Beneficial effects of Zingiber officinale on goldthioglucose induced obesity

An Ethnobotanical Survey and Pharmacological and Toxicity Review of Medicinal Plants Used in the Management of Obesity in the North Central Zone of Nigeria

Introduction: Obesity is increasing worldwide. Due to the unavailability of affordable obesity drugs in most parts of Nigeria, many overweight and obese people rely on medicinal plants to manage obesity. Thus, the aim of this study is to document medicinal plants traditionally used in the treatment and management of obesity in the North Central Zone of Nigeria, determine the plants to which pharmacological assessment of their use in obesity management has not been reported, and assess their toxicity based on the literature. Methods: Semistructured questionnaires and interviews were used to assess sociodemographic information of the 700 herb sellers/practitioners (100 for each state) who consented to participate in the study. Information gathered on plants that are traditionally used in the management of obesity included administration/dosage, method of preparation, plant part used, method of growth, and plant type. The field study was conducted over a one-year period, from March 2018 to March 2019. Reports of pharmacological activity pertaining to obesity as well as toxicity of the plants were obtained from the literature via scientific databases (Scopus, Web of Science, PubMed, Google Scholar, SciFinder, AJOL, PubChem, and other web sources) after the field survey. Results: A total of 39 families and 70 plant species were used to treat or manage obesity. The majority of plant species used resulted in the family Leguminosae. The relative frequency of citation (RFC) and percentage values for the five most frequently used plants were as follows: Citrus aurantifolia (0.0500; 3.56%), Citrus limon (0.0457; 3.26%), Garcinia kola (0.0429; 3.05%), Zingiber officinale (0.0429; 3.05%), and Allium sativum (0.0414; 2.95%). The majority of the medications were prepared as decoctions (50.5%), and cultivated plants (62.86%) were in the majority of plants used. Results showed that 23 plants have no pharmacological report for antiobesity activities while among the five frequently used plants, only Garcinia kola was reported toxic in preclinical models. Conclusions: This paper provides a valuable compilation of the plants used in obesity treatment in the study area by indigenous healers, highlights plants with no reported pharmacological activity pertaining to obesity, and indicates the toxicity profile of used plants. However, further studies on the mechanism of action are warranted, especially where no reports were obtained.

Ginger intervention on body weight and body composition in adults: a GRADE-assessed systematic review and dose-response meta-analysis of 27 randomized controlled trials

CONTEXT

Ginger consumption may have an inverse relationship with obesity and metabolic syndrome parameters; however, clinical trials have reported contradictory results.

OBJECTIVE

To systematically review and analyze randomized controlled trials (RCTs) assessing the effects of ginger on body weight and body composition parameters.

METHODS

Databases were searched for appropriate articles up to August 20, 2022. All selected RCTs investigated the impact of ginger on glycemic indices in adults. A random effects model was used to conduct a meta-analysis, and heterogeneity was assessed using the I2 statistic. Net changes in body weight, body mass index (BMI), waist circumference (WC), and percent body fat were used to calculate the effect size, which was reported as a weighted mean difference (WMD) and 95% confidence intervals (CIs). The risk of bias was assessed.

RESULTS

A total of 27 RCTs involving 1309 participants were included. The certainty in the evidence was very low for WC and BMI, and low for body weight and percent body fat as assessed by the GRADE evidence profiles. The meta-analysis showed a significant association between ginger supplementation and a reduction in body weight (WMD, -1.52 kg; 95%CI, -2.37, -0.66; P < 0.001), BMI (WMD, -0.58 kg/m2; 95%CI, -0.87, -0.30; P < 0.001), WC (WMD, -1.04 cm; 95%CI: -1.93, -0.15; P = 0.021), and percent body fat consumption (WMD, -0.87%; 95%CI, -1.71, -0.03; P = 0.042). The results of the nonlinear dose-response analysis showed a significant association between the ginger dose with body weight (Pnonlinearity = 0.019) and WC (Pnonlinearity = 0.042). The effective dose of ginger intervention for body mass reduction was determined to be 2 g/d in dose-response analysis. The duration of ginger intervention had a significant nonlinear relationship with body weight (Pnonlinearity = 0.028) with an effective duration of longer than 8 weeks.

CONCLUSIONS

Our findings provide evidence that ginger consumption may significantly affect body composition parameters nonlinearly. More, well-constructed RCTs are needed.

The Bioprotective Effects of Marigold Tea Polyphenols on Obesity and Oxidative Stress Biomarkers in High-Fat-Sugar Diet-Fed Rats

Background: The research is aimed at exploring the potential of marigold petal tea (MPT), rich in polyphenol contents, against oxidative stress and obesity in a rat model following a high-fat-sugar diet (HFSD). Methods: The MPT was prepared through the customary method of decoction and was subjected to analysis for its polyphenol composition using reversed-phase high-performance liquid chromatography (RP-HPLC). Two specific doses of MPT, namely, 250 and 500 mg/kg body weight (BW), were chosen for the study-referred to as MPT-250 and MPT-500, respectively. Result: The main phenolic acids and flavonoids identified in MPT, with concentrations exceeding 10 mg/100 mL of tea, included catechin, rutin, salicylic acid, gallic acid, sinapic acid, chlorogenic acid, cinnamic acid, and ellagic acid. The total phenolic (TP) and total flavonoid (TF) contents in MPT were measured to be 5.53 and 7.73 mg/g, respectively. Additionally, MPT demonstrated a 57.2% scavenging capacity with 2,2-diphenyl-1-picrylhydrazyl radical. Notably, the administration of a higher dose (MPT-500) showed a significant reduction in body mass index (BMI) and a 51.24% reduction in the rate of increase in BW compared to the HFSD group. The findings indicated that all the treatment groups, that is, orlistat treatment (OT), MPT-250, and MPT-500 groups, experienced reduced levels of serum total cholesterol (TC), triglyceride (TG), and markers of lipoproteins in contrast to the HFSD group. Moreover, MPT helped restore the levels of malondialdehyde (MDA), superoxide dismutase (SOD), and reduced glutathione (GSH), thereby demonstrating its potential in combating oxidative stress. The MPT-500 group also displayed decreased liver and kidney weights and an improved atherogenic index when compared to the HFSD group. Conclusion: The results clearly indicate that a high dosage of MPT showed antiobesity activity which was comparable to the same effects produced by the conventional drug orlistat.

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.

Antioxidant, Anti-Obesity, and Hypolipidemic Effects of Polyphenol Rich Star Anise (Illicium verum) Tea in High-Fat-Sugar Diet-Induced Obesity Rat Model

Star anise (Illicium verum Hook. fil.) is commonly utilized as a culinary and medicinal fruit and is most famous in indigenous systems of medicine. The present research work aims to appraise and validate the potential of polyphenol-rich star anise tea (SAT) on oxidative stress, obesity and related biochemical parameters in high-fat-sugar-diet (HFSD)-induced obesity model in rats. SAT was prepared using the traditional method in warm water. The Reverse Phase High Pressure Liquid Chromatography (RP-HPLC) analysis was performed for the simultaneous determination of phenolic acids and flavonoids in SAT. Two doses (250 and 500 mg/kg body weight) were selected to investigate the anti-obesity potential of SAT using HFSD-induced obese rat model. Major (>5 mg/100 mL) phenolic acids in SAT were p-coumeric acid, gallic aid, cinamic acid, chlorogenic acid and ferulic acid while catechin and rutin were the major flavonoids detected in the SAT. SAT exhibited 51.3% DPPH radical scavenging activity. In vivo study showed that higher doses of SAT (500 mg/kg body weight) significantly reduced the body weight increase (74.82%) and BMI (0.64 g/cm2). Moreover, significant reductions in the levels of serum total cholesterol, triglyceride, LDL and VLDL were recorded in all the treatment groups in comparison to the HFSDC group. Furthermore, SAT reduced the alterations in MDA, SOD and GSH levels of experimental groups thus showing the potential against oxidative stress. The SAT-500 group showed a significant decrease in the elevated kidney and liver weights and atherogenic index in comparison to the HFSDC group. The present study proved that SAT exhibited strong protective effects against obesity and oxidative stress, especially at higher doses.

Methanolic fruit extract of Myrica nagi protects the hypothalamus and attenuates inflammation associated with gold thioglucose- and high-fat diet-induced obesity via various adipokines

BACKGROUND

Myrica nagi is popular in unani and ayurveda. Chemical constituents like myricetin isolated from its fruit has been shown to exert beneficial effects against cardiovascular disease, cancer, inflammatory conditions, and metabolic disorders.

OBJECTIVES

This study aimed to elucidate the anti-obesity effect of the methanolic extract of M. nagi (MEMN) using in vivo animal models of obesity induced by gold thioglucose or a high-fat diet.

MATERIALS AND METHODS

The obese mice were treated or untreated with MEMN for 8 weeks. Thereafter, feed intake, Lee index, and body mass index (BMI); biochemical parameters such as lipid profile, liver enzymes and specific biomarkers of obesity, including insulin, leptin, adiponectin, free fatty acids (FFA), monocyte chemoattractant protein (MCP)-1, and resistin, were recorded. The weight and histopathology of organs and fat tissue were examined to validate the effectiveness of the extract.

RESULTS

MEMN administration at various doses significantly reduced the induced weight gain, feed intake, BMI, and Lee index. Adipose tissue decreased as the MEMN dose increased. MEMN attenuated liver enzyme activity, decreased lipid, leptin, MCP-1, resistin, and FFA levels, and increased adiponectin levels. It also increased protection of liver cells and decreased accumulation of mesenteric fat.

CONCLUSIONS

MEMN supplementation decreased weight and improved obesity serum/plasma lipid biomarker, insulin, leptin, adiponectin, MCP-1, and resistin levels. The weight-reducing activity of MEMN may be mediated by decreased gastrointestinal fat absorption and modulation of inflammation associated signaling pathways, leading to reduced adipose inflammation associated with energy expenditure.

Therapeutic potential of herbal medicine for the management of hyperlipidemia: latest updates

Hyperlipidemia, the most common form of dyslipidemia, is the main source of cardiovascular disorders, characterized by elevated level of total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C) with high-density lipoprotein cholesterol (HDL-C) in peripheral blood. It is caused by a defect in lipid metabolism in the surface of Apoprotein C-II or a defect in lipoprotein lipase activity as well as reported in genetic, dietary and environmental factors. Several electronic databases were investigated as information sources, including Google Scholar, PubMed, Web of Science, Scopus, ScienceDirect, SpringerLink, Semantic Scholar, MEDLINE and CNKI Scholar. The current review focused on the risk factors of dyslipidemia, synthetic medication with their side effects and different types of medicinal plants having significant potential for the management of hyperlipidemia. The management of hyperlipidemia mostly involves a constant decrease in lipid level using different remedial drugs like statin, fibrate, bile acid sequestrates and niacin. However, this extensive review suggested that the consequences of these drugs are arguable, due to their numerous adverse effects. The selected parts of herb plants are used intact or their extracts containing active phytoconstituents to regulate the lipids in blood level. It was also noted that the Chinese herbal medicine and combination therapy is promising for the lowering of hyperlipidemia. This review intends to provide a scientific base for future endeavors, such as in-depth biological and chemical investigations into previously researched topics.

Effects of polyphenol-rich traditional herbal teas on obesity and oxidative stress in rats fed a high-fat-sugar diet

Hibiscus rosa-sinensis and Zingiber officinalis teas are traditionally used for the therapies of various diseases, including obesity. The present research work was planned to appraise the potential of polyphenol-rich extracts of selected herbal plants in obesity and related biochemical parameters of high-fat-sugar diet-induced obese rats. Three herbal teas were prepared from Hibiscus rosa-sinensis flowers and Zingiber officinalis rhizomes and their mixture (3:1, respectively). Total phenolic contents (TPC) of Hibiscus rosa-sinensis and Zingiber officinalis extracts were found to be 5.82 and 1.45 mg/g of dry plant material, measured as GAE, while total flavonoid contents (TFC) were 9.17 and 1.95 mg/g of dry plant material, measured as CE, respectively. Two doses (250 and 500 mg/kg BW) of each tea were administered and body weight, BMI, kidney, liver, and atherogenic indices, TC, TG, HDL, LDL, VLDL, BT, AST, ALT, AP, SC, MDA, SOD, GSH, and TAC of rats groups were measured. Data showed that higher doses of Hibiscus rosa-sinensis significantly reduced the rat's BMI (0.50 g/cm2) in comparison with the high-fat-sugar diet group (0.79 g/cm2). All treatment groups, especially H-500 group, showed a significant decrease in the elevated kidney and liver weights and atherogenic index in comparison with HFSDC groups. Higher doses of Hibiscus rosa-sinensis significantly decreased the levels of AST, ALT, AP, and SC in comparison with the HFSDC group. A significant decrease in the levels of serum TC, TG, LDL, and VLDL was observed in all the treatment groups in comparison with the HFSDC group. Furthermore, all the teas, especially higher doses of Hibiscus rosa-sinensis, prevented the alterations in MDA, SOD, and GSH levels of experimental groups, thus showing the potential against oxidative stress. It can be concluded from these results that Hibiscus rosa-sinensis teas exhibited strong protective effects against obesity and oxidative stress, especially at higher doses.

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.

Non-alcoholic fatty liver disease: An overview of risk factors, pathophysiological mechanisms, diagnostic procedures, and therapeutic interventions

Non-alcoholic fatty liver disease (NAFLD) is a disorder of excessive fat accumulation in the liver, known as steatosis, without alcohol overconsumption. NAFLD can either manifest as simple steatosis or steatohepatitis, known as non-alcoholic steatohepatitis (NASH), which is accompanied by inflammation and possibly fibrosis. Furthermore, NASH might progress to hepatocellular carcinoma. NAFLD and NASH prevalence is in a continuous state of growth, and by 2018, NAFLD became a devastating metabolic disease with a global pandemic prevalence. The pathophysiology of NAFLD and NASH is not fully elucidated, but is known to involve the complex interplay between different metabolic, environmental, and genetic factors. In addition, unhealthy dietary habits and pre-existing metabolic disturbances together with other risk factors predispose NAFLD development and progression from simple steatosis to steatohepatitis, and eventually to fibrosis. Despite their growing worldwide prevalence, to date, there is no FDA-approved treatment for NAFLD and NASH. Several off-label medications are used to target disease risk factors such as obesity and insulin resistance, and some medications are used for their hepatoprotective effects. Unfortunately, currently used medications are not sufficiently effective, and research is ongoing to investigate the beneficial effects of different drugs and phytochemicals in NASH. In this review article, we outline the different risk factors and pathophysiological mechanisms involved in NAFLD, diagnostic procedures, and currently used management techniques.

Antioxidant properties, glycemic indices, and carbohydrate hydrolyzing enzymes activities of formulated ginger-based fruit drinks

The global prevalence of hyperglycemia has been attributed to unhealthy lifestyle and diet. The study assessed the antioxidant properties, glycemic indices, and carbohydrate hydrolyzing enzymes activities of ginger-based fruit drinks. Drinks prepared from blends of ginger (G), pineapple (P), and apple (A) at varied ratios-G50:P40:A10, G50:P30:A20, G50:P20:A30, G50:P10:A40, G100, and a commercial ginger drink (control) were analyzed for phenolic distribution and antioxidant properties using 2,2-diphenyl-1-picrylhydrazyl [DPPH] and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) [ABTS] radical scavenging abilities. The ferric reducing antioxidant property (FRAP), the glycemic indices and carbohydrate hydrolyzing enzymes activities were also investigated. G50:P10:A40 exhibited the highest phenolic distribution, highest DPPH● , ABTS●+ scavenging abilities as well as FRAP. All formulated ginger-based drinks exhibited low glycemic indices, the G50:P10:A40 showed the strongest inhibition against carbohydrate hydrolyzing enzymes. G50:P10:A40 blend may be suitable for the control of hyperglycemia and some degenerative conditions linked with oxidative stress. PRACTICAL APPLICATIONS: Unchecked activities of reactive oxygen species (ROS) are linked to health disorders such as diabetes mellitus, hypertension, cancer, neurodegenerative, and inflammatory diseases. A practical approach to the management of the deleterious effect of ROS is through the consumption of foods rich in nutritional antioxidants. Ginger (Zingiber officinale) is grown globally for its edible rhizome which has varied utilization in culinary and medicinal applications. Drinks produced from blends of ginger, pineapple, and apple were able to scavenge free radicals and able to exhibit hypoglycemic effects by inhibiting carbohydrate hydrolyzing enzymes. The Ginger-based fruit drinks would, therefore, be an effective functional dietary drink in the management and prevention of diabetes mellitus.

Decreased lipoprotein (a) and serum high-sensitivity C-reactive protein levels in male patients with atherosclerosis after supplementation with ginger: A randomized controlled trial

BACKGROUND

Although the antioxidant properties of ginger have been revealed, there is little available information on the effectiveness of ginger on inflammatory disorders such as atherosclerosis. This study was carried out to examine the effect of ginger on improving the complication of atherosclerosis.

METHODS

This study was a double-blind, placebo-controlled, randomized clinical trial conducted on patients with atherosclerosis. Participants in the ginger and control groups received 1600 mg of powdered ginger or placebo (wheat flour) in capsules daily for 8 weeks. Weight, body mass index (BMI), fasting blood sugar (FBS), cholesterol, triglyceride (TG), low-density lipoprotein (LDL), very-low-density lipoprotein (VLDL), high-density lipoprotein (HDL), lipoprotein (a) [Lp(a)], high-sensitivity C-reactive protein (hs-CRP), and total anti-oxidant capacity (TAC) were assessed before and after the intervention.

RESULTS

Ginger consumption in the intervention group significantly reduced serum Lp(a) level (27.25 ± 1.30 ng/ml vs. 23.57 ± 0.97 ng/ml) (P = 0.040) and also the level of hs-CRP in the intervention group was 1.90 ± 0.33 µg/ml and 1.24 ± 0.15 µg/ml (P = 0.010) before and after intervention, respectively, but the levels of Lp(a) and hs-CRP were not decreased significantly in the placebo group. The level of TAC in the ginger group was 0.71 ± 0.05 mM and after the trial was 0.57 ± 0.04 mM (P = 0.050); no significant differences were seen in TAC when ginger was administered at 1600 mg/daily for 60 days. Also the level of Lp(a) and hs-CRP but not TAC reduced significantly in ginger group compared to placebo group after intervention.

CONCLUSION

This study showed that ginger had anti-atherosclerosis and anti-glycemic properties associated through a significant decreased Lp(a) and FBS in patients with atherosclerosis supplemented with ginger.

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.

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.

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.

Biological activities of ginger against cadmium-induced renal toxicity

Our aim was to evaluate the protective and antioxidant effects of ginger extract against cadmium-induced renal toxicity in animal models and to support the use of ginger as anti-renal failure natural remedy. Seventy rats were examined in a 4-week experiment to evaluate the effect of Ginger (Zingiber officinale) at doses of 100 and 200 mg/kg body weight on molecular DNA content, antioxidant status, and renal function in rats intoxicated with cadmium at dose of (5 mg/kg) using biochemical and histological analysis. Renal dysfunction, kidney tissue damage, and oxidative effect were evident in cadmium intoxicated rats as estimated by significant increase in (creatinine, urea), decrease in (creatinine clearance and reabsorption rate of urine albumin), increase in MDA, decrease in total antioxidant status (TAC), reduction in DNA content, and histopathological changes of kidneys' tissues compared to control rats. Treatment with ginger resulted in significant restoring of renal function biomarkers, TAC, molecular DNA, and histological improvements which occurs via free radical scavenging and regenerative mechanisms. The activity of ginger was supported by estimation of bioactive phenolic and falvinods constituents. Twenty-eight polyphenolic compounds were estimated in ginger extract; [6]-gingerol, [6]-shogaol, citral and pyrogallol were the highest amounts in ginger, and supposed to be responsible for its major antioxidant and free radical scavenging activity as shown by In vitro DPPH/β-carotene-linolic acid assay tests. Consequently, ginger extracts could have a potent protective effects against nephrotoxicity induced by various toxicants.

Evaluation of daily ginger consumption for the prevention of chronic diseases in adults: A cross-sectional study

OBJECTIVES

The aim of this study was to assess daily ginger consumption and explore its correlation with chronic diseases among adults and to analyze further how different levels of ginger intake affect the prevalence of chronic diseases.

METHODS

We examined the prevalence rate of chronic diseases (diabetes, hypertension, coronary heart disease [CHD], hyperlipidemia, cerebrovascular disease, fatty liver, anemia, and tumor), as well as the daily ginger intake in a large cross-sectional study. In all, 4628 participants (1823 men and 2805 women) ages 18 to 77 y completed face-to-face dietary and health questionnaires. We extracted diagnoses and investigation results from the participants' health records. The association between the level of ginger intake (0-2 g/d, 2-4 g/d, and 4-6 g/d) and the prevalence of chronic diseases was analyzed by using χ2 statistical test and unconditional logistic model.

RESULTS

Overall, daily ginger consumption was associated with decreased risk for hypertension (odds ratio [OR], 0.92; 95% confidence interval [CI], 0.86-0.98) and CHD (OR, 0.87; 95% CI, 0.78-0.96) in adults ages ≥18 y. Differences were also observed in adults ages ≥40 y: hypertension (OR, 0.92; 95% CI, 0.87-0.99), CHD (OR, 0.87; 95% CI, 0.78-0.97). However, after 20 y, no association was seen for hypertension but there was still a difference between ginger consumption and CHD in adults ages ≥60 y (OR, 0.84; 95% CI, 0.73-0.96). Again, the probability of illness (hypertension or CHD) decreased when the level of daily ginger intake increased.

CONCLUSIONS

These data indicate that ginger has a potential preventive property against some chronic diseases, especially hypertension and CHD, as well as its ability to reduce the probability of illness.

Effects of the Hydroalcoholic Extract of Zingiber officinale on Arginase I Activity and Expression in the Retina of Streptozotocin-Induced Diabetic Rats

BACKGROUND

Emerging evidence suggests that an increased arginase activity is involved in vascular dysfunction in experimental animals. Zingiber officinale Roscoe, commonly known as ginger, has been widely used in the traditional medicine for treatment of diabetes.

OBJECTIVES

This study aimed at investigating the effects of the hydroalcoholic extract of Z. officinale on arginase I activity and expression in the retina of streptozotocin (STZ)-induced diabetic rats.

METHODS

In this experimental study, 16 male Wistar rats weighing 200 - 250 g were assessed. Diabetes was induced via a single intraperitoneal injection of STZ (60 mg/kg body weight). The rats were randomly allocated into four experimental groups. Untreated healthy and diabetic controls received 1.5 mL/kg distilled water. Treated diabetic rats received 200, and 400 mg/kg of the Z. officinale extract dissolved in distilled water (1.5 mL/kg). Body weight, blood glucose and insulin concentration were measured by standard methods. The arginase I activity and expression were determined by spectrophotometric and western blot analysis, respectively.

RESULTS

Our results showed that blood glucose concentration was significantly decreased in diabetic rats treated with the extract compared to untreated diabetic controls (P < 0.01). Treatment with 400 mg/kg of the extract reduced arginase I activity and expression (P < 0.05). A significant elevation in body weight was observed in diabetic rats treated with the extract. Serum insulin was significantly increased in diabetic rats treated with 400 mg/kg of the extract compared to diabetic controls (P < 0.05).

CONCLUSIONS

Our results suggest that the Z. officinale hydroalcoholic extract may potentially be a promising therapeutic option for treating diabetes-induced vascular disorders, possibly through reducing arginase I activity and expression in the retina.

Changes of serum adipocytokines and body weight following Zingiber officinale supplementation in obese women: a RCT

PURPOSE

The present randomized, double-blind, placebo-controlled study aimed to evaluate the effect of Zingiber officinale (ginger) consumption on some metabolic and clinical features of obesity.

METHODS

Eighty eligible obese women (aged 18-45 years) were randomly assigned to either ginger or placebo groups (receiving 2 g/day of ginger powder or corn starch as two 1 g tablets) for 12 weeks. Body mass index (BMI) and body composition were assessed every 4 weeks, and serum levels of leptin, adiponectin, resistin, insulin and glucose were determined before and after intervention. The homeostasis model assessment of insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI) were also calculated.

RESULTS

Ginger consumption significantly decreased BMI, serum insulin and HOMA-IR index, along with increasing QUICKIs as compared to the placebo. Moreover, significant reductions in serum leptin, resistin and glucose were observed in both groups, especially in ginger group with nonsignificant differences between groups. The body composition and serum levels of adiponectin were not significantly changed in study groups.

CONCLUSION

In conclusion, our findings demonstrate a minor beneficial effect of 2 g ginger powder supplementation for 12 weeks on weight loss and some metabolic features of obesity. However, given the lack of data in this area, ongoing clinical trials are needed to further explore ginger's effectiveness.

Effect of Zingiber officinale Supplementation on Obesity Management with Respect to the Uncoupling Protein 1 -3826A>G and ß3-adrenergic Receptor Trp64Arg Polymorphism

The present study aimed to investigate the effect of ginger (Zingiber officinale) supplementation on some obesity-associated parameters, with nutrigenetics approach. Accordingly, 80 eligible obese women (aged 18-45 years) were randomly assigned to receive either ginger (2-g ginger rhizomes powder as two 1-g tablets per day) or placebo supplements (corn starch with the same amount) for 12 weeks. Subjects were tested for changes in body weight, body mass index, waist and hip circumferences, body composition, appetite score, and dietary intake. Moreover, participants were genotyped for the -3826A>G and Trp64Arg polymorphisms of uncoupling protein 1 and ß3-adrenergic receptor genes, respectively. Over 12 weeks, ginger supplementation resulted in a slight but statistically significant decrease in all anthropometric measurements and total appetite score as compared with placebo group, which were more pronounced in subjects with the AA genotype for uncoupling protein 1 and Trp64Trp genotype for ß3-adrenergic receptor gene. However, there was no significant difference in changes of body composition and total energy and macronutrients intake between groups. In conclusion, our findings suggest that ginger consumption has potential in managing obesity, accompanying with an intervention-genotype interaction effect. However, further clinical trials need to explore ginger's efficacy as an anti-obesity agent in the form of powder, extract, or its active components.

The effect of ginger (Zingiber officinale) on glycemic markers in patients with type 2 diabetes

BACKGROUND

Ginger (Zingiber officinale) is one of the functional foods which contains biological compounds including gingerol, shogaol, paradol and zingerone. Ginger has been proposed to have anti-cancer, anti-thrombotic, anti-inflammatory, anti-arthritic, hypolipidemic and analgesic properties. Here, we report the effect of ginger supplementation on glycemic indices in Iranian patients with type 2 diabetes.

METHODS

A double-blind, placebo-controlled, randomized clinical trial was conducted on 20-60 -year-old patients with type 2 diabetes who did not receive insulin. Participants in the intervention and control groups were received 3 g of powdered ginger or placebo (lactose) (in capsules) daily for 3 months. Glycemic indices, total antioxidant capacity (TAC), malondialdehyde (MDA), C-reactive protein (CRP), serum paraoxonase, dietary intake and physical activity were measured at the beginning and end of the study, and after 12 h fasting.

RESULTS

Comparison of the indices after 3 months showed that the differences between the ginger and placebo groups were statistically significant as follows: serum glucose (-19.41 ± 18.83 vs. 1.63 ± 4.28 mg/dL, p < 0.001), HbA1c percentage (-0.77 ± 0.88 vs. 0.02 ± 0.16%, p < 0.001), insulin (-1.46 ± 1.7 vs. 0.09 ± 0.34 μIU/mL, p < 0.001), insulin resistance (-16.38 ± 19.2 vs. 0.68 ± 2.7, p < 0.001), high-sensitive CRP (-2.78 ± 4.07 vs. 0.2 ± 0.77 mg/L, p < 0.001), paraoxonase-1 (PON-1) (22.04 ± 24.53 vs. 1.71 ± 2.72 U/L, p < 0.006), TAC (0.78 ± 0.71 vs. -0.04 ± 0.29 µIU/mL, p < 0.01) and MDA (-0.85 ± 1.08 vs. 0.06 ± 0.08 µmol/L, p < 0.001) were significantly different.

CONCLUSIONS

This report shows that the 3 months supplementation of ginger improved glycemic indices, TAC and PON-1 activity in patients with type 2 diabetes.

Herbal medicines for the treatment of nonalcoholic steatohepatitis: current scenario and future prospects

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

The effect of ginger consumption on glycemic status, lipid profile and some inflammatory markers in patients with type 2 diabetes mellitus

OBJECTIVE

To assess the effect of ginger consumption on glycemic status, lipid profile and some inflammatory markers in patients with type 2 diabetes mellitus.

METHODS

In a double-blinded, placebo-controlled clinical trial, 70 type 2 diabetic patients were enrolled. They allocated randomly into ginger group and control group. They consumed 1600 mg ginger versus 1600 mg wheat flour placebo daily for 12 weeks. Serum sugar, lipids, CRP, PGE2 and TNFα were measured before and after intervention.

RESULTS

Ginger reduced fasting plasma glucose, HbA1C, insulin, HOMA, triglyceride, total cholesterol, CRP and PGE₂ significantly compared with placebo group (p < 0.05). There were no significant differences in HDL, LDL and TNFα between two groups (p > 0.05).

CONCLUSION

Ginger improved insulin sensitivity and some fractions of lipid profile, and reduced CRP and PGE₂ in type 2 diabetic patients. Therefore ginger can be considered as an effective treatment for prevention of diabetes complications.

The effect of ginger powder supplementation on insulin resistance and glycemic indices in patients with type 2 diabetes: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To identify the effect of some herbal products on insulin resistance. Regarding the scientific evidences existing about ginger, this research was therefore carried out to identify the effect of ginger supplementation on insulin resistance and glycemic indices in diabetes mellitus.

METHODS

This is a randomized, double-blind, placebo-controlled trial in which 88 participants affected by diabetes were randomly assigned into ginger (GG) and placebo (PG) groups. The GG received 3 one-gram capsules containing ginger powder whereas the PG received 3 one-gram microcrystalline-containing capsules daily for 8 weeks. HbA1c, fructosamine, fasting blood sugar (FBS), fasting insulin, homeostasis model assessment insulin resistance index (HOMA-IR), β-cell function (β%), insulin sensitivity (S%) and the quantitative insulin sensitivity check index (QUICKI) were assessed before and after the intervention.

RESULTS

FBS mean showed a decrease of 10.5% (p=0.003) in the GG whereas the mean had an increase of 21% in the PG (p=0.01). Variation in HbA1c mean was in line with that of FBS. Statistical difference was found in the two groups before and after the intervention in terms of median of fasting insulin level, S% and HOMA-IR (P<0.005). Moreover QUICKI mean increased significantly in the two groups, the mean difference, however, was significantly higher in the GG.

CONCLUSIONS

The study demonstrated that daily consumption of 3 one-gram capsules of ginger powder for 8 weeks is useful for patients with type 2 diabetes due to FBS and HbA1c reduction and improvement of insulin resistance indices such as QUICKI index.

Hepatoprotective, antioxidant, and ameliorative effects of ginger (Zingiber officinale Roscoe) and vitamin E in acetaminophen treated rats

Ginger is a remedy known to possess a number of pharmacological properties. This study investigated efficacy of ginger pretreatment in alleviating acetaminophen-induced acute hepatotoxicity in rats. Rats were divided into six groups; negative control, acetaminophen (APAP) (600 mg/kg single intraperitoneal injection); vitamin E (75 mg/kg), ginger (100 mg/kg), vitamin E + APAP, and ginger + APAP. Administration of APAP elicited significant liver injury that was manifested by remarkable increase in plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), arginase activities, and total bilirubin concentration. Meanwhile, APAP significantly decreased plasma total proteins and albumin levels. APAP administration resulted in substantial increase in each of plasma triacylglycerols (TAGs), malondialdhyde (MDA) levels, and total antioxidant capacity (TAC). However, ginger or vitamin E treatment prior to APAP showed significant hepatoprotective effect by lowering the hepatic marker enzymes (AST, ALT, ALP, and arginase) and total bilirubin in plasma. In addition, they remarkably ameliorated the APAP-induced oxidative stress by inhibiting lipid peroxidation (MDA). Pretreatment by ginger or vitamin E significantly restored TAGs, and total protein levels. Histopathological examination of APAP treated rats showed alterations in normal hepatic histoarchitecture, with necrosis and vacuolization of cells. These alterations were substantially decreased by ginger or vitamin E. Our results demonstrated that ginger can prevent hepatic injuries, alleviating oxidative stress in a manner comparable to that of vitamin E. Combination therapy of ginger and APAP is recommended especially in cases with hepatic disorders or when high doses of APAP are required.

Effects of ginger (Zingiber officinale) on plasma glucose level, HbA1c and insulin sensitivity in type 2 diabetic patients

The present study was aimed to evaluate the effects of Zingiber officinale on some biochemical parameters in type 2 diabetic (DM2) patients. In a randomized double-blind placebo controlled trial, 64 patients with DM2 were assigned to ginger or placebo groups (receiving 2 g/d of each). A 3 d diet record, anthropometric measurements and concentrations of fasting blood glucose (FPG), HbA1c, lipid profile (including total cholesterol, triglyceride, low density lipoprotein and high density lipoprotein) and also the homeostasis model assessment (HOMA) and quantitative insulin-sensitivity check index (QUICKI) were determined before and after 2 months of intervention. Ginger supplementation significantly lowered the levels of insulin (11.0 ± 2.3 versus 12.1 ± 3.3; p = 0.001), LDL-C (67.8 ± 27.2 versus 89.2 ± 24.9; p = 0.04), TG (127.7 ± 43.7 versus 128.2 ± 37.7; p = 0.03) and the HOMA index (3.9 ± 1.09 versus 4.5 ± 1.8; p = 0.002) and increased the QUICKI index (0.313 ± 0.012 versus 0.308 ± 0.012; p = 0.005) in comparison to the control group; while, there were no significant changes in FPG, TC, HDL-C and HbA1c (p > 0.05). In summary, ginger supplementation improved insulin sensitivity and some fractions of lipid profile in DM2 patients. Therefore it may be considered as a useful remedy to reduce the secondary complications of DM2.

Preventive and Protective Properties of Zingiber officinale (Ginger) in Diabetes Mellitus, Diabetic Complications, and Associated Lipid and Other Metabolic Disorders: A Brief Review

Zingiber officinale (ginger) has been used as herbal medicine to treat various ailments worldwide since antiquity. Recent evidence revealed the potential of ginger for treatment of diabetes mellitus. Data from in vitro, in vivo, and clinical trials has demonstrated the antihyperglycaemic effect of ginger. The mechanisms underlying these actions are associated with insulin release and action, and improved carbohydrate and lipid metabolism. The most active ingredients in ginger are the pungent principles, gingerols, and shogaol. Ginger has shown prominent protective effects on diabetic liver, kidney, eye, and neural system complications. The pharmacokinetics, bioavailability, and the safety issues of ginger are also discussed in this update.

Beneficial effects of ginger (Zingiber officinale) on carbohydrate metabolism in streptozotocin-induced diabetic rats

Zingiber officinale (ZO), commonly known as ginger, has been traditionally used in the treatment of diabetes mellitus. Several studies have reported the hypoglycaemic properties of ginger in animal models. The present study evaluated the antihyperglycaemic effect of its aqueous extract administered orally (daily) in three different doses (100, 300, 500 mg/kg body weight) for a period of 30 d to streptozotocin (STZ)-induced diabetic rats. A dose-dependent antihyperglycaemic effect revealed a decrease of plasma glucose levels by 38 and 68 % on the 15th and 30th day, respectively, after the rats were given 500 mg/kg. The 500 mg/kg ZO significantly (P<0·05) decreased kidney weight (% body weight) in ZO-treated diabetic rats v. control rats, although the decrease in liver weight (% body weight) was not statistically significant. Kidney glycogen content increased significantly (P<0·05) while liver and skeletal muscle glycogen content decreased significantly (P<0·05) in diabetic controls v. normal controls. ZO (500 mg/kg) also significantly decreased kidney glycogen (P<0·05) and increased liver and skeletal muscle glycogen in STZ-diabetic rats when compared to diabetic controls. Activities of glucokinase, phosphofructokinase and pyruvate kinase in diabetic controls were decreased by 94, 53 and 61 %, respectively, when compared to normal controls; and ZO significantly increased (P<0·05) those enzymes' activities in STZ-diabetic rats. Therefore, the present study showed that ginger is a potential phytomedicine for the treatment of diabetes through its effects on the activities of glycolytic enzymes.

Ginger consumption enhances the thermic effect of food and promotes feelings of satiety without affecting metabolic and hormonal parameters in overweight men: a pilot study

Evidence suggests that ginger consumption has anti-inflammatory, anti-hypertensive, glucose-sensitizing, and stimulatory effects on the gastrointestinal tract. This study assessed the effects of a hot ginger beverage on energy expenditure, feelings of appetite and satiety and metabolic risk factors in overweight men. Ten men, age 39.1±3.3 y and body mass index (BMI) 27.2±0.3 kg/m(2), participated in this randomized crossover study. Resting state energy expenditure was measured using indirect calorimetry and for 6h after consumption of a breakfast meal with or without 2 g ginger powder dissolved in a hot water beverage. Subjective feelings of satiety were assessed hourly using visual analog scales (VAS) and blood samples were taken fasted and for 3 h after breakfast consumption. There was no significant effect of ginger on total resting energy expenditure (P=.43) or respiratory quotient (P=.41). There was a significant effect of ginger on thermic effect of food (ginger vs control=42.7±21.4 kcal/d, P=.049) but the area under the curve was not different (P=.43). VAS ratings showed lower hunger (P=.002), lower prospective food intake (P=.004) and greater fullness (P=.064) with ginger consumption versus control. There were no effects of ginger on glucose, insulin, lipids, or inflammatory markers. The results, showing enhanced thermogenesis and reduced feelings of hunger with ginger consumption, suggest a potential role of ginger in weight management. Additional studies are necessary to confirm these findings.

Ginger and its health claims: molecular aspects

Recent research has rejuvenated centuries-old traditional herbs to cure various ailments by using modern tools like diet-based therapy and other regimens. Ginger is one of the classic examples of an herb used for not only culinary preparations but also for unique therapeutic significance owing to its antioxidant, antimicrobial, and anti-inflammatory potential. The pungent fractions of ginger, namely gingerols, shogaols, paradols, and volatile constituents like sesquiterpenes and monoterpenes, are mainly attributed to the health-enhancing perspectives of ginger. This review elucidates the health claims of ginger and the molecular aspects and targets, with special reference to anticancer perspectives, immunonutrition, antioxidant potential, and cardiovascular cure. The molecular targets involved in chemoprevention like the inhibition of NF-κB activation via impairing nuclear translocation, suppresses cIAP1 expression, increases caspase-3/7 activation, arrests cell cycle in G2 + M phases, up-regulates Cytochrome-c, Apaf-1, activates PI3K/Akt/I kappaB kinases IKK, suppresses cell proliferation, and inducts apoptosis and chromatin condensation. Similarly, facts are presented regarding the anti-inflammatory response of ginger components and molecular targets including inhibition of prostaglandin and leukotriene biosynthesis and suppression of 5-lipoxygenase. Furthermore, inhibition of phosphorylation of three mitogen-activated protein kinases (MAPKs), extracellular signal-regulated kinases 1 and 2 (ERK1/2), and c-Jun N-terminal kinase (JNK) are also discussed. The role of ginger in reducing the extent of cardiovascular disorders, diabetes mellitus, and digestive problems has also been described in detail. Although, current review articles summarized the literature pertaining to ginger and its components. However, authors are still of the view that further research should be immediately carried out for meticulousness.

Physiological and therapeutical roles of ginger and turmeric on endocrine functions

The natural product ginger (Zingiber officinale) has active constituents gingerol, Shogaol and Zerumbone, while turmeric (Curcuma longa) contains three active major curcuminoids, namely, curcumin, demethoxycurcumin, and bisdemethoxycurcumin. They have the same scientific classification and are reported to have anti-inflammatory and many therapeutic effects. This article reviews the physiological and therapeutic effects of ginger and turmeric on some endocrine gland functions, and signal pathways involved to mediate their actions. With some systems and adipose tissue, ginger and turmeric exert their actions through some/all of the following signals or molecular mechanisms: (1) through reduction of high levels of some hormones (as: T4, leptin) or interaction with hormone receptors; (2) by inhibition of cytokines/adipokine expression; (3) acting as a potent inhibitor of reactive oxygen species (ROS)-generating enzymes, which play an essential role between inflammation and progression of diseases; (4) mediation of their effects through the inhibition of signaling transcription factors; and/or (5) decrease the proliferative potent by down-regulation of antiapoptotic genes, which may suppress tumor promotion by blocking signal transduction pathways in the target cells. These multiple mechanisms of protection against inflammation and oxidative damage make ginger and curcumin particularly promising natural agents in fighting the ravages of aging and degenerative diseases, and need to be paid more attention by studies.

Regulation of low-density lipoprotein receptor and 3-hydroxy-3-methylglutaryl coenzyme A reductase expression by Zingiber officinale in the liver of high-fat diet-fed rats

Zingiber officinale has been used to control lipid disorders and reported to possess remarkable cholesterol-lowering activity in experimental hyperlipidaemia. In the present study, the effect of a characterized and standardized extract of Zingiber officinale on the hepatic lipid levels as well as on the hepatic mRNA and protein expression of low-density lipoprotein (LDL) receptor and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase was investigated in a high-fat diet-fed rat model. Rats were treated with an ethanol extract of Zingiber officinale (400 mg/kg) extract along with a high-fat diet for 6 weeks. The extract of Zingiber officinale significantly decreased hepatic triglyceride and tended to decrease hepatic cholesterol levels when administered over 6 weeks to the rats fed a high-fat diet. We found that in parallel, the extract up-regulated both LDL receptor mRNA and protein level and down-regulated HMG-CoA reductase protein expression in the liver of these rats. The metabolic control of body lipid homeostasis is in part due to enhanced cholesterol biosynthesis and reduced expression of LDL receptor sites following long-term consumption of high-fat diets. The present results show restoration of transcriptional and post-transcriptional changes in low-density lipoprotein and HMG CoA reductase by Zingiber officinale administration with a high-fat diet and provide a rational explanation for the effect of ginger in the treatment of hyperlipidaemia.

A systematic review of the efficacy and safety of herbal medicines used in the treatment of obesity

This review focuses on the efficacy and safety of effective herbal medicines in the management of obesity in humans and animals. PubMed, Scopus, Google Scholar, Web of Science, and IranMedex databases were searched up to December 30, 2008. The search terms were "obesity" and ("herbal medicine" or "plant", "plant medicinal" or "medicine traditional") without narrowing or limiting search elements. All of the human and animal studies on the effects of herbs with the key outcome of change in anthropometric measures such as body weight and waist-hip circumference, body fat, amount of food intake, and appetite were included. In vitro studies, reviews, and letters to editors were excluded. Of the publications identified in the initial database, 915 results were identified and reviewed, and a total of 77 studies were included (19 human and 58 animal studies). Studies with Cissus quadrangularis (CQ), Sambucus nigra, Asparagus officinalis, Garcinia atroviridis, ephedra and caffeine, Slimax (extract of several plants including Zingiber officinale and Bofutsushosan) showed a significant decrease in body weight. In 41 animal studies, significant weight loss or inhibition of weight gain was found. No significant adverse effects or mortality were observed except in studies with supplements containing ephedra, caffeine and Bofutsushosan. In conclusion, compounds containing ephedra, CQ, ginseng, bitter melon, and zingiber were found to be effective in the management of obesity. Attention to these natural compounds would open a new approach for novel therapeutic and more effective agents.

Protective effects of ethanolic extract of Zingiber officinale rhizome on the development of metabolic syndrome in high-fat diet-fed rats

Metabolic syndrome, including obesity, dyslipidaemia, hyperglycaemia and insulin resistance that predisposes type 2 diabetes is a major disease problem around the world and a plethora of herbal medicines are claimed to be effective in controlling these disorders. The rhizome of Zingiber officinale (Zingiberaceae) is commonly used as a spice in various foods and beverages. Apart from its other traditional medical uses, Z. officinale has been used to control diabetes and dyslipidaemia. In the present study, the protective effects of an ethanolic extract of Z. officinale on the development of metabolic syndrome were investigated in a high-fat diet-fed rat model at doses of 100, 200 and 400 mg/kg body weight. The marked rise in body weights, glucose, insulin, total cholesterol, LDL cholesterol, triglycerides, free fatty acids and phospholipids in serum of the rats that followed 6 weeks of high-fat diet treatment were significantly reduced by Z. officinale treatment. However, no significant change in serum HDL cholesterol was observed either with high-fat diet or Z. officinale compared to both control groups. The present results provide scientific evidence to substantiate the traditional use of Z. officinale in preventing metabolic disorders.

Some phytochemical, pharmacological and toxicological properties of ginger (Zingiber officinale Roscoe): a review of recent research

Ginger (Zingiber officinale Roscoe, Zingiberacae) is a medicinal plant that has been widely used in Chinese, Ayurvedic and Tibb-Unani herbal medicines all over the world, since antiquity, for a wide array of unrelated ailments that include arthritis, rheumatism, sprains, muscular aches, pains, sore throats, cramps, constipation, indigestion, vomiting, hypertension, dementia, fever, infectious diseases and helminthiasis. Currently, there is a renewed interest in ginger, and several scientific investigations aimed at isolation and identification of active constituents of ginger, scientific verification of its pharmacological actions and of its constituents, and verification of the basis of the use of ginger in some of several diseases and conditions. This article aims at reviewing the most salient recent reports on these investigations. The main pharmacological actions of ginger and compounds isolated therefrom include immuno-modulatory, anti-tumorigenic, anti-inflammatory, anti-apoptotic, anti-hyperglycemic, anti-lipidemic and anti-emetic actions. Ginger is a strong anti-oxidant substance and may either mitigate or prevent generation of free radicals. It is considered a safe herbal medicine with only few and insignificant adverse/side effects. More studies are required in animals and humans on the kinetics of ginger and its constituents and on the effects of their consumption over a long period of time.

Analgesic, antiinflammatory and hypoglycaemic effects of ethanol extract of Zingiber officinale (Roscoe) rhizomes (Zingiberaceae) in mice and rats

The present study was undertaken to investigate the analgesic, antiinflammatory and hypoglycaemic effects of Zingiber officinale dried rhizomes ethanol extract (ZOE) in mice and rats. The analgesic effect of ZOE was evaluated by 'hot-plate' and 'acetic acid' analgesic test methods in mice; while the antiinflammatory and hypoglycaemic effects of the plant extract were investigated in rats, using fresh egg albumin-induced pedal oedema, and streptozotocin (STZ)-induced diabetes mellitus models. Morphine (MPN, 10 mg/kg), diclofenac (DIC, 100 mg/kg) and chlorpropamide (250 mg/kg) were used as reference drugs for comparison. ZOE (50-800 mg/kg i.p.) produced dose-dependent, significant (p < 0.05-0.001) analgesic effects against thermally and chemically induced nociceptive pain in mice. The plant extract (ZOE, 50-800 mg/kg p.o.) also significantly (p < 0.05-0.001) inhibited fresh egg albumin-induced acute inflammation, and caused dose-related, significant (p < 0.05-0.001) hypoglycaemia in normal (normoglycaemic) and diabetic rats. The findings of this experimental animal study indicate that Zingiber officinale rhizomes ethanol extract possesses analgesic, antiinflammatory and hypoglycaemic properties; and thus lend pharmacological support to folkloric, ethnomedical uses of ginger in the treatment and/or management of painful, arthritic inflammatory conditions, as well as in the management and/or control of type 2 diabetes mellitus in some rural Africa communities.