The ethanol extract of Zingiber zerumbet Smith attenuates non-alcoholic fatty liver disease in hamsters fed on high-fat diet

Zingiber zerumbet: A Scoping Review of its Medicinal Properties

Zingiber zerumbet, a plant native to tropical and subtropical Asia, has a vast range of traditional uses and has been continuously studied for its medicinal properties. However, a systematic methodological approach in evidence synthesis on the plant's efficacy is lacking, and there is a need to elicit the current research status of this plant. This scoping review was conducted to systematically explore and collate the available scientific evidence on the efficacy of Z. zerumbet and its main phytoconstituents in various formulations, their biological mechanisms, and their safety. Results included 54 articles consisting of animal studies, while there were no published human studies. Only half of the included studies provided adequate reporting on the quality-related details of Z. zerumbet formulations. Identified pharmacological activities were analgesic, anti-inflammatory, anti-diabetic, anti-hyperlipidemic, anti-neoplastic, immunomodulatory, antioxidant, antipyretic, hepatoprotective, nephroprotective, gastroprotective, and locomotor-reducing activities. Notably, the ethanolic extract of Z. zerumbet was found to be well tolerated for up to 28 days. In conclusion, Z. zerumbet and zerumbone have various pharmacological effects, especially in analgesic and anti-inflammatory models. However, there is still a pressing need for comprehensive safety data to conduct clinical trials.

The promising roles of medicinal plants and bioactive compounds on hepatic lipid metabolism in the treatment of non-alcoholic fatty liver disease in animal models: molecular targets

Imbalance in hepatic lipid metabolism can lead to an abnormal triglycerides deposition in the hepatocytes which can cause non-alcoholic fatty liver disease (NAFLD). Four main mechanisms responsible for regulating hepatic lipid metabolism are fatty acid uptake, de novo lipogenesis, lipolysis and fatty acid oxidation. Controlling the expression of transcription factors at molecular level plays a crucial role in NAFLD management. This paper reviews various medicinal plants and their bioactive compounds emphasising mechanisms involved in hepatic lipid metabolism, other important NAFLD pathological features, and their promising roles in managing NAFLD through regulating key transcription factors. Although there are many medicinal plants popularly investigated for NAFLD treatment, there is still little information and scientific evidence available and there has been no research on clinical trials scrutinised on this matter. This review also aims to provide molecular information of medicinal plants in NALFD treatment that might have potentials for future scientifically controlled studies.

A systematic review and meta-analysis of preclinical and clinical studies on the efficacy of ginger for the treatment of fatty liver disease

Fatty liver disease (FLD) is the most common chronic liver disease worldwide. The pathogenesis of this disease is closely related to obesity and insulin resistance. Ginger has hypolipidemic and antioxidant effects and acts as an insulin sensitizer. This study aims to evaluate the effect of ginger supplementation on the fatty liver. A comprehensive search of Medline/PubMed, Embase, Scopus, Web of Science/ISI, and Cochrane databases was conducted without time or language restrictions. Eighteen eligible studies were identified, including 17 in-vivo experiments in quantitative analysis and 3 clinical trials in qualitative analysis. The present study provides comprehensive evidence of the efficacy of ginger to improve the liver levels of cholesterol (-5.60 mg/g), triglycerides (TG, -4.28 mg/g), malondialdehyde (-3.16 nmol/mg), catalase (CAT) (3.35 nmol/mg), superoxide dismutase (SOD, 3.01 U/mg), serum levels of alanine aminotransferase (ALT, -2.85 U/L), aspartate aminotransferase (AST, -0.98 U/L), TG (-4.98 mg/dL), low-density lipoprotein (LDL, -3.94 mg/dL), total cholesterol (TC, -3.45 mg/dL), high-density lipoprotein (HDL, 1.27 mg/dL), and fasting blood sugar (FBS, -2.54 mg/dL). Ginger administration may reduce many clinical aspects of FLD by several mechanisms, including insulin-sensitive effects, stimulating the expression of antioxidant enzymes, reducing the generation of reactive oxygen species (ROS), having antidyslipidemic activities, and reducing hepatic fat content. However, future clinical trials are essential to investigate the clinical application of ginger in this area.

A comprehensive review on phytochemicals for fatty liver: are they potential adjuvants?

Non-alcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of metabolic syndrome and, as such, is associated with obesity. With the current and growing epidemic of obesity, NAFLD is already considered the most common liver disease in the world. Currently, there is no official treatment for the disease besides weight loss. Although there are a few synthetic drugs currently being studied, there is also an abundance of herbal products that could also be used for treatment. With the World Health Organization (WHO) traditional medicine strategy (2014-2023) in mind, this review aims to analyze the mechanisms of action of some of these herbal products, as well as evaluate toxicity and herb-drug interactions available in literature.

Cold-pressed raspberry seeds oil ameliorates high-fat diet triggered non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is considered one of the most serious public health problems affecting liver. The reported beneficial impact of raspberries on obesity and associated metabolic disorder makes it a suitable candidate against NAFLD. In the current study, the chemical profile of raspberry seed oil (RO) was characterized by analysis of fatty acid and tocopherol contents using high-performance liquid chromatography (HPLC) in addition to the determination of total phenolic and flavonoids. High levels of unsaturated fatty acids, linoleic acid (49.9%), α-linolenic acid (25.98%), and oleic acid (17.6%), along with high total tocopherol content (184 mg/100 gm) were detected in oil. The total phenolic and flavonoid contents in RO were estimated to be 22.40 ± 0.25 mg gallic acid equivalent (GAE)/100 mg oil and 1.34 ± 0.15 mg quercetin (QU)/100 mg, respectively. Anti-NAFLD efficacy of RO at different doses (0.4 and 0.8 mL) in a model of a high-fat diet (HFD) fed rats was assessed by estimating lipid profile, liver enzyme activity, glucose and insulin levels as well as adipokines and inflammatory marker. Peroxisome proliferator-activated receptor γ (PPARγ), which is a molecular target for NAFLD was also tested. Liver histopathology was carried out and its homogenate was used to estimate oxidative stress markers. Consumption of RO significantly improved lipid parameters and hepatic enzyme activities, reduced insulin resistance and glucose levels, significantly ameliorated inflammatory and oxidative stress markers. Furthermore, RO treatment significantly modulated adipokines activities and elevated PPARγ levels. Raspberry seed oil administration significantly improved these HFD induced histopathological alterations. Moreover, a molecular docking study was performed on the identified fatty acids and tocopherols. Among the identified compounds, oleic acid, α-linolenic acid and γ-tocopherol exhibited the highest docking score as PPARγ activator posing them as a potential anti-NAFLD drug leads. Study findings suggest RO as an effective therapeutic candidate for ameliorating NAFLD.

Phytotherapy as Multi-Hit Therapy to Confront the Multiple Pathophysiology in Non-Alcoholic Fatty Liver Disease: A Systematic Review of Experimental Interventions

Non-alcoholic fatty liver disease (NAFLD), or metabolic dysfunction-associated fatty liver disease (MAFLD), is a metabolic condition distinguished by fat deposition in the hepatocytes. It has a prevalence of about 25% worldwide and is associated with other conditions such as diabetes mellitus, obesity, hypertension, etc. Background and Objectives: There is currently no approved drug therapy for NAFLD. Current measures in the management of NAFLD include lifestyle modification such as an increase in physical activity or weight loss. Development of NAFLD involves a number of parallel hits: including genetic predisposition, insulin resistance, disordered lipid metabolism, mitochondrial dysfunction, lipotoxicity, oxidative stress, etc. Herbal therapy may have a role to play in the treatment of NAFLD, due to their numerous bioactive constituents and the multiple pharmacological actions they exhibit. Therefore, this systematic review aims to investigate the potential multi-targeting effects of plant-derived extracts in experimental models of NAFLD. Materials and Methods: We performed a systematic search on databases and web search engines from the earliest available date to 30 April 2021, using relevant keywords. The study included articles published in English, assessing the effects of plant-derived extracts, fractions, or polyherbal mixtures in the treatment of NAFLD in animal models. These include their effects on at least disordered lipid metabolism, insulin resistance/type 2 diabetes mellitus (T2DM), and histologically confirmed steatosis with one or more of the following: oxidative stress, inflammation, hepatocyte injury, obesity, fibrosis, and cardiometabolic risks factors. Results: Nine articles fulfilled our inclusion criteria and the results demonstrated the ability of phytomedicines to simultaneously exert therapeutic actions on multiple targets related to NAFLD. Conclusions: These findings suggest that herbal extracts have the potential for effective treatment or management of NAFLD.

Resveratrol protects against nonalcoholic fatty liver disease by improving lipid metabolism and redox homeostasis via the PPARα pathway

Resveratrol (RSV), a well-known bioactive compound, has been reported to exert a broad range of health benefits. Accumulating evidence suggests that RSV is beneficial for many metabolic diseases, including nonalcoholic fatty liver disease (NAFLD). This study investigated the preventive and therapeutic effects of RSV on high-fat diet (HFD)-induced NAFLD in rats and palmitate acid (PA)-induced hepatocyte steatosis in HepG2 cells. Hepatocytes were incubated with inhibitors of peroxisome proliferator-activated receptor α (PPARα) or short interfering RNAs (siRNAs) targeting PPARα, AMP-activated protein kinase (AMPK), and protein kinase A (PKA) to determine the underlying mechanisms. We found that RSV noticeably ameliorated HFD-induced hepatic steatosis in rats and inhibited PA-induced lipid accumulation in HepG2 cells. Moreover, RSV improved lipid metabolism, enhanced antioxidant capacity, and restored mitochondrial respiratory chain activities. Incubation with inhibitors of PPARα or PPARα siRNA abolished the protective effects of RSV on lipid metabolism and redox homeostasis. Furthermore, RSV activated the PKA/AMPK/PPARα signaling pathway. Our results provided direct evidence for a novel, PPARα-mediated mechanism responsible for the beneficial effects of RSV on hepatic steatosis. These findings may have important theoretical and application prospects for the prevention and treatment of NAFLD. Novelty RSV improved lipid metabolism and redox homeostasis and oxidative stress in NAFLD via the PKA/AMPK/PPARα signaling pathway. RSV may have a greater beneficial effect in the early prevention of hepatic steatosis.

Wild ginseng cambial meristematic cells ameliorate hepatic steatosis and mitochondrial dysfunction in high-fat diet-fed mice

Objectives

The aim of this study was to determine the protective mechanisms of wild ginseng cambial meristematic cells (CMCs) on non-alcoholic fatty liver disease in high-fat diet (HFD)-fed mice.

Methods

Male C57BL/6 mice received either normal-fat diet or HFD for 10 weeks along with wild ginseng CMCs (75, 150 and 300 mg/kg) or vehicle (0.5% carboxyl methyl cellulose) by oral administration once a day. Triglyceride and total cholesterol contents were measured in liver and serum samples. Parameters for hepatic lipid metabolism and mitochondria biogenesis were assessed.

Key findings

Treatment with wild ginseng CMCs markedly attenuated body weight, serum and hepatic lipid contents, and serum aminotransferase activity. While wild ginseng CMCs attenuated the increases in sterol regulatory element-binding transcription factor 1 (SREBP-1) and carbohydrate-responsive element-binding protein (ChREBP) expression, it enhanced the increases in carnitine palmitoyltransferase 1A (CPT1A) and peroxisome proliferator-activated receptor alpha (PPAR-α) expression. HFD decreased glutamate dehydrogenase activity and glutathione content, and increased lipid peroxidation, which were all attenuated by wild ginseng CMCs. Furthermore, wild ginseng CMCs enhanced mitochondrial biogenesis-related factors, including peroxisome proliferator-activated receptor-γ co activator 1α (PGC1α), nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (TFAM).

Conclusions

Wild ginseng CMCs protect against HFD-induced liver injury, which prevents lipid accumulation and mitochondrial oxidative stress, and enhances mitochondrial biogenesis.

[6]-gingerol dampens hepatic steatosis and inflammation in experimental nonalcoholic steatohepatitis

The aim of the study was to investigate the effects of [6]-gingerol ((S)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-3-decanone) in experimental models of non-alcoholic steatohepatitis. HepG2 cells were exposed to 500 µmol/l oleic acid (OA) for 24 h and preincubated for an additional 24 h with [6]-gingerol (25, 50 or 100 µmol/l). [6]-Gingerol (100 µmol/l) inhibited OA-induced triglyceride and inflammatory marker accumulation in HepG2 cells. After being fed a high-fat diet (HFD) for 2 weeks, male golden hamsters were dosed orally with [6]-gingerol (25, 50 or 100 mg/kg/day) once daily for 8 weeks while maintained on HFD. [6]-Gingerol (100 mg/kg/day) alleviated liver steatosis, inflammation, and reversed plasma markers of metabolic syndrome in HFD-fed hamsters. The expression of inflammatory cytokine genes and nuclear transcription factor-κB (NF-κB) were increased in the HFD group; these effects were attenuated by [6]-gingerol. The hepatic mRNA expression of lipogenic genes such as liver X receptor-α, sterol regulating element binding protein-1c and its target genes including acetyl-CoA carboxylase, fatty acid synthase, stearoyl-CoA desaturase 1, and acyl-CoA:diacylglycerol acyltransferase 2 in HFD-fed hamsters was also blocked by [6]-gingerol. [6]-Gingerol may attenuate HFD-induced steatohepatitis by downregulating NF-κB-mediated inflammatory responses and reducing hepatic lipogenic gene expression.

Hypolipidemic Effect and Mechanism of Palmatine from Coptis chinensis in Hamsters Fed High-Fat diet

Palmatine (PAL) is one of the main alkaloids in Coptis chinensis. The present aim was to investigate the hypolipidemic effect and mechanism of palmatine in hamsters fed with high-fat diet (HFD). PAL treatment decreased serum total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) levels, as well as increased fecal excretion of TC and total bile acids (TBA) in hyperlipidemic hamsters. Furthermore, PAL treatment up-regulated low-density lipoprotein receptor (LDLR) and cholesterol 7α-hydroxylase (CYP7A1) mRNA and protein expression and down-regulated apical sodium-dependent bile salt transporter (ASBT) mRNA and protein expression. These results demonstrated that PAL as a potential natural cholesterol lowering agent works by up-regulating LDLR and CYP7A1 mRNA and protein expression, down-regulating ASBT mRNA and protein expression, as well as enhancing fecal excretion of TC and TBA. The findings in our study suggest that palmatine could be a potential natural agent for treating hyperlipidemia.

Plasma cholesterol-lowering activity of gingerol- and shogaol-enriched extract is mediated by increasing sterol excretion

The present study investigated the cholesterol-lowering activity of gingerol- and shogaol-enriched ginger extract (GSE). Thirty hamsters were divided into three groups and fed the control diet or one of the two experimental diets containing 0.5 and 1.0% GSE. Plasma total cholesterol, liver cholesterol, and aorta atherosclerotic plaque were dose-dependently decreased with increasing amounts of GSE added into diets. The fecal sterol analysis showed dietary GSE increased the excretion of both neutral and acidic sterols in a dose-dependent manner. GSE down-regulated the mRNA levels of intestinal Niemann-Pick C1-like 1 protein (NPC1L1), acyl CoA:cholesterol acyltransferase 2 (ACAT2), microsomal triacylglycerol transport protein (MTP), and ATP binding cassette transporter 5 (ABCG5), whereas it up-regulated hepatic cholesterol-7α-hydroxylase (CYP7A1). It was concluded that beneficial modification of the lipoprotein profile by dietary GSE was mediated by enhancing excretion of fecal cholesterol and bile acids via up-regulation of hepatic CYP7A1 and down-regulation of mRNA of intestinal NPC1L1, ACAT2, and MTP.

Lipid-lowering effects of zerumbone, a natural cyclic sesquiterpene of Zingiber zerumbet Smith, in high-fat diet-induced hyperlipidemic hamsters

We investigated the effects of zerumbone, a natural cyclic sesquiterpene of Zingiber zerumbet Smith, on high-fat diet (HFD)-induced hyperlipidemic hamsters. After being fed HFD for 2 weeks, Syrian golden hamsters were dosed orally with zerumbone (25, 50, and 100 mg/kg) once daily for 8 weeks. Decreased plasma levels of TC, TG and LDL-C, as well as the concentrations of hepatic lipids, with a simultaneous increase in fecal lipids were found. The ratios of LDL-C/HDL-C and TC/HDL-C were elevated by zerumbone. Zerumbone exhibited the ability to decreased hepatic mRNA levels of fatty acid synthase, malic enzyme, sterol-regulatory element binding protein and 3-hydroxy-3-methyl-glutaryl-CoA reductase reductase. The hepatic mRNA expression of peroxisome proliferator-activated receptor α, together with its target gene carnitine palmitoyl transferase and acyl-CoA oxidase were also upregulated by zerumbone. Zerumbone is effective to improve dyslipidemia by modulating the genes expression involving in the lipolytic and lipogenic pathways of lipids metabolism.