Search

Portulaca oleracea L. is a traditional oriental medicine known for its pharmacological effects. The present study aimed to investigate the immunostimulatory effects of PPCE on cyclophosphamide-stimulated rat model and in isolated spleen cells. The result showed that PPCE exerted an immunostimulatory effect in vivo and in vitro. Specifically, PPCE significantly enhanced splenocyte proliferation and upregulated inflammatory cytokines (IL-2, IL-12, TNF-α, and IFN-γ) and NK cell activity in vitro. The immunostimulatory effect was further investigated through various immunological assays. Oral administration of PPCE increased the swimming time and number of immune cells in rats. Histological analysis revealed that PPCE administration exerted splenic recovery. Thus, P. oleracea L. based complex extracts may be used as an immunostimulatory agent in medicine or functional foods. [ABSTRACT FROM AUTHOR]

Urodeles including newt and salamander have remarkable regenerative capacity during the postembryonic life span. Some of the unique features are the formation of the well-developed wound epidermis and the active dedifferentiation process in the early phase of regeneration. These are regarded as key events for the successful regeneration since no further regenerative activity is possible without them. In this study, we investigated the role of retinoic acid (RA) in salamander limb regeneration by blocking RA synthesis using disulfiram, an inhibitor of aldehyde dehydrogenase that oxidizes retinal to RA. Disulfiram treatment resulted in delaying the limb regeneration processes via inhibition of wound epidermis formation and dedifferentiation process. When RA was administered after disulfiram treatment, the inhibitory effect of disulfiram was rescued. In addition, disulfiram treatment after the dedifferentiation stage resulted in the mild retardation of limb regeneration, suggesting that RA might also be involved in the blastema outgrowth. Furthermore, salamander MMP-9 gene expression was also inhibited by disulfiram treatment. Collectively, our findings indicate that endogenous RA may play an important role(s) in the early phase of limb regeneration by regulating the expression of molecules responsible for the modification of intracellular and extracellular environment during salamander limb regeneration. [ABSTRACT FROM AUTHOR]