Phytotoxicity, cytotoxicity and antioxidant activity of the invasive shrub Austroeupatorium inulifolium (Kunth) R.M. King & H. Rob

Methanol and dichloromethane extracts of root, stem, leaves and flowers of invasive plant Austroeupatorium inulifolium were tested for cytotoxic, phytotoxic, antioxidant and antifungal activities. Significantly higher phytotoxicity was detected in methanol extracts of leaves and dichloromethane extracts of roots. This effect was most pronounced against amaranth seeds where the seed germination was reduced to 3.74 % with the addition of methanol extracts of leaves at 3000 mg/L. The dichloromethane extract of roots of A. inulifolium showed potent antifungal activity against Cladosporium cladosporioides. Cytotoxic activity was found in dichloromethane extract of roots (LD50 = 27.91 ± 8.55 mg/L), methanol extract of flowers (LD50 = 15.22±7.89 mg/L) and leaves (LD50 = 22.92±11.76 mg/L) against Artemia salina (brine shrimp) larvae. The results also revealed significant antioxidant activity in methanol extract of leaves (IC50 =33.66± 0.03 mg/L) against the reference α-tocopherol (IC50 =10.02 ± 0.01 mg/L)