Persea americana leaf extracts demonstrate enviable in vitro antioxidant, anti-inflammatory, and antihypertensive properties

Abstract

Scientific validation is crucial to substantiate therapeutic claims associated with natural products. This study examined the in vitro antioxidant, anti-inflammatory, and antihypertensive activities of Persea americana (PA) leaf extract which is an ethnomedicinal plant used in disease management in Africa. Following defatting with n-hexane, plant material was extracted using methanol and evaporated using rotary evaporator. The extract was then partitioned into n-hexane, chloroform, ethyl acetate, n-butanol, and aqueousmethanol fractions. Antioxidant assays included DPPH, nitric oxide, ABTS radical scavenging, metal chelation, reducing power, and hydroxyl radical inhibition. Anti-inflammatory activity was assessed via 15-lipoxygenase inhibition, while antihypertensive potential was measured through angiotensin I-converting enzyme (ACE) inhibition. Absorbance was measured using Elisa microplate reader and IC determined by using IC calibration curve. Statistical analysis was done by ANOVA The n-butanol fraction showed the most potent ABTS scavenging activity (IC = 12.93 ± 1.10 μg/mL), outperforming both the crude extract and standard, gallic acid. This fraction also exhibited the strongest DPPH inhibition (IC = 24.67 ± 5.13 μg/mL). The aqueous-methanol fraction was most effective against hydroxyl radicals, while metal chelating and nitric oxide inhibitory activities were highest in the chloroform and nhexane fractions, respectively. All fractions demonstrated maximal reducing power at 250 μg/mL, except for the n-butanol fraction at 125 μg/mL. Notably, the n-butanol fraction inhibited 15-lipoxygenase more effectively than indomethacin, though less than quercetin. However, the crude extract’s ACE inhibition was significantly lower than that of captopril. These findings suggest that Persea americana leaf fractions exhibit diverse in vitro bioactivities and may offer therapeutic benefits in managing hypertension and inflammation-related disorders. However, the precise mechanisms underlying these effects remain unclear. Future studies are needed to elucidate the specific phytochemicals and molecular pathways involved, alongside in vivo and clinical investigations to fully validate these therapeutic potentials.