New approaches to clarify antinociceptive and anti-inflammatory effects of the ethanol extract from Vernonia condensata leaves.

The present study was aimed at evaluating the antinociceptive and anti-inflammatory effects of the ethanol extract from Vernonia condensata leaves in animal models, in order to afford a better understanding of these properties. The extract reduced the number of abdominal contortions at doses of 100 (51.00 ± 3.00), 200 (42.00 ± 2.98) and 400 mg/kg (39.00 ± 4.00). In formalin tests, a significant reduction in the licking time (p < 0.01) was observed in the first phase by 25.14 (200 mg/kg = 51.50 ± 4.44) and 31.15% (400 mg/kg = 48.00 ± 4.37). The doses of 100 (43.37 ± 5.15), 200 (34.62 ± 4.16) and 400 mg/kg (28.37 ± 3.98) inhibited (p < 0.001) the second phase. After 60 and 90 min of treatment, a dose of 400 mg/kg (10.13 ± 0.39 and 11.14 ± 1.33, respectively) increased the latency time. Doses of 200 and 400 mg/kg potentiated the sleeping time induced by diazepam, pentobarbital and meprobamate. The extracts (100, 200 and 400 mg/kg) showed anti-inflammatory effects by a decrease in paw edema. The extracts also reduced the exudate volume at the doses of 200 and 400 mg/kg. The leukocyte migration had significant effect (p < 0.001) at doses of 100, 200 and 400 mg/kg. The completion of additional experiments in the investigation of the antinociceptive and anti-inflammatory activities of V. condensata allowed a better understanding of the central and peripheral mechanisms involved.

Pharmacological properties of the ethanol extract of Muehlenbeckia platyclada (F. Muell.) meisn. leaves.

Antinociceptive and anti-inflammatory activities of the Muehlenbeckia platyclada leaves' ethanol extract were investigated in animal models. The extract (p.o.) reduced the number of abdominal contortions induced by acetic acid by 21.57% (400 mg/kg). After intraplantar injection of formalin, a dose of 400 mg/kg (p.o.) inhibited the time spent paw licking in the first phase (26.43%), while the second phase was inhibited by 10.90 and 36.65% at the doses of 200 and 400 mg/kg, respectively. The extract (p.o.) increased the reaction time on a hot plate at a dose of 400 mg/kg (32.68 and 40.30%) after 60 and 90 minutes of treatment, respectively. The paw edema was reduced by extract (p.o.) at doses of 100 (15.46 and 16.67%), 200 (22.68 and 25.64%) and 400 mg/kg (29.50 and 37.33%) after 3 to 4 h of carrageenan application, respectively. Doses of 100, 200 and 400 mg/kg (p.o.), administered 4 h after the carrageenan injection, reduced the exudate volume (11.28, 21.54 and 45.13%), while leukocyte migration was reduced by 21.21 and 29.70% at the doses of 200 and 400 mg/kg, respectively. These results indicate that the ethanol extract from M. platyclada may constitute a potential target for the discovery of new molecules with antinociceptive and anti-inflammatory activities that can be explored for their therapeutic use.