Evaluation of the effectiveness of a syrup formulation derived from the ethanolic extract of red guava leaves (Psidium guajava Linn.) as an antipyretic agent in male mice

Abstract

Background: Guava leaves (Psidium guajava L.) contain phytochemicals with potential antipyretic activity, but evidence for their syrup formulations is limited. Objective: To evaluate the physicochemical characteristics and antipyretic response of guava leaf ethanolic extract and syrup in male mice with peptone-induced fever. Methods: Leaves were macerated in 96% ethanol; the extract was formulated into syrups containing 15.5%, 23.2%, and 31% extract. Physicochemical properties were assessed during four weeks. Temperature was recorded before induction, one hour after induction, and at 30-minute intervals for 120 minutes after treatment in five groups (n = 5 per group for each extract and syrup dataset). Results: Extract yield was 24.57%; syrup pH ranged from 6.04 to 6.84 and mean formulation viscosities from 29.98 to 59.26 cP across observation points. At 120 minutes, mean temperatures of extract-treated mice at nominal doses of 100, 150, and 200 mg/kg were 36.20, 36.00, and 36.30 °C versus 37.42 °C for negative controls. The corresponding syrup groups reached 36.62, 36.32, and 36.26 °C versus 37.64 °C for controls. Between-group differences were observed (p < 0.001 at 120 minutes; one-way analysis of variance). Conclusion: Both preparations exhibited antipyretic responses in this preliminary animal model; the 200 mg/kg nominal syrup group showed the largest mean reduction at 120 minutes. Confirmation of formulation dosing and further stability studies are warranted.