Anti-oxidant and anti-adipogenic effects of acorn (Quercus acutissima CARR.) shell extracts via regulation of wnt signaling in 3T3-L1 cells.

Acorn (Quercus acutissima CARR.) is a nut from the Fagaceae family that has been used in traditional medicine for many years. However, shells from acorns are regarded as a by-product and are mostly discarded. Anti-adipogenic activities of acorn shells were investigated using 3T3-L1 cells and methanol shell extracts (AE-M). AE-M demonstrated Cu2+-chelation activities and anti-oxidant activities via reduction of oxidative stress levels induced using AAPH. Six days after adipocyte differentiation, 50 and 100 µg/mL AE-M completely suppressed 3T3-L1 adipogenesis and the anti-adipogenic effect was stronger than for the positive control 50 µM quercetin. Treatment with AE-M in 3T3-L1 cells reduced mRNA expression levels of adipogenic genes. AE-M-inhibition was found in pre-adipogenic, early, and intermediate stages of adipogenesis in 3T3-L1 cells. The Wnt/ß-catenin signaling pathway is required for AE-M-inhibition of 3T3-L1 adipogenesis.

Antioxidant and anti-adipogenic activities of acorn shells.

Antioxidant and anti-adipogenic activities of water extract (WE) and methanol extract (ME) of acorn shells (AS), from Quercus acutissima Carruth. grown in Korea, were investigated. At a concentration of 50 µg/mL, the WE had a scavenging activity of 53.84% for the DPPH and 76.09% for the ABTS radical, while the ME had corresponding scavenging activities of 29.09 and 48.43%. Total phenolic contents of WE and ME were 375.96 and 288.01 mg gallic acid equivalents/g of extracts, respectively. Both extracts significantly inhibited 3T3-L1 adipogenesis in a dose-dependent manner, and concomitantly decreased the size and number of intracellular lipid droplets. Furthermore, the antiadipogenic activities of WE and ME are largely limited in the pre- and early stages of adipogenesis. The results suggest that AS may be a promising source of antioxidants and anti-obesity compounds.