ABSTRACT
Abstract The species Waltheria viscosissima A.St.-Hil, Malvaceae, which is known as 'malva-branca', is traditionally used in the Brazilian northeast for the treatment of coughs. This research looks towards reporting the isolation of phytoconstituents of W. viscosissima, as well as the quantification of its phenolics, total flavonoid content, and free radical scavenging potential, along with an evaluation of its larvicidal activity against Aedes aegypti larvae. Chromatographic techniques were used to isolate the compounds and a structural elucidation was performed by 1D and 2D NMR. The quantification of total phenolics and flavonoids and the DPPH˙ radical scavenging activity was determined through spectrophotometric methods. Consequently, the phytochemical investigation led to the identification of fourteen compounds from the aerial parts of the W. viscosissima: steroids, triterpenes, alkaloids, and eight flavonoids previously reported in the literature. The quantification of compounds showed that the aerial parts extract possessed high concentration of flavonoids, while the roots extract were rich in other phenolic compounds. At the DPPH˙ free radical scavenging assay, the roots extract presented EC50 = 77.32 ± 4.37 µg/ml and the aerial parts extracts showed EC50 = 118.10 ± 1.21 µg/ml. W. viscosissima roots extract showed the most potent larvicidal activity against Ae. aegypti (LC50 = 4.78 mg/ml), with the potential of being used in effective and economically viable preparations that can be catered for domestic use towards controlling the vector insect of severe diseases, such as dengue and Zika.
ABSTRACT
The present study is conducted to find the efficacy of plant extracts to act as mosquito repellents. Initially, the larvicidal activity of the extracts and the toxicity study was conducted. From the results, the extracts with maximum larvicidal activity and the minimum toxicity were used for the further analysis. The least toxicity was observed with the ethanol extracts of Lantana camara, Tagetes erecta and Tanacetum cineriifolium. The Lanatana camara and Tanacetum cineriifolium showed the maximum larvicidal activity. The DNA sugar damage assay is performed and read at 532 nm. The hemolytic activity of the extract is conducted and the results indicate that the extracts showed no hemolytic activity at the concentration of 100 and 200mg/L. Only the flower extracts of Tagaetes erecta, Lantana camara and Tanacetum cineriifolium showed moderate hemolytic activity at 500 and 1000 mg/L. Finally, the HPLC analysis of the extracts showed that the ethanol extracts of Lantana camara and Tanacetum cineriifloium revealed the presence of marker compound. Therefore the ethanol extracts of Lantana camara and Tanacetum cineriifolium were taken up for the membrane stabilization assay. The skin irritation potential of the cream prepared using the ethanol extract of Tanacetum cineriifolium was analysed, the cream showed no irritation.
ABSTRACT
The present study is conducted to find the efficacy of plant extracts to act as mosquito repellents. Initially, the larvicidal activity of the extracts and the toxicity study was conducted. From the results, the extracts with maximum larvicidal activity and the minimum toxicity were used for the further analysis. The least toxicity was observed with the ethanol extracts of Lantana camara, Tagetes erecta and Tanacetum cineriifolium. The Lanatana camara and Tanacetum cineriifolium showed the maximum larvicidal activity. The DNA sugar damage assay is performed and read at 532 nm. The hemolytic activity of the extract is conducted and the results indicate that the extracts showed no hemolytic activity at the concentration of 100 and 200mg/L. Only the flower extracts of Tagaetes erecta, Lantana camara and Tanacetum cineriifolium showed moderate hemolytic activity at 500 and 1000 mg/L. Finally, the HPLC analysis of the extracts showed that the ethanol extracts of Lantana camara and Tanacetum cineriifloium revealed the presence of marker compound. Therefore the ethanol extracts of Lantana camara and Tanacetum cineriifolium were taken up for the membrane stabilization assay. The skin irritation potential of the cream prepared using the ethanol extract of Tanacetum cineriifolium was analysed, the cream showed no irritation.