Phytochemical and bioactivity investigation of Thai pigmented-upland rice: Dam-Mong and Ma-led-Fy varieties

Abstract

Importance of the work: This is the first data on the bioactive compounds and biological activities of two Thai pigmented-upland rice varieties (Dam-Mong and Ma-led-Fy). Objectives: To examine the bioactive compounds and biological activities of the glutinous Dam-Mong and non-glutinous Ma-led-Fy Thai pigmented-upland rice varieties. Materials & Methods: Dam-Mong and Ma-led-Fy rice varieties were extracted using 50% ethanol to obtain Dam-Mong extract (DME) and Ma-led-Fy extract (MFE). The extracts were evaluated for their bioactive compounds (total phenolic, total flavonoid, anthocyanins and cyanidine-3-O-glucoside contents) and biological activities (anti-oxidant, anti-glucosidase, immunomodulatory and anti-inflammatory). Results: MFE and DME had antioxidant and anti-glucosidase enzyme activities. They both stimulated mouse splenocyte proliferation that revealed an immuneenhancing effect without cytotoxicity. In addition, in lipopolysaccharide-induced inflammatory macrophage cells, both rice extracts inhibited the up-regulated expression of inflammatory-related genes (cyclooxygenase-2, interleukin-1β, inducible nitric oxide synthase and tumor necrosis factor-α). The extracts inhibited the production of prostaglandin E2 and nitric oxide. Furthermore, they had anti-edematic action on rat's paws in a dose-dependent manner. In general, MFE had greater bioactivity than DME, which was related to their respective amounts of phytochemical contents. Main finding: Overall, for the first time, this study indicated that Thai pigmentedupland rice extracts could be developed as potential natural substances for novel dietary supplements or cosmeceutical products, especially the Ma-led-Fy variety.