“Bang Chang”, Thai Cultivar Chili Pepper (Capsicum annuum var. acuminatum) Extract in Rice Bran Oil and its Biological Activities

Abstract

The Thai cultivar Capsicum, namely “Bang Chang chili pepper” (C. annuum var. acuminatum), is originally planted in Samut Songkhram, Thailand. Rice bran oil (RBO) is a healthy oil for preventing cardiovascular diseases. The study aimed to extract this chili pepper using RBO maceration, which was deemed safer. Capsicum extract was determined for capsaicin and β-carotene contents as bioactives of Capsicum and γ-oryzanol and γ-tocopherol as bioactives of RBO. Total phenolic content (TPC) was also monitored. The extract was further evaluated for in vitro biological activities, including antioxidant, anti-inflammatory, anti-obesity and anti-diabetic properties. Capsaicin contained in the extract was 0.002±0.0 mg/100 g non-pungent (0-700 SHU). Therefore, β-carotene was 3,489.5±15.2 μg/100 g, higher than dried chili pepper. γ-oryzanol and α-tocopherol contained in the extract were 4,939.6±11.0 mg/kg and 20,090±45.3 μg/100 g, which may affect its biological activities. However, TPC was a low amount (1.05±0.05 mg GAE/g). Capsicum extract moderately scavenged DPPH radicals (IC50 = 72.46±8.8 mg/mL) and preferred anti-inflammatory activity by inhibiting albumin degradation (IC50 = 1.09±0.04 mg/mL) and inhibiting NO production from macrophage cells (21.31±4.26%, at 0.1 mg/mL). Capsicum extract exerted in vitro anti-diabetic activity by inhibiting α-amylase and α-glucosidase (IC50 = 1.35±0.26 and greater than 1,000 mg/mL), while there was a lack of anti-lipase. Capsicum extract (0.0001-1.0 mg/mL) was non-toxic against human fibroblast cells. In conclusion, the simple extraction of this Capsicum within RBO contained bioactive compounds with non-pungency and exhibited biological properties for health benefits with non-toxicity that can be applied for external medicinal use and food seasoning.