A number of Houttuynia cordata fermentation products are commercially available in Thailand. However, their anticancer activity remains to be investigated. In this study, the phenolic acid composition and anticancer activity of two commercialized H. cordata fermentation products were investigated. Reversed phase HPLC was used to identify and quantify phenolic acids. MTT and Annexin V staining assays were used to investigate antiproliferative and apoptosis induction activities, respectively. Seven phenolic acids including protocatechuic, p-hydroxybenzoic, vanillic, syringic, p-coumaric, ferulic, and sinapinic acids were detected in the water-soluble constituents of both fermentation products 1 and 2. Water-soluble constituents of fermentation product 2 containing a greater phenolic acid content were more effective than product 1 in inhibiting the growth of HeLa, HCT116, and HT29 cells in a dose-and time-dependent manner. The non-cancer cell line Vero cells appeared to be resistant to both fermentation products. The growth inhibitory effects of both fermentation products in HeLa, HCT116, and HT29 cells included induction of apoptosis. These results suggest that commercially available fermentation products of H. cordata contain several anticancer phenolic acids that may be beneficial in the treatment of human cancer.

Four new benzoyltyramines, atalantums H-K (1-4) and seven known compounds were isolated from the peels of Atalantia monophylla. All compounds were tested for cytotoxicity against HeLa, HCT116 and MCF-7 cell lines, as well as normal cells (Vero cells). Compound 5 showed cytotoxicity against HeLa, HCT116 and MCF-7 cell lines with IC 50 values ranging from 16-25 g/mL but was inactive against Vero cells. Compound 6 also showed interesting results as compound 5 with IC 50 values ranging from 15-18 g/mL and an IC 50 value of 80.20 g/mL against Vero cells. This means compounds 5 and 6 can be used as lead compounds for anticancer agents.

Capsaicin possesses cytotoxic/anticancer activity and shares some common structural features, including a benzene ring and a long hydrophobic carbon tail, with the histone deacetylase (HDAC) inhibitors trichostatin A and suberoylanilide hydroxamic acid. The aims of this study were to investigate HDAC inhibitory and cytotoxic activities of a synthetic derivative of capsaicin, hydroxycapsaicin (6-hydroxy-N-(4-hydroxy-3-methoxybenzyl)-8-methylnonenamide), in colon cancer cell lines. Hydroxycapsaicin inhibited HDAC activity in vitro (IC 50 = 72 µM) much more effectively than the prototype capsaicin (IC 50 > 13.1 mM) and also exhibited HDAC inhibitory activity in human cells (HeLa cells). MTT assay demonstrated that hydroxycapsaicin was less toxic than capsaicin against both cancer and noncancer cells; however, hydroxycapsaicin, with greater HDAC inhibitory activity, was more effective than capsaicin at inducing apoptosis in colon cancer cell lines, especially in HCT116 cells. Hydroxycapsaicin appeared to induce less apoptotic cell death than capsaicin in Vero cells. Moreover, only hydroxycapsaicin induced S-phase cell-cycle arrest in both HT29 and HCT116 cells. The current study demonstrates that hydroxycapsaicin can act as a novel HDAC inhibitor, which would lead to a promising strategy for the development of safe and effective chemotherapeutic drugs from the abundant natural capsaicin of chili pepper.

Four new acylphloroglucinol derivatives 1, 3, 5 and 13 were isolated from the fruits of Horsfieldia irya, and in addition, thirteen known compounds were also discovered. All compounds were evaluated for cytotoxicity against HeLa and HCT116 cell lines, as well as normal cells (Vero cells). Compound 13 showed cytotoxicity against HeLa and HCT116 cell lines with IC 50 values of 4.53 ± 0.05 and 4.53 ± 0.16 g/mL, respectively, and showed less activity against normal cells (IC 50 = 13.38 ± 0.75 g/mL). Compound 13 may be useful for the development of anticancer agents. It was found that decanoyl side chain may be necessary for the cytotoxicity. The chemical structures of all isolated compounds were elucidated using spectroscopic methods including 1D-NMR, 2D-NMR, MS and IR data.

No abstract