Antidengue potential of leaf extracts of Pavetta tomentosa and Tarenna asiatica (Rubiaceae) against dengue virus and its vector Aedes aegypti (Diptera: Culicidae)

The aim of the present study was to screen the anti-dengue potential of crude leaf extracts of two plants from Pavetta tomentosa and Tarenna asiatica. For larvicidal assay, the acetone extract of both plants showed maximum effects, with the least LC₅₀ and LC₉₀ values (P. tomentosa (5.968 and 7.493 μg/ml) and T. asiatica (1.288 and 1.992 μg/ml)) and the same extract of both plants exhibited better pupicidal potency. The adulticidal activity of both plants (0-60 min interval periods) recorded best results in acetone extracts and the LC₅₀ and LC₉₀ values were recorded as P. tomentosa (32.105 and 41.001 μg/ml) and T. asiatica (09.012 and 11.854 μg/ml). Among the two plants P. tomentosa acetone leaf extract have good antiviral property against Dengue viral cell line. In addition, the phytochemical nature of the plant reveals the presence of saponins, flavonoids and alkaloids in all the tested extracts of both plants. GC-MS analysis revealed Hexanedioic acid, Bis(2-Ethylhexyl) Ester (22.54) and 2,6,10,14,18,22- Tetracosahexane, 2,6,10, 15, 19,15,19,23- Hexamethyl-(ALL-E)- (25.33) identified as two major phytoconstitutents in P. tomentosa and Tetracontane (23.580) is a major compound identified from T. asiatica acetone extracts. The functional groups of chemical compounds (aromatis, alkanes, alkyls and carboxylic acids) from P. tomentosa and T. asiatica were analyzed by FT-IR spectrum.