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

Abstract

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.

Rosmarinic acid attenuates hepatic steatosis by modulating ER stress and autophagy in oleic acid-induced HepG2 cells

“…6 The lack of systemic and validated results poses a hindrance in the development of a better treatment strategy for NAFLD, while the current therapy is more directed towards weight loss and increase in insulin sensitivity through exercise and dietary regimes rather than targeting the disease itself. 7,8 Over the past few years, medicines from natural sources have earned mounting attention as prospective therapeutic agents to treat NAFLD, accounting for their higher efficacy and lower risk of side effects. 9 In this line, recent studies have elucidated the protective role of polyphenols in modulating several phenotypic components of NAFLD.…”

Morin enhances hepatic Nrf2 expression in a liver fibrosis rat model

“…Previous studies have found that the development and progression of liver fibrosis are significantly related to oxidative stress in which a large number of free radicals lead to cell metabolic disorders and subsequent destruction of normal liver cells[ 2 - 5 ]. Although there is currently no effective therapy for curing liver fibrosis, previous studies showed that the pathological changes in liver fibrosis could be reversed[ 6 , 7 ].…”

Effect of high-fructose diet-induced metabolic syndrome on the pituitary-gonadal axis from adolescence through adulthood in male albino rats and the possible protective role of ginger extract. A biochemical, histological and immunohistochemical study

“…Autophagy is a master cellular process that helps cell survival from death stimuli through the removal of damaged organelles or proteins [38]. Additionally, autophagy decreases triglyceride and cholesterol accumulation, improves insulin signaling and prevents cellular injury from oxidative stress as reported by Liu et al [47]. However, Zhang et al [91] suggested that autophagy, when it occurs excessively or it is impaired, it may be deleterious and lead to activation of apoptosis mediated cellular death.…”