A Comparative Phylogenetic Evaluation of Chloroplast ITS Sequences to Analyze the Bioactivity in Medicinal Plants: A Case Study of Clerodendrum Plant Genus (Lamiaceae)

According to World Health Organization (WHO) approximately 47% of drugs used today to cure many diseases were derived from natural products such as plants. Although many approved and clinical-trial drugs have been derived from natural products, the last 20 years have shifted emphasis from natural products to less expensive synthetic products. Due to the paucity of traditional medicinal knowledge and lack of ethnobotanical information about most of the medicinal plants, the emphasis has shifted to synthetic products. Multidisciplinary research with phylogeny to incorporate ethnobotanical knowledge as well as traditional medicinal knowledge will facilitate researchers to identify new drug molecules. In this paper, we use phylogeny inferred from ITS sequence of chloroplast DNA of thirty eight different species of Clerodendrum plant to predict chemical diversity and potential medicinal activity of plants from Lamiaceae family. Phylogenetic signal in medicinal properties in plants is used to identify nodes on phylogeny with high bioscreeing potential. Phytosterol diversity and inhibition of angiotensin receptors by these compounds is significantly correlated with phylogeny. We produced a phylogenetic hypothesis for medicinally important plants of Laminaceae family based on the maximum likelihood, Neighborjoining, minimum evolution, UPGMA, and maximum parsimony methods. The genealogical trees generated with each method proved phylogenetic hypothesis by densely clustering plants with similar medicinal uses and plants belonging to same distribution. Different species of Clerodendrum plant genus were studied and their medicinal uses were evaluated in the light of phylogenetic relationships.