Averrhoa carambola family Oxalidaceae is largely found in Malaysia and many other tropical countries. This plant has
hypoglycemic, hypocholesterolemic, antimicrobial, anti-inflammatory and antioxidant activities. The present study aimed to
evaluate the in vitro cytotoxicity and antioxidant activities of aqueous and methanolic extracts of various parts of A. carambola.
All aqueous and methanolic extracts of ripe fruit, unripe fruit, leaves and stems of A. carambola were found to cause no
cytotoxic effect on the four cancer cell lines used (K-562, HL-60, kasumi and HCT-116). On the other hand, the methanolic
extracts of stem and leaves showed higher total phenolic contents of 198.08 and 46.74 mg gallic acid equivalent (GAE)/100g
extract and total flavonoid 114.8 and 36.76 mg quercetin equivalent (QE)/100g extract, respectively. Both methanolic and
aqueous extracts of stem showed most potent reducing power of 0.087 and 0.042 μmol FeSO4/ mL, respectively. In contrast,
the methanolic extract of stem and leaves exhibited radical scavenging activity with IC50 values of 6.86 and 22.84 in DPPH
assay and 68.8, 23.2 μg/mL in ABTS assay, respectively. In conclusion, methanolic extracts showed higher antioxidant
capacity compared to aqueous extracts in particular, the stem and leaves extracts..