ABSTRACT
OBJECTIVE@#To investigate the larvicidal activity, inhibition effect on development, histopathological alteration and morphological aberration induced by the extracts derived from seaweeds Bryopsis pennata (B. pennata), Sargassum binderi (S. binderi) and Padina australis in Aedes aegypti (Ae. aegypti) larvae and to characterize the phytochemical components of the three seaweeds.@*METHODS@#Larvicidal activity of the seaweeds towards the larvae of Ae. aegypti was determined according to WHO. The inhibition effect of seaweeds was assessed by determining the mortality, adult emergence rate, larval and pupa duration of the treated larvae. Histopathological effect on midgut epithelium of larvae and morphological aberration induced by the methanol extracts were examined. Phytochemical analysis was done to determine the presence of alkaloids, saponins, steroids and terpenoids in the seaweeds.@*RESULTS@#Chloroform partition of B. pennata extract exhibited the strongest larvicidal activity (LC50 = 82.55 μg/mL), followed by methanol extract of B. pennata (LC50 = 160.07 μg/mL) and chloroform partition of S. binderi extract (LC50 = 192.43 μg/mL). The methanol extract of S. binderi exhibited the strongest effect on prolongation of larval period (1.5-fold longer as compared to control) and resulted in strongest inhibition effect in adult emergence (98.67%). The histopathological study showed that larvae treated with seaweed extracts had cytopathological alteration of the midgut epithelium. The morphological observation revealed that the anal papillae and terminal spiracles of larvae were the common sites of aberrations.@*CONCLUSIONS@#The study provided information on various effects of seaweed extracts on Ae. aegypti. Further investigation on identifying the active compounds and their mechanisms of action is recommended.
ABSTRACT
Objective: To investigate the larvicidal activity, inhibition effect on development, histopathological alteration and morphological aberration induced by the extracts derived from seaweeds Bryopsis pennata (B. pennata). Sargassum binderi (S. binderi) and Padina australis in Aedes aegypti (Ae. aegypti) larvae and to characterize the phytochemical components of the three seaweeds. Methods: Larvicidal activity of the seaweeds towards the larvae of Ae. aegypti was determined according to WHO. The inhibition effect of seaweeds was assessed by determining the mortality, adult emergence rate, larval and pupa duration of the treated larvae. Histopathological effect on midgut epithelium of larvae and morphological aberration induced by the methanol extracts were examined. Phytochemical analysis was done to determine the presence of alkaloids, saponins, steroids and terpenoids in the seaweeds. Results: Chloroform partition of B. pennata extract exhibited the strongest larvicidal activity (LC
ABSTRACT
As algas marinhas representam uma rica fonte de compostos bioativos, algumas delas precursoras de ferramentas farmacológicas e de substâncias potencialmente úteis para o desenvolvimento de novos fármacos. A macroalga Bryopsis pennata, Cloroficea pertencente à ordem Caulerpales, sin. Bryopsidales é uma espécie tropical encontrada em diversos costões rochosos. Essa espécie produz uma defesa química tóxica para organismos herbívoros e potencial de se tornar invasiva e dominante em condições ambientais favoráveis. Este trabalho é uma investigação do efeito cardiotônico da fração polar da B. pennata .O cultivo, em ambiente controlado destituído de contaminantes, foi realizado no intuito de comparar seus efeitos com os efeitos da alga coletada. O efeito cardiotônico cronotrópico positivo em tiras ventriculares de anuros ficou fortemente evidenciado nos testes com frações polares de algas coletadas e cultivadas, não apresentando diferenças significativas entre as frações. O propranolol antagonizou o efeito cardiotônico e enzimas endopeptidases não reagiram com a fração polar da B. pennata. Testes bioquímicos demonstraram que a fração com efeito cardiotônico é de caráter ácido e apresenta peso molecular menor que 10.000 daltons.
Marine algae are a rich source of bioactive compounds and some of them have shown to be useful for the development of new pharmacological tools and medicines. Bryopsis pennata, (Clorofícea, Caulerpales, sin. Bryopsidales) is a marine algae that can be found in the Southeastern Brazilian coast and elsewhere. The species produces a toxic chemical defense to the herbivorous organisms and possesses a potential to become invasive and dominant in favorable environmental conditions.The present study is about the investigation of the cardiotonic effect of the polar extract of B. pennata. The cultive in laboratory without any contaminants was made to compare studies performed with the collected algae extracts and the ones cultivated effect. The cardiotonic effect in the anurous ventricular strips was strongly unequivocal when it was tested with the polar extracts from the collected and cultivated algae. The propranolol antagonized polar effects of these algae and the endopeptidase enzyme did not change the effects of polar extracts of Bryopsis pennata. Biochemical tests showed that the polar fraction presenting the inotropic cardiac activity weighs less than 10.000 Daltons and has an acid character.