Anti-Obesity Effects of Aqueous Extracts of Sunbanghwalmyung-Eum in High-Fat- and High-Cholesterol-Diet-Induced Obese C57BL/6J Mice

Two Triterpenoids, ARM-2 and RA-5, From Protorhus longifolia Exhibit the Potential to Modulate Lipolysis and Lipogenesis in Cultured 3T3-L1 Adipocytes

Triterpenoids have been identified as potential novel lipid-lowering drugs for the treatment of hypertriglyceridemia. This study investigated the potential antilipogenic and/or antilipolytic effects of two triterpenoids (ARM-2 and RA-5) isolated from the stem bark of Protorhus longifolia (Benrh.) Engl. Employing a combination of in silico predictions and in vitro assays, the interactions between these triterpenoids and key proteins involved in lipogenesis and lipolysis were investigated. In silico molecular docking analysis predicted a favourable binding affinity of both triterpenoids to PPARγ, SREBP-1, and AMPK, with lower binding affinity to C/EBPα, pancreatic lipase, and hormone-sensitive lipase (HSL). Both triterpenoids exhibited in vitro inhibition of pancreatic lipase with Ki and IC50 values ranging from 28.7 to 52.9 μM and 27.6 to 35.8 μM, respectively. Total and neutral lipid accumulation in differentiated 3T3-L1 adipocytes and the oleic acid-induced HepG2 cell model was inhibited, with ARM-2 showing better inhibition than RA-5. In the HepG2 model, the inhibitory activity of the two triterpenoids (at 25 and 100 μM) was comparable to 50 μM lovastatin, although the latter was cytotoxic, whereas both ARM-2 and RA-2 lacked cytotoxicity. Associated gene expression was similar to the effect of simvastatin where the expression of SREBP-1, PPARγ, C/EBPα, and HSL was reduced and that of AMPK was unchanged. In vitro studies confirmed that ARM-2 and RA-5 also inhibited adipocyte lipolysis, where the reduction in glycerol release by 25 and 100 μM was similar to 50 μM lovastatin and simvastatin. This study identifies that the triterpenoids, ARM-2 and RA-5, have the potential to modulate lipogenesis and lipolysis.

Anti-Obesity Effect of Chitoglucan in High-Fat-Induced Obesity Mice

BACKGROUND

Chitoglucan (CG) is a bioactive component obtained from Flammulina velutipes Sing, an edible mushroom, which is known to have an anti-obesity effect. However, its biological and hormonal activities in alleviating obesity through regulation of adipocyte-derived proteins have not been examined yet.

PURPOSE

The present study aimed to investigate the anti-obesity effects of chitoglucan and its hormonal mechanisms in high-fat diet (HFD)-induced mice.

METHODS

The mice were fed either a normal diet (Normal group) or a high fat diet (HFD group) over 6 weeks. The HFD fed mice were administered with saline (HFD group), adipex (HFD + adipex group), chitoglucan 50, 150, or 300 mg/kg/day for 3 weeks (HFD + CG groups). The food consumption, body weight, fat contents, and the levels of serum leptin and resistin were assessed after treatment of chitoglucan.

RESULTS

the HFD produced a marked increase in body and fat weights after 6 weeks of feeding compared with the Normal group. Administration of chitoglucan for 3 weeks tended to reduce body weight and significantly decreased parametrical adipose tissues in HFD groups. The level of serum leptin in the HFD group was markedly higher than that in the Normal group, whereas the level of leptin in the chitoglucan treated groups was significantly decreased in comparison with the HFD group. In addition, the level of serum resistin in high-fat diet group tended to be more increased than Normal group. However, the serum resistin level was significantly reduced in HF diet groups after treatment with chitoglucan (50 mg/kg or 150 mg/kg).

CONCLUSION

Collectively, these data suggest that chitoglucan from the Flammulina velutipes may be useful in the treatment of high diet-induced obesity and metabolic syndrome.