Cosmeceutical Potential of Psidium guajava (Guava) and Carica papaya (Pawpaw) Leaf Extracts: Phytochemical Composition, Antioxidant, Antifungal and Sun Protection Properties

Abstract

Aim: This study aimed to evaluate the phytochemical, antioxidant, antifungal and sun protection factor (SPF) properties of Psidium guajava and Carica papaya leaf extracts and assess their potential as sustainable ingredients in cosmetic formulations. Methodology: Ethanol leaf extracts of Psidium guajava (guava) and Carica papaya (pawpaw) were evaluated for their suitability as cosmeceutical ingredients. Dried leaves were extracted in absolute ethanol by maceration and analysed for total phenolic, flavonoid and tannin contents using spectrophotometric methods. Antioxidant activity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay, and the 50% inhibitory concentration (IC₅₀) was calculated. Antifungal activity against seven fungal isolates, Candidasp., Microsporumsp., Trichophytonsp., Epidermophytonsp., Trichophyton rubrum, Microsporum canis and Candida albicans, was evaluated using the agar well-diffusion method, with nystatin as the positive control. The in vitro sun protection factor (SPF) was determined spectrophotometrically using the Mansur equation. Results: Psidium guajava produced a higher extraction yield (10.67%) than C. papaya (8.69%). The guava extract exhibited higher total phenolic (311.40 ± 0.15 µg GAE/mL) and tannin contents (285.67 ± 0.24 µg TAE/mL), whereas pawpaw exhibited a higher flavonoid content (282.88 ± 0.12 µg QE/mL). The antioxidant activity of P. guajava (IC₅₀ = 67.23 µg/mL) was greater than that of C. papaya (IC₅₀ = 248.68 µg/mL) and was closer to that of ascorbic acid (48.05 µg/mL). Both extracts demonstrated concentration-dependent antifungal activity against all tested fungi. At higher concentrations, the inhibition zones were comparable to those of nystatin. Furthermore, P. guajava showed higher ultraviolet (UV)-protective activity (SPF = 5.80) than C. papaya (SPF = 4.02). Conclusion: The findings suggest that both leaf extracts, particularly P. guajava, may provide natural sources of antioxidant, antifungal and UV-shielding agents for further evaluation as multifunctional ingredients in sustainable cosmeceutical formulations.