Survey of Antioxidant and Cytotoxic Activities of Gracilaria corticata (a Red Seaweed), Against RKO, AGS and HepG2 Human Cancer Cell Lines

Abstract

One of the problems in cancer pharmaceutical treatment is development of drugs that not only have minimum complication, but are also prepared from natural compounds. Marine algae with antibacterial, antiviral, antifungal, antioxidative and anticancer potentials are one of the natural resources in this field. The source of Gracilaria corticata which a red alga is different sea coasts in the world including coasts in countries of India, China, Persian Gulf countries, etc. In this research, antioxidant activity and anticancer potential of aqueous extract from Gracilaria corticata against three kinds of human cancer cell lines, human gastric adenocarcinoma (AGS), human colon cancer (RKO) and human hepatocellular carcinoma (HepG2) were studied. Various concentration of algal extract were employed for cell treatment. In addition, extract cytotoxicity was measured using Methyl thiazolyl tetrazolium (MTT) assay in 540nm. The results showed that 9μg μl-1 of algal extract had the highest effectiveness against HepG2, RKO and AGS with 74%, 69% and 68% cytotoxicity effects respectively. 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) antioxidant assay was used to determine the probable antioxidant activity of this algae. Samples were prepared according to kit instruction and treated by different concentration of algal extract. Next, free radical scavenging activity of extracts was compared with measuring of the absorbency of the samples at 405nm using spectrophotometer. Descending order of the cell lines which had affected antioxidant activity of upper concentration of algal extract was as follows: HepG2, RKO and AGS respectively and the most effective concentration of algal extract that had the highest antioxidant efficacy on selected cancer cell lines was 9 μg μl-1. The water crude extract of Gracilaria corticata had significant antioxidant and anticancer effect and it could be a good option for more studies for creating a compound with natural origin as an anticancer agent that can be employed for the development of potential anticancer medicine and new pharmaceutical endeavors.