The Preliminary Study Of Regulating Mechanism Of Sulfate Polysaccharide From Pine Pollen Affects Blood Glucose In T2MD Mice

Former studies in our laboratory have demonstrated that the SPPM60couldsignificantly improve intracellular calcium ion concentration in mice spleen, butPPM60is not obvious. SPPM60could improve cellular calcium ion concentration byregulated calcium within the internal flow and release. Many studies have confirmedthat the glucose stimulated insulin secretion is closely related to the concentration ofcalcium ions. To examine the effect of PPM60and SPPM60, we blocked the calciumand calcium channels in MIN6cell. Our results shown that SPPM60couldsignificantly improve insulin secrete in MIN6cells. To study the mechanisms ofPPM60and SPPM60ameliorate T2MD mice, we examined whether treatment withPPM60and SPPM60could improve insulin sensitivity in diabetes mice. Then wecould provide theoretical basis for the polysaccharide from Pine massoniana Pollencan be a treatment for diabetes drug candidate or health food.Firstly, polysaccharide was extracted and sulfated.1000g sporoderm-brokenpollen of masson pine was extracted by hot water extraction and alcoholsedimentation to prepare the polysaccharide, and then we got22.560g PPM60purifiedfrom crude polysaccharide by60%ethanol precipitation. We measured PPM60sugarcontent by phenol-sulfuric acid method was64.20%. After sulfuric acid esterification,5g PPM60became to7.141g SPPM60. The Sulfate substitution degree is1.96.Ultraviolet spectrum showed that PPM60and SPPM60didn’t contain nucleic acidpolysaccharide and protein.Secondly, choose the appropriate concentration of polysaccharides. High sugarand high fat feed combination with intraperitoneal injection35mg/kg STZ intodiabetes model. The creation of diabetic model rate is more than90%. Similar to those of human diabetes, mice also appear obesity and high blood glucose. Theexperimental group characteristics were hyperglycaemia and excessive increase inweight. Our results shown that blood glucose level significantly decreased in PPM60high-dose group, SPPM60low dose group (P<0.05) and PPM60medial-dose group,SPPM60medial-dose group, SPPM60high dose group (P<0.01) and SPPM60after4week treatment. Blood glucose levels of all the SPPM60groups are dosage-effectrelationship. Furthermore, PPM60high-dose and SPMM60high-dose groups had theleast weight gain. So we choose the most suitable concentration of PPM60andSPPM60was200mg/kg/d.Thirdly, use high sugar and high fat feed combination with intraperitonealinjection35mg/kg STZ to get the diabetes model. The creation of diabetic model ratewas more than95%, low mortality rate in mice. Similar to those of human diabetes,mice also appear obesity and high blood glucose. Mice were divided into5groupsafter4weeks: untreated control group, untreated diabetic group,200mg/kg/dPPM60-treated diabetic group,200mg/kg/d SPPM60-treated diabetic group,200mg/kg/d metformin-treated group. After10weeks of oral medication, we tested someindexes such as fasting blood-glucose, serum insulin level, OGTT, HOMA-IR, SI,GLUT-4mRNA expression in skeletal muscle and the morphological changes ofpancreatic islets. Untreated diabetic mice developed persistent hyperglycemia,hyperinsulinemia, impaired glucose tolerance and insulin resistance（IR）. Comparedto control, the morphological changes of pancreatic islets of diabetic mice weresignificantly damaged. Although PPM60treatment group improved the hyperglycemia(P<0.05), there was not significant difference in insulin and insulin sensitivity.However, SPPM60and metformin treatment groups improved the hyperglycemi(P<0.01、P<0.01), hyperinsulinemia (P<0.01、P<0.01) and HOMA-IR (P<0.01、P<0.01). The morphology of pancreatic islets damage had got some recovery. All theindicators were improved obviously in STZ-induced diabetic mice between theSPPM60and the PPM60treated groups.These results shown that:⑴PPM60had weak effects on regulation of fastingand plasma glucose insulin levels in type2diabetes mice, but its SPPM60after acid esterification did produce some varies degrees antidiabetic effects.⑵The optimalconcentration of SPPM60could significantly reduce the blood glucose and insulinlevels in diabetes mice, effectively improve the insulin resistance and glucosetolerance, increased insulin sensitivity in diabetes mice. Compared the increasedinsulin sensitivity between the SPPM60and the PPM60, they had significantdifferences.⑶The morphology of pancreatic islets damage had got some recoveryafter treatment by PPM60and SPPM60, the repair effect of SPPM60was close tometformin.