Cytotoxic activity of the methanolic extract of leaves and rhizomes of Curcuma amada Roxb against breast cancer cell lines

Correlation between cytotoxicity in cancer cells and free radical-scavenging activity: In vitro evaluation of 57 medicinal and edible plant extracts

Cancer is a complex interaction among multiple signaling pathways involving a variety of target molecules. Cancer causes morbidity and mortality in millions of people worldwide, and due to its prevalence, the discovery of novel anticancer drugs is urgently required. Nature is considered an important source of the discovery of anticancer treatments, and many of the cytotoxic medicines in clinics today are derived from plants and other natural sources. Reactive oxygen species (ROS) induce a variety of human cancers, and antioxidants or scavengers are used to counteract them. The current study reports on the screening of extracts from 57 plants that are used in the galilee district as a food and/or for traditional medicine. Investigating the free radical scavenging capacity and these plants, and their cytotoxicity, may prove helpful to high-throughput screening projects that use antioxidants and cytotoxic natural products. The current study assessed the correlation between free radical scavenging and cytotoxicity. Correlational analysis is important for increasing the efficiency of the screening process. In the present study, free radical scavenging was assessed using a DPPH assay, while cytotoxicity was measured using a XTT assay. A total of 9 extracts were indicated to exhibit EC₅₀ values <250 µg/ml, and 4 others exhibited a high antioxidant content, with EC₅₀ values, for free radical scavenging, of <0.5 µg/ml. An in-depth analysis of the results revealed that the extracts of plants that exhibit an EC₅₀ of free radical scavenging ≤10 µg/ml show a degree of enrichment toward increased cytotoxicity. It is recommended that future studies test the validity of the conclusions of the current study on other cancer cell-lines, and isolate and identify the bioactive agents that are found in the most cytotoxic extracts of plants.

Cytotoxic effect of Cyperus rotundus rhizome extract on human cancer cell lines

The wild weed Cyperus rotundus is commonly used as traditional medicine in different parts of the world. Sequential extraction of C. rotundus rhizome with solvents of different polarity namely hexane, chloroform, ethyl acetate, methanol and water were prepared and the free radical scavenging activity was determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Based on high antioxidant activity of methanolic extract of C. rotundus rhizome (MRCr) was further investigated for its cytotoxic effect on different human cancer cell lines-breast (MCF-7), cervical (HeLa), liver (Hep G2), prostate (PC-3), colorectal (HT-29) and normal cell line (MCF-12A) by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay evaluated as 50% inhibition of growth (IC₅₀). Apoptosis cells were analysed by flow cytometry stained with annexin V-Fluorescein isothiocyanate conjugate (AF) and propidium iodide (PI). The cellular and nuclear changes were examined under light and fluorescent microscope using 4', 6' diamino-2-phenylindole (DAPI) stain, dual stains of AF/PI and acridine orange/ethidium bromide (AO/EB). The cytotoxic effects on the tested cancer cell lines ranged from 4.52±0.57 to 9.85±0.68μgml^-1. The migration assay was showed the inhibitory effect with MRCr. The MRCr showed significant anticancer activity against all the tested cancer cell lines and also protected the non-cancer cells. The anticancer activity suggests further elucidation for the formulation of natural pharmaceutical products in the treatment of cancer.

Comparative evaluation of free radical scavenging activities and cytotoxicity of various solvent fractions of Sandong Sageretia thea (Osbeck) M.C. Johnst. branches

Sageretia thea (Osbeck) M.C.Johnst., an evergreen tender shrub of the Rhamnaceae, has been used as folk medicine and in traditional tea. To the best of our knowledge, this is the first study that investigates the free radical scavenging activity and cell cytotoxicity of S. thea branches. The ethyl acetate fraction and n-butanol fraction were identified to be rich in phenolic compounds exhibiting impressive antioxidant activity after stepwise partitioning of solvent fractions of the methanol extracts of S. thea branches (MB). Among the different human cancer cells tested, maximum cytotoxicity was found in MDA-MB-231 human breast cancer cells with MB, chloroform, ethyl acetate, n-butanol and water fraction. A significant (p<0.05) correlation between antioxidant activities and cytotoxicity exists in each fraction. These results suggest the branches of S. thea can be a valuable source of antioxidants, and they can serve as natural anticancer constituents in nutraceutical and pharmaceutical applications.