Effects of Lycopersicon esculentum extract on hair growth and alopecia prevention

To evaluate the potential hair growth–promoting activity and the expression of cell growth factors of Lycopersicon esculentum extracts, each 3% (w/w) of ethyl acetate extract (EAE), and supercritical CO₂ extract (SCE) of L. esculentum and isolated lycopene Tween 80 solution (LTS) and test hair tonic (THT) containing LTS were applied on the dorsal skin of C57BL/6 mice, once a day for 4 weeks. At week 4, LTS and THT exhibited hair growth–promoting potential similar to that of 3% minoxidil as a positive control (PC). Further, in the LTS group, a significant increase of mRNA expression of vascular endothelial growth factor (VEGF), keratinocyte growth factor, and insulin-like growth factor-1 (IGF-1) was observed than PC, as well as the negative control (NC). In the THT group, increases in IGF-1 and decrease in VEGF and transforming growth factor-β expression were significant over the NC. In a histological examination in the THT group, the induction of anagen stage of hair follicles was faster than that of NC. In the Draize skin irritation study for THT, no observable edema or erythema was observed on all four sectors in the back skin after exposure for 24 or 72 h for any rabbit. Therefore, this study provides reasonable evidence that L. esculentum extracts promote hair growth and suggests that applications could be found in hair loss treatments without skin irritation at moderate doses.