Cancer is one of the world’s top killers. Chemotherapy is a major method to defeat cancer. Recently, novel anticancer compounds were discovered from Garcinia species by high-throughput drug screening....[ Read more ]

Cancer is one of the world’s top killers. Chemotherapy is a major method to defeat cancer. Recently, novel anticancer compounds were discovered from Garcinia species by high-throughput drug screening.

Different parts of the plants were extracted with ethanol and water respectively. These extractions were tested with the HeLa-C3 cells. Effective extractions were further fractionated and tested. After several rounds, we got eight effective compounds among which OC (Oblongifolin C) and GO-11 (2H,6H-Pyrano[3,2-b]xanthen-6-one, 7,9,12-trihydroxy-2,2-dimethyl-) are the most interesting ones without published report.

OC is a polyprenylated benzoylphloroglucinol discovered from Garcinia yunnanensis. It could induce apoptosis in HeLa cells in a caspases-dependent way. Upon OC treatment, Caspase-8 activation, Bid cleavage and Bax translocation were detected resulting in cytochrome c release and caspase-3 activation. Pan-caspase inhibitor or over-expressed Bcl-xL could significantly inhibit OC-induced cell death, which indicated mitochondria and caspases are the key players in the pathway of OC-induced apoptosis in HeLa cells.

In addition, OC showed significant antitumor effects in xenografted nude mice inoculated by MDA-MB-435 cells. For the OC-treated group, the tumor growth was successfully repressed and the body weight didn’t drop. H&E staining of tumor tissues showed massive vacuolization for the OC treated mice. Caspase-3 assay indicated dramatic elevation of Caspase-3 activity in tumor tissues of OC-treated mice.

GO-11, which is a prenylated xanthone screened out from Garcinia oblongifolia, was found capable to arrest HeLa cells in G2/M phase by cell cycle analysis. In the arrested cells, microtubule cannot assemble successfully while DNA could condense to chromosomes indicating cells were arrested in prometaphase.

These two compounds may be the promising drug candidates because of the significant effects and the sufficient source. More works are needed to further investigate them thoroughly.