In vitro and in vivo evaluation of the antimalarial, anti-inflammatory and free radical scavenging potentials of the hydro-alcoholic leaf extract of Microdesmis puberula Hook. F. ex Planch (Pandaceae)

Microdesmis puberula (Pandaceae) is an edible shrub noted in traditional medicine for its antimalarial and anti-inflammatory effects. This study assessed the anti-plasmodial, antimalarial, anti-oedema, and radical scavenging potentials of the hydro-ethanolic leaf extract of M. puberula. In vitro anti-plasmodial activity was assessed by the SYBR green I assay against P. falciparum cultures. Antimalarial activity was evaluated in murine models by Peter’s 4-day suppressive and Rane’s curative assays. The carrageenan-induced paw oedema in chicks and DPPH radical scavenging assays were used to investigate the anti-inflammatory and antioxidant activities, respectively. The total phenolic content was determined by the Folin Ciocalteu assay. The leaf extract demonstrated significant anti-plasmodial activity with IC₅₀ 1.984 ± 0.092 μg/mL, 1.8180 ± 0.2596 μg/mL, and 2.11 ± 0.0357 μg/mL, respectively, for chloroquine-sensitive 3D7, chloroquine-resistant K1, and chloroquine-resistant Dd2 Plasmodium falciparum strains. The extract had no significant cytotoxicity towards uninfected red blood cells (CC₅₀ = 80.45 µg/mL) and hepatic cell lines (CC₅ = 82.01 µg/mL). A dose-dependent chemo-suppression of P. berghei infection was elicited by the extract (50–400 mg/kg) in the suppressive test with maximum parasitemia suppression of 81.69%. Further, the extract at 400 mg/kg caused 83.59% parasitemia reduction in established P. berghei infection in the curative assay. Significant reductions in body temperature, packed cell volume, and body weight were averted in infected animals. Increased paw oedema was reduced by 56.20 ± 15.08% by M. puberula leaf extract at 300 mg/kg. Low antioxidant activity was recorded in the DPPH radical scavenging assay (IC₅₀ of 117.7 ± 17.97 µg/mL). Tannins, triterpenoids, alkaloids, coumarins, and flavonoids were identified in the phytochemical screening, and the total phenolic content was determined to be 85.06 ± 3.82 mg/g gallic acid equivalent. The study gives scientific credence to the traditional medicinal uses of M. puberula and reveals the plant as a potential source of antimalarial, anti-inflammatory, and antioxidant compounds.