Phytochemical analysis, antioxidant and antimicrobial activity of wildand in vitro derived plants of Ceropegia thwaitesii Hook – An endemicspecies from Western Ghats, India

Ceropegia thwaitesii Hook (Asclepiadaceae), an endemic plant species, due to habitat destruction and overexploitation has a very restricted distribution in the Western Ghats of Tamil Nadu, India. The presentwrok aimed to determine the chemical composition, the total phenolic (TPC), flavonoid (TFC) and tannincontent (TEC), and to assess the antioxidant properties of various extracts of in vivo plants (IVP) andin vitro regenerated plants (IRP) of C. thwaitesii. Some phenolic compounds like gallic acid, cathechol,vanillin and salicylic acid were identified and quantified by HPLC. All the extracts possessed relevant rad-ical scavenging activity on DPPH, Superoxide radical scavenging activity, and Nitric oxide radicals as wellas total antioxidant ability. DPPH assay of in vitro methanol stems extracts and ethanol leaves extractsrevealed the best antioxidant properties with important IC50values of 0.248 ± 0.45 mg/mL and 0.397 ±0.67 mg/mL, respectively, whereas in vivo chloroform stems extracts showed a lower antioxidant activity(IC50of 10.99 ± 0.24 mg/mL). The IRP methanol extracts of stem and leaves had good inhibitory activityagainst all tested microorganisms in a dose-dependent manner. These results suggested that in vitroraised plants of C. thwaitesii are an excellent source of antioxidant compounds to be exploited on anindustrial level as food additive.