Larvicidal activity of Eugenia uniflora in Aedes aegyptii

In Brazil, the leaves of Eugenia uniflora L. are crushed and spread on the floor for its flavour and fly-repellent property [1]. Insecticidal activity of the oil [2] and larvicidal activity of the extract has been reported[3]. The larvicidal activity of the leaf methanol extract was therefore investigated to determine the most active subfraction from which the active compounds could be isolated.The leaf methanol extract was partitioned into n-hexane, chloroform, ethylacetate, butanol and aqueous phase and tested for larvicidal activities, using the larvae of Aedes aegyptii, the most active n-hexane fraction (B₁) was sequentially subjected to Vacuum Liquid Chromatography (VLC) to yield 10 fractions C₁-C₁₀ that were equally tested. The calculated percentage mortalities of the extract, fractions and subfractions of the leaf as well as of endosulphan, positive control, were used to determine their LC₅₀ and LC₉₀ values. The result showed that methanol extract had larvicidal activity that was statistically comparable (P>0.05) to that of endosulphan. Fraction B₁ had LC₅₀ and LC₉₀ values that were insignificantly different from those of methanol extract and endosulphan. Fractions C₁ and C₂ had significantly greater activity than B₁ and comparable to that of endosulphan, making them to be the most active fractions. Work is in progress in order to isolate the active compounds from these most active fractions.

Keywords: Eugenia uniflora, larvicidal, extract, leaf

References: 1. Morton J (1987) Surinam Cherry. In: Fruits of Warm Climates, JF Morton, Miami Florida.

2. Gbolade AA, Adebayo T (1993) Insec Sci Appl 4(5/6): 631–636.

3.Luna JS et al. (2005)J Ethnopharmacol 97(2):199–206.