ISOLATION AND THERAPEUTIC STUDIES OF ESSENTIAL OIL FROM THE LEAF OF ANNONA MURICATA (SOURSOP) FROM GIREI LOCAL GOVERNMENT AREA, ADAMAWA STATE, NIGERIA

Annona muricata (Annonaceae) is a fruit-bearing evergreen tree traditionally used in tropical medicine. Commonly known as soursop, graviola, or guanabana, it is widely distributed in tropical and subtropical regions, where its extracts are used for managing ailments such as fever, diabetes, and cancer. Fresh leaves of A. muricata were subjected to modified steam distillation to obtain the essential oil, which was analyzed using gas chromatography–mass spectrometry (GC–MS). GC–MS analysis revealed thirty-six compounds, accounting for 99.96% of the total oil composition. The major constituents were dehydro-aromadendrene (14.83%), caryophyllene (9.45%), γ-muurolene (7.49%), alloaromadendrene (7.32%), naphthalene, 1,2,3,5,6,8a-hexahydro-4,7-dimethyl-1-(1-methylethyl)-(1S-cis)- (7.17%), isolongifolene, 9,10-dehydro- (5.17%), bicyclo[7.2.0]undec-4-ene, 4,11,11-trimethyl-8-methylene-[1R-(1R*,4Z,9S*)]- (4.20%), 1H-benzocycloheptene, 2,4a,5,6,7,8-hexahydro-3,5,5,9-tetramethyl-(R)- (4.17%), tricosane (4.32%), cyclononasiloxane, octadecamethyl- (3.90%), α-muurolene (3.76%), cis-muurola-3,5-diene (3.08%), and aromadendrene (3.07%). The antioxidant activity assessed using the DPPH assay showed moderate free radical scavenging activity, with an IC₅₀ value of 54.18 µL/mL and percentage inhibition ranging from 50.67% to 57.27%. Antibacterial assays indicated moderate activity against both Gram-positive and Gram-negative bacteria, with Staphylococcus epidermidis showing the highest inhibition zone (10 mm), followed by Escherichia coli and Salmonella typhimurium (9 mm), and Staphylococcus aureus (8 mm). Proteus vulgaris was resistant to the oil. Overall, these findings provide preliminary evidence of antioxidant and antibacterial properties of A. muricata leaf essential oil, partially supporting its traditional use. Further toxicity, mechanistic, and in vivo studies are required to validate its therapeutic potential.