Repellency Effects, Cytotoxicity Assessment and Chemical Compositions of Citrus  limon Seeds Extracts and Fractions Against Anopheles gambiae sl Mosquitoes

Mukaram Akintunde  Adeniyi-Akee; Kingsley Adibe  Mbachu; Kolade  Ibrahim; Paul Matthew  Osamudiamen; Olapeju  Oluyemisi Aiyelaagbe; Sunday Olakunle  Idowu; Olajire Aremu  Adegoke

doi:10.18502/ajmb.v17i1.17678

Mukaram Akintunde Adeniyi-Akee Department of Pharmaceutical Chemistry, College of Pharmacy, Igbinedion University, Nigeria
Kingsley Adibe Mbachu Department of Chemistry, Faculty of Science, University of Ibadan, Oyo State, Nigeria
Kolade Ibrahim Department of Zoology, Faculty of Science, University of Ibadan, Oyo State, Nigeria
Paul Matthew Osamudiamen Department of Chemistry, Faculty of Science, University of Ibadan, Oyo State, Nigeria
Olapeju Oluyemisi Aiyelaagbe Department of Chemistry, Faculty of Science, University of Ibadan, Oyo State, Nigeria
Sunday Olakunle Idowu Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ibadan, Oyo State, Nigeria
Olajire Aremu Adegoke Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ibadan, Oyo State, Nigeria

DOI: https://doi.org/10.18502/ajmb.v17i1.17678

Keywords: Anopheles, Citrus, Gas chromatography-mass spectrometry, Insect repellents

Abstract

Background: Citrus limon seeds have limited exploration, compared to other parts. The increasing prevalence of mosquito menace prompted the investigation into the repellent effects of the seed n-hexane extract and fractions of Citrus limon (Rutaceae) against adult Anopheles gambiae sl mosquitoes. The cytotoxicity and chemical constituents of the 100% n-Hexane Fraction (HF) were also evaluated.

Methods: Successive extraction was done with cold-maceration using, n-hexane, Ethyl Acetate (EA) and methanol. The three solvent extracts were screened against Anopheles gambiae sl mosquitos, using human bait method, at doses, 1.5, 2.5 and 5.0 mg/ml and with Deet and acetone used as positive and negative controls respectively. The n-hexane extract was further fractionated with column chromatography. Ten fractions (100% n-hexane, 10, 20, 30, 40, 60, 80% EA in n-hexane, 100% EA, 50% methanol in EA, and 100% methanol) were collected, and all tested at a single optimized dose of 5 mg/ml for 2 hr. The cytotoxicity and the chemical constituents of HF were determined using brine shrimp lethality test and gas chromatography-mass spectrometry respectively.

Results: N-hexane extract and HF, both at 5 mg/ml, showed the most protective effect of 97.52 and 89.40% respectively, compared with standard (Odomos Deet) 100% activity, with no significant difference (p>0.05) between the three. HF was toxic with LC₅₀ values of 29.2354 ppm. Thirty compounds representing 79.25% of HF were identified. Major compounds present in the fraction were heptadecanamine (8.31%), N-(3-methylbutyl) acetamide (7.89%), 2-ethyl- 1-hexanamine (6.65%).

Conclusion: This promising repellent activity further justified the traditional usage of Citrus limon as mosquito repellent.