Protective Effect Of Procyanidins On Experimental Rats With Intracerebral Hemorrhage And Its Possible Mechanisms

Background and Objective: Intracerebral hemorrhage (ICH) is the bleeding with nonsurgical trauma of brain parenchymatous. ICH is generally characterized by strong attack rate, acute onset, severe pathogenetic condition, hard to recover, and is a type of stroke with the highest morbidity and the lowest healing rate. As a common disease, ICH causes 10% of stroke cases in the US and Europe and 20% to 30% in Asian populations. In addition to its high mortality which is 35% to 52% within one month, intracerebral hemorrhage is a devastating tape of stroke, it imparts some form of disability to 88% of its survivors, 10% were living independently after 1 month, and only 20% were independent at 6 months, quality of life is diminished greatly in many who are left with permanent disability. Thus, it can cause great suffering to survivors and their family. In that case, primary stroke prevention has become a major public health priority. Functional defect of nerves after ICH is result in the direct and secondary injury of blood tumor and tissues around hematoma, on account of the pathology and physiological mechanism after ICH is very complicated, medical expectant treatment is a fundamental method to treat it in clinical customarily, but the effect is not ideal; For sufferers whose hematoma was comparatively large,or cerebrospinal fluid circulation was in trouble, or cerebral hernia was emerged, surgery also can be considered to remove the hematoma, but the dispute is a little big to use surgery until now, some standpoint think that surgery can not cut down the mortality and disability of ICH patients effectively, on the contrary, even causing rehaemorrhagia because of operation. Accordingly, looking for an effective medicine to prevent brain damage after ICH is becoming an imminent problem that need to solve. Masses of scholars focused on etiopathogenesis of ICH and try to find a valid instrument to prevent and cure it, but there is still a lack of available medicine currently.Procyanidins is the generic term of a large class of polyphenol compounds widespread in the plant kingdom, often extract from grape seed, Hindu lotus seedpod and so on. Procyanidins have several pharmacological action including cardiovascular protection, prevention and treatment of cancer, anti-inflammatory action, anti-diabetic effect, anti-gastrelcosis, protect liver, antiradiation, elevate memory of learning, promote Hair growth, and protect brain ischemia from damage. Because of such pharmacological effects, and also the characteristics of high efficiency and low toxicity, Procyanidins is the latest craze all over the word, widely used in medicines, cosmetics, health products, etc. Thus, Procyanidins have enormous market potentiality and economic returns. However, there is no literature display that whether Procyanidins have an effect on ICH. Since there are some resemblance on brain damage which is caused by ICH and cerebral ischemia, such as cerebral edema, apoptosis and inflammatory reaction, meanwhile, as there is also some ischemia injury due to regional cerebral blood flow descent in tissues around hematoma, we could suppose that Procyanidins may have a protective effect on brain in rats with ICH.In this study, we investigate the effect of Procyanidins on brain damage of experimental rats with ICH and its possible mechanisms by detecting changes of three different aspects including neuroethology, neuropathology and neurobiochemistry, in order to provide some evidence for its clinical application.Methods: Rats were divided into six groups randomly: sham-operated group, model groups of ICH,treatment group with procyanidins at doses of 50㎎·㎏-1, 100㎎·㎏-1 and 200㎎·㎏-1,and positive control group with Nimodipine at dose of 10㎎·㎏-1. Dissolve Procyanidins powder by distilled water, give it to rats of treatment groups once a day by intragastric administration, lasting two weeks and once again at 1hour before operation (an infusion of collagenase), so was Nimodipine. The sham-operation group and model group was administrated with Sodium Chloride of the equal volume. ICH model was established by injecting collagenase (typeⅦ)with microinjector into the brain caudate nucleus which was located according to the brain stereotaxic atlas. For sham-operated group, only inject sodium chloride to brain caudate nucleus. Rat behavior was evaluated over the time course (4 h, 8 h, 12 h, 24 h) in each group by four neuroethology score standardization. Twenty-four hours after operation, make the blood serum of rats ready to measure the level of creatine kinase (CK) and lactate dehydrogenase (LDH); brain water content (BWC) was observed by Dry-weight method, the brain tissue pathomorphology was observed by Hematoxylin-Eosin staining, simultaneously, the brain homogenate was prepared to detect the content of malondialdehyde (MDA) , glutathione (GSH) and the activity of superoxide dismutase (SOD) , catalase (CAT) in rat's brain tissues; In addition, the level of Bax , Bcl-2 and the expression of TNF-α, NF-κB were detected by method of immunohistochemistry, apoptosis in brain tissues was detected by method of TUNEL.Results:(1) In Procyanidins groups(50,100,200㎎·㎏-1)and Nimodipine group, the neurological behavioral score, level of CK, LDH in blood-serum, and BWC were significantly lower than those in ICH group(P <0.05, P <0.01 ) . In Procyanidins groups(50,100,200㎎·㎏-1)and Nimodipine group, pathomorphological changes of the brain tissue were relieved to different degrees compaired with ICH group respectively;(2)In Procyanidins groups(50,100,200㎎·㎏-1)and Nimodipine group the content of MDA was significantly lower than those in ICH group(P <0.05, P <0.01), whereas the activity of SOD was higher than that in ICH group(P <0.05). Meanwhile, Procyanidins(50, 100, 200㎎·㎏-1)and Nimodipine inhibited apoptosis and the expression of Bax, NF-κB and TNF-α( P <0.05,P <0.01 )according to immunohistochemical results. In addition, Procyanidins (100㎎·㎏ -1,200㎎·㎏ -1) and Nimodipine enhanced the expression of Bcl-2(P < 0.05, P < 0.01 ). Moreover, the quantity of positive TUNEL cells in procyanidins groups (50, 100, 200 mg·kg-1) was lower than that in ICH group.Conclusion:(1) Procyanidins (50, 100, 200 mg·kg-1) could relieve behavioral deficiency of nerves, degrade brain content water, lessen injured degree of nerve cell, cut down the level of CK, LDH. In short,Procyanidins have protective effect on experimental rats with intracerebral hemorrhage;(2) Procyanidins could protect brain from damage in experiment rats with cerebral hemorrhage, and the protective effect may be result from improving lipid peroxidation and reducing free radicals to generate; Simultaneously, Procyanidins could relieve cerebral edema probably via regulate the expression of inflammatory protein. Otherwise, Procyanidins could lessen apoptosis perhaps through adjust the expression of apoptosis related proteins as well as regulate the expression of inflammatory protein;(3) In Procyanidins group (50 mg·kg-1), the expression of Bax was significantly lower than those in ICH group, whereas the changes of Bcl-2 expression is not manifest. This phenomenon reveal that maybe there is not only one way for Procynidins to prevent brain apoptosis in rats with intracerebral hemorrhage.It's come to a summary that procyanidins could protect brain from damage in experiment rats with ICH, and the mechanisms may be as follows: first of all is relieve oxidative damage, then regulate the expression of some inflammatory protein to lessen cerebral edema, and accommodate the expression of apoptosis-related proteins to lighten apoptosis of brain tissues, improve brain damage eventually.