Zerumbone (ZER), a potential anticancer compound, isolated from the fresh rhizomes of Zingiber zerumbet. In this investigation, the cytotoxic properties of ZER were evaluated, on cancer cells of human cervix (HeLa), breast and ovary, and normal cells of Chinese Hamster ovary, using MTT assay. Apoptogenic effects of ZER on HeLa were studied using fluorescence microscopy (AO/PI double staining), scanning and transmission electron microscopy (SEM and TEM), and colorimetric assay of the apoptosis promoter enzyme, caspase-3. The results of MTT assay showed that ZER has less effect on normal cells compared to cancer cells. The lowest IC(50) of ZER was observed on HeLa cells. Cytological observations showed nuclear and chromatin condensation, cell shrinkage, multinucleation, abnormalities of mitochondrial cristae, membrane blebbing, holes, cytoplasmic extrusions and formation of apoptotic bodies as confirmed collectively by double staining of AO/PI, SEM and TEM. Statistical analysis (two-tailed t-test) of differential counting of 200 cells under fluorescence microscope revealed significant difference in apoptotic cells populations between treated and untreated HeLa cells. In addition, ZER has increased the cellular level of caspase-3 on the treated HeLa cells. It could be concluded that ZER was able to produce distinctive morphological features of cell death that corresponds to apoptosis.
Antiapoptotic and antioxidant activities of aqueous-methanolic extract (CAME) of Orthosiphonstamineus Benth(OS), and its hexane (HF), chloroform (CF), n-butanol (NBF), ethyl acetate (EAF) and water (WF) fractions were investigated. Antioxidant properties were evaluated using the assays of Folin-Ciocalteu, aluminiumtrichloride, β-carotene bleaching and DPPH. The role of OS against hydrogen peroxide induced apoptosis on MDA-M231 epithelial cells was examined using MTT assay, phase contrast microscope, colorimetric assay of caspase-3, western blot and quantitative real-time PCR. Results showed that EAF showed the highest total phenolic content followed by CAME, NBF, WF, CF and HF, respectively. Flavonoid content was in the order of the CF > EAF > HF > CAME > NBF > WF. The IC(50) values on DPPH assay for different extract/fractions were 126.2 ± 23, 31.25 ± 1.2, 15.25 ± 2.3, 13.56 ± 1.9, 23.0 ± 3.2, and 16.66 ± 1.5 μg/ml for HF, CF, EAF, NBF, WF and CAME, respectively. OSreduced the oxidation of β-carotene by hydroperoxides. Cell death was dose-dependently inhibited by pretreatment with OS. Caspase-3 and distinct morphological features suggest the anti-apoptotic activities of OS. This plant not only increased the expression of Bcl-2, but also decreased Bax expression, and ultimately reduced H(2)O(2)-induced apoptosis. The current results showed that phenolics may provide health and nutritional benefits.