Paper Title
Antioxidant activity of golden barrel cactus (Echinocactus Grusonii Hildm.) Crude Extracts

Abstract
- Presently, international scientists have studied cactus extract from various species for different phytochemicals that benefit human health. In this study, we focus on the Golden barrel cactus, a Thai cultivar cactus known as the Tang Thong in Thailand, at differing maturities. This work studies on proximate composition and antioxidant activity of Golden barrel cactus stem extract. Total phenolic contents was 3,545.35 and 2,557.96 mg gallic acid equivalent per 100g of dry weight for Golden barrel cactus aged 3 and 6 years crude extracts, respectively. The crude extracts of Golden barrel cactus aged 3 and 6 years were evaluated with DPPH, ABTS and FRAP assay. Extracts from Golden barrel cactus aged 3 years showed IC50 values of 112.60 mg/ml, 44.62 mg/ml and 0.014 mmol Fe2+/g of dry weight, while the crude extracts of Golden barrel cactus aged 6 years showed IC50 values of 191.90 mg/ml, 81.84 mg/ml, and 0.01mmol Fe2+/g of dry weight for each assay. In conclusion, the total phenolic and antioxidant activity of 3 years old Golden barrel cactus extract is significant higher (p < 0.05) than 6 years old crude extract of Golden barrel cactus. Keywords- Golden barrel cactus (Echinocactus grusonii), Antioxidant activity