Reactive oxygen species contribute to the development of various human diseases. Ischemia is characterized by both significant oxidative stress and characteristic changes in the antioxidant defense mechanism. Heat shock protein 27 (HSP27) has a potent ability to increase cell survival in response to oxidative stress. In the present study, we have investigated the protective effects of PEP‐1–HSP27 against cell death and ischemic insults. When PEP‐1–HSP27 fusion protein was added to the culture medium of astrocyte and primary neuronal cells, it rapidly entered the cells and protected them against cell death induced by oxidative stress. Immunohistochemical analysis revealed that, when PEP‐1–HSP27 fusion protein was intraperitoneally injected into gerbils, it prevented neuronal cell death in the CA1 region of the hippocampus in response to transient forebrain ischemia. Our results demonstrate that transduced PEP‐1–HSP27 protects against cell death in vitro and in vivo, and suggest that transduction of PEP‐1–HSP27 fusion protein provides a potential strategy for therapeutic delivery in various human diseases in which reactive oxygen species are implicated, including stroke.

Oriental medicine Samhwangsasim-tang (SHSST) has traditionally been used in East Asia to treat hypertension and its complications. However, little is known about its potential value regarding the treatment of chronic inflammatory diseases such as multiple sclerosis (MS). In this study, we investigated whether SHSST has a beneficial effect in treating myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis (EAE). Onset-treatment with SHSST was found to alleviate neurological symptoms as well as demyelination and glial activation in the spinal cords from the EAE mice. The SHSST also attenuated the mRNA or protein expression of pro-inflammatory cytokines (interleukin-1beta and tumor necrotic factor-alpha); chemokines (RANTES, monocyte chemotactic protein-1, and macrophage inflammatory protein-1alpha); inducible nitric oxide synthase; and cyclooxygenase-2 in correspondence with the down-regulation of the nuclear factor-kappa B and mitogen-activated protein kinases signal pathways in the spinal cords from EAE mice. Interestingly, the protective effect of the SHSST was related to a decreased number of Th1 cells and an increased number of Treg cells in spinal cords from EAE mice. Taken together, our finding firstly suggested that SHSST could delay or mitigate EAE with a wide therapeutic time-window by suppressing Th1 cell responses and upregulating Treg cell responses. Also, our findings are strong enough to warrant further investigation of SHSST as a treatment for chronic autoimmune diseases including MS.