Phytochemical Composition and in vitro Antioxidant Potential of the Ethanolic Extract of Trigonella foenum-graecum (fenugreek) Seeds

Abstract

Medicinal plant serves as a natural source of antioxidants that protect against oxidative stress and related pathologies. Trigonella foenum-graecum L. (fenugreek) is a medicinal plant that is known to possess antioxidant and anti-inflammatory properties due to their rich phytochemical compounds. This study investigated the phytochemical composition and in vitro antioxidant potential of the ethanolic extract of Trigonella foenum-graecum (fenugreek) seeds. The seeds were authenticated, dried, ground, and extracted with 70% ethanol. Qualitative and quantitative phytochemical analyses were conducted using standard methods, while antioxidant activities were evaluated through nitric oxide (NO), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays. Phytochemical screening revealed the presence of alkaloids, phenols, flavonoids, tannins, saponins, terpenoids, steroids, and cardiac glycosides, with flavonoids (5.51 ± 0.07 mg/g), phenols (4.61 ± 0.05 mg/g), and saponins (3.26 ± 0.04 mg/g) being abundant. These phytochemicals are known to contribute to antioxidant and anti-inflammatory activities. The extract demonstrated concentration-dependent antioxidant activity in all assays. Nitric oxide scavenging ranged from 10.31 ± 0.07% to 61.58 ± 0.11% (IC₅₀ = 361.21 µg/mL), DPPH inhibition from 18.56 ± 0.12% to 70.39 ± 0.25% (IC₅₀ = 242.4 µg/mL) and FRAP activity from 3.32 ± 0.04% to 41.20 ± 0.14% (IC₅₀ = 505.8 µg/mL), compared with vitamin C standards that showed higher activity in each case. The extract showed concentration-dependent radical scavenging effects, with NO inhibition ranging from 10.31 ± 0.07% to 61.58 ± 0.11% and an IC₅₀ value of 361.21 µg/mL compared to 156.75 µg/mL for vitamin C. The strong antioxidant activities observed in fenugreek seed extract are attributed to its high content of flavonoids, phenolics,and saponins. These findings support the potential application of fenugreek seeds as a natural antioxidant source and provide a scientific insight for its use in nutraceutical and therapeutic formulations targeting oxidative stress–related disorders such as hypothyroidism.