Comparative study of Phytochemicals, antioxidant and antibacterial activity of Phlogacanthus thyrsiformis Nees. and Justicia adhatoda Linn

Abstract

Phlogacanthus thyrsiformis Nees. and Justicia adhatoda Linn., belongs to the family Acanthaceae and is a traditional medicinal plant native to Asia and widely used in medicine of Siddha, Ayurveda, Unani, homeopathy and naturopathy. The present study addresses the comparative study of phytochemicals, antioxidant, antibacterial activity and GC-MS analysis of matured dried leaves of Phlogacanthus thyrsiformis Nees. and Justicia adhatoda Linn., using crude extracts of acetone and methanol. The phytochemical analysis shows the presence of glycosides, tannins, proteins, triterpenoids, saponins, phenols and flavonoids in both plant extracts. Ferric chloride reducing power and DPPH radical scavenging assay were also performed to test the antioxidant activity and the IC50 value was also calculated and a positive result was obtained. The crude extracts were also tested against three gram negative and two gram-positive bacteria. All extracts showed dose-dependent antibacterial activity. GC-MS chromatogram analysis of the crude extracts revealed multiple peaks indicating the presence of numerous phytochemical compounds. The result clearly shows that more compounds were identified in Justicia adhatoda Linn. methanolic extract. In this comparative study, methanol extract was found to have more activity in testing phytochemical, antioxidant and antibacterial activity and J.adhatoda Linn. has greater potential medicinal value compared to P.thyrsiformis Nees.