Investigation of in-vitro antioxidant and cytotoxic potential of methanolic extract of oroxylum indicum

Abstract

Oroxylum indicum (O. indicum) is a local herbal medicinal plant which is commonly known as Sonapatha or Shyonaka. Literature review revealed that the roots, stem, leaf of this plant have been used as drug or component of drug for the treatment of various disorders. Different parts of this plant extract has therapeutic effects for example antitumor, anti-arthritic, antibacterial, anti-mutagenic and many more. In this study, the methanolic extract of the leaf and stem of O. indicum was screened for the evaluation of different phytochemicals, antioxidant and cytotoxic activity by standard methods. Several antioxidant screening methods have been used in this study for example DPPH test, total phenolic content, total flavonoid content and total antioxidant capacity for the determination of antioxidant activity. Along with this, MTT assay has been used for investigating cytotoxic activity. The present study has shown that the leaf and stem contain sugars, flavonoids, saponins, steroids and alkaloids. The antioxidant potential of this plant has been studied with stem extract and the findings have showed that with the increase of concentration the total phenolic content, total flavonoid content and total antioxidant capacity increased. In case of DPPH test at the lowest concentration of 50 μg/mL, the extract showed notable % of inhibition which was 84.87%. Extract showed good antioxidant capacity which was expressed as 67.25 mg of ascorbic acid per gram of dried extract which was at the lowest concentration of 200 μg/mL and in case of total phenolic content, with the highest concentration extract showed 98.075 mg of gallic acid per gram of dried extract. The cytotoxic activity was assessed by introducing the leaf extract on MOLT-4 (human acute lymphoblastic leukemia, T cell) of concentration of 0.025 mg/mL, 0.25 mg/mL, 2.5 mg/mL, and 25 mg/mL. At the highest concentration of 25 mg/mL it showed 90 % of the cell death where the cell survival was only 10%. Other concentration did not show remarkable % of cell death. So, antioxidant potential was significant in two methods and cytotoxic activity was not that significant. However, further study can be done on this plant for such as in-vivo antioxidant potential assessment and other bioactivities screening.