In the present paper, we overview the discovery of new biological activities induced by ginsenoside Rg1 and Rb1 and discuss possible mechanisms of action. Both compounds could increase neural plasticity in efficacy and structure; especially Rg1, as one small molecular drug, can increase proliferation and differentiation of neural progenitor cells in dentate gyrus of hippocampus of normal adult mice and global ischemia model in gerbils. This finding has great value for treatment of Alzheimer's disease and other neurodegenerative disorders which is characterized by neurons loss. Increase of expression of brain derived neurotrophic factor, Bcl-2 and antioxidant enzyme, enhanced new synapse formation, inhibition of apoptosis and calcium overload are also important neuron protective factors. Rg1 and Rb1 have common effects, but there are some differences in pharmacology and mechanism. These differences may attribute to their different chemical structure. Rg1 is panaxtriol with two sugars, while Rb1 is panaxtriol with four sugars.

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Radiation-induced lung injury (RILI) is one of the most common and fatal complications of thoracic radiotherapy, whereas no effective interventions are available. Andrographolide, an active component extracted from Andrographis paniculate, is prescribed as a treatment for upper respiratory tract infection. Here we report the potential radioprotective effect and mechanism of Andrographolide on RILI. C57BL/6 mice were exposed to 18 Gy of whole thorax irradiation, followed by intraperitoneal injection of Andrographolide every other day for 4 weeks. Andrographolide significantly ameliorated radiation-induced lung tissue damage, inflammatory cell infiltration, and pro-inflammatory cytokine release in the early phase and progressive fibrosis in the late phase. Moreover, Andrographolide markedly hampered radiation-induced activation of the AIM2 inflammasome and pyroptosis in vivo. Furthermore, bone marrow-derived macrophages (BMDMs) were exposed to 8 Gy of X-ray radiation in vitro and Andrographolide significantly inhibited AIM2 inflammasome mediated-pyroptosis in BMDMs. Mechanistically, Andrographolide effectively prevented AIM2 from translocating into the nucleus to sense DNA damage induced by radiation or chemotherapeutic agents in BMDMs. Taken together, Andrographolide ameliorates RILI by suppressing AIM2 inflammasome mediated-pyroptosis in macrophage, identifying Andrographolide as a novel potential protective agent for RILI.

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Treatment of rodents after stroke with bone marrow stromal cells (BMSCs) improves functional outcome. However, the mechanisms underlying this benefit have not been ascertained. This study focused on the contribution of neurotrophic and growth factors produced by BMSCs to therapeutic benefit. Rats were subjected to middle cerebral artery occlusion and the ischemic brain extract supernatant was collected to prepare the conditioned medium. The counterpart normal brain extract from non-ischemic rats was employed as the experimental control. Using microarray assay, we measured the changes of the neurotrophin associated gene expression profile in BMSCs cultured in different media. Furthermore, real-time RT-PCR and fluorescent immunocytochemistry were utilized to validate the gene changes. The morphology of BMSCs, cultured in the ischemic brain-conditioned medium for 12 h, was dramatically altered from a polygonal and flat appearance to a fibroblast-like long and thin cell appearance, compared to those in the normal brain-conditioned medium and the serum replacement medium. Forty-four neurotrophin-associated genes in BMSCs were identified by microarray assay under all three culture media. Twelve out of the 44 genes (7 neurotrophic and growth factor genes, 5 receptor genes) increased in BMSCs cultured in the ischemic brain-conditioned medium compared to the normal brain-conditioned medium. Real time RT-PCR and immunocytochemistry validated that the ischemic brain-conditioned medium significantly increased 6/7 neurotrophic and growth factor genes, compared with the normal brain-conditioned medium. These six genes consisted of fibroblast growth factor 2, insulin-like growth factor 1, vascular endothelial growth factor A, nerve growth factor beta, brain-derived neurotrophic factor and epidermal growth factor. Our results indicate that transplanted BMSCs may work as 'small molecular factories' by secreting neurotrophins, growth factors and other supportive substances after stroke, which may produce therapeutic benefits in the ischemic brain.