6-Shogaol and 6-gingerol, the pungent of ginger, inhibit TNF-alpha mediated downregulation of adiponectin expression via different mechanisms in 3T3-L1 adipocytes

10-Gingerol reduces cytoplasmic lipid droplets and induces lipolysis in 3T3-L1 adipocytes

Obesity is a globally prevalent metabolic disorder characterized by an increased number of adipose cells and excessive fat in adipocytes. Herbal medicines, such as ginger, have shown potential in treating obesity by inhibiting adipogenesis and reducing adipocyte hypertrophy. Ginger contains bioactive compounds, particularly gingerols, which have demonstrated anti-adipogenic and/or lipolytic effects. However, research on the effects of 10-gingerol on adipose tissue remains limited. This study aimed to evaluate the effect of 10-gingerol on lipid content, lipolysis markers, and the expression of genes related to lipid metabolism in 3T3-L1 adipocytes. Three groups were analyzed: a negative control (preadipocytes), a positive control (mature adipocytes), and a group treated with 10-gingerol (10-G). Results showed that 10-G reduced lipid accumulation by 42.16% in mature adipocytes compared to the control, without affecting cell viability. Additionally, 10-G increased glycerol release and downregulated lipogenic genes such as Pparγ, Acaca, Fabp4, and Mtor, while upregulating genes related to fatty acid oxidation, including Cebpα, Cpt1a, Lipe, and Prkaa1. In conclusion, 10-gingerol reduces lipid content in mature adipocytes by downregulating lipogenesis, increasing lipolysis, and enhancing fatty acid oxidation.

10-Gingerol Increases Antioxidant Enzymes and Attenuates Lipopolysaccharide-Induced Inflammation by Modulating Adipokines in 3T3-L1 Adipocytes

BACKGROUND

Obesity increases reactive oxygen species production and alters adipokines levels, resulting in a low-grade chronic inflammation state, which contributes to tissue metabolic dysfunction. 10-gingerol, a phenol present in ginger, has shown potential anti-obesogenic effects in vitro. However, the antioxidant and anti-inflammatory properties of 10-gingerol have not been approached. The aim of this study was to investigate the effects of 10-gingerol on antioxidant enzymes' expression and adipokine production in 3T3-L1 adipocytes in response to lipopolysaccharide (LPS)-induced inflammation.

METHODS

10-gingerol antioxidant capacity was assessed through Oxygen Radical Absorbance Capacity (ORAC) , Ferric Reducing Antioxidant Power (FRAP), and radical scavenging activity of 2,2-diphenyl-2-picrylhydrazyl (DPPH) assays. 3T3-L1 cells were differentiated and stimulated with 100 ng/mL LPSs. Then, 15 µg/mL 10-gingerol was added for 48 h. The mRNA expression and protein abundance of antioxidant enzymes were evaluated by qPCR and Western blot, respectively. Adipokine levels were determined by ELISA.

RESULTS

10-gingerol showed low FRAP and DPPH values but a moderate ORAC value. Moreover, 10-gingerol increased Gpx1 and Sod1 but downregulated Cat expression. Additionally, 10-gingerol significantly increased CAT and GPx1 levels but not SOD-1. Finally, adiponectin and leptin concentrations were increased while resistin and tumor necrosis factor alpha (TNFα) were decreased by 10-gingerol.

CONCLUSIONS

10-gingerol presented antioxidant potential by increasing antioxidant enzymes and attenuated LPS-induced inflammation by modulating adipokines in 3T3-L1 adipocytes.

Curative role of natural PPARγ agonist in non-alcoholic fatty liver disease (NAFLD)

NAFLD is a condition that develops when the liver accumulates excess fat without alcohol consumption. This chronic liver ailment progresses along with insulin resistant and is typically not diagnosed until the patients have cirrhosis. Nuclear hormone receptor superfamily PPARs are essential for metabolism of fatty acids and glucose. In liver, lipid metabolism is regulated by nuclear receptors and PPARα, and PPARβ/δ encourages fatty acid β-oxidation. PPAR-γ, an energy-balanced receptor is a crucial regulator in NAFLD. The partial activation of PPAR-γ could lead to increased level of adiponectin and insulin sensitivity, thus improved NAFLD. Because of less side effects, natural compounds are emerged as potential therapeutic agents for NAFLD by PPARγ agonists. Although the results from preclinical studies are promising, further research is needed to determine the potential dosing and efficacy of mentioned compounds in human subjects. In this review, we summarize the effect of natural PPARγ agonist in the NAFLD.

Effect of grape-derived products on the serum levels of enzymes mainly produced by the liver: A systematic review and meta-analysis of parallel randomized controlled trials

In recent years, an increase in the incidence of liver diseases has been reported all over the world. This study aims to comprehensively summarize and quantitatively analyze the existing evidence concerning the effectiveness of grape-derived products on liver enzymes through a systematic review and meta-analytic approach. PubMed, Scopus, Cochrane Library, and ISI Web of Science were comprehensively searched until January 2024. Articles that reported the effect of grape-derived products on serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) levels were included. Weighted mean differences (WMDs) were pooled using a random-effects model. Nine studies were included in the meta-analysis. The results revealed that grape-derived products did not significantly change the concentrations of ALT (WMD: -2.70 IU/L, 95% CI: -6.14 to 0.75, p = 0.12), and AST (WMD: -1.42 IU/L, 95% CI: -3.54 to 0.70, p = 0.18). However, a significant reduction was observed in serum ALP levels (WMD: -5.49 IU/L, 95% CI: -9.57 to -1.4, p = 0.008). The present findings suggest that grape-derived products positively influence serum ALP levels among adults. However, a more comprehensive decision necessitates additional studies.

The Effects of Body Fat Reduction through the Metabolic Control of Steam-Processed Ginger Extract in High-Fat-Diet-Fed Mice

The prevalence of metabolic syndrome is increasing globally due to behavioral and environmental changes. There are many therapeutic agents available for the treatment of chronic metabolic diseases, such as obesity and diabetes, but the data on their efficacy and safety are lacking. Through a pilot study by our group, Zingiber officinale rhizomes used as a spice and functional food were selected as an anti-obesity candidate. In this study, steam-processed ginger extract (GGE) was used and we compared its efficacy at alleviating metabolic syndrome-related symptoms with that of conventional ginger extract (GE). Compared with GE, GGE (25-100 μg/mL) had an increased antioxidant capacity and α-glucosidase inhibitory activity in vitro. GGE was better at suppressing the differentiation of 3T3-L1 adipocytes and lipid accumulation in HepG2 cells and promoting glucose utilization in C2C12 cells than GE. In 16-week high-fat-diet (HFD)-fed mice, GGE (100 and 200 mg/kg) improved biochemical profiles, including lipid status and liver function, to a greater extent than GE (200 mg/kg). The supplementation of HFD-fed mice with GGE (200 mg/kg) resulted in the downregulation of SREBP-1c and FAS gene expression in the liver. Collectively, our results indicate that GGE is a promising therapeutic for the treatment of obesity and metabolic syndrome.

Effects of curcumin/turmeric supplementation on the liver enzymes, lipid profiles, glycemic index, and anthropometric indices in non-alcoholic fatty liver patients: An umbrella meta-analysis

Non-alcoholic fatty liver disease (NAFLD) is one of the leading causes of chronic liver disease worldwide. The evidence for curcumin's effects on patients with NAFLD is accumulating; however, meta-analyses have reported mixed results. The current umbrella meta-analysis aimed to assess the present evidence and provide an accurate estimate of the overall effects of curcumin/turmeric on NAFLD patients. The Web of Science, Scopus, PubMed, ScienceDirect, and Google Scholar databases were searched till March 2023 using MeSH terms and related keywords based on the PICO criteria. Meta-analysis studies evaluating the effects of curcumin/turmeric supplementation on NAFLD patients that reported the effect sizes (ES) and corresponding confidence intervals (CI) were eligible for inclusion in this study. All articles were screened by considering the eligibility criteria by two independent reviewers and required data were extracted from the included meta-analyses. The meta-analysis was performed utilizing a random-effects model by STATA software. Findings of 11 meta-analyses of 99 randomized controlled trials comprising 5546 participants revealed that curcumin/turmeric supplementation reduced AST (ES = -1.072, 95% CI (-1.656, -0.488), p = 0.000), ALT (ES = -0.625, 95% CI (-1.170, -0.134), p = 0.014), and TG (ES = -0.469, 95% CI (-1.057, 0.119), p = 0.128) levels, and HOMA-IR (ES = -0.291, 95% CI (-0.368, -0.214), p = 0.000), BMI (ES = -0.205, 95% CI (-0.304, -0.107), p = 0.000), and WC (ES = -1.290, 95% CI (-2.038, -0.541), p = 0.001) in comparison to the control group. However, the effects of curcumin on GGT, ALP, TC, LDL-C, HDL-C, FBS, and HbA1C levels and body weight were not significant. The findings suggest the beneficial effects of curcumin/turmeric supplementation in patients with NAFLD, such as improving liver function, decreasing serum TG levels, ameliorating insulin resistance, and reducing general and central obesity. Nevertheless, high-quality research is further required to prove these achievements.

Improving Ginger's Bioactive Composition by Combining Innovative Drying and Extraction Technologies

Ginger extracts (GEs) are antioxidant, antimicrobial, and anti-inflammatory. Their bioactivity can benefit foods and active packaging by extending shelf life, enhancing safety, and providing health benefits. Highly bioactive GEs are crucial to formulating potent active products and avoiding negative effects on their properties. Sesquiterpenes and phenolics are the main bioactives in ginger, but drying and extraction affect their composition. GEs are usually obtained from dry rhizomes; however, these operations have been studied independently. Therefore, a combined study of innovative drying and extraction technologies to evaluate their influence on extracts' composition will bring knowledge on how to increase the bioactivity of GEs. The effects of an emergent drying (vacuum microwave, VMD) followed by an emergent extraction (ultrasound, UAE, 20 or 80 °C) were investigated in this work. Microwave extraction (MAE) of fresh ginger was also studied. Convective oven drying and Soxhlet extraction were the references. Drying kinetics, powder color, extract composition, and antioxidant activity were studied. While MAE preserved the original composition profile, VMD combined with UAE (20 °C) produced extracts richer in phenolics (387.6 mg.GAE/g) and antioxidant activity (2100.7 mmol.Trolox/mL), with low impact in the sesquiterpenes. VMD generated shogaols by its high temperatures and facilitated extracting bioactives by destroying cellular structures and forming pores. UAE extracted these compounds selectively, released them from cell structures, and avoided losses caused by volatilization and thermal degradation. These findings have significant implications, as they provide an opportunity to obtain GE with tailored compositions that can enhance the formulation of food, active packaging, and pharmacological products.

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.

The effect of zingiber officinale on prooxidant-antioxidant balance and glycemic control in diabetic patients with ESRD undergoing hemodialysis: a double-blind randomized control trial

BACKGROUND

Diabetes management in hemodialysis patients with end-stage renal disease needs precision to avoid complications. The study aimed to investigate the effect of ginger supplementation on prooxidant-antioxidant balance, glycemic management, and renal function in diabetic hemodialysis patients.

TRIAL DESIGN AND METHODS

Forty-four patients were randomly allocated to either the ginger or the placebo group in this randomized, double blind, placebo-controlled study. Patients in the ginger group received 2000 mg/d ginger for eight weeks, whereas those in the placebo group received equivalent placebos. After a 12- to 14-h fast, serum levels of fasting blood glucose (FBG), insulin, urea, creatinine, and prooxidant-antioxidant balance (PAB) were measured at baseline and at the end of the study. The homeostatic model evaluation of insulin resistance was used to determine insulin resistance (HOMA-IR).

RESULTS

Serum levels of FBG (p = 0.001), HOMA-IR (p = 0.001), and urea (p = 0.017) were considerably lower in the ginger group compared to baseline, and the difference was significant when compared to the placebo group (p < 0.05). Moreover, ginger supplementation decreased serum levels of creatinine (p = 0.034) and PAB (p = 0.013) within the group, but the effect was insignificant between groups (p > 0.05). On the other hand, insulin levels did not vary significantly across and among the groups (p > 0.05).

CONCLUSION

In summary, this study indicated that in diabetic hemodialysis patients, ginger could result to lower blood glucose levels, enhanced insulin sensitivity, and lower serum urea levels. Further studies with a more extended intervention period and various doses and forms of ginger are needed.

TRIAL REGISTRATION

IRCT20191109045382N2. (06/07/2020), Retrospectively registered, https://www.irct.ir/trial/48467.

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.

Prevention and Treatment of Obesity-Related Inflammatory Diseases by Edible and Medicinal Plants and Their Active Compounds

Obesity, defined by excessive fat mass and its associated low-grade chronic inflammation, leads to insulin resistance, diabetes, and metabolic dysfunctions. The immunomodulatory properties of natural agents have gained much interest in recent decades. Some of the plant-derived agents are known to be immunomodulators that can affect both innate and adaptive immunity, e.g., thymoquinone, curcumin, punicalagin, resveratrol, quercetin, and genistein. Natural immunomodulators may contribute to the treatment of a number of inflammatory diseases, as they have significant efficacy and safety profiles. The immunomodulatory effects of traditional Greco-Arab and Islamic diets and medicinal plants are well acknowledged in abundant in vitro studies as well as in animal studies and clinical trials. This review highlights the role of Greco-Arab and Islamic diets and medicinal plants in the management of inflammation associated with obesity. Although previously published review articles address the effects of medicinal plants and phytochemicals on obesity-related inflammation, there is no systematic review that emphasizes clinical trials of the clinical significance of these plants and phytochemicals. Given this limitation, the objective of this comprehensive review is to critically evaluate the potential of the most used herbs in the management of obesity-related inflammation based on clinical trials.

Dual Beneficial Effects of Methylnissolin-3-O-β-d-Glucopyranoside on Obesity-Induced Inflammatory Responses in Adipocyte-Macrophage Co-Culture

Methylnissolin-3-O-β-d-glucopyranoside (MNG) is a pterocarpan analog, which protects EA.hy926 cells against oxidative damage through the Nrf2/HO-1 pathway. However, the effects of MNG on obesity-induced inflammatory responses in adipocyte-macrophage co-culture remain unclear. A differentiated murine preadipocyte cell line (3T3-L1) was co-cultured with a murine macrophage cell line (RAW264.7). Intracellular lipid accumulation was determined using Oil Red O staining. Western blotting was performed to investigate the expression of adipogenesis- and inflammation-associated proteins. Cell culture supernatants were assayed using ELISA kits to measure the levels of proinflammatory cytokines such as interleukin 6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1). MNG inhibited lipid accumulation and the production of IL-6 and MCP-1 in the 3T3-L1 and RAW264.7 cell co-culture. Moreover, MNG inhibited the protein expression of CCAAT/enhancer-binding protein alpha (C/EBPα), C/EBPβ, peroxisome proliferator-activated receptor γ (PPARγ), cyclooxygenase 2 (COX-2), and inducible nitric oxide synthase (iNOS) under the same co-culture conditions. MNG also inhibited IL-6 and MCP-1 production compared with the co-culture control. These findings demonstrate that MNG inhibited lipid accumulation and inflammatory response by downregulating IL-6 and MCP-1 production and protein expression of C/EBPβ, C/EBPα, PPARγ, COX-2, and iNOS in co-culture conditions with 3T3-L1 and RAW264.7 cells. These results suggest that MNG may be beneficial in preventing obesity-related inflammatory status.

Nutritional benefits of ginger for patients with non-communicable diseases

Ginger (Zingiber officinale) is a famous dietary spice rich in bioactive components like gingerols, and it has been used for a long time as food and medicine. Indeed, clinical studies have confirmed the anti-inflammatory and antioxidant properties of ginger. Thus, ginger seems to be an excellent complementary nutritional strategy for non-communicable diseases (NCD) such as obesity, diabetes, cardiovascular disease and chronic kidney disease. This narrative review aims to discuss the possible effects of ginger on the mitigation of common complications such as inflammation, oxidative stress, and gut dysbiosis in NCD.

Impact of drying and extractions processes on the recovery of gingerols and shogaols, the main bioactive compounds of ginger

Ginger extracts have anti-inflammatory, antioxidant, antitumor, and antibacterial activities mainly due to gingerols and shogaols. Extract composition and functionality can be affected by drying and extraction processes. Alternative methods to obtain ginger extracts based on high contents of gingerols and shogaols have been reported. However, there were no studies that present a broad overview of how these methods affect the composition and functionalities of ginger extracts. Based on literature data from 2011 to 2022, this review shows how drying, extraction, and complementary processes (i.e., enzymatic, acidic, and carbonic maceration) affect the composition and bioactivity of the ginger extract. Lower temperature processes, including freeze-drying, cold ultrasound-, or enzyme-assisted extraction, lead to extracts richer in phenolics, gingerols, and antioxidant activity. On the other hand, acidic solvents or "hot" processes including microwave-drying, pressurized liquid, and microwave-assisted extraction can favor higher shogaols concentrations, which have higher antitumor, anti-inflammatory, and antimicrobial activities than the gingerols precursors. Thus, in this review, we analyzed and discussed the relation between ginger processing and their bioactive compounds, focusing especially on gingerols and shogaols, as well as the main processes that increase the content of 6-shogaol without compromising other phenolic compounds to produce highly functional extracts for future applications in the food packaging sector.

Small Molecule Compounds of Natural Origin Target Cellular Receptors to Inhibit Cancer Development and Progression

Receptors are macromolecules that transmit information regulating cell proliferation, differentiation, migration and apoptosis, play key roles in oncogenic processes and correlate with the prognoses of cancer patients. Thus, targeting receptors to constrain cancer development and progression has gained widespread interest. Small molecule compounds of natural origin have been widely used as drugs or adjuvant chemotherapeutic agents in cancer therapies due to their activities of selectively killing cancer cells, alleviating drug resistance and mitigating side effects. Meanwhile, many natural compounds, including those targeting receptors, are still under laboratory investigation for their anti-cancer activities and mechanisms. In this review, we classify the receptors by their structures and functions, illustrate the natural compounds targeting these receptors and discuss the mechanisms of their anti-cancer activities. We aim to provide primary knowledge of mechanistic regulation and clinical applications of cancer therapies through targeting deregulated receptors.

The Effect of Herbal Medicine and Natural Bioactive Compounds on Plasma Adiponectin: A Clinical Review

Noncommunicable diseases (NCDs) are one of the major public health concerns globally. Most of the NCDs including insulin resistance, metabolic syndrome, type 2 diabetes mellitus, fatty liver disease, and coronary heart disease are related to obesity and are called obesity-related NCDs (OR-NCDs). However, adipocytes can reduce OR-NCDs by secreting adiponectin. Adiponectin has an inverse relationship with body fat. Obese people have impairment in differentiating pre-adipocytes to adipocytes, the process facilitated by adiponectin. Adiponectin directly increases insulin sensitivity and reduces obesity-related insulin resistance by down-regulating hepatic glucose production and increasing fatty acid (FA) oxidation in skeletal muscle. Considering the various beneficial effects of adiponectin on health, increasing adiponectin might be a promising approach to prevent and treat OR-NCDs. Recent studies have shown that nutraceuticals and medicinal compounds isolated from plants could prevent and treat various diseases, particularly cardiovascular diseases (CVDs), diabetes mellitus, obesity, and non-alcoholic fatty liver disease. However, to our knowledge, the effect of these natural products, including herbal supplements and functional foods on adiponectin, has not yet been fully reviewed. The main aim of this review is to summarize the effects of nutraceuticals and herbal bioactive compounds on plasma adiponectin concentrations based on clinical studies. It can be concluded that medicinal plants, and herbal bioactive compounds, particularly curcumin, anthocyanins, resveratrol, soy, walnut, and dihydromyricetin can be used as adjunct or complementary therapeutic agents to increase plasma adiponectin, which could potentially prevent and treat NCDs.

Anti-Obesity Effect of α-Cubebenol Isolated from Schisandra chinensis in 3T3-L1 Adipocytes

The efficacy of α-cubebenol isolated from Schisandra chinensis has been studied in several diseases, including cecal ligation, puncture challenge-induced sepsis, and degranulation of neutrophils. To identify the novel functions of α-cubebenol on lipid metabolism, alterations on the regulation of lipogenesis, lipolysis, and inflammatory response were observed in 3T3-L1 adipocytes treated with α-cubebenol. Most lipogenic targets, including lipid accumulation, level of lipogenic transcription factors, and expression of lipogenic regulators, were suppressed in MDI (3-isobutyl-1-methylxanthine, dexamethasone, and insulin)-stimulated 3T3-L1 adipocytes treated with α-cubebenol without significant cytotoxicity. In addition, similar inhibition effects were observed in the iNOS-induced COX-2 mediated pathway and NLRP3 inflammasome pathway of MDI-stimulated 3T3-L1 cells treated with α-cubebenol. Lipolytic targets, such as cAMP concentration, expression of adenylyl cyclase and PDE4, and their downstream signaling pathway, in MDI-stimulated 3T3-L1 cells were stimulated by the α-cubebenol treatment. The levels of transcription factors and related proteins for β-oxidation were significantly higher in the MDI + α-cubebenol treated group than in the MDI + Vehicle treated group. These results show that α-cubebenol has a novel role as a lipogenesis inhibitor, lipolysis and β-oxidation stimulator, and inflammasome suppressor in MDI-stimulated 3T3-L1 adipocytes.

Effects of Zingiber officinale extract supplementation on metabolic and genotoxic parameters in diet-induced obesity in mice

Obesity is an epidemic associated with many diseases. The nutraceutical Zingiber officinale (ZO) is a potential treatment for obesity; however, the molecular effects are unknown. Swiss male mice were fed a high-fat diet (59 % energy from fat) for 16 weeks to generate a diet-induced obesity (DIO) model and then divided into the following groups: standard diet + vehicle; standard diet + ZO; DIO + vehicle and DIO + ZO. Those in the ZO groups were supplemented with 400 mg/kg per d of ZO extract (oral administration) for 35 d. The animals were euthanised, and blood, quadriceps, epididymal fat pad and hepatic tissue were collected. DIO induced insulin resistance, proinflammatory cytokines, oxidative stress and DNA damage in different tissues. Treatment with ZO improved insulin sensitivity as well as decreased serum TAG, without changes in body weight or adiposity index. TNF-α and IL-1β levels were lower in the liver and quadriceps in the DIO + ZO group compared with the DIO group. ZO treatment reduced the reactive species and oxidative damage to proteins, lipids and DNA in blood and liver in obese animals. The endogenous antioxidant activity was higher in the quadriceps of DIO + ZO. These results in the rat model of DIO may indicate ZO as an adjuvant on obesity treatment.

JNK signaling pathway in metabolic disorders: An emerging therapeutic target

Metabolic Syndrome is a multifactorial disease associated with increased risk of cardiovascular disorders, type 2 diabetes mellitus, fatty liver disease, etc. Various stress stimuli such as reactive oxygen species, endoplasmic reticulum stress, mitochondrial dysfunction, increased cytokines, or free fatty acids are known to aggravate progressive development of hyperglycemia and hyperlipidemia. Although the exact mechanism contributing to altered metabolism is unclear. Evidence suggests stress kinase role to be a crucial one in metabolic syndrome. Stress kinase, c-jun N-terminal kinase activation (JNK) is involved in various metabolic manifestations including obesity, insulin resistance, fatty liver disease as well as cardiometabolic disorders. It emerged as a foremost mediator in regulating metabolism in the liver, skeletal muscle, adipose tissue as well as pancreatic β cells. It has three isoforms each having a unique and tissue-specific role in altered metabolism. Current findings based on genetic manipulation or chemical inhibition studies identified JNK isoforms to play a central role in the regulation of whole-body metabolism, suggesting it to be a novel therapeutic target. Hence, it is imperative to elucidate its role in metabolic syndrome onset and progression. The purpose of this review is to elucidate in vitro and in vivo implications of JNK signaling along with the therapeutic strategy to inhibit specific isoform. Since metabolic syndrome is an array of diseases and complex pathway, carefully examining each tissue will be important for specific treatment strategies.

The effect of cinnamon supplementation on liver enzymes in adults: A systematic review and meta-analysis of randomized controlled trials

AIMS

The aim of this study was to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) to examine the effect of cinnamon supplementation on liver enzymes.

METHODS

A systematic search was performed in electronic databases including PubMed-Medline, Scopus, and ISI Web of Science up to November 2020. We used a random effects model to estimate pooled effect size of alanine aminotransferase (ALT), alkaline phosphatase (ALP), and aspartate aminotransferase (AST) levels.

RESULTS

Seven RCTs (9 treatment arms) fulfilled the eligibility criteria of the present meta-analysis. Overall, meta-analysis could not show any beneficial effect of cinnamon supplementation on AST, ALT, and ALP. Subgroup analyses showed that the effect of cinnamon supplementation on ALT was significant at the dosages of <1500 mg/day (Hedges's: -0.61; 95 % CI: -1.11, -0.10; P = 0.002), in trials lasting>12 weeks (Hedges's: -0.83; 95 % CI: -1.36, -0.30; P = 0.01), and in trials conducted of both gender (Hedges's: -0.72; 95 % CI: -1.45, -0.01; P = 0.04).

CONCLUSION

In summary, cinnamon supplementation had no significant effect on liver enzymes in adults. However, the effect of cinnamon on ALT levels was significant at the dosages of <1500 mg/day, in trials lasting>12 weeks, and in trials conducted of both gender. Nevertheless, further studies should be performed to confirm our results.

Ginger (Zingiber officinale Rosc.) and its bioactive components are potential resources for health beneficial agents

Zingiber officinale Rosc. (Zingiberacae), commonly known as ginger, is a perennial and herbaceous plant with long cultivation history. Ginger rhizome is one of the most popular food spices with unique pungent flavor and is prescribed as a well-known traditional Chinese herbal medicine. To date, over 160 constituents, including volatile oil, gingerol analogues, diarylheptanoids, phenylalkanoids, sulfonates, steroids, and monoterpenoid glycosides compounds, have been isolated and identified from ginger. Increasing evidence has revealed that ginger possesses a broad range of biological activities, especially gastrointestinal-protective, anti-cancer, and obesity-preventive effects. In addition, gingerol analogues such as 6-gingerol and 6-shogaol can be rapidly eliminated in the serum and detected as glucuronide and sulfate conjugates. Structural variation would be useful to improve the metabolic characteristics and bioactivities of lead compounds derived from ginger. Furthermore, some clinical trials have indicated that ginger can be consumed for attenuating nausea and vomiting during early pregnancy; however, there is not sufficient data available to rule out its potential toxicity, which should be monitored especially over longer periods. This review provides an up-to-date understanding of the scientific evidence on the development of ginger and its active compounds as health beneficial agents in future clinical trials.

Effect of ginger (Zingiber officinale) on inflammatory markers: A systematic review and meta-analysis of randomized controlled trials

The aim of this systematic review and meta-analysis was to investigate the efficacy of ginger supplementation on circulating levels of C-reactive protein (CRP), high sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-α), soluble intercellular adhesion molecule (sICAM), and interleukin-6 (IL-6) concentrations in randomized controlled trials (RCTs). The search included PubMed-Medline, EMBASE, Scopus, Web of Science and Cochrane Library databases to identify randomized clinical trials on the effect of ginger supplementation on circulation levels of CRP, hs-CRP, IL-6, sICAM, and TNF-α published up until February 1st, 2020. We did not restrict articles based on language of publication. Standard mean differences and 95% confidence intervals were calculated for net changes in inflammatory mediators using a random-effects model. Sixteen RCTs comprising 1010 participants were found to be eligible for this meta-analysis. There was a significant reduction of circulating CRP (SMD: -5.11, 95% CI: -7.91, -2.30, I2 = 98.1%), hs-CRP (SMD: -0.88, 95% CI: -1.63, -0.12, I2 = 90.8%) and TNF-α levels (SMD: -0.85, 95% CI: -1.48, -0.21, I2 = 89.4%) following ginger supplementation. However, meta-analysis results did not show any significant impact of ginger supplementation on IL-6 (SMD: -0.45, 95% CI: -1.29, 0.38, I2 = 89.2%), and sICAM levels (SMD: -0.05, 95% CI: -0.36, 0.26, I2 = 00.0%). This systematic review and meta-analysis of RCTs demonstrates a significant impact of ginger in lowering circulating CRP, hs-CRP and TNF-α levels. Large-scale RCTs are still needed to draw concrete conclusions about the effect of ginger on other inflammatory mediators.

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.

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.

Phytochemicals against TNFα-Mediated Neuroinflammatory Diseases

Tumor necrosis factor-alpha (TNF-α) is a well-known pro-inflammatory cytokine responsible for the modulation of the immune system. TNF-α plays a critical role in almost every type of inflammatory disorder, including central nervous system (CNS) diseases. Although TNF-α is a well-studied component of inflammatory responses, its functioning in diverse cell types is still unclear. TNF-α functions through its two main receptors: tumor necrosis factor receptor 1 and 2 (TNFR1, TNFR2), also known as p55 and p75, respectively. Normally, the functions of soluble TNF-α-induced TNFR1 activation are reported to be pro-inflammatory and apoptotic. While TNF-α mediated TNFR2 activation has a dual role. Several synthetic drugs used as inhibitors of TNF-α for diverse inflammatory diseases possess serious adverse effects, which make patients and researchers turn their focus toward natural medicines, phytochemicals in particular. Phytochemicals targeting TNF-α can significantly improve disease conditions involving TNF-α with fewer side effects. Here, we reviewed known TNF-α inhibitors, as well as lately studied phytochemicals, with a role in inhibiting TNF-α itself, and TNF-α-mediated signaling in inflammatory diseases focusing mainly on CNS disorders.

Effect of Ginger Powder Supplementation in Patients with Non-Alcoholic Fatty Liver Disease: A Randomized Clinical Trial

Background

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver disorders. The main causes of NAFLD are associated with insulin resistance, severe lipid metabolism disorders, oxidative stress and inflammation. Previous studies have reported that ginger has positive metabolic results.

Aim

The aim of this study was to determine the effect of ginger powder supplement on lipid profiles, insulin resistance, liver enzymes, inflammatory cytokines and antioxidant status in patients with NAFLD.

Methods

In this randomized clinical trial, 46 people with NAFLD were parted into two groups and subjected to the ginger or placebo capsules (3 capsules daily, each containing 500 mg of ginger or wheat flour) over 12 weeks. All patients received a diet with balanced energy and physical activity during the intervention period. Liver ultrasonography, anthropometric indices and biochemical parameters were measured before and after intervention.

Results

No significant difference was found between the two groups in the baseline variables at the beginning of the study. At the end of the study, serum levels of alanine aminotransferase (ALT), total cholesterol, low-density lipoprotein (LDL-C), fasting blood glucose, and insulin resistance index (HOMA), C-reactive protein (hs-CRP), and fetuin-A in the group receiving a ginger supplement significantly decreased compared to placebo. However, there was no significant difference between the two groups in body weight, fasting insulin, HDL-C, triglyceride, adiponectin, alpha-tumor necrosis factor (TNF-α), total antioxidant capacity (TAC), gamma-glutamyl transferase (GGT), aspartate aminotransferase (AST), fatty liver index (FLI), fatty liver grade and blood pressure.

Conclusion

The ginger supplement may be used as a complementary therapy along with existing therapies to reduce insulin resistance, liver enzymes and inflammation in patients with non-alcoholic fatty liver.

The effect of ginger supplementation on IL2, TNFα, and IL1β cytokines gene expression levels in patients with active rheumatoid arthritis: A randomized controlled trial

Background: Rheumatoid arthritis (RA) is a chronic autoimmune and inflammatory disease that affects the joints and consequently leads to the destruction of cartilage and bone lesions. Traditionally, ginger has been consumed in treatment of osteoarthritis, joint and muscle pain, neurological diseases, and inflammation of gums, tooth pain, asthma, stroke, diabetes, and constipation. The aim of this study was to determine the effect of ginger on some immunological and inflammatory markers in patients with rheumatoid arthritis. Methods: In this study, which was performed during 2013-2016, 66 patients with active rheumatoid arthritis who referred to the rheumatology clinic at Shariati hospital were en-rolled. Patients were randomly divided into 2 groups: one group consumed 1.5 gr ginger per day, and the other group took roasted wheat flour (placebo), respectively. To determine the effect of confounding factors on the findings of the study, questionnaires for nutrient intake, physical activity, and medication were filled, and BMI was measured. For each participant, at the beginning and end of the study, Serum hs-CRP and mRNA levels of IL-1β, IL-2 and TNF-α were determined by ELISA and Quantitative Real Time PCR, respectively. Statistical analysis was performed using SPSS software. Significance level was set at p<0.05. Results: Results of the study showed ginger powder supplementation caused a significant decline in CRP (p=0.050) and IL-1β mRNA level (p=0.021). TNFα mRNA levels reduced in ginger group compared to placebo groupalthough the difference was not significant between the 2 groups (p=0.093). Ginger had no effects on IL2 gene expression. Conclusion: This study showed that ginger reduces inflammatory factors hs-CRP and IL-1β gene expression in patients with active RA and it seems that ginger can improve the inflam-mation in the patients.

Western diet-induced fear memory impairment is attenuated by 6-shogaol in C57BL/6N mice

Dementia is a progressive cognitive diminution impeding with normal daily activities that is constantly on the increase. Currently, the estimated prevalence is 50 million affected people worldwide, a figure expected to triple within the next 30 years. While the pathophysiology of the different types of dementia is complex, likely involving the interplay between multiple genetic and environmental factors, strong evidence points towards an important link between diet and cognitive health. Here we examined the consequences of high-fat, high-sugar Western diet (HFSD)-induced obesity on cognitive performance in the fear conditioning task in mice and explored a possible beneficial effect of 6-shogaol (6S), an active constituent of ginger, in this model. Chronic exposure to HFSD significantly enhanced body weight gain in C57BL/6N mice and this effect was prevented by treatment with 6S. HFSD + vehicle-treated mice presented with a selective deficit in cued fear memory, which was not observed in HFSD + 6S-treated animals. The findings of this study provide first evidence for a beneficial effect of 6S on HFSD-induced obesity and emotional memory deficit in mice.

Zingiber officinale formulation reduces hepatic injury and weight gain in rats fed an unhealthy diet

This study investigated the ability of formulation containing Zingiber officinale (ginger) to reverse health changes promoted by unhealthy diet in Wistar rats. Five compounds from the gingerol family and three from the shogaol family were identified in the chromatographic analyzes of the extract. The animals were fed a combination of unhealthy foods, the cafeteria diet, which promoted increases in body weight, hepatocyte nucleus area, total hepatocyte area and liver fat accumulation, as well as reduced hepatic glutathione S-transferase concentration, compared to the control group, which received commercial chow. The treatment with ginger improved all these results, highlighting the reduction of 10% of body weight and 66% of the total area of lipid droplets deposited, compared to the group that received the cafeteria diet. Ginger treatments also attenuated lipid peroxidation, with a mean reduction of 41% in malondialdehyde levels and a mean increase of 222% in glutathione S-transferase activity in the liver. The cafeteria diet and ginger extract did not promote significant changes in glycemic and lipid profile, liver weight and liver enzymes compared to the control group. We suggest that ginger can have beneficial effects on health complications associated with unhealthy diet, such as excessive adiposity, oxidative stress and hepatic injury.

The effect of ginger supplementation on some immunity and inflammation intermediate genes expression in patients with active Rheumatoid Arthritis

OBJECTIVE

Rheumatoid Arthritis (RA) is an autoimmune disease. The aim of this study was to investigate the effect of ginger supplementation on the expression of some immunity and inflammation intermediate genes in patients who suffer from RA.

METHODS

In this randomized double-blind placebo-controlled clinical trial, seventy active RA patients were allocated randomly into two groups who either received 1500 mg ginger powder or placebo daily for 12 weeks. Disease activity score and gene expression of NF-κB, PPAR-γ, FoxP3, T-bet, GATA-3, and RORγt as immunity and inflammation intermediate factors were measured using quantitative real-time PCR before and after the intervention.

RESULTS

After the intervention, FoxP3 genes expression increased significantly within ginger group and between the two groups (P-value = 0.02). Besides, T-bet and RORγt genes expression decreased significantly between the two groups (P-value < 0.05). In ginger group, PPAR-γ genes expression increased significantly (P-value = 0.047) but the difference between the two groups wasn't statistically significant (P-value = 0.12). The reduction in disease activity score was statistically significant within ginger group and between the two groups after the intervention.

CONCLUSION

It seems that ginger can improve RA by decreasing disease manifestations via increasing FoxP3 genes expression and by decreasing RORγt and T-bet genes expression.

Ginger (Zingiber officinale Rosc.) Ameliorated Metabolic and Inflammatory Dysfunction Induced by High-Refined Carbohydrate-Containing Diet in Mice

This study aimed to evaluate the effects and the mechanisms of ginger extract intake in the adiposity gain, metabolic and inflammatory disturbances induced by a high-refined carbohydrate (HC) diet in mice. Ginger extract at doses of 200, 600, and 1800 mg/kg was supplemented in the daily food of obese Balb/c mice during an 8-week experiment. Our findings indicate that consumption of high doses of ginger extracts prevents the increase of adiposity induced by HC diet, improves lipid profile, and promotes decrease of inflammatory markers in mice. We showed that ginger addition to HC diet leads to decrease in the recruitment of cells visualized in vivo in the microvasculature of adipose tissue, decrease of inflammatory cytokines, and increase of adiponectin serum levels. These results indicate that the consumption of ginger decreases the negative metabolic consequences induced by HC diet.

Ginger Extract Ameliorates Obesity and Inflammation via Regulating MicroRNA-21/132 Expression and AMPK Activation in White Adipose Tissue

Ginger is a plant whose rhizome is used as a spice or folk medicine. We aimed to investigate the effect of ginger root extract on obesity and inflammation in rats fed a high-fat diet. Sprague-Dawley rats were divided into three groups and fed either a 45% high-fat diet (HF), HF + hot-water extract of ginger (WEG; 8 g/kg diet), or HF + high-hydrostatic pressure extract of ginger (HPG; 8 g/kg diet) for 10 weeks. The HPG group had lower body weight and white adipose tissue (WAT) mass compared to the HF group. Serum and hepatic lipid levels of HPG group were lower, while fecal lipid excretion of the HPG group was higher than that of the HF group. In the WAT of the WEG and HPG groups, mRNA levels of adipogenic genes were lower than those of the HF group. Moreover, HPG group had lower mRNA levels of pro-inflammatory cytokines than did the HF group. MicroRNA (miR)-21 expression was down-regulated by both WEG and HPG. Additionally, miR-132 expression was down-regulated by HPG. The adenosine monophosphate-activated protein kinase (AMPK) activity of HPG group was greater than that of the HF group. HPG may have beneficial effects on obesity and inflammation, partially mediated by regulation of miR-21/132 expression and AMPK activation in WAT.

Pro-inflammatory cytokines: The link between obesity and osteoarthritis

Osteoarthritis (OA), characterized by joint malfunction and chronic disability, is the most common form of arthritis. Clinical and animal experiments reveal that age-related OA is associated with many factors such as age, sex, trauma, and obesity. One of the most influential and modifiable risk factors is obesity. Obesity not only increases mechanical stress on the tibiofemoral cartilage, but also leads to a higher prevalence of OA in non-weight-bearing areas. There is a link between obesity and inflammation. Adipose tissues play a crucial role in this context because they are the major source of cytokines, chemokines, and metabolically-active mediators named adipokines. The adipokines, including adiponectin and leptin, have been demonstrated to regulate inflammatory immune responses in cartilage. Obese people and animals show a higher level of serum tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL)-1β and IL-6, all of which are produced by macrophages derived from adipose tissue. These pro-inflammatory cytokines regulate the proliferation and apoptosis of adipocytes, promote lipolysis, inhibit lipid synthesis and decrease blood lipids through autocrine and paracrine mechanisms. Elevated levels of TNF-α, IL-1 and IL-6 have been found in the synovial fluid, synovial membrane, subchondral bone and cartilage of OA patients, confirming their important roles in OA pathogenesis. TNF-α, IL-6 and IL-1 are the factors released by fat to negatively regulate cartilage directly. Moreover, TNF-α, IL-1 and IL-6 can induce the production of other cytokines, matrix metalloproteinases (MMPs) and prostaglandins and inhibit the synthesis of proteoglycans and type II collagen; thus, they play a pivotal role in cartilage matrix degradation and bone resorption in OA. Activated chondrocytes also produce MMP-1, MMP-3, MMP-13, and aggrecanase 1 and 2 (ADAMTS-4, ADAMTS-5). In addition, IL-1, TNF-α and IL-6 may cause OA indirectly by regulating release of adiponectin and leptin from adipocytes. In this review, we first summarize the relationship between obesity and inflammation. Then we summarize the roles of IL-1, TNF-α and IL-6 in OA. We further discuss how IL-1, TNF-α and IL-6 regulate the communication between fat and OA, and their pathological roles in obesity-related OA. Lastly, we discuss the possibility of using the pro-inflammatory signaling pathway as a therapeutic target to develop drugs for obesity-related OA.

Antibiofilm and Antivirulence Activities of 6-Gingerol and 6-Shogaol Against Candida albicans Due to Hyphal Inhibition

Candida albicans is an opportunistic pathogen and responsible for candidiasis. C. albicans readily forms biofilms on various biotic and abiotic surfaces, and these biofilms can cause local and systemic infections. C. albicans biofilms are more resistant than its free yeast to antifungal agents and less affected by host immune responses. Transition of yeast cells to hyphal cells is required for biofilm formation and is believed to be a crucial virulence factor. In this study, six components of ginger were investigated for antibiofilm and antivirulence activities against a fluconazole-resistant C. albicans strain. It was found 6-gingerol, 8-gingerol, and 6-shogaol effectively inhibited biofilm formation. In particular, 6-shogaol at 10 μg/ml significantly reduced C. albicans biofilm formation but had no effect on planktonic cell growth. Also, 6-gingerol and 6-shogaol inhibited hyphal growth in embedded colonies and free-living planktonic cells, and prevented cell aggregation. Furthermore, 6-gingerol and 6-shogaol reduced C. albicans virulence in a nematode infection model without causing toxicity at the tested concentrations. Transcriptomic analysis using RNA-seq and qRT-PCR showed 6-gingerol and 6-shogaol induced several transporters (CDR1, CDR2, and RTA3), but repressed the expressions of several hypha/biofilm related genes (ECE1 and HWP1), which supported observed phenotypic changes. These results highlight the antibiofilm and antivirulence activities of the ginger components, 6-gingerol and 6-shogaol, against a drug resistant C. albicans strain.

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.

A systematic review of the anti-obesity and weight lowering effect of ginger (Zingiber officinale Roscoe) and its mechanisms of action

Recently, the beneficial effects of ginger on obesity is taken into consideration. Albeit, it seems that the anti-obesity effect of ginger and its mechanism of action has not yet been reviewed. Therefore, the aim of this study was to systematically review the effect of Zingiber officinale Roscoe on obesity management. Databases including PubMed, Scopus, Google scholar, and Science Direct were searched from 1995 until May 2017 using the definitive keywords. Searching was limited to articles with English language. All of the relevant human and animal studies and also in vitro studies were included. Review articles, abstract in congress, and also other varieties of ginger were excluded. Eligibility of included articles were evaluated by 3 reviewers, which also extracted data. Articles were critically assessed individually for possible risk of bias. Twenty-seven articles (6 in vitro, 17 animal, and 4 human studies) were reviewed. Most of the experimental studies supported the weight lowering effect of ginger extract or powder in obese animal models, whereas the results of the available limited clinical studies showed no changes or slight changes of anthropometric measurements and body composition in subjects with obesity. Ginger could modulate obesity through various potential mechanisms including increasing thermogenesis, increasing lipolysis, suppression of lipogenesis, inhibition of intestinal fat absorption, and controlling appetite. This review article provides some convincing evidence to support the efficacy of ginger in obesity management and demonstrates the importance of future clinical trials.

Occurrence, biological activity and metabolism of 6-shogaol

As one of the main bioactive compounds of dried ginger, 6-shogaol has been widely used to alleviate many ailments. It is also a major pungent flavor component, and its precursor prior to dehydration is 6-gingerol, which is reported to be responsible for the pungent flavor and biological activity of fresh ginger. Structurally, gingerols including 6-gingerol have a β-hydroxyl ketone moiety and is liable to dehydrate to generate an α,β-unsaturated ketone under heat and/or acidic conditions. The conjugation of the α,β-unsaturated ketone skeleton in the chemical structure of 6-shogaol explicates its higher potency and efficacy than 6-gingerol in terms of antioxidant, anti-inflammatory, anticancer, antiemetic and other bioactivities. Research on the health benefits of 6-shogaol has been conducted and results have been reported recently; however, scientific data are scattered due to a lack of systematic collection. In addition, action mechanisms of the preventive and/or therapeutic actions of 6-shogaol remain obscurely non-collective. Herein, we review the preparations, biological activity and mechanisms, and metabolism of 6-shogaol as well as the properties of 6-shogaol metabolites.

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.

Effects of Ginger (Zingiber officinale Roscoe) on Type 2 Diabetes Mellitus and Components of the Metabolic Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective

This article aims to assess the effects of ginger (Zingiber officinale Roscoe) on type 2 diabetes mellitus (T2DM) and/or components of the metabolic syndrome (MetS).

Methods

Electronic literature was searched in PubMed, Embase, the Cochrane Library, Chinese Biomedical Database, China National Knowledge Infrastructure, and Wanfang Database from inception of the database to May 19, 2017, and supplemented by browsing reference lists of potentially eligible articles. Randomized controlled trials on research subjects were included. Data were extracted as a mean difference (MD) and 95% confidence interval (CI). Subgroup analysis of fasting blood glucose (FBG) was performed.

Results

10 studies met the inclusion criteria with a total of 490 individuals. Ginger showed a significant beneficial effect in glucose control and insulin sensitivity. The pooled weighted MD of glycosylated hemoglobin (HbA1c) was −1.00, (95% CI: −1.56, −0.44; P < 0.001). Subgroup analysis revealed that ginger obviously reduced FBG in T2DM patients (−21.24; 95% CI: −33.21, −9.26; P < 0.001). Meanwhile, the significant effects of improvement of lipid profile were observed. Most analyses were not statistically heterogeneous.

Conclusion

Based on the negligible side effects and obvious ameliorative effects on glucose control, insulin sensitivity, and lipid profile, ginger may be a promising adjuvant therapy for T2DM and MetS.

Molecular mechanisms of the anti-obesity effect of bioactive ingredients in common spices: a review

The mechanisms of the anti-obesity effects of bioactive compounds in common spices in adipocytes, animal models and human participants have been reviewed.

Chronic ethanol increases calcium/calmodulin-dependent protein kinaseIIδ gene expression and decreases monoamine oxidase amount in rat heart muscles: Rescue effect of Zingiber officinale (ginger) extract

OBJECTIVE

Association between chronic alcohol intake and cardiac abnormality is well known; however, the precise underlying molecular mediators involved in ethanol-induced heart abnormalities remain elusive. This study investigated the effect of chronic ethanol exposure on calcium/calmodulin-dependent protein kinase IIδ (CaMKIIδ) gene expression and monoamine oxidase (MAO) levels and histological changes in rat heart. It was also planned to find out whether Zingiber officinale (ginger) extract mitigated the abnormalities induced by ethanol in rat heart.

METHODS

Male wistar rats were divided into three groups of eight animals each: control, ethanol, and ginger extract treated-ethanol (GETE) groups.

RESULTS

After 6 weeks of treatment, the results revealed a significant increase in CaMKIIδtotal and isoforms δ2 and δ3 of CaMKIIδ gene expression as well as a significant decrease in the MAO levels in the ethanol group compared to that in the control group. Moreover, compared to the control group, the ethanol group showed histological changes, such as fibrosis, heart muscle cells proliferation, myocyte hypertrophy, vacuolization, and focal lymphocytic infiltration. Consumption of ginger extract along with ethanol ameliorated CaMKIIδtotal. In addition, compared to the ethanol group, isoforms gene expression changed and increased the reduced MAO levels and mitigated heart structural changes.

CONCLUSION

These findings indicate that ethanol-induced heart abnormalities may, in part, be associated with Ca2+ homeostasis changes mediated by overexpression of CaMKIIδ gene and the decrease of MAO levels and that these effects can be alleviated by using ginger extract as an antioxidant and anti-inflammatory agent.

Polyphenols and their effects on diabetes management: A review

Background: Type 2 diabetes is a growing public health problem and is associated with increased morbidity and mortality. The worldwide prevalence of type 2 diabetes is rising. Polyphenols, such as flavonoids, phenolic acid, and stilbens, are a large and heterogeneous group of phytochemicals in plant-based foods. In this review, we aimed at assessing the studies on polyphenols and diabetes management. Methods: A literature search in the PubMed, EMBASE, Scopus, and ISI Web of Science databases was conducted to identify relevant studies published from 1986 to Jan 2017. Results: Several animal models and a limited number of human studies have revealed that polyphenols decrease hyperglycemia and improve acute insulin secretion and insulin sensitivity. The possible mechanisms include decrease in glucose absorption in the intestine, inhibition of carbohydrates digestion, stimulation of insulin secretion, modulation of glucose release from the liver, activation of insulin receptors and glucose uptake in insulin-sensitive tissues, modulation of intracellular signaling pathways, and gene expression. Conclusion: Growing evidence indicates that various dietary polyphenols may influence blood glucose at different levels and may also help control and prevent diabetes complication. However, we still need more clinical trials to determine the effects of polyphenols- rich foods, their effective dose, and mechanisms of their effects in managing diabetes.