Antioxidant properties, phenolic and mineral profiling, assessment of angiotensin I converting enzyme (ACE) inhibitory potential of Elsholtzia communis (Collett & Hemsl.) Diels from North East India

Elsholtzia communis (Collett & Hemsl.) Diels, (family: Lamiaceae) is a wild edible plant consumed as a vegetable by many tribes of the North-Eastern states of India. The objective of our study was to explore the antioxidant capacity, phenolic and mineral composition and angiotensin-I converting enzyme (ACE) inhibitory properties of E. communis. The leaf, stem, and root extract of E. communis were screened for their antioxidant and ACE inhibitory properties. Quantification of ten phenolics was conducted using reverse phase HPLC-DAD analysis and the five phenolics were isolated using conventional column chromatography and correlated with antioxidant activities using Pearson's coefficient. An assessment of dietary minerals present in the leaf, stem, and root of this herb was carried out using ion chromatography. The leaf exhibited the most potent DPPH scavenging and ACE inhibitory activity with IC50 value of 20.38± 0.061 µg/mL and 20.34± 0.025 µg/mL respectively. Leaf was recognized as the most prominent source of TPC, TFC, K+, Na+, Ca2+ and Mg2+. The HPLC analysis had established the stem as a rich source of gallic acid (1.08±0.002 mg/g DW), quercetin (0.26±0.001 mg/g DW) and p-coumaric acid (0.17± 0.001 mg/g DW), while catechol (0.19±0.005 mg/g DW) and vanillic acid (0.07±0.005 mg/g DW) contents were found to be highest in the leaf. NMR and HRMS data confirmed the structures of the isolated phenolics. Thus, diverse pharmacological behavior and distinctive presence of nutraceuticals and important dietary minerals suggest that this herb may be useful in the future development of herbal formulations.