Babatunde S. K., Adedayo R.M., Ajiboye E.A, Sunday Ojo, Ajuwon Israel B. Phytochemical composition and larvicidal Activity of Ocimum canum (L.) Essential Oil against Anopheles gambiae (Diptera: Culicidae). European Journal of Medicinal Plants. 2016; 11(4)
ABSTRACT
Background: Malaria is a serious health problem in many countries of the world especially sub-
Saharan African. Anopheles mosquito which is the vector of this disease has developed resistance
against synthetic pyrethroids which are the main stay of insecticide treated bed nets. The
development of insecticide resistance and side effects associated with synthetic pesticides has
triggered intense research efforts towards natural products.
Aim: This study aimed at investigating quality and quantity of phytochemical constituents of
Ocimum canum leaf extract and determined larvicidal effect of essential oil component of this plant
extract on 3rd instar larvae stage of Anopheles gambiae.
Methods: The essential oil was extracted by hydro-distillation using Clevenger type apparatus.
Standard methods previously described by other authors were used to determine the quality and
quantity of phytochemical components of the plant and larvicidal bioassay method was used to
determine the effect of essential oil of O. canum on the mosquito larva.
Results: The analysis of the phytochemical revealed the presence of the following compounds:
Tannin, phenol, saponin, trepenoid, alkaloid, steroid, and flavonoid, with the following quantities
22.14, 19.83, 14.08, 10.97, 8.16, 3.40 and 5.29 mg/g respectively. The mosquito larvicidal bioassay
showed LC50 and LC90 values of 49.51 and 103.54×10-3 mg/ml respectively after 24 hours exposure
to essential oil extract.
Conclusion: The results obtained showed that the essential oil of O. canum is a promising
mosquito larvicidal compound.