestingly, AGE levels were higher in plasma (~32 fold) and muscle (~26 fold) of diabetic mice than in control mice. RAGE knock-down (RAGE_kd) reduced the expressions of MYOD and MYOG and myotube formation in C2C12 cells. In silico studies of interactions between curcumin or gingerol and myostatin (MSTN; an inhibitor of myogenesis) and their observed affinities for activin receptor type IIB (ACVRIIB) suggested curcumin and gingerol reduce the interaction between MSTN and ACVRIIB. The findings of this study suggest enhanced AGE production and subsequent RAGE-AGE interaction obstruct the muscle development program, and that curcumin and gingerol attenuate the effect of AGEs on myoblasts.

Beneficial effects of ginger Zingiber officinale Roscoe on obesity and metabolic syndrome: a review

In recent years, metabolic syndromes (MetSs), including diabetes mellitus, dyslipidemia, and cardiovascular diseases, have become a common health problem in both developed and developing countries. Accumulating data have suggested that traditional herbs might be able to provide a wide range of remedies in prevention and treatment of MetSs. Ginger (Zingiber officinale Roscoe, Zingiberaceae) has been documented to ameliorate hyperlipidemia, hyperglycemia, oxidative stress, and inflammation. These beneficial effects are mediated by transcription factors, such as peroxisome proliferator-activated receptors, adenosine monophosphate-activated protein kinase, and nuclear factor κB. This review focuses on recent findings regarding the beneficial effects of ginger on obesity and related complications in MetS and discusses its potential mechanisms of action. This review provides guidance for further applications of ginger for personalized nutrition and medicine.

6-Paradol and 6-Shogaol, the Pungent Compounds of Ginger, Promote Glucose Utilization in Adipocytes and Myotubes, and 6-Paradol Reduces Blood Glucose in High-Fat Diet-Fed Mice

The anti-diabetic activity of ginger powder (Zingiber officinale) has been recently promoted, with the recommendation to be included as one of the dietary supplements for diabetic patients. However, previous studies presented different results, which may be caused by degradation and metabolic changes of ginger components, gingerols, shogaols and paradols. Therefore, we prepared 10 ginger active components, namely 6-, 8-, 10-paradols, 6-, 8-, 10-shogaols, 6-, 8-, 10-gingerols and zingerone, and evaluated their anti-hyperglycemic activity. Among the tested compounds, 6-paradol and 6-shogaol showed potent activity in stimulating glucose utilization by 3T3-L1 adipocytes and C2C12 myotubes. The effects were attributed to the increase in 5' adenosine monophosphate-activated protein kinase (AMPK) phosphorylation in 3T3-L1 adipocytes. 6-Paradol, the major metabolite of 6-shogaol, was utilized in an in vivo assay and significantly reduced blood glucose, cholesterol and body weight in high-fat diet-fed mice.

The effect of ginger supplementation on serum C-reactive protein, lipid profile and glycaemia: a systematic review and meta-analysis

Aim

To undertake a systematic review and meta-analysis of prospective studies to determine the effect of ginger supplementation on serum C-reactive protein (CRP), lipid profile, and glycaemia.

Method

PubMed-MEDLINE, Web of Science, Cochrane Database, and Google Scholar databases were searched (up until July 2016) to identify prospective studies evaluating the impact of ginger supplementation on serum CRP. Random-effects model meta-analysis was used for quantitative data synthesis. Sensitivity analysis was conducted using the leave-one-out method. Heterogeneity was quantitatively assessed using the I² index. Systematic review registration: CRD42016035973.

Results

From a total of 265 entries identified via searches, 9 studies were included in the final selection. The meta-analysis indicated a significant reduction in serum CRP concentrations following ginger supplementation [weighted mean difference (WMD)−0.84 mg/L (95% CI −1.38 to −0.31, I² 56.3%)]. The WMD for fasting blood glucose and HbA1c was −1.35 mg/dl (95% CI −2.04 to −0.58, I² 12.1%) and −1.01 (95% CI −1.28 to −0.72, I² 9.4%), respectively. Moreover, high-density lipoprotein and triglyceride significantly improved after ginger administration [1.16 mg/dl (95% CI 0.52 to 1.08, I² 12.3%) and −1.63 mg/dl (95% CI −3.10 to −0.17, I² 8.1%), respectively]. These findings were robust in sensitivity analyses. Random-effects meta-regression revealed that changes in serum CRP levels were independent of the dosage of ginger supplementation (slope −0.20; 95% CI −0.95 to 0.55; p=0.60).

Conclusions

This meta-analysis suggests that ginger supplementation significantly reduces serum CRP and improves glycaemia indexes and lipid profile. Randomized control trials with larger sample size and with a longer-term follow-up period should be considered for future investigations.

Spices in the management of diabetes mellitus

Diabetes mellitus (DM) remains a major health care problem worldwide both in developing and developed countries. Many factors, including age, obesity, sex, and diet, are involved in the etiology of DM. Nowadays, drug and dietetic therapies are the two major approaches used for prevention and control of DM. Compared to drug therapy, a resurgence of interest in using diet to manage and treat DM has emerged in recent years. Conventional dietary methods to treat DM include the use of culinary herbs and/or spices. Spices have long been known for their antioxidant, anti-inflammatory, and anti-diabetic properties. This review explores the anti-diabetic properties of commonly used spices, such as cinnamon, ginger, turmeric, and cumin, and the use of these spices for prevention and management of diabetes and associated complications.

Gingerol activates noxious cold ion channel TRPA1 in gastrointestinal tract

TRPA1 channels are non-selective cation channels that could be activated by plant-derived pungent products, including gingerol, a main active constituent of ginger. Ginger could improve the digestive function; however whether ginger improves the digestive function through activating TRPA1 receptor in gastrointestinal tract has not been investigated. In the present study, gingerol was used to stimulate cell lines (RIN14B or STC-1) while depletion of extracellular calcium. TRPA1 inhibitor (rethenium red) and TRPA1 gene silencing via TRPA1-specific siRNA were also used for mechanistic studies. The intracellular calcium and secretion of serotonin or cholecystokinin were measured by fura-2/AM and ELISA. Stimulation of those cells with gingerol increased intracellular calcium levels and the serotonin or cholecystokinin secretion. The gingerol-induced intracellular calcium increase and secretion (serotonin or cholecystokinin) release were completely blocked by ruthenium red, EGTA, and TRPA1-specific siRNA. In summary, our results suggested that gingerol derived from ginger might improve the digestive function through secretion releasing from endocrine cells of the gut by inducing TRPA1-mediated calcium influx.

Antidiabetic effect of enterolactone in cultured muscle cells and in type 2 diabetic model db/db mice

Enterolactone (ENL) is formed by the conversion of dietary precursors like strawberry lignans via the gut microbiota. Urinary concentrations of lignan metabolites are reported to be significantly associated with a lower risk of Type 2 diabetes (T2D). In the present study, antidiabetic effect of ENL and its modes of action were studied in vitro and in vivo employing a rat skeletal muscle-derived cell line, L6 myocytes in culture, and T2D model db/db mice. ENL dose-dependently increased glucose uptake in L6 myotubes under insulin absent condition. This increase by ENL was canceled by compound C, an inhibitor of 5'-adenosine monophosphate-activated protein kinase (APMK). Activation (=phosphorylation) of AMPK and translocation of glucose transporter 4 (GLUT4) to plasma membrane in L6 myotubes were demonstrated by Western blotting analyses. Promotion by ENL of GLUT4 translocation to plasma membrane was also visually demonstrated by immunocytochemistry in L6 myoblasts that were transfected with glut4 cDNA-coding vector. T2D model db/db mice were fed the basal 20 % casein diet (20C) or 20C supplemented with ENL (0.001 or 0.01 %) for 6 weeks. Fasting blood glucose (FBG) levels were measured every week and intraperitoneal glucose tolerance test (IPGTT) was conducted. ENL at a higher dose (0.01 % in 20C) suppressed the increases in FBG levels. ENL was also demonstrated to improve the index of insulin resistance (HOMA-IR) and glucose intolerance by IPGTT in db/db mice. From these results, ENL is suggested to be an antidiabetic chemical entity converted from dietary lignans by gut microbiota.

Effects of Ginger on Serum Lipids and Lipoproteins in Peritoneal Dialysis Patients: A Randomized Controlled Trial

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BACKGROUND

In peritoneal dialysis (PD) patients, one of the major risk factors for cardiovascular disease is lipid abnormalities. This study was designed to investigate the effects of ginger supplementation on serum lipids and lipoproteins in PD patients. ♦

METHODS

In this randomized, double-blind, placebo-controlled trial, 36 PD patients were randomly assigned to either the ginger or the placebo group. The patients in the ginger group received 1,000 mg ginger daily for 10 weeks, while the placebo group received corresponding placebos. At baseline and at the end of week 10, 7 mL of blood were obtained from each patient after a 12- to 14-hour fast, and serum concentrations of triglyceride, total cholesterol, low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C), and lipoprotein (a) [Lp (a)] were measured. ♦

RESULTS

Serum triglyceride concentration decreased significantly up to 15% in the ginger group at the end of week 10 compared with baseline (p < 0.01), and the reduction was significant in comparison with the placebo group (p < 0.05). There were no significant differences between the 2 groups in mean changes of serum total cholesterol, LDL-C, HDL-C, and Lp (a). ♦

CONCLUSION

This study indicates that daily administration of 1,000 mg ginger reduces serum triglyceride concentration, which is a risk factor for cardiovascular disease, in PD patients.

Chemical characterization and antioxidant activities comparison in fresh, dried, stir-frying and carbonized ginger

Ginger (Zingiber officinale Rosc.) is a common dietary adjunct that contributes to the taste and flavor of foods, and is also an important Traditional Chinese medicine (TCM). Different processing methods can produce different processed gingers with dissimilar chemical constituents and pharmacological activities. In this study, an ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC/QTOF-MS) was applied to identify the complicated components from fresh, dried, stir-frying and carbonized ginger extracts. All of the 27 compounds were identified from four kinds of ginger samples (fresh, dried, stir-frying and carbonized ginger). Five main constituents (zingerone, 6-gingerol, 8-gingerol, 6-shogaol and 10-gingerol) in these four kinds of ginger sample extracts were simultaneously determined by UPLC-PDA. Meanwhile, the antioxidant effect of fresh, dried, stir-frying and carbonized gingers were evaluated by three assays (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis(3-ethylbenzthiazolinesulfonic acid) diammonium salt (ABTS), and ferric reducing antioxidant power (FRAP)). The results demonstrated that antioxidant activity of dried ginger was the highest, for its phenolic contents are 5.2-, 1.1- and 2.4-fold higher than that of fresh, stir-frying and carbonized ginger, respectively, the antioxidant activities' results indicated a similar tendency with phenolic contents: dried ginger>stir-frying ginger>fresh ginger>carbonized ginger. The processing contributed to the decreased concentration of gingerols and the increased levels of shogaols, which reducing the antioxidant effects in pace with processing. This study elucidated the relationship of the heating process with the constituents and antioxidant activity, and provided a guide for choosing different kinds of ginger samples on clinical application.