Altitudinal variation in gallic acid content in fruits of Phyllanthus emblica L. and its correlation with antioxidant and antimicrobial activity

Abstract

Gallic acid is one of the most important organic compounds in fruits of Phyllanthus emblica. Therefore, the objective of the present study is to find out the effect of altitude on gallic acid content in fruits of P. emblica and its correlation with antioxidant and antimicrobial activity. Phytochemicals such as phenolics, tannins, flavonoids, carbohydrates, glycosides, phytosteroids, alkaloids and saponins were detected in fruit extracts of P. emblica collected from different regions of Himachal Pradesh. Fruits extract from Mandi (239.74 ± 39.28 mg/g gallic acid equivalents, GAE) district showed a higher amount of total phenolic content (TPC), whereas, total flavonoid content (TFC) was higher from Kangra (356 ± 27.63 mg/g rutin equivalents, RE) district. Methanolic extracts showed inhibition to the growth of both Gram-positive (B. subtilis, S. aureus), and Gram-negative bacteria (E. coli, K. pneumoniae). The methanolic extract of fruits of Bilaspur district showed the highest antibacterial activity against B. subtilis (19.5 ± 0.71 mm), S. aureus (21.0 ± 1.41 mm), E. coli (17.5 ± 0.71) and K. pneumoniae (21.5 ± 2.12) as compared to other regions and amoxyclav. High-performance thin-layer chromatography (HPTLC) method was used for the quantification of gallic acid in the extracts of fruits of P. emblica. HPTLC chromatogram showed the highest content of gallic acid in methanolic extracts of fruits from Kangra followed by Bilaspur, Mandi, and Una. However, antioxidant and antibacterial activity was higher in fruits extracts of high altitude (Bilaspur region). In summary, Bilaspur region of Himachal Pradesh could be used for mass cultivation of fruits of P. emblica because of their high antioxidant and antimicrobial potential under these geographical conditions.