Anti-Inflammatory and Anticancer Activities of Taiwanese Purple-Fleshed Sweet Potatoes (Ipomoea batatas L. Lam) Extracts

Purple-fleshed sweet potato (PFSP) (Ipomoea batatas L. Lam) has been known to possess high amount of anthocyanins which contribute to its antioxidant activity. However, a few reports are available concerning its anti-inflammatory and anticancer properties. In this study, PFSP "Tainung 73," which is locally grown in Taiwan, was steamed and extracted using acidified ethanol pH 3.5 under 80°C. Two kinds of crude anthocyanins extracts were obtained, namely, SP (Steamed, Peeled) and SNP (Steamed, No Peeled). Then, anti-inflammatory and anticancer activities of these extracts were investigated. Cell viability assay (MTT) showed that SP and SNP extracts were not toxic to RAW 264.7 cells. They even exhibited anti-inflammatory activities by suppressing the production of NO and proinflammatory cytokines, such as NF-κβ, TNF-α, and IL-6, in LPS-induced macrophage cells. Anticancer activities of these extracts were displayed through their ability to inhibit the growth of cancer cell lines, such as MCF-7 (breast cancer), SNU-1 (gastric cancer), and WiDr (colon adenocarcinoma), in concentration- and time-dependent manner. Further studies also revealed that SP extracts could induce apoptosis in MCF-7 and SNU-1 cancer cells through extrinsic and intrinsic pathway. In the future, PSFP extracts may have potential to be applied in nutraceutical, pharmaceutical, and food industries.