Flavonoid Profile of Peperomia pellucida Extract and Its Potential for Ophthalmic Therapy

Abstract

Peperomia pellucida is a tropical plant known for antioxidant, anti-inflammatory, and antibacterial activities attributed mainly to its flavonoid content. This study aimed to determine the total flavonoid content of the ethanolic leaf extract of P. pellucida and to evaluate its potential to reduce intraocular pressure (IOP) in Balb/C mice with Staphylococcus aureus–induced ocular infection. Total flavonoids were quantified spectrophotometrically using the aluminium chloride (AlCl₃) method at 415 nm with quercetin as the reference standard. An in vivo assay was conducted on 25 mice randomly allocated into five groups, comprising a negative control (distilled water), a positive control (0.5% timolol), and three groups receiving P. pellucida extract eye drops at different concentrations. IOP was measured with a Schiotz tonometer before infection, after infection, and after therapy. The ethanolic extract contained 66.96 mg quercetin equivalents (QE)/g dry extract. The group receiving a 60% extract concentration showed the greatest mean IOP reduction (9.35 mmHg), whereas lower and higher concentrations produced smaller decreases. However, one-way ANOVA showed no statistically significant differences in IOP reduction among treatment groups (p = 0.822). These findings indicate a biological tendency toward IOP lowering by P. pellucida extract, but the current evidence is preliminary; studies with larger sample sizes, optimised dosing regimens, and more refined outcome measures are required to confirm its therapeutic significance in infection-related ophthalmotonus.