Title : Enhanced anti-hyperalgesic effect of a nanoemulsion-base formulation of ethanolic crude extract obtained from the leaves of casearia sylvestris sw
Abstract:
Casearia sylvestris Sw. has shown previously anti-inflammatory effects and it is widely used in popular medicine to treat conditions associated with pain. This study aimed to evaluate if the incorporation of the ethanolic crude extract of Casearia sylvestris Sw (ECE-CS) into nanoemulsion promotes an increase of its anti-hyperalgesic activity. Experimental procedures: Male Swiss mice were subjected to carrageenan-induced inflammation (hind-paw) and orally treated with sterile saline (vehicle), nanoemulsion formulation without extract (Nano vehicle), dexamethasone 0.5 mg/kg, ECE-CS or nanoemulsion-base formulation of ECE-CS (Nano ECE-CS, 30 mg/kg in sterile saline). Treatment was repeated at 24, 48 and 72 h after the inflammation induction. Mechanical hyperalgesia were evaluated before and up to 5 h post treatment. Results: Mechanical hyperalgesia (vehicle at 5 h: 80 ± 23.90% of response; Nano vehicle group at 5 h: 77.50 ± 22.52% of response) was reduced by ECE-CS (at 5 h: 42.50 ± 27.12% of response) or Nano ECE-CS (at 5 h: 27.50 ± 23.75% of response). Basal values for hyperalgesia (37.50 ± 22.52% of response) on the Nano ECE-CS group were statistically lower than that observed for control groups, such as vehicle group (at day 3; hyperalgesia: 77.50 ± 16.69% of response), respectively from days 2 or 3, suggesting a cumulative effect of the Nano ECE-CS treatment.
