Antinociceptive and antioxidant potential of the crude ethanol extract of the leaves of Ageratum conyzoides grown in Bangladesh

Abstract Context: Ageratum conyzoides Linn. (Asteraceae) is an annual herbaceous plant with a long history of traditional medicinal and agricultural uses; it is usually grown in the northeast part of Bangladesh. Objective: The ethanol extract of the plant leaves was evaluated for preliminary phytochemical screening with its antinociceptive and antioxidant activities. Materials and methods: The preliminary phytochemical analysis was performed on the basis of standard procedures. The analgesic activity of the extract was investigated using the acetic acid-induced writhing method in mice. Five complementary tests such as DPPH free radical scavenging, nitric oxide (NO) scavenging, reducing power, Fe++ ion chelating ability and total phenolic content were used for determining antioxidant activities. Results: The results of preliminary phytochemical analysis showed the presence of alkaloids, reducing sugars, saponins, gums, steroids, tannins and flavonoids. The extract possessed a significant dose-dependent DPPH free radical scavenging activity with an IC50 value of 18.91 μg/ml compared to ascorbic acid (IC50: 2.937 μg/ml) and butylated hydroxyanisole (IC50: 5.10 μg/ml). The IC50 value of the extract for NO scavenging (41.81 μg/ml) was also found to be significant compared to the IC50 value of ascorbic acid (37.93 μg/ml). Moreover, the extract showed reducing power activity and Fe++ ion chelating ability. The total phenolic amount was also calculated as quite high (378.37 mg/g of gallic acid equivalents) in the crude ethanol extract. Discussion and conclusion: Therefore, the obtained results tend to suggest the antinociceptive and antioxidant activities of the ethanol extract of the plant leaves and justify its use in folkloric remedies.