Tomato Seed Extract Containing Lycoperoside H Improves Skin Elasticity in Japanese Female Subjects: A Randomized, Placebo-Controlled, Double-Blind Trial

Background and Objective: Tomato seeds are edible seeds unconsciously ingested with the fruit. However, there are few reports regarding the constituents and biological activities of tomato seed extract (TSE). Recently, we found that saponins are major constituents of TSE including lycoperoside H. Previous reports have described that several plant-derived saponins improve skin diseases such as wounds and microangiopathy. Therefore, to discover the effect of TSE on the skin condition, we conducted a clinical trial of TSE (Tomato Seed Extract-P) standardized with lycoperoside H when orally ingested. Methods: The study was performed as a randomized, double-blind, placebo-controlled study. TSE (200 mg daily) containing 1 mg of lycoperoside H was used as the active sample. We enrolled 44 Japanese women who have concerns about facial elasticity and relatively low facial skin elasticity. All subjects were randomly allocated into either the active group (n = 22) or the placebo group (n = 22) using a computerized random-number generator. Capsules containing either the active sample or a placebo were administered for 8 weeks between October 12, 2020, and January 16, 2021. Facial elasticity, specifically the R7 value, was evaluated as the primary outcome. The remaining facial R parameters, upper arm R parameters, and other skin parameters including epidermal moisture, trans epidermal water loss, dermal parameters, and advanced glycation end products (AGEs) parameters were measured at 0, 4, and 8 weeks of ingestion. Blood, urine, and body parameters were also evaluated for safety. Results: Forty-three subjects completed the trial, and the per protocol set comprised 21 subjects in the TSE group and 22 subjects in the placebo group. After ingesting TSE for 8 weeks, the R7 value was significantly higher in the TSE group compared to the placebo group. Furthermore, the change in R7 values from the baseline at 4 and 8 weeks were also higher in the TSE group. Among the secondary outcomes, facial elasticity parameters including R2, R5, R1, and R4 at 4 weeks and facial R5, R1, and R4 and upper arm R2 at 8 weeks were higher in the TSE group. In addition, plasma pentosidine significantly decreased in the TSE group after 8 weeks of ingestion. There were no significant differences in moisture, DermaLab® parameters and AGEs parameters except plasma pentosidine. Laboratory tests revealed no abnormalities suggesting adverse effects of TSE. Conclusions: TSE (200 mg/day) standardized with lycoperoside H improved the facial elasticity parameters. Thus, daily ingestion of TSE was suggested to be beneficial for maintaining the facial skin elasticity. However, the relationship between the reduction of pentosidine and skin elasticity by TSE ingestion should be clarified through further studies. Trial Registration: UMIN-CTR: UMIN000041881. Foundation: Oryza Oil & Fat Chemical Co., Ltd.