| Abstract: | Purple-fleshed sweet potato (PFSP) (Ipomoea batatas L. Lam) has been known to possess high amount of anthocyanin. Besides its antioxidant activity, anthocyanin is often associated with health preventive effects, such as reduce risk of inflammation and cancer. Thus, in this study, anthocyanin-rich extracts of steamed PFSP “Tainung 73”, which is locally grown in Taiwan, were evaluated for anti-inflammatory, anti-cancer, and anti-bacterial activities. Anthocyanins were extracted using acidified ethanol pH 3.5 under 80oC. There were two kinds of anthocyanin-rich extracts obtained, namely SP (Steamed, Peeled) and SNP (Steamed, No Peeled) extracts. Cell viability assay (MTT) showed that anthocyanin-rich PFSP extracted were not toxic to RAW 264.7 cells. Furthermore, both SP and SNP extracts exhibited anti-inflammatory activity by suppressing the production of NO and pro-inflammatory cytokines, such as NF-β, TNF-α, and Il-6, in LPS-induced macrophage cells. Both extracts also displayed inhibitory effect on the growth of tested cancer cell lines, such as MCF-7 (breast cancer), SNU-1 (gastric cancer), and WiDr (colon adenocarcinoma) in a concentration and time-dependent manner. The best inhibition of the extracts was found on human gastric cancer cell. Further study on molecular mechanism also revealed that SP extracts could induce apoptosis in cancer cell line MCF-7 and SNU-1 through extrinsic and intrinsic pathway. In addition, study on the growth of pathogen bacteria in liquid culture demonstrated that SP and SNP extracts exerted antibacterial activity against both Gram-positive and Gram-negative bacteria. After 24 h incubation, SP extracts showed the strongest effect on Bacillus cereus and Escherichia coli. Meanwhile, Streptococcus sp. was the most affected bacteria against SNP extracts. These results suggested that PSFP extracts have potential anti-inflammatory, anti-cancer, and anti-bacterial properties. In the future, PFSP TNG 73 extracts can be applied in nutraceutical or drug and food industries. |
