Investigation of in vitro anti-hyperpigmentation, antidiabetic, neuroprotective and antioxidant potential of Medicago murex WILLD. (Fabaceae)

Background and Aims: Most of the Medicago species are considered good quality forage crops due to their rich protein content. This study reports antioxidant properties, total phenolic and flavonoid content, enzyme (acetylcholinesterase (AChE), tyrosinase, [alpha]-amylase and [alpha]-glucosidase) inhibition activities of methanol (MeOH), ethyl acetate (EA) and, aqueous (AQ) extracts of Medicago murex (M. murex). Methods: The antioxidant activity of the different extracts of M. murex were evaluated using FRAP and CUPRAC assays. The contents of total phenolic and flavonoid were determined by the Folin-Ciocalteu and the Aluminium chloride (Al[Cl.sub.3]) colorimetric methods. Also, the enzyme inhibition activities were shown spectrophotometrically for AChE, [alpha]-amylase, [alpha]-glucosidase and tyrosinase enzymes. Results: Total phenolic and flavonoid contents of different extracts were determined between 83.70-163.93 mg GAE/g extract and 24.48-26.05 [micro]g QE/g extract, respectively. AQ extracts were the most active extracts in FRAP while being the best inhibitor of the AChE enzyme. On the other hand, EA extracts were the most active extracts in CUPRAC methods and the best inhibitors for other enzymes. Conclusion: Considering the findings, M. murex appears to be an important source of natural antioxidants and enzyme inhibitors, and it provides important baseline data for the food and pharmaceutical industries. Keywords: M. murex, bioactive substances content, antioxidant potential, enzyme inhibition