Hexane Extract ofGarcinia quaesitaFruits Induces Apoptosis in Breast Cancer Stem Cells Isolated from Triple Negative Breast Cancer Cell Line MDA-MB-231

Development of therapy resistance is a major clinical issue in breast cancer treatments. Breast cancer stem cells (bCSCs) have a clearly defined role in the development of breast cancer therapy resistance and tumor recurrence. Therefore, discovery of new treatment strategies to circumvent cancer therapy resistance and tumor recurrence by targeting bCSCs is desperately needed. Fruits of manyGarciniaspecies are edible and, possess a range of health benefits.Garcinia quaesita, a species in the genusGarcinia,is endemic to Sri Lanka. Dried fruits ofG. quaesitaare commonly used to flavor dishes in Sri Lanka. The present study assessed the potential anticancer and apoptotic properties ofG. quaesitafruit extracts in bCSCs using WST-1 cell proliferation assay, sphere formation assay, caspase 3/7 assay, real-time PCR and fluorescent and phase-contrast microscopy. DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate), ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) and FRAP (Ferric Reducing Anti-oxidant Power) assays were used as anti-oxidant assays. The hexane extract ofG. quaesitafruits was found to mediate cytotoxicity in bCSCs through induction of apoptosis. Furthermore, the hexane extract showed free radical scavenging ability. This pilot investigation provides a rationale to consumeG. quaesitafruits as an anticancer dietary supplement for breast cancer patients.