Joy Onyewonuwa Acha1,
Godfrey Rume Kweki1,
Othuke Bensandy Odeghe1,
Jackson Erozueme Onuelu2,
Vanessa Akpevwe Derhie1,
Innocent Onyesom1 
For correspondence:- Innocent Onyesom Email: ionyesom@delsu.edu.ng
Received: 21 July 2025 Accepted: 18 November 2025 Published: 30 November 2025
Citation: Acha JO, Kweki GR, Odeghe OB, Onuelu JE, Derhie VA, Onyesom I. Mosquito repellent and anti-ageing potential of Ocimum gratissimum essential oil. Trop J Pharm Res 2025; 24(11):1383-1393 doi: https://dx.doi.org/10.4314/tjpr.v24i11.6
© 2025 The authors.
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Purpose: To assess Ocimum gratissimum essential oil (OgEO) repellent and anti-ageing potentials for possible cosmeceutical application. Methods: Ocimum gratissimum essential oil was extracted from O. gratissimum leaves by hydro-distillation and analyzed via GC-MS. Repellent activity was tested against Anopheles gambiae using the mosquito landing assay. Anti-ageing effects were assessed by in vitro tyrosinase and elastase inhibition assays, with kinetic analysis via Lineweaver-Burk plots and cytotoxicity by the MTT assay. In silico docking targeted A. gambiae AgamOBP1 and P5CR for repellency, and tyrosinase/elastase for anti-ageing, with ADMET profiling of key compounds. Results: The extracted oil repelled A. gambiae (RD50 = 37.4 μg/mL) when compared to N, N-diethyl-meta-toluamide (DEET; 23.7 μg/mL). It inhibited tyrosinase (IC50 = 18.70 μg/mL; kojic acid: 5.33 μg/mL) competitively and elastase (IC50 = 9.35 μg/mL; ursolic acid: 6.66 μg/mL) non-competitively. In silico analysis identified dihydrogeraniol and phytol as bioactive compounds with strong binding to repellent and anti-ageing targets, showing favourable ADMET properties. Conclusion: The essential oil exhibits potent mosquito repellent and anti-ageing properties, with dihydrogeraniol and phytol as key actives, deserving further investigation as natural cosmeceutical alternatives.
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