In vitro antioxidant, anticholinesterase, tyrosinase activity studies, and LC-MS/MS simultaneous determination of 37 bioactive compounds in Indigofera heterantha

The flowering plant Indigofera heterantha generally known as Indigo of Himalayan, was extracted with n-hexane, ethyl acetate, and methanol by using Soxhlet apparatus. The extracts were studied for their antioxidants and enzyme inhibition activities. Against DPPH free radical-scavenging activity methanol extract was found moderately active (IC50: 158.41 ± 1.1.66 µg/mL). The ethyl acetate and n-hexane extracts exhibited the best ABTS radical scavenging activity (IC50: 31.32 ± 2.50 and 52.0 ± 0.89 µg/mL respectively). Against the metal chelating activity, n-hexane extract was active IC50: 52.36 ± 0.95 µg/mL. The n-hexane and ethyl acetate extracts demonstrated the best β–carotene antioxidant activity (IC50: 22.32 ± 0.84 and 60.66 ± 0.35 μg/mL respectively). Against acetylcholinesterase (AChE), ethyl acetate and methanol extracts were moderate active (IC50: 133.58 ± 0.870, and 137.97 ± 0.97 µg/mL respectively). The ethyl acetate extract showed Butyrylcholinesterase (BChE) inhibitory activity with IC50 value of 121.9 ± 1.13 µg/mL. Against tyrosinase activity, ethyl acetate and n-hexane extracts activity with an IC50 value of 79.25 ± 0.15 and 131.48 ± 0.88 µg/mL respectively. The phenolic contents of the methanolic extract of I. heterantha were also determined by using LC-MS/MS. The major constituents were Quinic acid (57,333.04 μg/g), malic acid (1135.16 μg/g), gallic acid (201.13 μg/g), isoquercitrin (113.63 μg/g), Rutin (92.97 μg/g), and Salicylic acid (40.45 μg/g). Keeping in view the overall biological activities of I. heterantha, it might be used in food industries and pharmaceuticals as a potential functional food ingredient.