Humulus japonicus Extract Ameliorates Hepatic Steatosis Through the PPARα-Mediated Suppression of Alcohol-Induced Oxidative Stress.

Humulus japonicus has been used to treat obesity, hypertension, and nonalcoholic fatty liver and to alleviate inflammation and oxidative stress. In the present study, we aimed to investigate the effects of H. japonicus ethanol extracts (HE) and luteolin 7-O-ß-d-glucoside (LU), which is identified as a major active component of H. japonicus, on ethanol-induced oxidative stress and lipid accumulation in primary hepatocytes. Mouse primary hepatocytes were treated with HE and stimulated with ethanol. The MTT test was used to determine cell viability. By using Western blotting, the effects of HE on the expression of different proteins were investigated. Experimental mice were given a 5% alcohol liquid Lieber-DeCarli diet to induce alcoholic fatty liver. We found that both HE and LU individually attenuated ethanol-induced lipid accumulation, lipogenic protein expression, and cellular oxidative stress in hepatocytes. Treatment with HE or LU increased PPARα and SOD1 expression and catalase activity in a dose-dependent manner. Small interfering RNA of PPARα reduced the effects of HE on oxidative stress, lipid metabolism, and levels of antioxidants. We also observed that orally administered HE treatment alleviated hepatic steatosis in a diet containing ethanol-fed mice. This study suggests HE as a functional food that can improve hepatic steatosis, thereby preventing hepatic injury caused by alcohol consumption.

The Aqueous Extract of Humulus japonicus Ameliorates Cognitive Dysfunction in Alzheimer's Disease Models via Modulating the Cholinergic System.

Humulus japonicus (HJ) is an herbal medicine, which has been reported as being antioxidative and anti-inflammatory. The present study aimed to investigate the effect of oral administration of HJ water extract (HJW) on cognitive function through the cholinergic system in Alzheimer's disease (AD) mouse models. Institute of Cancer Research mice injected with beta-amyloid (Aß) (1-42) (i.c.v.) and APP/PS1 transgenic (TG) mice were orally administered with HJW at 500 mg/kg/day for 3 weeks. Aß-injected mice and APP/PS1 TG mice showed cognitive dysfunction, which was evaluated by various behavioral tests. HJW treatment significantly attenuated memory impairments in Aß-injected mice and APP/PS1 TG mice. Aß injection decreased acetylcholine (ACh) concentrations and choline acetyltransferase (ChAT) activity, and increased acetylcholinesterase (AChE) activity. These cholinergic impairments were also found in APP/PS1 TG mice. HJW significantly attenuated cholinergic alterations in Aß-injected mice and TG mice. In addition, HJW significantly decreased Aß plaque deposition in the cerebral cortex and hippocampus of TG mice. Therefore, the present study demonstrated that HJW protected against AD-related memory impairments via enhancing the cholinergic system and inhibiting Aß plaque deposition.