Effects Of Panax Quinquefolium 20s-Protopanaxdiol Saponins (PQDS) On Experimental Cerebral Ischemia In Rats

With the improved living standard and the ageing of population, the rate of ischemic cerebral disease has increased year by year, ischemia cerebral disese has become main disease threatening human health in the whole world. Thus, to search safe and effective drugs used for preventing and curing ischemic cerebral disease is an important task of medicine research.Panax quinquefolium L is a kind of Acanthopanax gracilistylus family plants. It is an important drug which is acknowledged in the world. It has the functions of anti-fatigue, anti-aging, anti-cancer. Modern research indicated that: its main active components are saponins, polysaccharoses, amino acids. It has widespread pharmacological effect to central nervous system, stress reaction, immune system, cardiovascular system and so on. Now there are few researches on PQDS's effect on cerebral ischemia. PQDS was separated from total saponins extracted from leaves of Panax quinquefolium L. Our previous research discove- red that PQDS had a cure effect on acute myocardial infarction. We studied the effect of PQDS on cerebral ischemia in rats, to approach the mechanism and to supply scientific evidence for clinic exploitation from multi-view.50 rats were randomly divided into five groups: sham group, model group, low dose group (PQDS25mg/kg), high dose group (PQDS 50mg/kg) and KDZI group(25mg/kg). The drug was given by peritoneal injection, once daily, succe- ssive administration for three days. The acute experimental cerebral ischemia models were made by ligation of bilateral common carotid arteries.The rats were exanguinated after 3h ligating for measuring platelet adhesion, platelet aggrega- tion, blood viscosity. Remaining blood was centrifuged to separate serum for measuring malondialdehyde(MDA), nitrogen monoxidum (NO) content and superoxide dismutase (SOD), nitricoxide synthase (NOS) activities. After exsa- nguinations, the rats were decapitated, take out the brain , divide the whole brain into two parts, a half weigh wet weight, and put it into 110℃drying oven till constant weight, calculate cerebral index and brain water content. The other half was made into brain homogenate for measuring malondialdehyde(MDA), calci- um(Ca2+)content and superoxide dismutase(SOD), Na+-K+-ATPase, Ca2+-Mg2+- ATPase activities.The results showed that: (1)compared with sham group, platelet adhesion, platelet aggregation, blood viscosity of model group were much higher(P<0.05 or P<0.01), which indicated that hemorrheology was abnormal when cerebral ischemia. Platelet adhesion, platelet aggregation, blood viscosity of PQDS 25,50mg/kg were degraded significantly compared with model group (P<0.05 or P<0.01). The result hint that: PQDS can improve platelet function and hemorrh- eology circumstance in rats of experimental cerebral ischemia(2) Compared with sham group, cerebral index and brain water content of model group were much higher(P<0.05 or P<0.01), which indicated that cereb- ral ischemia can lead to cerebral edema. Cerebral index and brain water content of PQDS 25,50mg/kg group were degraded significantly compared with model group(P<0.05). The result hint that: PQDS can inhibit cerebral edema, lighten damage of brain tissue.(3) Compared with sham group, serum MDA, NO, NOS contents of model group were much higher while SOD activity was much lower(P<0.05or P<0.01), which indicated that cerebral ischemia can lead to free radical damage. Serum MDA, NO contents and NOS activity of PQDS 25,50mg/kg group were much lower and SOD activity was higher compared with model group (P<0.05 or P<0.01). The result hint that: PQDS can inhibit free radical damage in rats of experimental cerebral ischemia.(4) Compared with sham group, MDA, Ca²⁺ contents of model group were increased, while the level of SOD, Na⁺-K⁺-ATPase and Ca²⁺-Mg²⁺-ATPase were declined signficatly(P<0.05 or P<0.01), which indicated that cerebral ischemia lead to free radical damage, calcium overload, energy metabolism disturbance. MDA, Ca²⁺ contents of PQDS25, 50mg/kg group were declined while the activ- eties of SOD, Na⁺-K⁺-ATPase and Ca²⁺-Mg²⁺-ATPase were increased signficatly (P<0.05 or P<0.01). The result hint that: PQDS can inhibit free radical damage, calcium overload, energy metabolism disturbance to prevent brain injured.What we observed suggest that: PQDS had protective effect on ischemic cerebral. The mechanism of the effect was not only decreasing platelet adhesion, platelet aggregation,blood viscosity, inhibiting cerebral edema, but also blocking calcium channel, decreasing MDA, NO, Ca²⁺ content and NOS activity, increas- ing SOD, Na⁺-K⁺-ATPase and Ca²⁺-Mg²⁺-ATPase activities.The study showed that PQDS probably can be explored to a new anti- ischemic cerebral drug, also provideed experimental evidences to take use of PQDS in ischemic cerebrovascular disease.