Phenolic contents, elemental analysis, antioxidant and lipoxygenase inhibitory activities of Zanthoxylum armatum DC fruit, leaves and bark extracts

Abstract

Zanthoxylum armatum (DC) is a traditional spice and important herb used in Asia as a part of food and household medicine for the treatment of various conditions. The present study was designed to investigate in vitro for phenolic/flavonoid contents, antioxidant activities, lipoxygenase inhibitory activity, minerals and heavy-metal contents. The leaves, bark and fruit of Zanthoxylum armatum were extracted with organic solvent and evaluated for phenolic contents (Folin-Chiocalteu method), for flavonoids contents (colorimetric method), for in vitro antioxidant assays (DPPH and FRAP), lipoxygenase inhibitory activity (5-LOX assay), mineral contents (atomic absorption), and for heavy-metal contaminants (atomic absorption). The fruit contained the highest phenolic (25.6±1.2mg GAE/g) and flavonoid (26.3±1.4mg QE/g) contents and therefore, exhibited the most effective antioxidant properties in DPPH (88.5±0.9% inhibition) and FRAP (94.21±3.2% inhibition) assays. The extracts also inhibited the LOX enzyme, and the fruit showed more inhibition (63.8±1.2 %) as compared with the leaves and bark. Z. armatum contain valuable minerals and fortified with magnesium (4.948±0.2, 3.07±0.03 and 3.53±0.12) and potassium (0.19±0.011, 1.91±0.003, and 1.90±0.05) for leaves, fruit, and bark, respectively. The chemical profiling for heavy metals showed that their concentrations were within permissible limits. The data suggest that Z. armatum is a safe and valuable natural agent with functional properties for food and pharmaceutical industries.