The antinociceptive effects of a standardized ethanol extract of the Bidens odorata Cav (Asteraceae) leaves are mediated by ATP-sensitive K+ channels

Ethnopharmacological relevanceBidens odorata Cav (Asteraceae) is used for the empirical treatment of inflammation and pain.Aim of the studyThis work evaluated the in vitro and in vivo toxicity, antioxidant activity, as well as the anti-inflammatory and antinociceptive effects of an ethanol extract from Bidens odorata leaves (BOE).Materials and methodsThe in vitro toxicity of BOE (10-1000 µg/ml) was evaluated with the comet assay in PBMC. The in vivo acute toxicity of BOE (500-5000 mg/kg) and the effect of BOE (10-1000 µg/ml) on the level of ROS in PBMC were determined. The in vivo anti-inflammatory activity of BOE was assessed using the TPA-induced ear edema in mice. The antinociceptive activities of BOE (50-200 mg/kg p.o.) were assessed using the acetic acid and formalin tests. The antinociceptive mechanism of BOE was determined using naloxone and glibenclamide.ResultsBOE lacked DNA damage, and showed low in vivo toxicity (LD50 > 5000 mg/kg p.o.). BOE inhibited ROS production (IC50 = 252.13 ± 20.54 µg/ml), and decreased inflammation by 36.1 ± 3.66%. In both antinociceptive test, BOE (200 mg/kg) exerted activity with similar activity than the reference drugs.ConclusionB. odorata exerts low in vitro and in vivo toxicity, antioxidant effects, moderate in vivo anti-inflammatory activity, and antinociceptive effects mediated by ATP-sensitive K+ channels.

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