Evaluation of antioxidant capacity and acetylcholinesterase inhibitory activity of field-grown plants and in vitro plantlets of Enicostemma littorale

Abstract

Background: Enicostemma littorale is an ethno-medicinally important plant belonging to Gentianaceae family. Objective: The main aim of this study was to establish tissue culture of E. littorale and compare the antioxidant capacities and acetylcholinesterase inhibitory (AChEi) properties of in vitro and field-grown E. littorale plants. Materials and Methods: Antioxidant capacities for various E. littorale extracts were studied in terms of 1,1-diphenyl-2- picrylhydrazyl and 2,2′-azinobis-3 ethylbenzothiazoline-6-sulfonic acid free-radical scavenging along with ferric reducing antioxidant power and total phenolic content was also determined. AChEi properties were also compared between fieldgrown and in vitro E. littorale extracts. Results: In vitro plantlets of E. littorale was established in Murashige and Skoog (MS) medium with three different hormonal combinations, viz. naphthalene acetic acid (1 mg/l) and 6-benzylaminopurine (BAP)(0.2 mg/l) or N₁B_0.2, BAP (1 mg/l) and kinetin (0.1 mg/l) or B₁K_0.1 and indole butyric acid (IBA) (1 mg/l) or IBA₁. Alcoholic extracts of shoots developed in MS medium supplemented with B₁K_0.1 showed highest antioxidant potential than other extracts. Alcoholic extracts of plantlets grown in MS medium supplemented with IBA₁ showed both antioxidant and AChEi potential equivalently to field-grown extracts. Conclusion: In vitro plantlets grown in MS medium half strength supplemented with IBA₁ can be considered as most suitable for rapid proliferation because it offers advantage of equivalent potential of bioactivity in terms of antioxidant capacity and AChEi when compared to field-grown plants. Further studies can lead to better utilization of therapeutic potential of E. littorale.