Enhanced cytotoxic effects of Clinacanthus nutans and doxorubicin in combination toward breast cancer cell lines

Breast cancer is one of the most common cancers with a relatively high mortality rate. Despite the advancement of its medical treatments, many patients are still seeking complementary alternative medicines, namely Clinacanthus nutans which is found mainly in South-East Asian countries. We aim to find the antioxidant properties and cytotoxic activity of the plant extract toward breast cancer cell lines Michigan Cancer Foundation-7 (MCF7) and T47D individually and in combination with doxorubicin. Extractions of C. nutans with ethanol, n-hexane, and ethyl acetate were done using rotatory vacuum evaporators with the reflux method. Screening of biochemical properties was conducted. Antioxidant activity was measured toward α, α-diphenyl-β-picrylhydrazyl (DPPH) with IC(50) scores were shown to be highest in ethyl acetate extract. Cytotoxic effects of all three extracts were shown to be low in both MCF7 and T47D cells. However, combinations of 125 μg/ml n-hexane extract of C. nutans, and 0.1 μg/ml doxorubicin in T47D cancer cells showed further proliferation reduction compared to the single administration. The results suggested possible synergisms of the treatment combination.