TANNIN CONTENT AND ANTIOXIDANT ACTIVITY OF  EUPHORBIA HIRTA LINN. EXPOSED TO SHADE

Alma  P. Rosillo-Magno,

TANNIN CONTENT AND ANTIOXIDANT ACTIVITY OF EUPHORBIA HIRTA LINN. EXPOSED TO SHADE

Abstract:

Influence of light intensity on condensed and hydrolysable tannin production and antioxidant activity of Euphorbia hirta L. crude extracts derived from whole-plant, inflorescence, leaves, stems and roots were investigated. Full sunlight and 48% shade were compared. Shading significantly decreased the ratio of condensed tannin to hydrolysable tannin in the whole plant from 1:1.62 under full sunlight to 1:1.06 under shade. However, the distribution of tannins and their proportion in the plant was organ-specific and not affected by shading. The high amount of hydrolysable tannins were obtained in leaves and inflorescence, while stems and roots had more condensed tannin. Results on the antioxidant activity of E. hirta crude extracts showed that shading may affect the antioxidant activity of the plant samples depending on whether stored dried as the whole plant or separated accordingly into plant organs. However, the antioxidant activity of the extracts was strongly influenced by the type of plant organs, with leaves and inflorescence obtaining the highest activity. It is concluded that shading can influence the production of tannin in the whole plant but not indifferent plant organs. Antioxidant activity of E. hirta crude extracts strongly depends on the type of plant organ and not on light condition.