Brine shrimp lethality test as a biological model for preliminary selection of pediculicidal components from natural source

Abstract

Brine shrimp lethality test as a biological model for the preliminary selection of pediculicidal components from a natural source. In order to achieve a good correlation between pediculicidal activity and brine shrimp lethality (BSL) test, several pediculicidal substances and active essential oils were tested in BSL test, with the purpose to use the latter as convenient preliminary protocol for pediculicidal activity. Benzyl benzoate, deltametrine and essential oil of Eucalyptus were purchased and clove essential oil obtained by hydrodistillation, besides essential oils, chloroform extracts from Duguetia furfuracea were also submitted to BSL test. All of them were carried out with same protocol described to pediculicidal assay found in the literature, i.e, flask tests were examined every five minutes in the first half hour and then every ten minutes until all the naupli were dead or no movements were observed (knockdown). During the BSL test, it was possible to observe the effect of a particular lethal dose or only a knockdown in the arthropod, as occurred in the test with lice. The results of the BSL test for essential oils and other active substances are essentially in agreement with those described in literature for pediculicidal activity. Extracts and essential oil obtained from aerial parts of D. furfuracea did not present activity, but the essential oil from underground stem bark was active. ï¡-asarone has already been isolated from the underground stem and it has been previously described to possess insecticidal activity.