A Clinical Trial to Compare the Photoprotective Effects of Cucumber Seed Extract vs Placebo in Filipino Adults by Measurement of Minimal Erythema Dose

A monocentric, randomized, split-body, double-blind, controlled trial was conducted on 29 Filipino adults with Fitzpatrick skin types III-V. Topical 2% and 4% cucumber seed extract gels and placebo were applied to randomized sites on the lower back, followed by incremental narrow-band UVB exposure. MED was assessed 24 hours post-exposure. Repeated measures ANOVA and paired t-tests were used for statistical analysis.

Inclusion Criteria: \- Filipinos aged 18 to 59 years with Fitzpatrick skin phototypes III to V were included in the study. Exclusion Criteria: * Elderly and pediatric populations were excluded due to differences in skin structure, immune responses, and the presence of age-related comorbidities that may confound study findings. * Additional exclusions applied to individuals who were pregnant or breastfeeding; * Had a history of phototoxic, photoallergic, or abnormal responses to sunlight; ----Reported allergies to cosmetic products, sunscreens, topical drugs, cucumber, or any study formulation component * Participants were also excluded if they presented with pre-existing or dormant dermatologic conditions, sunburn, suntan, scars, active lesions, or uneven pigmentation on the lower back. * Other exclusion criteria included current or recent use of medications known to cause hyperpigmentation (e.g., minocycline, clofazimine, amiodarone, antimalarials, chemotherapeutic agents), systemic treatments affecting skin status within the past 15-30 days, sun exposure of the lower back within four weeks prior to inclusion, or intake of skin-whitening supplements such as glutathione within one month before the study.