The diapause duration P. ussuriensis eggs is known to either one year or prolonged to additional years. This complex life cycle is mainly caused by the interruption at two embryonic stages: early stage (initial diapause) and fully developed late stage (final diapause). The environmental cues, such as temperature, is critical to determine the diapause duration but the precise diapause mechanism of P. ussuriensis eggs is unclear. We demonstrated temperature effects on the entrance of initial diapause. Newly oviposited eggs were incubated at two temperature conditions (20℃and 30℃) for 60 days. When eggs were incubated at 20℃, egg weights were not significantly changed, but at 30℃ those were gradually increased to 1.5 times for 50 days. Genomic DNA contents of eggs were similarly increased at 30℃. Total RNA contents at 30℃ were highly increased from the 15-days-old but not at 20℃. In addition, we further analysed expression levels of two heat shock protein 70 (hsp70a, hap70b) genes during embryonic development. Our results suggest that initial diapause occurred between 10 and 15 days after oviposition and its entrance was blocked by high temperature incubation.
Herb extracts commercially used in Korea were screened for PPAR-γ agonist test and α-glucosidase inhibition assay. Total 16 herb plants had a PPAR-γ agonist activity. Specially, Alisma orientale Juz (108.41%), Ephedra sinica (98.22%), Sasa japonica Makino var. purpurascens Nakai (140.68%), Astragalus membranaceus Bunge (106.79%) and Cnidium officinale Makino (113.00%) showed high PPAR-γ agonist activity rate compared with rosiglitazone's (167.46%). And Cornus officinalis S. et Z. (90.3%), Cinnamomum cassia Blume (89.2%), Psoralea corylifolia L. (89.8%), Paeonia japonica (Makino) Miyabe (92.4%) and Paeonia suffruticosa Andr (93.2%), showed high α-glucosidase inhibition rates. These results support previous reports of the efficacy of Oriental medicinal plants used for diabetes mellitus.