Anti-Lipoxygenase Activity of Leaf Gall Extracts of Terminalia chebula (Gaertn.) Retz. (Combretaceae)

Lipoxygenase (LOX) inhibitors are the promising therapeutic target for treating a wide spectrum of inflammatory-related diseases such as cancer, asthma, lymphoma, leukemia, and autoimmune disorders. In the present study, the photochemical constituents and the anti-LOX potential of leaf galls of Terminalia chebula are evaluated to exemplify its further potential development as medicine. Extracts of T. chebula galls were tested for anti-LOX activity using linoleic acid as substrate and lipoxidase as an enzyme and also the total content of polyphenols with phytochemical analysis of the extract were determined. The presence of highest total phenolic and flavonoid content of 141 ± 2.2 mg of gallic acid equivalent/g d.w and 125 ± 1.4 mg of quercetin equivalent/g d.w and maximal LOX inhibitory activity (52.67%) at 800 μg/mL concentrations were identified in the ethanolic extracts of leaf galls of T.chebula. The higher LOX inhibitory activity was positively correlated to the high content of total polyphenols/flavonoids. The results of this study confirm the folklore use of T. chebula leaves gall extracts as a natural anti-inflammatory agent and justify its ethnobotanical use. Therefore, the results encourage the use of T. chebula leave gall extracts for medicinal health, functional food, and nutraceuticals applications.

The present investigation demonstrated promising anti-LOX proper-ties of T. chebula leaves gall extracts. Presumably, these activities could be attributed in part to the polyphenolic features of the extract, as there was a strong correlation of higher LOX inhibiting activities with that of high total phenolic and flavonoid content in the methanolic leaf gall extracts of T. chebula. The results of this study confirm the folklore use of T. chebula leaves gall extracts as a natural anti-inflammatory agent and justify the ethnobotanical approach in the search for novel bioactive com-pounds.