Efficient enhancement of gallic acid accumulation in cell suspension cultures of Barringtonia racemosa L. by elicitation

This study was conducted to evaluate the effects of elicitation process on gallic acid accumulation in the cell suspension cultures of Barringtonia racemosa L. Gallic acid was acknowledged as the main bioactive compound from phenolic group in this species. Two types of elicitors at various concentrations from biotic (10, 150 and 300mg/l chitosan) and abiotic (1, 15 and 30mg/l silver nitrate) origins were added into the cell suspension cultures of B. racemosa and were further harvested after 24, 48 and 72h of elicitor feeding for gallic acid content analysis by using high performance liquid chromatography(HPLC). Elemental composition of the treated cultures which showed the greatest accumulation of gallic acid were further examined through elemental differential x-ray (EDX)analysis. The results revealed that the cultures treated with 30mg/l silver nitrate and harvested after 24h of culture recorded the greatest fresh weight of cell biomass (325.77 +/- 2.46g/l), meanwhile the greatest dry weight (DW) was identified in the cultures treated with 150mg/l chitosan harvested after 72h of culture (17.81 +/- 0.82g/l). After 72h of elicitation, the cultures treated with 30mg/l silver nitrate accumulated the highest gallic acid content up to 2.64 folds higher (193.83 +/- 25.96 mu g/g DW) than that of control. Besides, this analysis showed that the deficiency and depletion of certain mineral elements in the optimally elicited cell cultures could be attributed to the increased accumulation of gallic acid. The study suggested the effectiveness of elicitation process in enhancing the accumulation of gallic acid in the cell suspension cultures of B. racemosa.