2020, Vol. 8, Issue 5, Part C

author(s)
MIS Safeena and JSM Nethmi Numesha Samarakoon

abstract
Antioxidants have the capability of decreasing adverse effects of reactive oxygen species. The present study was performed to evaluate the antioxidant properties of 12 medicinal plants which are used in the Aryurvedic medicinal system as well as reported to be used as dainty leafy vegetables in Sri Lanka. The qualitative screening of plants showed significant positive results of existence of all tested phytochemicals. The tannin concentration of all 12 plants tested was within the range from 0.41 - 29.51 mg TAE/g dw. Among the all tested plants, O. octandra showed remarkably high concentration of tannins (29.51 and 12.27 mg TAE/g dw), flavonoids (111.49 mg RE/g) and total phenolic contents (94.53 mg GAE/g dw). There was a significant correlation (P= 0.05) between total phenolics and three antioxidant capacities assays (FRAP, DPPH and ABTS). Similarly, there were high correlation between FRAP and ABTS assays (R²= 0.912) and ABTS and DPPH assays (R²= 0.873). Total chlorophyll content in twelve plants were ranged from 12.61 - 18.39 µg/ mL of fresh leaf samples. All plants evaluated showed significantly high amount of total chlorophyll content (>12 µg/ mL) including in M. oppositifolia which had exhibited less content of phytochemicals for all tests carried out in this study. The carotenoid content was ranged from of 0.68 - 1.59 µg/ mL. The results showed that all 12 medicinal plants had good antioxidant potential and they can be used in therapeutics as well as leafy vegetables for day today consumption.