In vitro studies on different extracts of fenugreek (Trigonella spruneriana BOISS.): Phytochemical profile, antioxidant activity, and enzyme inhibition potential

The side effects of synthetic antioxidants make it necessary to find a natural alternative. Therefore, the current study investigates the potential of T. spruneriana as a new alternative in terms of natural bioactive components. In this context, antioxidant activity, enzyme inhibition, and phenolic compounds of different extracts including ethanol, methanol, ethyl acetate, and aqueous were identified. The results show that the ethyl acetate (113.59 ± 2.73 mg GAE/g) has the highest phenolic content, but ethanol extract has the highest scavenging activity for DPPH and TAC. The ethanol extract showed stronger inhibition on cholinesterase and α-amylase compared to other extracts. Besides, 12 bioactive compounds were characterized in T. spruneriana extracts by HPLC-DAD. Our findings support that T. spruneriana could be considered as a new source of active phytochemicals, as well as provide remarkable data on biological activities of some main enzymes playing role in the healing of hyperpigmentation, Alzheimer, and diabetes. PRACTICAL APPLICATIONS: This study reports the total content, types and amounts of bioactive compounds and potential beneficial bioactivities of the different extracts of T. spruneriana. Trigonella is abundant in nature and spread over a wide geographical area, and is used in making cheese, pastries, spices, and sausages in different countries, as well as for antidiabetic purposes. Trigonella leaves are a good source of bioactive compounds that contain compounds like quercetin, catechin, cinnamic acid, and coumaric acid, along with it have also a high content of soluble fibers and is suggested for body weight control. Apart from being the first study conducted to point out the potential of T. spruneriana as being a natural food additive, this study also demonstrated its medicinal importance by revealing the anti-hyperpigmentation, antidiabetic, neuroprotective, and antioxidant properties of T. spruneriana.

Keywords: Trigonella; anti-hyperpigmentation; antidiabetic; antioxidants; bioactive compounds; enzyme inhibition.