In vitro antioxidant activity of Stevia rebaudiana leaves and callus

Abstract

Stevia rebaudiana is a shrub which is known for non-caloric natural sweetener called stevioside, which is the main component for its sweetness. In present investigation ex vitro studies were conducted to analyze effect of different concentrations of plant growth hormone, gibberellic acid. Foliar spray was used to mediate the experiment. Biochemical parameters (moisture, crude protein, total soluble sugars, free amino acids, chlorophyll content, calcium, total phenols, and antioxidant activity) and stevioside content were checked from ex vitro grown plants. Different concentrations (15, 30 and 60 µM) of gibberellic acid were applied as a foliar spray on in vivo vegetatively propagated plants of Stevia. From the biochemical growth parameters studied, total soluble sugar, free amino acids, chlorophyll content, calcium, total phenol and antioxidant activity were increased significantly. Whereas moisture and crude protein content were decreased significantly, however protein content was found to increase significantly within the treatments but still it is lower than control plant. Stevioside content in the leaf of ex vitro (control) grown plant was recorded 7.58% on dry weight basis which was increased significantly up to 18.08% on dry weight basis.