Antioxidant and cytotoxic potential of leaf extracts of Costus igneus

Background: Costus igneus leaves are traditionally used to treat diabetes and this plant is commonly known as insulin plant. Hypothesis: The purpose of this study was to evaluate the antioxidant and cytotoxic potential of different leaf extracts of C. igneus. Materials and Methods: The antioxidant potential of various leaf extracts of C. igneus was established by ferric reducing antioxidant power (FRAP) assay, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay, metal-chelating activity, phosphomolybdenum assay, superoxide radical scavenging activity, 2,2-diphenylpicrylhydrazyl (DPPH) assay, reducing power assay, and cytotoxic activity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on breast cancer cell line Michigan Cancer Foundation (MCF-7). Results: In FRAP assay, acetone extract showed higher activity of 276.31 mmol Fe (II) E/mg extract. In ABTS assay, hexane extract showed the highest scavenging activity of 12878.893 μM Trolox equivalent antioxidant capacity (TEAC)/g extract. Hot water extract registered higher metal ion-chelating ability with 2.94 mg ethylenediaminetetraacetic acid equivalent/g extract. Hexane extract has recorded the highest total antioxidant capacity of 65.00 mg AAE/mg in phosphomolybdenum assay. Superoxide radical scavenging activity was found maximum in acetone extract with 41.11%. In DPPH assay, acetone extract recorded total free radical scavenging capacity with IC50 value of 40.70 μg/ml. Hexane extract has recorded significant highest reducing power at concentration 100 μg/μl with maximum optical density of 0.177. Acetone extract of C. igneus leaf extract at concentration of 150 μg/ml showed the highest cytotoxic activity on cancer cell line with cell viability of 65.51%. Conclusion: The present study explored that C. igneus shows efficient antioxidant activity as well as cytotoxic activity and could act as safe and cost-effective with potential biological applications.