: Guava (Psidium guajava) contain a great deal of polyphenol compound and work on the treatment of Diabetes mellitus effectively. In this study, the bioactivities of aqueous extract (GLEx) of guava leaf were investigated. Total phenolic contents of GLEx was 266.9 ㎎ tan/g. The effects of GLEx on digestive enzymes, α-amylase, maltase and sucrase were investigated. IC 50 values of GLEx against α-amylase, maltase and sucrase were 0.65 ㎎/㎖, 2.0 ㎎/㎖ and 3.5 ㎎/㎖ respectively. The effect of GLEx on oral glucose tolerance test (OGTT) was performed in normal ICR mouse, control (dstilled water) and GLEx (aqueous extract of Guava leaf) were co-administered orally with glucose, showed reducing effect on the blood glucose level. The guava is likely to useful for prevention or improvement of hyperglycemia by lowering the blood glucose level and inhibiting glycoside hydrolase activity.

Purpose: Ultraviolet (UV) irradiation decreases epidermal hydration, which is maintained by reduction of natural moisturizing factors (NMFs). Among various NMFs, free amino acids (AA) are major constituents generated by filaggrin degradation. This experiment was conducted to determine whether or not dietary supplementation of green tea extract (GTE) in UV-irradiated mice can improve epidermal levels of hydration, filaggrin, free AAs, and peptidylarginine deiminase-3 (PAD3) expression (an enzyme involved in filaggrin degradation). Methods: Hairless mice were fed a diet of 1% GTE for 10 weeks in parallel with UV irradiation (group UV+1%GTE). As controls, hairless mice were fed a control diet in parallel with (group UV+) or without (group UV-) UV irradiation. Results: In group UV+, epidermal levels of hydration and filaggrin were lower than those in group UV-; these levels increased in group UV+1% GTE to levels similar to group UV-. Epidermal levels of PAD3 and major AAs of NMF, alanine, glycine and serine were similar in groups UV-and UV+, whereas these levels highly increased in group UV+1% GTE. Conclusion: Dietary GTE improves epidermal hydration by filaggrin generation and degradation into AAs.