Antioxidant and Cytotoxicity Activities of Karamunting (Melastoma malabathricum L.) Fruit Ethanolic Extract and Quercetin

Melastoma malabathricum L. is a type of plant naturally grows in Kalimantan that has medicinal properties. Ethanolic extract of M. malabathricum L. flower has quercetin and kaempferol contents that have antioxidant and anticancer activities. But the antioxidant and cytotoxicity activities of M. malabathricum L. fruit ethanolic extract were not known. This study measured the quercetin and kaempferol level in M. malabathricum L. fruit ethanolic extract using HPLC MS/MS, antioxidant activity using DPPH method, and cytotoxicity activity using Brine Shrimp Lethality Test (BSLT) method. Results showed the level of quercetin and kaempferol from M. malabathricum L fruit ethanolic extract are 67.78 µg/g and 43.52 µg/g, respectively. Beside, the antioxidant activity with by IC50 was 16.82±0.24 ppm and 7.38±0.41 ppm. The cytotoxicity activities of M. malabathricum L. fruit ethanolic extract and quercetin are shown by the LC50 of 313.44 ppm (95%CI 283.97-344.43) and 37.24 ppm, respectively.

Oxidants-Antioxidants Profile in the Breast Cancer Cell Line MCF-7

Reactive oxygen species (ROS) have various biological effects and they are non-linear in characteristic. In high oxidative stress, they may cause cytotoxicity, inhibit cell proliferation, and induce cell death in the form of apoptosis/necrosis; while in low or medium oxidative stress, ROS may cause DNA damage, cell mutation, inflammation, cell proliferation, and eventually they may induce carcinogenesis. Antioxidants are compounds with the ability to reduce ROS. Cell line MCF-7 is one of the breast cancer cell lines that is known to have small amount of antioxidant MnSOD compared to the other cell lines. Low antioxidant MnSOD level in breast cancer cell line MCF-7 leads to low concentration of hydrogen peroxide, because antioxidant MnSOD will convert radical superoxide to hydrogen peroxide. The aim of this research was to analyze oxidants and antioxidants profile in breast cancer cell line MCF-7 and their relationship with cell number. Observations were conducted for 5 days. The cell number was counted with tryphan blue method and haematometer. The concentration of radical superoxide was measured with DHE staining using LSCM tipe Olympus Fluoview FV 1000-Ver 1.7. MnSOD activity, hydrogen peroxide concentration, and catalase activity were measured with ELISA. The results showed that the longer of observation, the greater concentration of oxidants and MnSOD activity, but there was no change in catalase activity. Conclusion the increase in cancer cells number is influenced by radical superoxide.