Evaluation of the Anti-inflammatory and Antioxidant Potential of Aqueous Corn Silk Extract in Carrageenan-Induced Inflammation in Albino Rats

Abstract

In the present study, an investigation was carried out to evaluate the potential anti-inflammatory and antioxidant activities of the aqueous extract of corn silk (Stigma maydis) using a carrageenan-induced inflammation model in albino rats. Corn silk is known for its significant medicinal value, attributed to a wide range of bioactive phytochemicals, including polyphenols, phenolic acids, flavonoids, anthocyanins, glycosides, carotenoids, and water-soluble vitamins. Key active constituents responsible for its anti-inflammatory effects include tannins, phenols, alkaloids, flavonoids, carotenoids, β-sitosterol, vanillin, hydroxymellein, moringine, moringinine, β-sitostenone, and 9-octadecenoic acid.

The aqueous extract of corn silk was administered at doses of 100 mg/kg and 200 mg/kg (p.o.), which produced a statistically significant reduction in carrageenan-induced paw edema, with effects comparable to the standard control group. Notably, the 400 mg/kg dose of the aqueous extract exhibited maximum anti-inflammatory activity, comparable to the standard drug indomethacin (10 mg/kg). The antioxidant potential of the extract was assessed by nitric oxide scavenging assay using a UV-Visible spectrophotometer. Sodium nitroprusside (5 mM) in phosphate buffer was mixed with varying concentrations of the extract (25–800 µg/mL) and incubated at 25°C for 30 minutes. A control sample containing sodium nitroprusside without the extract was used for comparison. Additionally, the aqueous extract of corn silk demonstrated ABTS radical scavenging activity, confirming its antioxidant capacity. The extract decolorized ABTS radicals by donating hydrogen atoms, indicating strong radical scavenging potential, with an IC₅₀ value of 60 µg/mL. These findings suggest that corn silk aqueous extract possesses significant anti-inflammatory and antioxidant activities, which may be attributed to its rich phytochemical composition.