Antioxidant, analgesic and CNS depressant effects of Synedrella nodiflora

Background:Synedrella nodiflora (L) Gaertn. belonging to the family Asteraceae contains steroids, reducing sugars, phenolic, flavonoids, saponins, tannins and triterpenoids. Therefore, this study is designed to investigate its antioxidant, analgesic and CNS depressant effects. Materials and Methods: The antioxidant activity of methanolic extract of S. nodiflora (SN) was determined using Folin Ciocalteu reagent, phosphomolybdenum method, free radical scavenging activity by 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and the reducing power activity. Analgesic activity was done by acetic acid and formalin model and CNS depressant activity was measured by the hole cross and open field method. Results: The total phenols and total antioxidant capacity of SN was found to be 37.38 < 2.01 mg/g equivalent of gallic acid and 433.37 < 4.22 mg/gm equivalent of ascorbic acid. The percentage (%) scavenging of DPPH free radical was found to be concentration dependent and IC50 value was 125.89 < 2.23 μg/ml while the IC50 value of standard ascorbic acid was found to be 16.76 < 0.11 μg/ml. The reducing power of SN was found to be concentration dependent. Acetic acid and formalin models are peripherally acting analgesic methods. The oral administration of both doses (100 and 200 mg/kg b.wt.) of SN significantly (p<0.001) inhibited 40.06% and 61.83% writhing response induced by acetic acid whereas oral administration of the same doses of SN significantly (p<0.001) inhibited 56.96% and 62.60% itching response induced by formalin. The methanolic extract of SN, at the dose of 250 mg/kg and 500 mg/kg b.wt. produced significant (P<0.001) decrease of locomotion. This is the first report of CNS depressant activity of the plant. Conclusion: The extract showed moderate antioxidant, analgesic and CNS depressant potency. The present investigation suggests that SN may be a source of natural antioxidant with analgesic and CNS activity.