Evaluation of antioxidant, antimicrobial and cytotoxic activities of seed crude extracts of Ammi majus grown in Oman

Abstract

Ammi majus has long been used as an herbal medicine in several countries for skin disorders, regulation of menstruation and for conditions in which diuresis is indicated. The present study was undertaken to evaluate the antioxidant, antimicrobial and cytotoxic activities of the crude extracts of locally growing Ammi majus (A. majus). Initially, methanol crude extract was prepared from powdered seed samples of A. majus by applying Soxhlet extraction method. Successive extracts were then derived by suspending methanol free crude extract in water followed by successive extraction with solvents of different polarities in an order of increasing polarity. The evaluations of antioxidant, antimicrobial and cytotoxic activities of seed crude extracts of A. majus were determined by 1, 1-diphenyl-2-picrylhydrazyl (DPPH), agar disc diffusion and Artemia lethality methods, respectively. The highest antioxidant activity was observed in case of chloroform crude extract whereas the lowest activity was corresponding to methanol crude extract. However, the highest IC50 value was obtained with chloroform crude extract but the lowest result was observed in case of ethyl acetate crude extract. All crude extracts of A. majus displayed moderate antimicrobial activity against one Gram positive bacteria, Staphylococcus aureus (S. aureus), and three Gram negative bacteria, namely Escherichia coli (E. coli), Haemophilus influenzae (H. influenzae), and Proteus spp (Proteus spp), with growth inhibition zone of 0–15 mm. The cytotoxic activity results showed that all crude extracts of the seed had killed all the Artemia larvae at a concentration of 1000 µg/mL, being the highest for all extracts. However, regarding the overall magnitude of cytotoxic effect, chloroform crude extract showed the highest activity followed in a diminishing order by hexane, methanol, ethyl acetate, butanol and water crude extract. As such, the highest lethality was observed in case of chloroform crude extract where the lethal concentration (LC50) was 49.16 µg/mL, whereas the lowest lethal concentration was seen with water crude extract where the LC50 was 652.38 µg/mL. The present study demonstrates that all seed crude extracts of A. majus have significant antioxidant, antimicrobial and cytotoxic effects. These results warrant follow up bioassay intended for isolation of the active compounds from this plant.