Objective: To evaluate and compare the analgesic and anti-inflammatory activity of pure compound, piperine along with hexane and ethanol extracts of Piper nigrum L. fruit in mice and rats. Methods: The analgesic activity was determined by tail immersion method, analgesy-meter, hot plate and acetic acid induced writhing test. While the anti-inflammatory activity was evaluated by carrageenan-induced paw inflammation in rats. Results: Piperine at a dose of 5 mg/kg and ethanol extract at a dose of 15 mg/kg after 120 min and hexane extract at a dose of 10 mg/kg after 60 min exhibited significant (P<0.05) analgesic activity by tail immersion method, in comparison to ethanol extract at a dose of 10 mg/kg using analgesy-meter in rats. However, with hotplate method, piperine produced significant (P<0.05) analgesic activity at lower doses (5 and 10 mg/kg) after 120 min. A similar analgesic activity was noted with hexane extract at 15 mg/kg. However, in writhing test, ethanol extract significantly (P<0.05) stopped the number of writhes at a dose of 15 mg/kg, while piperine at a dose of 10 mg/kg completely terminated the writhes in mice. In the evaluation of anti-inflammatory effect using plethysmometer, piperine at doses of 10 and 15 mg/kg started producing anti-inflammatory effect after 30 min, which lasted till 60 min, whereas hexane and ethanol extracts also produced a similar activity at a slightly low dose (10 mg/kg) but lasted for 120 min. Conclusions: It is concluded from the present study that Piper nigrum L possesses potent analgesic and anti-inflammatory activities.

Objective: To evaluate the combination therapy of pyronaridine tetraphosphate and diminazene aceturate against Babesia in vitro and in vivo. Methods: Bioinformatic analysis was performed using atom pair fingerprints. An in vitro combination test was performed against Babesia bovis and Theileria equi. Moreover, the in vivo chemotherapeutic efficacy of pyronaridine tetraphosphate in combination with diminazene aceturate was investigated against the growth of Babesia microti in mice using a fluorescence inhibitory assay. Results: Pyronaridine tetraphosphate and diminazene aceturate exhibited nearly similar molecular weights. The in vitro combination of pyronaridine tetraphosphate and diminazene aceturate was synergistic on Babesia bovis and additive on Theileria equi. In addition, 5 mg/kg pyronaridine tetraphosphate combined with 10 mg/kg diminazene aceturate inhibited Babesia microti growth significantly compared with those observed after treatment with 25 mg/kg diminazene aceturate alone from day 6 post treatment to day 12 post treatment. The combination therapy also normalized the hematological parameters of infected mice. Conclusions: An oral dose of pyronaridine tetraphosphate combined with a subcutaneous dose of diminazene aceturate inhibits Babesia in vitro and in mice, suggesting it might be a new paradigm for the treatment of babesiosis.