Polyphenol composition and antimicrobial activity of stem, inflorescence fruit and seed methanolic extracts of Andrographis paniculata (Burm.f) Wall. ex Nees

The major goal of this research work was to identify potential sources of polyphenolic compounds, in various components of Andrographis paniculata (Burm.f.) Wall. ex Nees for future novel pharmaceutical formulations. Plant phenolics and flavonoids have strong biological impacts including antioxidant and antibacterial activity. The preliminary phytochemical screening of stem, inflorescence, fruit and seed showed the presence of phenolics and flavonoids. Quantitative estimation of total phenolic content (TPC), total flavanoid content (TFC), antioxidant activity were carried out by using Folin-Ciocalteu method, aluminum chloride technique and FRAP techniques, respectively. The stem had significantly higher quantities of total phenolic (138.5±0.02 μg GAE mg⁻¹ extract) and total flavonoid (474.5±2.2 μg QE mg⁻¹ extract) compared to other plant parts. The FRAP experiment showed strong antioxidant activity in stem components, because overall phenolic content correlates with antioxidant activity. Antibacterial activity was carried out for each plant parts in which stem showed maximum zone of inhibition in Staphylococcus aureus (10 mm wide).