Andrographis Echioides Molecular Characterization and Phylogenetic Study Using DNA Barcoding Technique

With the advancement in various molecular diagnostic tools, DNA Barcoding has emerged as a gold standard molecular diagnostic tool across the globe. Since ancient times, medicinal plants have been widely used in Indian Ayurvedic medicine for treating a variety of ailments. Plants of the genus Andrographis have been extensively used for treating different types of ailments. In this study, rarely studied medicinal plant species were isolated, sequenced at the genetic level and studied for their evolutionary characteristics using phylogenetic analysis. In the present study, the identity of A. echioides was confirmed by targeting different barcoding genes such as ribulose-bisphosphate carboxylase, internal transcribed spacer, RNA polymerase-beta subunit, maturase K, and photosystem II protein D1 genes using a phylogenetic approach. After successful isolation and amplification of genomic DNA, specific primers were utilised for sequencing of each barcoding gene, followed by nucleotide BLAST analysis to determine the sequence percent identity of each gene with that from other plant species. The best homologs were then utilised for conducting phylogenetic analysis which confirmed the identity of the plant as Andrographis echioides.

Synergistic effect of Andrographis echioides and Cadaba trifoliata leaf extracts against larvae of dengue mosquito Aedes aegypti L

Objective: The larvicidal potential of Andrographis echioides and Cadaba trifoliata leaf extract was tested separately against larvae of Aedes aegypti and also tested mixture of these two plant extracts for synergistic effect against the larvae. Methods: Pulverized leaves of A. echioides and C.trifoliata were subjected separately to soxhlet extraction using organic solvent of ethanol. These two plant extracts were examined separately against 4th instar larvae of A.aegypti with gradually increasing concentration i.e. from 50 to 250mg/l using WHO protocol. To observe the synergistic effect, extracts of these two plants were mixed at different concentrations and tested against the larva. The 24h LC50 values of individual plant extract and mixed extracts were determined following probit analysis. Results: A. echioides extract shows more lethal effect than C. trifoliata extract towards larvae of A.aegypti with LC50 values of 108.3 and 123.4 mg/l, respectively, whereas , synergistic larvicidal effect was found to be even more effective than the plant extract tested separately in terms of LC50 being 68.3 mg/l. Conclusions: From the results, it is evident that synergistic effect of A. echioides and C. trifoliata can be considered as a more powerful arsenal for the control of A.aegypti than the usage of these two extract separately.