Micropropagation and Evaluation of Phenolic Content, Antioxidant and Antimicrobial Activities of Vernonia cinerea (Linn.) Less

Abstract

Vernonia cinerea, belonging to the family Asteraceae, is of wide medicinal application. This study investigated the antimicrobial, antioxidant activities and the total phenolic contents of wild plant of Vernonia cinerea with its respective shoot cultures.Nodal explants of V. cinerea were cultured on Murashige and Skoog (MS) medium supplemented with various combinations of BAP (0.5-2.5 mg/L) and NAA (0.1-0.5 mg/L) including various concentrations of Gibberllic acid for subculturing. The antimicrobial activity of plant extracts was tested using agar well diffusion and macrodilution methods for zone of inhibition (ZI), minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC).The free radical scavenging test was conducted using 2,2, diphenyl-1-picryl hydrazyl (DPPH) reagent while total phenolic contents (TPC) were measured by Folin–Ciocalteau reagent. Maximum shoot proliferation of 11.42 ± 2.26 cm was obtained from MS medium supplemented with 0.5 mg/L BAP + 0.1 mg/L NAA. All extracts displayed moderate antimicrobial potential against the tested pathogens in the range of 9.0-13.1 mm ZI, with highest MIC of 0.78 mg/mL and 1.56 mg/mL fromMPE and WPE, respectively.The IC₅₀ values of 4.49 and 5.10 μg/mL was obtained in WPE and MPE. The MPE had TPC of 6.66 ± 0.83 mg GAE/g compared to the WPE with TPC of 5.43 ± 1.31 mg GAE/g. The crude methanol extracts of wild and micropropagated plants of V. Cinerea showed high amounts of phenolic compounds, which could present them as candidates for future search for antimicrobial and antioxidant agents for different ailments.

Keywords: Micropropagation, Antioxidant, DPPH, Phenolic Compound, Vernonia cinerea