Abstract: Objective To observe the effect of porphyra yezoensis polysaccharide (PYP) on cerebrum tissue of diabetic rats and apoptosis. Methods 60 Wistar rats were randomly divided into normal control group, diabetic model group, and treated groups respectively with PYP (0.25 g/kg × d), PYP (0.5 g/kg × d), and PYP (1 g/kg × d). The cerebrum pathologic changes were observed by HE staining method, and the number of apoptotic cells was observed by electrophoresis and the mRNA expression of p53 and bcl-2 was confirmed by RT-PCR. Results PYP improved the cerebrum pathologic changes of diabetic rats. With comparison to the diabetic model group, the cerebrum pathologic change in the treated groups also improved. And the number of apoptotic cells, the expression of p53 in cerebrum tissue decreased and expressions of bcl-2 rose. Conclusion PYP can decrease the expression of p53 in cerebrum tissue and rise expressions of bcl-2 so as to protect brain tissues from cerebral ischemia.

Key words: diabetes mellitus, porphyra yezoensis polysaccharide, neuropathy, apoptosis, p53 gene, bcl-2 gene