Anti-Inflammatory and Antinociceptive Activity of Herbal Lipospheres of Pentaclethra macrophylla (Fabaceae) Stem Bark Extract

Abstract

Purpose: Inflammation of various degrees is common among humans. There are associated side effects with orthodox delivery systems and anti-inflammatory agents; hence, the study investigated the characteristics of herbal lipospheres and the anti-inflammatory potency of the lipospheres formulated from Pentaclethra macrophylla with the view to having a drug with a better delivery system and lesser side effects. Methods: Herbal lipospheres were formulated using solidified reverse micellar solutions (SRMS) of P90H and goat fat and characterized for particle size and morphology, pH time dependent analysis, encapsulation efficiency (EE%), and Fourier Transform infrared spectroscopy. The in vitro antinociceptive and anti-inflammatory studies were carried out using membrane stabilization by hypotonicity-induced hemolysis and the determination of anti-platelet aggregatory activity models. The in vivo antinociceptive and anti-inflammatory studies on egg albumin- and formaldehyde-induced arthritis models were conducted. A total white blood cell count and differential blood count were carried out on the rats. Results: The results showed that there was no change in pH for the PM-unloaded lipospheres and 2.5 g of PM-loaded lipospheres from day 1 to day 7, but there was a mild variation in the rest of the formulations. The EE ranged from 35.2% to 94%, increasing according to the drug concentration. The photomicrographs of the lipospheres showed that the particles were spherical in shape. The particle sizes were within the acceptable range for lipospheres. FTIR showed no interaction. In the arthritis study, PM-loaded lipospheres inhibited edema consistently throughout the duration of observation. Inhibition of the membrane increased steadily with an increase in concentration of PM in the lipospheres and the standard drug. The platelet aggregatory inhibition decreased steadily with an increase in concentration of the PM in the lipospheres as well as the standard. The T50 dose of PM had the highest percentage of WBC, and it decreased as the treatment doses increased from T100 to T200. There were no significant differences among the Neutrophil counts of the different groups. Conclusions: The study, therefore, showed that the methanol extract of Pentaclethra macrophylla formed efficient herbal lipospheres with antinociceptive and anti-inflammatory activities.