Antioxidant and anti-adipogenic activities of the nuts of Castanopsis cuspidata var. thunbergii

Abstract

The antioxidant and anti-adipogenic activities of the water extract (WE) and methanol extract (ME) of the shell and kernel of Castanopsis cuspidata var. thunbergii (CCT) nuts were evaluated. The shell extracts showed higher DPPH and ABTS radical scavenging activities (RSAs) than did the kernel extracts. Furthermore, the RSA of the ME was higher than that of the WE, regardless of the part. The total phenolic contents (TPCs) of the ME of the shell and kernel were 71.38 and 10.56 mg gallic acid equivalent (GAE)/100 mg extract, respectively. The TPCs of the WE of the shell and kernel were 17.44 and 9.27 mg GAE/100 mg extract, respectively. The WE inhibited 3T3-L1 adipogenesis more effectively than did the ME, and the shell extracts suppressed 3T3-L1 adipogenesis more effectively than did the kernel extracts. These results suggest that CCT nut kernels (ME) and shells (WE) may be strategically used to enhance antioxidant or and anti-obesity materials.

Keywords: Anti-adipiogenic; Antioxidant; Castanopsis cuspidata var. thunbergii; Nut.

Fig. 1

DPPH radical scavenging activities (RSA) of water extract (WE) and methanol extract (ME) from (A) kernel and (B) shell of nuts of Castanopsis cuspidate var. thunbergii. Each value is mean ± SD. Values with different letters on the bars in each figure are significantly different by Duncan’s multiple range test at p < 0.05

Fig. 2

ABTS radical scavenging activities (RSA) of water extract (WE) and methanol extract (ME) from (A) kernel and (B) shell of nuts of Castanopsis cuspidate var. thunbergii. Each value is mean ± SD. Values with different letters on the bars in each figure are significantly different by Duncan’s multiple range test at p < 0.05

Fig. 3

Effects of CCT extracts treatment on the adipogenesis in 3T3-L1 cells. Scheme of CCT (WE and ME) treatment and 3T3-L1 adipocytes differentiation (A). Lipid accumulation levels of 3T3-L1 adipocytes treated with WE and ME prepared from kernel (B) and shell (C) by ORO staining at day 6. Each value was expressed by mean ± SD. Values with different letters on the bars in each figure indicate significant differences by Duncan’s multiple range test at p < 0.05

Fig. 4

Inhibitory effects of CCT extracts treatment on the number and size of lipid droplets in ORO-stained 3T3-L1 cells at day 6. Pre, preadipocytes; Adi, mature 3T3-L1 adipocytes (Day 6)