Gangjihwan, a polyherbal composition, inhibits fat accumulation through the modulation of lipogenic transcription factors SREBP1C, PPARγ and C/EBPα

Diterpenoid Alkaloids Isolated from Delphinium brunonianum and Their Inhibitory Effects on Hepatocytes Lipid Accumulation

This research aimed to excavate compounds with activity reducing hepatocytes lipid accumulation from Delphinium brunonianum. Four novel diterpenoid alkaloids, brunodelphinine B–E, were isolated from D. brunonianum together with eleven known diterpenoid alkaloids through a phytochemical investigation. Their structures were elucidated by comprehensive spectroscopy methods including HR-ESI-MS, NMR, IR, UV, CD, and single-crystal X-ray diffraction analysis. The inhibitory effects of a total of 15 diterpenoid alkaloids on hepatocytes lipid accumulation were evaluated using 0.5 mM FFA (oleate/palmitate 2:1 ratio) to induce buffalo rat liver (BRL) cells by measuring the levels of triglyceride (TG), total cholesterol (TC), alanine transaminase (ALT), aspartate transaminase (AST), and the staining of oil red O. The results show that five diterpenoid alkaloids—brunodelphinine E (4), delbruline (5), lycoctonine (7), delbrunine (8), and sharwuphinine A (12)—exhibited significant inhibitory effects on lipid accumulation in a dose-dependent manner and without cytotoxicity. Among them, sharwuphinine A (12) displayed the strongest inhibition of hepatocytes lipid accumulation in vitro. Our research increased the understanding on the chemical composition of D. brunonianum and provided experimental and theoretical evidence for the active ingredients screened from this herbal medicine in the treatment of the diseases related to lipid accumulation, such as non-alcoholic fatty liver disease and hyperlipidemia.

In search of an ideal drug for safer treatment of obesity: The false promise of pseudoephedrine

Obesity is a major public health problem worldwide. Only relatively few treatment options are, at present, available for the management of obese patients. Furthermore, treatment of obesity is affected by the widespread misuse of drugs and food supplements. Ephedra sinica is an old medicinal herb, commonly used in the treatment of respiratory tract diseases. Ephedra species contain several alkaloids, including pseudoephedrine, notably endowed with indirect sympathomimetic pharmacodynamic properties. The anorexigenic effect of pseudoephedrine is attributable primarily to the inhibition of neurons located in the hypothalamic paraventricular nucleus (PVN), mediating satiety stimuli. Pseudoephedrine influences lipolysis and thermogenesis through interaction with β3 adrenergic receptors and reduces fat accumulation through down-regulation of transcription factors related to lipogenesis. However, its use is associated with adverse events that involve to a large extent the cardiovascular and the central nervous system. Adverse events of pseudoephedrine also affect the eye, the intestine, and the skin, and, of relevance, sudden cardiovascular death related to dietary supplements containing Ephedra alkaloids has also been reported. In light of the limited availability of clinical data on pseudoephedrine in obesity, along with its significantly unbalanced risk/benefit profile, as well as of the psychophysical susceptibility of obese patients, it appears reasonable to preclude the prescription of pseudoephedrine in obese patients of any order and degree.

Adipogenesis and therapeutic potentials of antiobesogenic phytochemicals: Insights from preclinical studies

Obesity is one of the most serious public health problems in both developed and developing countries in recent years. While lifestyle and diet modifications are the most important management strategies of obesity, these may be insufficient to ensure long-term weight reduction in certain individuals and alternative strategies including pharmacotherapy need to be considered. However, drugs option remains limited due to low efficacy and adverse effects associated with their use. Hence, identification of safe and effective alternative therapeutic agents remains warranted to combat obesity. In recent years, bioactive phytochemicals are considered as valuable sources for the discovery of new pharmacological agents for the treatment of obesity. Adipocyte hypertrophy and hyperplasia increases with obesity and undergo molecular and cellular alterations that can affect systemic metabolism giving rise to metabolic syndrome and comorbidities such as type 2 diabetes and cardiovascular diseases. Many phytochemicals have been reported to target adipocytes by inhibiting adipogenesis, inducing lipolysis, suppressing the differentiation of preadipocytes to mature adipocytes, reducing energy intake, and boosting energy expenditure mainly in vitro and in animal studies. Nevertheless, further high-quality studies are needed to firmly establish the clinical efficacy of these phytochemicals. This review outlines common pathways involved in adipogenesis and phytochemicals targeting effector molecules of these pathways, the challenges faced and the way forward for the development of phytochemicals as antiobesity agents.

A Review of the Ephedra genus: Distribution, Ecology, Ethnobotany, Phytochemistry and Pharmacological Properties

Ephedra is one of the largest genera of the Ephedraceae family, which is distributed in arid and semiarid regions of the world. In the traditional medicine from several countries some species from the genus are commonly used to treat asthma, cold, flu, chills, fever, headache, nasal congestion, and cough. The chemical constituents of Ephedra species have been of research interest for decades due to their contents of ephedrine-type alkaloids and its pharmacological properties. Other chemical constituents such as phenolic and amino acid derivatives also have resulted attractive and have provided evidence-based supporting of the ethnomedical uses of the Ephedra species. In recent years, research has been expanded to explore the endophytic fungal diversity associated to Ephedra species, as well as, the chemical constituents derived from these fungi and their pharmacological bioprospecting. Two additional aspects that illustrate the chemical diversity of Ephedra genus are the chemotaxonomy approaches and the use of ephedrine-type alkaloids as building blocks in organic synthesis. American Ephedra species, especially those that exist in Mexico, are considered to lack ephedrine type alkaloids. In this sense, the phytochemical study of Mexican Ephedra species is a promising area of research to corroborate their ephedrine-type alkaloids content and, in turn, discover new chemical compounds with potential biological activity. Therefore, the present review represents a key compilation of all the relevant information for the Ephedra genus, in particular the American species, the species distribution, their ecological interactions, its ethnobotany, its phytochemistry and their pharmacological activities and toxicities, in order to promote clear directions for future research.

The Impacts of Herbal Medicines and Natural Products on Regulating the Hepatic Lipid Metabolism

The dysregulation of hepatic lipid metabolism is one of the hallmarks in many liver diseases including alcoholic liver diseases (ALD) and non-alcoholic fatty liver diseases (NAFLD). Hepatic inflammation, lipoperoxidative stress as well as the imbalance between lipid availability and lipid disposal, are direct causes of liver steatosis. The application of herbal medicines with anti-oxidative stress and lipid-balancing properties has been extensively attempted as pharmaceutical intervention for liver disorders in experimental and clinical studies. Although the molecular mechanisms underlying their hepatoprotective effects warrant further exploration, increasing evidence demonstrated that many herbal medicines are involved in regulating lipid accumulation processes including hepatic lipolytic and lipogenic pathways, such as mitochondrial and peroxisomal β-oxidation, the secretion of very low density lipoprotein (VLDL), the non-esterified fatty acid (NEFA) uptake, and some vital hepatic lipogenic enzymes. Therefore, in this review, the pathways or crucial mediators participated in the dysregulation of hepatic lipid metabolism are systematically summarized, followed by the current evidences and advances in the positive impacts of herbal medicines and natural products on the lipid metabolism pathways are detailed. Furthermore, several herbal formulas, herbs or herbal derivatives, such as Erchen Dection, Danshen, resveratrol, and berberine, which have been extensively studied for their promising potential in mediating lipid metabolism, are particularly highlighted in this review.

Chrysophanol: A Natural Anthraquinone with Multifaceted Biotherapeutic Potential

Chrysophanol is a unique anthraquinone having broad-spectrum therapeutic potential along with ecological importance. It is the first polyketide that has been reported to be biosynthesized in an organism-specific manner. The traditional Chinese and Korean medicinal systems provide evidence of the beneficial effects of chrysophanol on human health. The global distribution of chrysophanol encountered in two domains of life (bacteria and eukaryota) has motivated researchers to critically evaluate the properties of this compound. A plethora of literature is available on the pharmacological properties of chrysophanol, which include anticancer, hepatoprotective, neuroprotective, anti-inflammatory, antiulcer, and antimicrobial activities. However, the pharmacokinetics and toxicity studies on chrysophanol demand further investigations for it to be used as a drug. This is the first comprehensive review on the natural sources, biosynthetic pathways, and pharmacology of chrysophanol. Here we reviewed recent advancements made on the pharmacokinetics of the chrysophanol. Additionally, we have highlighted the knowledge gaps of its mechanism of action against diseases and toxicity aspects.

Chlorogenic Acid Functions as a Novel Agonist of PPARγ2 during the Differentiation of Mouse 3T3-L1 Preadipocytes

Rosiglitazone (RG) is a well-known activator of peroxisome proliferator-activated receptor-gamma (PPARγ) and used to treat hyperglycemia and type 2 diabetes; however, its clinical application has been confounded by adverse side effects. Here, we assessed the roles of chlorogenic acid (CGA), a phenolic secondary metabolite found in many fruits and vegetables, on the differentiation and lipolysis of mouse 3T3-L1 preadipocytes. The results showed that CGA promoted differentiation in vitro according to oil red O staining and quantitative polymerase chain reaction assays. As a potential molecular mechanism, CGA downregulated mRNA levels of the adipocyte differentiation-inhibitor gene Pref1 and upregulated those of major adipogenic transcriptional factors (Cebpb and Srebp1). Additionally, CGA upregulated the expression of the differentiation-related transcriptional factor PPARγ2 at both the mRNA and protein levels. However, following CGA intervention, the accumulation of intracellular triacylglycerides following preadipocyte differentiation was significantly lower than that in the RG group. Consistent with this, our data indicated that CGA treatment significantly upregulated the expression of lipogenic pathway-related genes Plin and Srebp1 during the differentiation stage, although the influence of CGA was weaker than that of RG. Notably, CGA upregulated the expression of the lipolysis-related gene Hsl, whereas it did not increase the expression of the lipid synthesis-related gene Dgat1. These results demonstrated that CGA might function as a potential PPARγ agonist similar to RG; however, the impact of CGA on lipolysis in 3T3-L1 preadipocytes differed from that of RG.

GCN2 deficiency protects against high fat diet induced hepatic steatosis and insulin resistance in mice

Nonalcoholic fatty liver disease (NAFLD) is characterized by hepatic lipid deposition and oxidative stress. It has been demonstrated that general control nonderepressible 2 (GCN2) is required to maintain hepatic fatty acid homeostasis under conditions of amino acid deprivation. However, the impact of GCN2 on the development of NAFLD has not been investigated. In this study, we used Gcn2^-/- mice to investigate the effect of GCN2 on high fat diet (HFD)-induced hepatic steatosis. After HFD feeding for 12 weeks, Gcn2^-/- mice were less obese than wild-type (WT) mice, and Gcn2^-/- significantly attenuated HFD-induced liver dysfunction, hepatic steatosis and insulin resistance. In the livers of the HFD-fed mice, GCN2 deficiency resulted in higher levels of lipolysis genes, lower expression of genes related to FA synthesis, transport and lipogenesis, and less induction of oxidative stress. Furthermore, we found that knockdown of GCN2 attenuated, whereas overexpression of GCN2 exacerbated, palmitic acid-induced steatosis, oxidative & ER stress, and changes of peroxisome proliferator-activated receptor gamma (PPARγ), fatty acid synthase (FAS) and metallothionein (MT) expression in HepG2 cells. Collectively, our data provide evidences that GCN2 deficiency protects against HFD-induced hepatic steatosis by inhibiting lipogenesis and reducing oxidative stress. Our findings suggest that strategies to inhibit GCN2 activity in the liver may provide a novel approach to attenuate NAFLD development.