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

Table 1 The beneficial properties of traditional Chinese herbal extracts in non-alcoholic fatty liver disease

Chinese herbs	Model		Treatment		Pharmacological mechanisms	Ref.
	Animal model	Cell model	Animal model	Cell model
Resveratrol (RSV)	ULK1 heterozygous knockout mice were fed with high-fat diet for 12 wk	-	Oral feeding with 50 mg/kg per day RSV from week 9 to week 12	-	Improved NAS score, insulin resistance, oxidative stress, inflammation, glucose tolerance and modulated autophagy	[45]
	4-wk induction of NAFLD with high-fat diet (60% fat) in 129/SvJ mice	Steatosis was induced by incubating HepG2 cells with palmitate acid (0.2 mmol/L) for 24 h	Diet containing RSV (0.4%) for 4 wk	Treated with RSV at various concentrations (10, 20, 40, 80 μmol/L) for a further 24 h	Reduced lipid accumulation, stimulated β-oxidation and induced autophagy through cAMP-PRKA-AMPK-SIRT1	[46]
Lycium barbarum polysaccharides (LBPs)	NASH induced by high-fat diet for 12 wk in adult female Sprague-Dawley rats	Steatosis was induced by incubating BRL-3A cells with sodium palmitate acid	Oral gavage feeding with 1 mg/kg per day LBPs once a day from week 9 to week 12	Treated with LBPs for 24 h	Reduced insulin resistance, serum aminotransferases, inflammatory responses, apoptosis and induced autophagy	[51]
Dioscin	NAFLD induced by high-fat diet (45% kcal fat) for 10 wk in C57BL/6J mice and ob/ob mice	-	Oral feeding with different dioscin concentrations (20, 40, 80 mg/kg per day)	-	Reduced body weight, lipid accumulation, inflammation oxidative damage and induced β-oxidation, autophagy, energy expenditure	[55]
Bergamot polyphenol fraction (BPF)	NAFLD induced by cafeteria diet (15% fat) every other day in addition to standard chow diet ad libitum for 14 wk in male Rcc:Han WIST rats	-	Drinking water containing 50 mg/kg per day BPF for 3 mo	-	Reduced serum triglyceride, blood glucose, hepatic steatosis and induced autophagy	[59]
Capsaicin	NAFLD induced by high-fat diet (49% fat) for 24 wk in TRPV1-/- and C57BL/6 wild-type mice	Steatosis was induced by incubating HepG2 cells with 1 mmol/l oleate/palmitate (2:1)	Diet containing 0.01% capsaicin for 24 wk	Treated by various capsaicin concentrations (0.1-10 μmol/L)	Reduced lipogenesis (FAS, SREBP-1, LXR, PPARα) and induced lipolysis (phospho-HSL, CPT1), autophagy through PPARδ-dependent manner	[65]
Garlic-derived S-allylmercaptocysteine (SAMC)	NAFLD induced by high unsaturated fat diet (30% fish oil) for 8 wk in female Sprague-Dawley rats	-	Intraperitoneal injection of 200 mg/kg SAMC, 3 times per week for 8 wk	-	Reduced lipogenesis (SREBP-1c), fibrosis (TGF-β1, α-SMA, PC-1), oxidative stress (CYP2E1), inflammation (TNF-α, IL-1β, iNOS, COX-2, MCP-1, MIP-2, KC) and induced lipolysis (adiponection), antioxidative stress (CAT, GPx)	[67]
	NAFLD induced by high unsaturated fat diet (30% fish oil) for 8 wk in female Sprague-Dawley rats	-	Intraperitoneal injection of 200 mg/kg SAMC, 3 times per week for 8 wk	-	Reduced intrinsic apoptosis (Bcl-2, Bcl-XL, Bakl, Bax) and extrinsic apoptosis (Fas, TRAIL, FADD, cleaved caspase-8), induced autophagy (vps34, beclin1, Atg12, LC3II, phosphorylated mTOR and p62)	[68]

NAFLD: Non-alcoholic fatty liver disease.