Garlic-derived S-allylmercaptocysteine is a hepato-protective agent in non-alcoholic fatty liver disease in vivo animal model

Influence of Garlic on the Glycemic Control and Lipid Profile in Animals with Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-analysis

Nonalcoholic fatty liver disease is the hepatic sign of metabolic syndrome. Here, we aimed to assess the effects of garlic and its major components on fasting plasma glucose, fasting insulin, and lipid profile levels in animal models of nonalcoholic fatty liver disease. A systematic search in PubMed, Scopus, ProQuest, and Web of Science was performed. After the screening process and data extraction, the pooled effect sizes were estimated using a random-effect model and stated as standardized mean differences and a 95% confidence interval. Out of 839 reports, 22 articles were included in the present study. The pooled results revealed that garlic and its components significantly decreased fasting plasma glucose (standardized mean difference: - 0.77, 95% confidence interval: - 1.42 to - 0.12, I2 : 58.85%), fasting insulin (standardized mean difference: - 1.88, 95% confidence interval: - 3.07 to - 0.69, I2 : 70.42%), serum triglyceride (standardized mean difference: - 1.01, 95% confidence interval: - 1.43 to - 0.59, I2 : 61.41%), cholesterol (standardized mean difference: - 1.00, 95% confidence interval: - 1.39 to - 0.60, I2 : 52.12%), and low-density lipoprotein cholesterol (standardized mean difference: - 0.98, 95% CI: - 1.63 to - 0.32, I2 : 71.58%) and increased high-density lipoprotein cholesterol (standardized mean difference: 1.05, 95% confidence interval: 0.52 to 1.58, I2 : 59.39%) levels. The type of animal, nonalcoholic fatty liver disease induction model, kind and duration of intervention, study model, and risk of bias were detected as possible sources of heterogeneity across studies. We conclude that garlic and its major components have a favorable impact on glycemic control and lipid profile in diet-induced nonalcoholic fatty liver disease animal models.

Green Alternatives in Treatment of Liver Diseases: the Challenges of Traditional Medicine and Green Nanomedicine

Over the last decade, liver diseases have become a global problem, with approximately two million deaths per year. The high increase in the mortality rate of these diseases is mostly related to the limitations in the understanding of the evolutionary clinical cases of liver diseases, the low delivery of drugs in the liver, the non-specific administration of drugs, and the side effects generated at the systemic level by conventional therapeutic agents. Today it is common knowledge that phytochemicals have a high curative potential, even in the prevention and/or reversibility of liver disorders; however, even using these green molecules, researchers continue to deal with the same challenges implemented with conventional therapeutic agents, which limits the pharmacological potential of these friendly molecules. On the other hand, the latest advances in nanotechnology have proven that the use of nanocarriers as a delivery system for green active ingredients, as well as conventional ones, increases the pharmacological potential of these active ingredients due to their physicochemical characteristics (size, Zeta potential, etc.,) moldable depending on the therapeutic objective; in addition to the above, it should be noted that in recent years, nanoparticles have been developed for the specific delivery of drugs towards a specific target (stellar cells, hepatocytes, Kupffer cells), depending on the clinical state of the disease in the patient. The present review addresses the challenges of traditional medicine and green nanomedicine as alternatives in the treatment of liver diseases.

Bioactive Compounds for Customized Brain Health: What Are We and Where Should We Be Heading?

Many strides have been made in the field of nutrition that are making it an attractive field not only to nutrition professionals but also to healthcare practitioners. Thanks to the emergence of molecular nutrition, there is a better appreciation of how the diet modulates health at the cellular and molecular levels. More importantly, the advancements in brain imaging have produced a greater appreciation of the impact of diet on brain health. To date, our understanding of the effect of nutrients on brain health goes beyond the action of vitamins and minerals and dives into the intracellular, molecular, and epigenetic effects of nutrients. Bioactive compounds (BCs) in food are gaining a lot of attention due to their ability to modulate gene expression. In addition, bioactive compounds activate some nuclear receptors that are the target of many pharmaceuticals. With the emergence of personalized medicine, gaining an understanding of the biologically active compounds may help with the customization of therapies. This review explores the prominent BCs that can impact cognitive functions and mental health to deliver a potentially prophylactic framework for practitioners. Another purpose is to identify potential gaps in the literature to suggest new research agendas for scientists.

Allium sativum: A potential natural compound for NAFLD prevention and treatment

Introduction

Non-alcoholic fatty liver disease (NAFLD) results from an excessive accumulation of fat particles that causes liver inflammation, which ultimately causes liver damage. There is still considerable uncertainty about the effects of any nutritional supplements compared to no additional intervention. This review aimed to evaluate the efficacy of Allium sativum (A. sativum), known as garlic, in preventing and treating NAFLD.

Methods

A systematic search based on a search strategy consisting of two components of "NAFLD" and "Allium sativum" in databases including PubMed, Web of Science (WoS), and SCOPUS was conducted on papers evaluating the effects of A. sativum on NAFLD treatment and prevention. We obtained studies from inception until 20 September 2022, followed by study selection and data extraction based on our eligibility criteria. Consequently, qualitative and quantitative synthesis was conducted.

Results

Our qualitative analysis reveals that A. sativum consumption is linked to the prevention of NAFLD, especially in males, although qualitative data in this study regarding the therapeutic properties of NAFLD was controversial. Our meta-analysis showed that NAFLD patients treated with A. sativum have significantly declined aminotransferase levels. That is to say, our meta-analysis revealed a lower alanine transaminase (ALT) (SMD = -0.580, 95%CI = -0.822 to -0.338), and aspartate transaminase (AST(SMD = -0.526, 95%CI = -0.767 to -0.284) in NAFLD patients treated with A. sativum compared to the placebo group. Also, pooling data from case-control studies showed that A. sativum consumption decreases the odds of being diagnosed with NAFLD by 46% (OR = 0.538, 95%CI = 0.451-0.625).

Conclusion

A. sativum consumption is not merely associated with NAFLD prevention but also results in a considerable decline in blood aminotransferase levels in patients diagnosed with NAFLD. To put it simply, A. sativum is linked to a decline in AST and ALT, which are considered reliable biomarkers of NAFLD response to treatment. Nevertheless, A. sativum is insufficient to improve NAFLD independent of other dietary amendments and lifestyle modifications.

Natural Foods for the Treatment of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide. The etiology of NAFLD is highly heterogeneous, which occurs and develops under the joint action of metabolism, inflammation, genetics, environment, and gut microbiota. At present, the principal therapeutic modalities targeting NAFLD are lifestyle interventions such as weight loss through diet and exercise. At present, there is no established therapy for the treatment of NAFLD, and many therapies are associated with a variety of side effects. A great number of in vitro and in vivo experiments have indicated that there are many natural foods that have therapeutic potential for NAFLD. This review summarizes the natural foods and their mechanisms that were found in recent years, furthermore, provides further information relevant to the treatment of NAFLD.

Therapeutic Effects and Mechanisms of Action of Garlic (Allium sativum) on Nonalcoholic Fatty Liver Disease: A Comprehensive Systematic Literature Review

Nonalcoholic fatty liver disease (NAFLD) is globally the leading cause of hepatic dysfunction. Garlic has many physiological benefits, including anti-inflammatory, antioxidant, anticancer, lipid-lowering, and antidiabetes effects. The present study aimed to systematically review the effects of garlic (Allium sativum) and its mechanisms of function in managing NAFLD and its associated complications. The guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statements were applied to perform the study (CRD42021289348). The Scopus, Embase, Web of Science, Cochrane PubMed, and Google Scholar databases were searched until February 2022. According to the inclusion criteria, finally, 12 studies were entered into the study. The evidence provided in the study revealed that garlic could regulate the development of NAFLD via several mechanisms of action, such as lowering body weight, modulating lipid and glucose metabolism, and reducing inflammation and oxidative stress (OS). Overall, the beneficial effects of garlic in the treatment of NAFLD make it a potential therapeutic and efficient agent in managing NAFLD and its related risk factors. There is an insufficient number of clinical trials addressing the effects of garlic in humans; therefore, conducting more human research in the future is recommended.

Garlic: A systematic review of the effects on cardiovascular diseases

Allium sativum (garlic) certainly is one of the oldest horticultural crops in the world and presents bioactive compounds that are related to the garlic's effects on human health. Several authors have shown beneficial effects on diabetes, hypertension, dyslipidemia, obesity, and cardiovascular diseases (CVD), which are among the most relevant causes of mortality in the world. The aim of this systematic review was to evaluate the effects of garlic in the risk factors of CVD and evaluate its economic importance. MEDLINE-PubMed, COCHRANE, EMBASE, and Google Scholar databases were searched. The included studies showed that the use of garlic can reduce blood pressure, waist circumference, body mass index, LDL-c, non-HDL-c, total cholesterol, triglycerides, and inflammatory markers. It also can increase the levels of HDL-c and can improve cardiovascular parameters such as coronary artery calcium, microcirculation, epicardial and periaortic adipose tissue, post occlusive reactive hyperemia, low attenuation plaque, carotid intima-media thickness; and carotid intima-media thickness. Due to these reasons, garlic can be considered in the prevention and treatment of CVD risk factors.

Water extract of Ferula lehmanni Boiss. prevents high-fat diet-induced overweight and liver injury by modulating the intestinal microbiota in mice

Obesity, often accompanied by hepatic steatosis, has been associated with an increased risk of health complications such as fatty liver disease and certain cancers. Ferula lehmannii Boiss., a food and medicine homologue, has been used for centuries as a seasoning showing anti-bacterial and anti-oxidant effects on digestive discomfort. In the present study, we sought to investigate whether a short-term oral administration of water extract of Ferula lehmanni Boiss. (WEFL) could prevent high-fat diet (HFD)-induced abnormal weight gain and hepatic steatosis in mice and its underlying mechanisms. WEFL reduced HFD-increased body weight, liver injury markers and inflammatory cytokines (i.e. IL-6 and IL-1β), and inhibited the elevation of AMPKα, SREBP-1c and FAS in HFD. Moreover, WEFL reconstructed the gut microbiota composition by increasing the relative abundances of beneficial bacteria, e.g. Akkermansia spp., while decreasing Desulfovibrio spp. and so on, thereby reversing the detrimental effects of HFD in mice. Removal of the gut microbiota with antibiotics partially eliminated the hepatoprotective effects of WEFL. Notably, WEFL substantially promoted the levels of short-chain fatty acids, especially butyric acid. To clarify the functional components at play in WEFL, we used UPLC-MS/MS to comprehensively detect its substance composition and found it to be a collection of polyphenol-rich compounds. Together, our findings demonstrate that WEFL prevented HFD-induced obesity and liver injury through the hepatic-microbiota axis, and such health-promoting value might be explained by the enriched abundant polyphenols.

Chemical constituents and medicinal properties of Allium species

Allium species, belonging to Alliaceae family, are among the oldest cultivated vegetables used as food. Garlic, onions, leeks and chives, which belong to this family, have been reported to have medicinal properties. The Allium species constituents have been shown to have antibacterial and antioxidant activities, and, in addition, other biological properties. These activities are related to their rich organosulfur compounds. These organosulfur compounds are believed to prevent the development of cancer, cardiovascular, neurological, diabetes, liver diseases as well as allergy and arthritis. There have also been reports on toxicities of these compounds. The major active compounds of Allium species includes, diallyl disulfide, diallyl trisulfide, diallyl sulfide, dipropyl disulfide, dipropyl trisulfide, 1-propenylpropyl disulfide, allyl methyl disulfide and dimethyl disulfide. The aim of this review is to focus on a variety of experimental and clinical reports on the effectiveness, toxicities and possible mechanisms of actions of the active compounds of garlic, onions, leek and chives.

S-Allylmercapto-N-acetylcysteine ameliorates elastase-induced chronic obstructive pulmonary disease in mice via regulating autophagy

Autophagy-impairment is involved in the pathological process of chronic obstructive pulmonary disease (COPD), and relates to inflammation and emphysema in lung injury. This study aimed to elucidate the protective effect of S-Allylmercapto-N-acetylcysteine (ASSNAC) against COPD via regulating the autophagy. Firstly, porcine pancreatic elastase (PPE)-induced COPD model in A549 cells was established, and ASSNAC was verified to alleviate the autophagy-impairment from the results of western blotting analysis of LC3BⅡ/Ⅰ and monodansylcadaverine (MDC) staining of autophagosome. Secondly, Balb/c mice were stimulated by PPE to induce the COPD model in vivo. The histological analysis of lung tissues presented that ASSNAC could alleviate the lung injury induced by PPE. Thirdly, the secretions of NO, TNF-α and IL-1β in serum and BALF were reduced by ASSNAC compared with the PPE group. Finally, the mechanism of therapeutic effects of ASSNAC against COPD through regulating the autophagy-impairment was clarified. That is, ASSNAC inhibits the phosphorylation of PI3K/Akt/mTOR signaling pathways. In a word, this research provides a reference for ASSNAC to be an effective drug for pulmonary diseases.

Hepatoprotective Effect of Mixture of Dipropyl Polysulfides in Concanavalin A-Induced Hepatitis

The main biologically active components of plants belonging to the genus Allium, responsible for their biological activities, including anti-inflammatory, antioxidant and immunomodulatory, are organosulfur compounds. The aim of this study was to synthetize the mixture of dipropyl polysulfides (DPPS) and to test their biological activity in acute hepatitis. C57BL/6 mice were administered orally with DPPS 6 h before intravenous injection of Concanavalin A (ConA). Liver inflammation, necrosis and hepatocytes apoptosis were determined by histological analyses. Cytokines in liver tissue were determined by ELISA, expression of adhesive molecules and enzymes by RT PCR, while liver mononuclear cells were analyzed by flow cytometry. DPPS pretreatment significantly attenuated liver inflammation and injury, as evidenced by biochemical and histopathological observations. In DPPS-pretreated mice, messenger RNA levels of adhesion molecules and NADPH oxidase complex were significantly reduced, while the expression of SOD enzymes was enhanced. DPPS pretreatment decreased protein level of inflammatory cytokines and increased percentage of T regulatory cells in the livers of ConA mice. DPPS showed hepatoprotective effects in ConA-induced hepatitis, characterized by attenuation of inflammation and affection of Th17/Treg balance in favor of T regulatory cells and implicating potential therapeutic usage of DPPS mixture in inflammatory liver diseases.

S-Allylmercaptocysteine improves alcoholic liver disease partly through a direct modulation of insulin receptor signaling

Alcoholic liver disease (ALD) causes insulin resistance, lipid metabolism dysfunction, and inflammation. We investigated the protective effects and direct regulating target of S-allylmercaptocysteine (SAMC) from aged garlic on liver cell injury. A chronic ethanol-fed ALD in vivo model (the NIAAA model) was used to test the protective functions of SAMC. It was observed that SAMC (300 mg/kg, by gavage method) effectively ameliorated ALD-induced body weight reduction, steatosis, insulin resistance, and inflammation without affecting the health status of the control mice, as demonstrated by histological, biochemical, and molecular biology assays. By using biophysical assays and molecular docking, we demonstrated that SAMC directly targeted insulin receptor (INSR) protein on the cell membrane and then restored downstream IRS-1/AKT/GSK3β signaling. Liver-specific knock-down in mice and siRNA-mediated knock-down in AML-12 cells of Insr significantly impaired SAMC (250 μmol/L in cells)-mediated protection. Restoration of the IRS-1/AKT signaling partly recovered hepatic injury and further contributed to SAMC's beneficial effects. Continuous administration of AKT agonist and recombinant IGF-1 in combination with SAMC showed hepato-protection in the mice model. Long-term (90-day) administration of SAMC had no obvious adverse effect on healthy mice. We conclude that SAMC is an effective and safe hepato-protective complimentary agent against ALD partly through the direct binding of INSR and partial regulation of the IRS-1/AKT/GSK3β pathway.

Hepatic steatosis integrated approach: nutritional guidelines and joined nutraceutical administration

BACKGROUND

The nonalcoholic fat liver disease (NAFLD) progresses in 30% of the patients to not alcoholic steatohepatitis (NASH) and subsequently in liver fibrosis and even primary cancer and death. Due to the complex physiopathology of the liver steatosis, NASH is an area orphan of specific drugs, but many authors suggest an integrated treatment based upon diet, lifestyle change, and pharmacology.

METHODS

Our clinical study selected from a wider patient cohort, 13 subjects, appealing to the Second Opinion Medical Consulting Network, for liver and nutritional problems. The diet was integrated with regular prescription of an herbal derivative based on Chrysanthellum americanum and Pistacia lentiscus L. extracts. Clinical data of the recruited patients including body weight, Body Mass Index, were recorded before and after treatment. Each patient underwent pre-post accurate clinical examination and lab exams. The liver stiffness and liver steatosis were evaluated by a trained hepatologist with FibroScan^®.

RESULTS

A significant reduction of anthropometric parameters was detected in all the patients at the end of the study; liver fibrosis and steatosis were instrumentally decreased in 8 subjects, but not significant changes in lab exams and no adverse effects were reported.

CONCLUSIONS

Chrysanthellum americanum and Pistacia lentiscus L. extracts were absolutely safe and effective and gave a substantial contribution to the life quality benefit, metabolic balance and gut function in patients with hepatic steatosis.

Beneficial Effects of Plant-Derived Natural Products on Non-alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease is becoming in one of the most prevalent liver diseases that leads to liver transplantation. This health problem is a multisystem disease with a complex pathogenesis that involves liver, adipose tissue, gut, and muscle. Although several pharmacological agents have been investigated to prevent or treat non-alcoholic fatty liver disease, currently there is no effective treatment for the management of this chronic liver disease. Nonetheless, the use of natural products has emerged as a alternative therapeutic for the treatment of hepatic diseases, including non-alcoholic fatty liver disease, due to its anti-inflammatory, antioxidant, antidiabetic, insulin-sensitizing, antiobesity, hypolipidemic, and hepatoprotective properties. In the present review, we have discussed the evidence from experimental and clinical studies regarding the potential beneficial effects of plant-derived natural products (quercetin, resveratrol, berberine, pomegranate, curcumin, cinnamon, green tea, coffee, garlic, ginger, ginseng, and gingko biloba) for the treatment or prevention of non-alcoholic fatty liver disease.

Aerobic exercise and eugenol supplementation ameliorated liver injury induced by chlorpyrifos via modulation acetylcholinesterase activation and antioxidant defense

The primary metabolize of chlorpyrifos (CPF) is in the liver tissue, which it can cause oxidative damage and apoptosis in liver cells. The use of exercise with antioxidant supplements could have a protective effects in the liver tissue especially by improve mitochondria function. The aim of the present study was to investigate the protective effect of aerobic exercise and eugenol (Eu) supplementation on destructive effects of CPF in liver tissue. Sixty-four adult male albino rats were randomly divided into eight groups (eight rats in each group). Four experimental groups received intraperitoneal injection of either 3.0 mg/kg body weight CPF in dimethyl sulfoxide for six consecutive weeks. Aerobic exercise was performed 5 days per week over 4 weeks for exercise groups. Finally, the animals were sacrificed for the histomorphometric analysis and biochemical measurement in the liver tissue. The result of this study show that consumption of CPF alone, caused collagen deposition, increased apoptosis, tumor necrosis factor α, malondialdehyde, and decreased catalase, superoxide dismutase, acetylcholinesterase (AChE) compared to control and exercise groups (healthy groups) in liver tissue (P ˂ .05). Prescription of exercises and Eu supplements in CPF consumer groups, neutralized this destructive effects of CPF. However, concomitant administration of Eu with exercise had better effects on liver tissue (P ˂ .05). It seems that consumption of Eu with aerobic exercise have a protective role in tissue destruction, inflammatory damage by improving antioxidant defense and modulating AChE activity in hepatocytes.

S-allylmercaptocysteine improves nonalcoholic steatohepatitis by enhancing AHR/NRF2-mediated drug metabolising enzymes and reducing NF-κB/IκBα and NLRP3/6-mediated inflammation

PURPOSE

To investigate the novel molecular mechanisms of the antioxidant and anti-inflammatory properties of S-allylmercaptocysteine (SAMC) based on a transcriptomic study in a nonalcoholic steatohepatitis (NASH) rat model METHODS: NASH was induced in Sprague-Dawley rats by feeding with a high fat diet (HFD) for 12 weeks. 200 mg/kg SAMC was fed by oral gavage for 4 weeks from 9 to 12 week.

RESULTS

SAMC co-administration attenuated HFD-induced liver injury, including the increased serum ALT, hepatic oxidative stress and inflammation. Transcriptomic analysis revealed that SAMC dramatically induced the XRE- and ARE-driven drug metabolising enzymes (DMEs) including Akr7a3, Akr1b8, and Nqo1. The nuclear translocation of the upstream regulator of xenobiotics metabolism, AHR, and regulator of antioxidant responses, NRF2, were significantly increased by SAMC treatment. Furthermore, SAMC counteracted the effects of HFD on NF-κB/IκB and NLRP3/6 pathways with decreasing protein levels of ASC, cleaved caspase-1, IL-18, and IL-1β. These results were further verified in another mice NASH model induced by an MCD diet with SAMC co-administration.

CONCLUSION

We propose that SAMC triggers AHR/NRF2-mediated antioxidant responses which may further suppress the NLRP3/6 inflammasome pathway and NF-κB activation, contributing to the improvement of NASH.

Herbal Medicine in the Treatment of Non-Alcoholic Fatty Liver Diseases-Efficacy, Action Mechanism, and Clinical Application

Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease with high prevalence in the developed countries. NAFLD has been considered as one of the leading causes of cryptogenic cirrhosis and chronic liver disease. The individuals with obesity, insulin resistance and diabetes mellitus, hyperlipidaemia, and hypertension cardiovascular disease have a high risk to develop NAFLD. The related critical pathological events are associated with the development of NAFLD including insulin resistance, lipid metabolism dysfunction, oxidative stress, inflammation, apoptosis, and fibrosis. The development of NAFLD range from simple steatosis to non-alcoholic steatohepatitis (NASH). Hepatic steatosis is characterized by fat accumulation, which represents the early stage of NAFLD. Then, inflammation triggered by steatosis drives early NAFLD progression into NASH. Therefore, the amelioration of steatosis and inflammation is essential for NAFLD therapy. The herbal medicine have taken great effects on the improvement of steatosis and inflammation for treating NAFLD. It has been found out that these effects involved the multiple mechanisms underlying lipid metabolism and inflammation. In this review, we pay particular attention on herbal medicine treatment and make summary about the research of herbal medicine, including herb formula, herb extract and naturals compound on NAFLD. We make details about their protective effects, the mechanism of action involved in the amelioration steatosis and inflammation for NAFLD therapy as well as the clinical application.

Effect of garlic powder supplementation on hepatic steatosis, liver enzymes and lipid profile in patients with non-alcoholic fatty liver disease: a double-blind randomised controlled clinical trial

Non-alcoholic fatty liver disease (NAFLD) includes a range of disorders from simple steatosis to non-alcoholic steatohepatitis. There is no proven drug treatment for NAFLD, and diet modification is considered part of the main line of treatment for this disease. The aim of this study was to investigate the efficacy of garlic supplementation in NAFLD patients. The effect of garlic powder supplementation on hepatic steatosis, liver enzymes and lipid profile was investigated in NAFLD patients. Ninety NAFLD patients were randomly assigned to take either a garlic powder supplement or a placebo for 12 weeks. The treatment group received four tablets of garlic daily (each tablet contained 400 mg garlic powder). The control group received four tablets of placebo (each placebo contained 400 mg starch). At the end of the study, hepatic steatosis was significantly reduced in the treatment group compared with the control group (P = 0·001). In addition, a significant decrease was seen in the serum concentration of alanine transaminase (P < 0·001), aspartate transaminase (P = 0·002), γ-glutamyltransferase (P = 0·003) as well as total cholesterol (P = 0·009), TAG (P < 0·001), HDL-cholesterol (P < 0·001) and LDL-cholesterol (P = 0·01) in the treatment group compared with the control group. No significant difference was seen between the two groups in serum concentration of alkaline phosphatase. Overall, garlic powder supplementation improved hepatic features and lipid profile among NAFLD patients.

Determination of S-Allylmercaptocysteine in Rat Plasma by LC-MS/MS and its Application to a Pharmacokinetics Study

In this work, a rapid, simple, sensitive and specific LC-MS/MS method was developed and validated for the quantification of S-Allylmercaptocysteine (SAMC) in plasma. After a simple sample procedure by one step protein precipitation with acetontrile, the samples were separated on Gemini-NX C18 column (2.1 mm i.d. 150 mm, 3 μm, Phenomenex). The mobile phase was composed of water-acetonitrile (20:80, v/v) at an isocratic flow rate of 0.3 mL/min. The developed method was validated based on the International Conference on Harmonization (ICH) guidelines. The results show that the method had satisfactory specificity, precision and accuracy in a linear range of 50-3,000 ng/mL for SAMC. The precision conformed to the acceptance criteria, and the lower limit of quantification was 50 ng/mL for the analyte. The plasma samples stored for 10 days or after two freeze-thaw cycles (-80°C) were stable. This method was successfully applied to a pharmacokinetics study of SAMC in rats. It was found that SAMC metabolized very quickly in rats and its plasma half-life was less than 5 min.

S-allylmercaptocysteine ameliorates lipopolysaccharide-induced acute lung injury in mice by inhibiting inflammation and oxidative stress via nuclear factor kappa B and Keap1/Nrf2 pathways

The garlic-derived organosulfur compound S-allylmercaptocysteine (SAMC) has been reported to exhibit anti-inflammatory and anti-oxidative activities, whereas its potential therapeutic effect on lipopolysaccharide (LPS)-induced acute lung injury (ALI) is unknown. In this study, we focused on exploring the therapeutic effects of SAMC on LPS-induced ALI mice and the involvement of underlying molecular mechanisms. BalB/c mice were treated with SAMC (10, 30 and 60 mg/kg) or positive control N-acetylcysteine (NAC, 500 mg/kg) by gavage after intratracheal instillation of LPS for 30 min and were sacrificed 24 h after LPS administration. Our results indicate that the treatment with SAMC not only ameliorated the histological changes but also decreased LPS-triggered lung edema. Moreover, SAMC displayed an anti-inflammatory effect through reducing inflammatory cells infiltration, myeloperoxidase (MPO) formation and inhibiting pro-inflammatory cytokines/mediator production including tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX2) via suppressing the activation of nuclear factor-kappaB (NF-κB) signaling pathway. Furthermore, SAMC attenuated oxidative stress evoked by LPS via diminishing malondialdehyde (MDA) formation and reversing glutathione (GSH) and superoxide dismutase (SOD) depletion. Meanwhile, SAMC up-regulated expressions of endogenous antioxidant/detoxifying proteins including heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase 1(NQO1) through reversing the suppression of Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid-2 related factor 2 (Nrf2) signaling pathway. Our results demonstrate that SAMC effectively attenuated LPS-induced ALI which was largely dependent upon inhibition of inflammation and oxidative stress via NF-κB and Keap1/Nrf2 signaling pathways.

Contributing Roles of CYP2E1 and Other Cytochrome P450 Isoforms in Alcohol-Related Tissue Injury and Carcinogenesis

The purpose of this review is to briefly summarize the roles of alcohol (ethanol) and related compounds in promoting cancer and inflammatory injury in many tissues. Long-term chronic heavy alcohol exposure is known to increase the chances of inflammation, oxidative DNA damage, and cancer development in many organs. The rates of alcohol-mediated organ damage and cancer risks are significantly elevated in the presence of co-morbidity factors such as poor nutrition, unhealthy diets, smoking, infection with bacteria or viruses, and exposure to pro-carcinogens. Chronic ingestion of alcohol and its metabolite acetaldehyde may initiate and/or promote the development of cancer in the liver, oral cavity, esophagus, stomach, gastrointestinal tract, pancreas, prostate, and female breast. In this chapter, we summarize the important roles of ethanol/acetaldehyde in promoting inflammatory injury and carcinogenesis in several tissues. We also review the updated roles of the ethanol-inducible cytochrome P450-2E1 (CYP2E1) and other cytochrome P450 isozymes in the metabolism of various potentially toxic substrates, and consequent toxicities, including carcinogenesis in different tissues. We also briefly describe the potential implications of endogenous ethanol produced by gut bacteria, as frequently observed in the experimental models and patients of nonalcoholic fatty liver disease, in promoting DNA mutation and cancer development in the liver and other tissues, including the gastrointestinal tract.

Anti-cancer activities of S-allylmercaptocysteine from aged garlic

While most types of malignancies remain recalcitrant to treatment, application of natural products or their analogs in daily life has offered some hopes as an effective prophylaxis against cancer onset and progression in the past decades. Emerging evidence supports a link between garlic consumption and decreased cancer incidence. Notably, aged garlic extract (AGE) exhibits stronger anti-cancer activities than that of fresh garlic, by virtue of enrichment of several AGE-specific organosulfur compounds, including S-allylmercaptocysteine (SAMC). In this review, we summarize the up-to-date mechanistic pathways associated with the anti-proliferative, anti-metastatic and pro-apoptotic effects of SAMC in various cancer models. Based upon the proven safety and improved understanding on its anti-neoplastic properties, SAMC has gained recognition as a promising daily food supplement for cancer prevention or management.

Herbal Extracts and Natural Products in Alleviating Non-alcoholic Fatty Liver Disease via Activating Autophagy

Non-alcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease world-wide, and currently therapeutic options for NAFLD are limited. Herbal medicine (HM) may offer an attractive alternative for the treatment of NAFLD. Recent years have witnessed a growing interest in the autophagy-inducing agents, and autophagy activation has been recognized as an efficient strategy in managing NAFLD and related complications. Pharmacological studies have demonstrated certain potential of HM extracts and natural products in inducing autophagy, which might contribute to the efficacy of HM in preventing and treating NAFLD. This review aims to summarize current understanding of mechanisms of HM extracts and natural products in preventing and treating NAFLD. Specially, we focused on mechanisms by which autophagy can target the main pathogenesis events associated with NAFLD, including hepatic steatosis, inflammation, oxidative stress, and apoptosis. It is hoped that this brief review can provide a general understanding of HM extracts and natural products in treating NAFLD, and raise awareness of potential clinical application of HM in general.

S-Alk(en)ylmercaptocysteine suppresses LPS-induced pro-inflammatory responses in murine macrophages through inhibition of NF-κB pathway and modulation of thiol redox status

The Allium vegetable-derived metabolite, S-alk(en)ylmercaptocysteine (CySSR), has been reported to modulate oxidative stress and inflammatory responses. However, the underlying mechanisms of action and structure-activity relationships are not completely understood. We investigated the mechanistic basis of the protective effects of CySSR on pro-inflammatory responses involving redox/oxidative stress induced by E. coli lipopolysaccharide (LPS) using RAW 264.7 cells. CySSR (R = allyl, "A" or 1-propenyl, "Pe") pre-treatments conferred concentration-dependent reductions in cytokines (TNF-α, IL-1β and IL-6), NO production and iNOS (inducible nitric synthase) overexpression, and attenuated oxidant production in LPS-stimulated RAW 264.7 cells where viability remained > 90%. These protective effects were manifested through inhibited activation of the nuclear factor-kappa B (NF-κB) signaling pathway via suppression of the IκB kinases (IKK) phosphorylation possibly by transforming growth factor β-activated kinase 1 or a kinase further upstream the canonical NF-κB signaling pathway. The attenuation of LPS-induced inflammation by CySSRs was associated with enhanced levels of cellular cysteine (CySH) and glutathione (GSH) mediated by cellular import/reduction of CySSR and the induction of glutamate cysteine ligase (GCL), one of > 200 nuclear factor erythroid 2-related factor 2 (Nrf2) regulated proteins. The reduction of anti-inflammatory effect of CySSR following pretreatment of cells with L-buthionine-S,R-sulfoximine (BSO) implicates GSH having a major role in reducing inflammation, likely in the context of other Nrf2-regulated antioxidant enzymes that scavenge H₂O₂ and peroxides using GSH as co-substrate. The anti-inflammatory effect of CySSPe was significantly greater than CySSA for almost all indicators measured, and cell metabolites of CySSRs may have a role in attenuating NF-κB signaling.

Aged Garlic and Cancer: A Systematic Review

Cancer is one of the leading causes of morbidity and mortality worldwide, which increases health-care costs. It has been reported that some dietary components such as aged garlic, one of the garlic preparations with no strong odor and harsh irritating taste, exhibits anticancer effects. This review summarizes the potential beneficial effects of aged garlic on cancer incidences as well as prevention and improvement of factors related to malignancy. Electronic databases, including MEDLINE, Web of Science, the Cochrane Library, and Google Scholar were searched. All study designs which were focused on cancer incidence, or indices related to malignancy as outcomes in human, animal, and human cells studies, and aged garlic and its ingredients as exposures were reviewed in accordance to the items for systematic reviews (PRISMA) guidelines. Initially, 304 articles were identified. Then, 25 articles which met the inclusion criteria were selected. Based on the evaluation, overall quality score of human studies was well. Although there were inconsistent evidence from human studies, results of the animal and laboratory results were mostly consistent. The overall findings may suggest that intakes of aged garlic are inversely associated with cancer. In this regard, the studies have shortcomings. Therefore, more precise investigations will be necessary to decide whether aged garlic consumption is recommendable as a part of cancer prevention or control programs. However, due to anticancer properties of aged garlic, its consumption along with healthy diet may have beneficial effects on cancer.

Potential Therapeutic Benefits of Herbs and Supplements in Patients with NAFLD

Our aim is to review the efficacy of various herbs and supplements as a possible therapeutic option in the treatment and/or prevention of nonalcoholic fatty liver disease (NAFLD). We performed a systematic review of medical literature using the PubMed Database by searching the chemical names of many common herbs and supplements with “AND (NAFLD or NASH)”. Studies and medical literature that discussed the roles and usage of herbs and supplements in NAFLD and nonalcoholic steatohepatitis (NASH) from inception until 20 June 2018 were reviewed. Many studies have claimed that the use of various herbs and supplements may improve disease endpoints and outcomes related to NAFLD and/or NASH. Improvement in liver function tests were noted. Amelioration or reduction of lobular inflammation, hepatic steatosis, and fibrosis were also noted. However, well-designed studies demonstrating improved clinical outcomes are lacking. Furthermore, experts remain concerned about the lack of regulation of herbs/supplements and the need for further research on potential adverse effects and herb–drug interactions. In conclusion, preliminary data on several herbs have demonstrated promising antioxidant, anti-inflammatory, anti-apoptotic, and anti-adipogenic properties that may help curtail the progression of NAFLD/NASH. Clinical trials testing the safety and efficacy must be completed before widespread use can be recommended.

Ginsenoside Rg1 Protects against Non-alcoholic Fatty Liver Disease by Ameliorating Lipid Peroxidation, Endoplasmic Reticulum Stress, and Inflammasome Activation

Non-alcoholic fatty liver disease (NAFLD) is increasingly prevalent and represents a growing challenge in terms of prevention and treatment. The purpose of this study is to investigate the protective effects of ginsenoside Rg1 (Rg1), an active ingredient of a natural medicine, and further clarify its protective mechanisms, in a mouse model of NAFLD induced by a high-fat diet. Rg1 significantly reduced liver weight, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), liver free fatty acids (FFAs) and malondialdehyde (MDA) levels, and increased superoxide dismutase (SOD) activity. Rg1 also upregulated the expression of peroxisome proliferator-activated receptor-alpha (PPARα), which stimulated fatty acid beta oxidation and promoted the metabolism of FFAs and TG. It also suppressed the expression of CCAAT/enhancer binding protein (C/EBP) homologous protein (CHOP), cysteine-containing aspartate-specific proteases 12 (Caspase 12), and glucose-regulated protein78 (GRP78), which reduced endoplasmic reticulum (ER) stress. Furthermore, Rg1 alleviated liver inflammation by inhibiting the activation of nucleotide binding oligomerization domain (NOD)-like receptor family pyrin domain-containing 3 (NLRP3) and thus reduced the production of inflammatory cytokines, such as interleukin 1-beta (IL-1β) and interleukin 18 (IL-18). These results suggested that Rg1 may protect against NAFLD, through regulation of lipid peroxidation, ER stress and inflammasome activation.

Total sesquiterpene glycosides from Loquat (Eriobotrya japonica) leaf alleviate high-fat diet induced non-alcoholic fatty liver disease through cytochrome P450 2E1 inhibition

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease characterized by hepatic steatosis, which affects 20-40% of the population in the world. Loquat (Eriobotrya japonica) Leaf possesses several pharmacological actions. Many sesquiterpene glycosides were reported to be isolated exclusively from the Loquat Leaf, however, their biological activity has been rarely investigated. The present study was designed to evaluate the pharmacological effect of total sesquiterpene glycosides (TSG) in high-fat diet (HFD) induced NAFLD mice with its related mechanisms of action. Mice were fed with a normal diet or HFD for 8 weeks. TSG (25 and 100mg/kg/day), simvastatin (10mg/kg/day) or vehicle were orally administered for last 4 weeks of the 8-week HFD feeding period. From the result, it was showed that TSG significantly reduced the body weight and fat deposition in the liver of NAFLD mice. It also decreased total cholesterol (TC) and triglyceride (TG) contents in the serum. Compared with NAFLD mice, superoxide dismutase (SOD) and malondialdehyde (MDA) levels were increased and decreased after the administration of TSG in a dose of 100mg/kg, respectively. TSG reduced alanine aminotransferase (ALT) activity as well. Finally, TSG was found to suppress the expression of cytochrome P450 2E1 (CYP2E1) and the phosphorylation of c-jun terminal kinase (JNK) in NAFLD mice. In summary, this study demonstrates that TSG reduces oxidative stress by downregulating of CYP2E1 expression and JNK phosphorylation in NAFLD, and alleviates NAFLD ultimately. TSG potentially serves as bioactive compounds for the treatment of NAFLD.

Traditional Chinese herbal extracts inducing autophagy as a novel approach in therapy of nonalcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is one of the leading causes of chronic liver diseases around the world due to the modern sedentary and food-abundant lifestyle, which is characterized by excessive fat accumulation in the liver related with causes other than alcohol abuse. It is widely acknowledged that insulin resistance, dysfunctional lipid metabolism, endoplasmic reticulum stress, oxidative stress, inflammation, and apoptosis/necrosis may all contribute to NAFLD. Autophagy is a protective self-digestion of intracellular organelles, including lipid droplets (lipophagy), in response to stress to maintain homeostasis. Lipophagy is another pathway for lipid degradation besides lipolysis. It is reported that impaired autophagy also contributes to NAFLD. Some studies have suggested that the histological characteristics of NAFLD (steatosis, lobular inflammation, and peri-sinusoid fibrosis) might be improved by treatment with traditional Chinese herbal extracts, while autophagy may be induced. This review will provide insights into the characteristics of autophagy in NAFLD and the related role/mechanisms of autophagy induced by traditional Chinese herbal extracts such as resveratrol, Lycium barbarum polysaccharides, dioscin, bergamot polyphenol fraction, capsaicin, and garlic-derived S-allylmercaptocysteine, which may inhibit the progression of NAFLD. Regulation of autophagy/lipophagy with traditional Chinese herbal extracts may be a novel approach for treating NAFLD, and the molecular mechanisms should be elucidated further in the near future.

Beneficial effects of paeoniflorin on non-alcoholic fatty liver disease induced by high-fat diet in rats

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent form of chronic liver diseases. This study sought to evaluate the insulin-sensitizing effect of paeoniflorin (PF) on high-fat diet-induced NAFLD and possible molecular mechanisms. Male Sprague Dawley rats were fed a high-fat diet (HFD) for 10 weeks to establish the NAFLD model, and PF (20 mg/kg/d) was gavaged to the NAFLD rats for another four weeks. Our results demonstrated that HFD resulted in hepatocellular ballooning, micro-/macrovesicular steatosis, and oxidative stress in the liver, accompanied by increased serum total cholesterol (TC), triglyceride (TG), free fatty acid (FFA), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels and homeostasis model of insulin resistance (HOMA-IR) index. PF treatment improved the biochemical and histopathological changes in NAFLD rats. Moreover, we also found that PF could inhibit lipid ectopic deposition via regulating lipid metabolism (inhibiting lipid synthesis of cholesterol and de novo pathway), and exert insulin sensitizing effect by regulating the insulin signaling pathway IRS/Akt/GSK3β and anti-oxidation. The study findings suggest that PF has therapeutic potential against NAFLD and that it acts through multiple signaling pathways.

Kukoamine A attenuates insulin resistance and fatty liver through downregulation of Srebp-1c

Nonalcoholic fatty liver disease (NAFLD) refers to a pathological condition of hepatic steatosis. Insulin resistance is believed to be the key mechanism mediating initial accumulation of fat in the liver, resulting in hepatic steatosis. Kukoamine A (KuA), a spermine alkaloid, is a major bioactive component extracted from the root barks of Lycium chinense (L. chinense) Miller. In the current study, we aimed to explore the possible effect of KuA on insulin resistance and fatty liver. We showed that KuA significantly inhibited the increase of fasting blood glucose level and insulin level, and the glucose levels in response to glucose and insulin load in HFD-fed mice, which was in a dose-dependent manner. KuA dose-dependently decreased the histological injury of liver, levels of hepatic triglyceride (TG), and serum AST and ALT activities in HFD-fed mice. The increase of serum levels of TNFɑ, IL-1β, IL-6 and C reactive protein in HFD-fed mice was inhibited by KuA. HFD feeding-induced increase of hepatic expression of Srebp-1c and its target genes, including fatty acid synthase (FAS) and acetyl CoA carboxylase 1 (ACC1), was significantly inhibited by KuA. Moreover, upregulation of Srebp-1c notably inhibited KuA-induced improvement of insulin-stimulated glucose uptake, decrease of lipid accumulation and H₂O₂ level in palmitic acid-treated AML-12 cells. In conclusion, we reported that KuA inhibited Srebp-1c and downstream genes expression and resulted in inhibition of lipid accumulation, inflammation, insulin resistance and oxidative stress. Overall, our results provide a better understanding of the pharmacological activities of KuA against insulin resistance and hepatic steatosis.

S-Allylmercaptocysteine Attenuates Cisplatin-Induced Nephrotoxicity through Suppression of Apoptosis, Oxidative Stress, and Inflammation

Cisplatin is a potent chemotherapeutic agent, but its clinical usage is limited by nephrotoxicity. S-allylmercaptocysteine (SAMC), one of the water-soluble organosulfur garlic derivatives, has antioxidant and anti-inflammatory properties and plays an important role in protecting cells from apoptosis. This study aims to examine the protective effects of SAMC on cisplatin nephrotoxicity and to explore the mechanism of its renoprotection. Rats were treated with cisplatin with or without pre-treatment with SAMC. Renal function, histological change, oxidative stress markers and antioxidant enzyme activities were investigated. Apoptotic marker, nuclearfactor (NF)-κB activity, expression of nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H:quinone oxidoreductase 1 (NQO1) and inflammatory cytokines were also examined. The effect of SAMC on cell viability and apoptosis was examined in cultured human kidney (HK-2) cells. SAMC was confirmed to significantly attenuate cisplatin-induced renal damage by using histological pathology and molecular biological method. Pre-treatment with SAMC reduced NF-κB activity, up-regulated Nrf2 and NQO1 expression and down-regulated inflammatory cytokine levels after cisplatin administration. Cisplatin-induced apoptosis in HK-2 cells was significantly attenuated by SAMC. Thus our results suggest that SAMC could be a potential therapeutic agent in the treatment of the cisplatin-induced nephrotoxicity through its anti-apoptotic, anti-oxidant and anti-inflammatory effects.

Antioxidant activities of ginsenoside Rg1 against cisplatin-induced hepatic injury through Nrf2 signaling pathway in mice

Oxidative stress is mainly caused by reactive oxygen species (ROS). The damage causes a net stress on normal organs, leading to a gradual loss of vital physiological function. ROS, such as free radicals, represent a class of molecules which are derived from the metabolism of oxygen and exist inherently. However, excessive produced ROS can damage all aerobic organisms. Ginseng is one of the most commonly used alternative herbal medicines, also as a traditional Chinese medicine. The aim of this study is to investigate the antioxidant potential function of ginsenoside Rg1 against cisplatin-caused hepatic damage. Male mice were treated with cisplatin to induce oxidative stress to mimic the side effect of anti-cancer drug cisplatin. Ginsenoside Rg1 effectively prevented against cisplatin-induced hepatotoxicity, alleviating histological lesions. Antioxidant functions of Rg1 were restrained by the activation of p62-Keap1-Nrf2 signaling pathway, simultaneously accompanied with expression of protein products. Accumulative p62 and increased activation of JNK in hepatocytes promoted the activation of Nrf2. For the other, degradation of Nrf2 was guided by tyrosine phosphorylation, ubiquitin, and Keap1. In summary, Rg1 prevents hepatotoxicity mainly by inhibiting the binding of Keap1 and Nrf2, partly by p62 accumulation, and more importantly by increasing the production of antioxidative proteins associated to Nrf2. Pharmacological activation of Nrf2 is an effective way in combating against liver injury.

Effect of Alkaloids from Nelumbinis Plumula against Insulin Resistance of High-Fat Diet-Induced Nonalcoholic Fatty Liver Disease in Mice

This study aimed to investigate the effects of total alkaloids from Nelumbinis Plumula (NPA) on insulin resistance (IR) of high-fat diet- (HFD-) induced nonalcoholic fatty liver disease (NAFLD). Rats were fed with HFD for 8 weeks to induce NAFLD. Then, the effect of NPA on ameliorating IR in HFD-induced NAFLD was evaluated. Fasting serum insulin was determined using an enzyme-linked immunosorbent assay (ELISA) kit for insulin following the manufacturer's protocol. Some inflammatory cytokines such as tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) were determined using ELISA kits to assess the inflammatory burden in rats. The results showed that HFD could induce a significant increase in blood glucose and IR in rats. However, rats treated with NPA (400 or 600 mg/kg) showed improved IR and reduction in serum inflammatory cytokines TNF-α and IL-6. Further investigation indicated that NPA could inhibit IR by restoring the insulin receptor substrate-1 (IRS-1) and suppressing the expression of c-Jun N-terminal kinase (JNK) phosphorylation. The present results supported the view that the pathogenesis of NAFLD was complex with inflammation, together with increasing serum glucose and IR. Also, JNK and IRS phosphorylation were suggested for their involvement in the modulating of IR during NAFLD progression. Therefore, NPA may serve as a potential natural remedy against IR in NAFLD.

Inhibition of caspase-9 aggravates acute liver injury through suppression of cytoprotective autophagy

Acute liver disease is characterized by inflammation, oxidative stress and necrosis, which can greatly influence the long term clinical outcome and lead to liver failure or cancer. Here, we initially demonstrated the beneficial role of caspase-9-dependent autophagy in acute liver injury. Treatment with caspase-9 inhibitor z-LEHD-FMK in HepG2 cells, AML12 cells and C57BL/b6N mice exacerbated CCl₄-induced acute hepatocellular damage, and also down-regulated autophagy markers expression levels, indicating that caspase-9 inhibition may aggravate acute liver damage by suppressing cytoprotective autophagy. CCl₄ was used as an acute liver injury inducer which caused oxidative stress and apoptosis through up-regulation of HIF-1α, as well as triggered hepatic inflammation and necroptosis via TLR4/NF-κB pathway. Caspase-9 Thr125 site was firstly phosphorylated by ERK1/2 which subsequently activated the cytoprotective autophagy process to attenuate acute CCl₄ injury. Caspase-9 inhibition further aggravated hepatic necroptosis through NF-κB expression, leading to increased pro-inflammatory mediators levels, suggesting a protective role of caspase-9-dependent autophagy in the inflammatory process as well as its possibility being a new therapeutic target for the treatment of acute liver injury.

Development of an Analytic Method for Sulfur Compounds in Aged Garlic Extract with the Use of a Postcolumn High Performance Liquid Chromatography Method with Sulfur-Specific Detection

BACKGROUND

Garlic and its processed preparations contain numerous sulfur compounds that are difficult to analyze in a single run using HPLC.

OBJECTIVE

The aim of this study was to develop a rapid and convenient sulfur-specific HPLC method to analyze sulfur compounds in aged garlic extract (AGE).

METHODS

We modified a conventional postcolumn HPLC method by employing a hexaiodoplatinate reagent. Identification and structural analysis of sulfur compounds were conducted by LC-mass spectrometry (LC-MS) and nuclear magnetic resonance. The production mechanisms of cis-S-1-propenylcysteine (cis-S1PC) and S-allylmercaptocysteine (SAMC) were examined by model reactions.

RESULTS

Our method has the following advantages: less interference from nonsulfur compounds, high sensitivity, good correlation coefficients (r > 0.98), and high resolution that can separate >20 sulfur compounds, including several isomers, in garlic preparations in a single run. This method was adapted for LC-MS analysis. We identified cis-S1PC and γ-glutamyl-S-allyl-mercaptocysteine in AGE. The results of model reactions suggest that cis-S1PC is produced from trans-S1PC through an isomerization reaction and that SAMC is produced by a reaction involving S-allylcysteine/S1PC and diallyldisulfide during the aging period.

CONCLUSION

We developed a rapid postcolumn HPLC method for both qualitative and quantitative analyses of sulfur compounds, and this method helped elucidate a potential mechanism of cis-S1PC and SAMC action in AGE.

Antibiotic-induced imbalances in gut microbiota aggravates cholesterol accumulation and liver injuries in rats fed a high-cholesterol diet

Increasing evidence suggests that maintenance of homeostasis between gut microbiota and host plays an important role in human health. Many diseases, such as those affecting the liver, have been linked to imbalances in gut microbial communities. However, it is not clear whether an imbalance in gut microbiota promotes the onset of liver injury or if the imbalance results from the pathological state. In the current study, antibiotics were used to disturb the gut microbiota of both rats fed a high-cholesterol diet and rats fed a normal diet (controls). The prevalence of Bacteroidetes and Firmicutes were reduced, and Proteobacteria was greatly increased in the guts of rats after antibiotic treatment. The antibiotic-induced perturbation of gut microbiota aggravated cholesterol accumulation and liver injury in rats fed a high-cholesterol diet. This may have been due to an increase in intestinal permeability and plasma lipopolysaccharide (LPS), which lead to an increase in LPS absorption and activation of TLR4 signaling, resulting in the synthesis of pro-inflammatory cytokines and chemokines in liver tissues. This study suggests that imbalances in gut microbiota may be a predisposing factor for the onset of metabolic diseases and liver injuries related to cholesterol and high-cholesterol diets. Modulation of gut microbiota could be a novel target for preventing cholesterol-related metabolic disorders.

Translational Implications of the Alcohol-Metabolizing Enzymes, Including Cytochrome P450-2E1, in Alcoholic and Nonalcoholic Liver Disease

Fat accumulation (hepatic steatosis) in alcoholic and nonalcoholic fatty liver disease is a potentially pathologic condition which can progress to steatohepatitis (inflammation), fibrosis, cirrhosis, and carcinogenesis. Many clinically used drugs or some alternative medicine compounds are also known to cause drug-induced liver injury, which can further lead to fulminant liver failure and acute deaths in extreme cases. During liver disease process, certain cytochromes P450 such as the ethanol-inducible cytochrome P450-2E1 (CYP2E1) and CYP4A isozymes can be induced and/or activated by alcohol and/or high-fat diets and pathophysiological conditions such as fasting, obesity, and diabetes. Activation of these P450 isozymes, involved in the metabolism of ethanol, fatty acids, and various drugs, can produce reactive oxygen/nitrogen species directly and/or indirectly, contributing to oxidative modifications of DNA/RNA, proteins and lipids. In addition, aldehyde dehydrogenases including the mitochondrial low Km aldehyde dehydrogenase-2 (ALDH2), responsible for the metabolism of acetaldehyde and lipid aldehydes, can be inactivated by various hepatotoxic agents. These highly reactive acetaldehyde and lipid peroxides, accumulated due to ALDH2 suppression, can interact with cellular macromolecules DNA/RNA, lipids, and proteins, leading to suppression of their normal function, contributing to DNA mutations, endoplasmic reticulum stress, mitochondrial dysfunction, steatosis, and cell death. In this chapter, we specifically review the roles of the alcohol-metabolizing enzymes including the alcohol dehydrogenase, ALDH2, CYP2E1, and other enzymes in promoting liver disease. We also discuss translational research opportunities with natural and/or synthetic antioxidants, which can prevent or delay the onset of inflammation and liver disease.

Antioxidant treatment enhances human mesenchymal stem cell anti-stress ability and therapeutic efficacy in an acute liver failure model

One of the major problems influencing the therapeutic efficacy of stem cell therapy is the poor cell survival following transplantation. This is partly attributed to insufficient resistance of transplanted stem cells to oxidative and inflammatory stresses at the injured sites. In the current study, we demonstrated the pivotal role of antioxidant levels in human umbilical cord mesenchymal stem cells (hUCMSCs) dynamic in vitro anti-stress abilities against lipopolysaccharide (LPS)/H₂O₂ intoxication and in vivo therapeutic efficacy in a murine acute liver failure model induced by D-galactosamine/LPS (Gal/LPS) by either reducing the antioxidant levels with diethyl maleate (DEM) or increasing antioxidant levels with edaravone. Both the anti- and pro-oxidant treatments dramatically influenced the survival, apoptosis, and reactive oxygen species (ROS) production of hUCMSCs through the MAPK-PKC-Nrf2 pathway in vitro. When compared with untreated and DEM-treated cells, edaravone-treated hUCMSCs rescued NOD/SCID mice from Gal/LPS-induced death, significantly improved hepatic functions and promoted host liver regeneration. These effects were probably from increased stem cell homing, promoted proliferation, decreased apoptosis and enhanced secretion of hepatocyte growth factor (HGF) under hepatic stress environment. In conclusion, elevating levels of antioxidants in hUCMSCs with edaravone can significantly influence their hepatic tissue repair capacity.

Vitex agnus-castus L. (Verbenaceae) Improves the Liver Lipid Metabolism and Redox State of Ovariectomized Rats

Vitex agnus-castus (VAC) is a plant that has recently been used to treat the symptoms of menopause, by its actions on the central nervous system. However, little is known about its actions on disturbances in lipid metabolism and nonalcoholic fat liver disease (NAFLD), frequently associated with menopause. Ovariectomized (OVX) rats exhibit increased adiposity and NAFLD 13 weeks after ovary removal and were used as animal models of estrogen deficiency. The rats were treated with crude extract (CE) and a butanolic fraction of VAC (ButF) and displayed the beneficial effects of a reduction in the adiposity index and a complete reversion of NAFLD. NAFLD reversion was accompanied by a general improvement in the liver redox status. The activities of some antioxidant enzymes were restored and the mitochondrial hydrogen peroxide production was significantly reduced in animals treated with CE and the ButF. It can be concluded that the CE and ButF from Vitex agnus-castus were effective in preventing NAFLD and oxidative stress, which are frequent causes of abnormal liver functions in the postmenopausal period.