BACKGROUND： The mechanisms of brain injury Following diabetes could be related to amyloid precursor protein （APP） mRNA overexpression. Studies have shown that Gingko biloba leaf extract （EGb） is effective in prom...BACKGROUND： The mechanisms of brain injury Following diabetes could be related to amyloid precursor protein （APP） mRNA overexpression. Studies have shown that Gingko biloba leaf extract （EGb） is effective in promoting functional recovery of the brain after traumatic injury. EGb is also effective in improving central nervous system plasticity and learning and memory functions of the elderly. OBJECTIVE： To study the effects of EGb on learning and memory, as well as hippocampal APP mRNA expression in the brains of diabetic rats, using Morris water maze behavioral testing and reverse transcription polymerase chain reaction （RT-PCR）, respectively. DESIGN： Complete random design, controlled experimental study. SETTING： Department of Pharmacology, Pharmaceutical School, Guangxi Medical University. MATERIALS： A total of 70 male Wistar rats （180-220 g）, 8 weeks old and specific pathogen free, were used for this study. GbE （containing 24.8% flavone glycosides and 6.2% diterpene lactone） was purchased from Guilin Sitejia Natural Plants Pharmaceutical Factory （Guangxi Province, Lot NO. 200405）. Streptozotocin was purchased from Sigma （USA）. Protamine zinc insulin injection was purchased from WANBANG Biochemical Pharmaceutical Co., Ltd. （Xuzhou Jiangsu, China）. METHODS： The experiment was performed in the Experimental Center of Guangxi Medical University from March to October 2005.（1） Experimental intervention： 70 rats were divided randomly into normal control group, diabetic model group （DM group）, diabetic model ＋10 μ g/kg insulin group （DM ＋ Ins group）, diabetic model ＋ 100 mg/kg ginkgo leaf extract group （DM ＋ EGb high-dose group）, and diabetic model ＋ 50 mg/kg ginkgo leaf extract group （DM ＋ EGb low-dose group）; there were 14 rats in each group. Rats with an intraperitoneal （i.p.） injection of citrate buffer solution （pH 4.4） served as the control group. To establish the diabetes model, rats were treated with i.p. injection of 55 mg/kg streptozotocin. Insulin （10 U/kg） was injected subcutaneously （s.c.） every day for 6 months in the DM group. EGb （100 mg/kg） and EGb （50 mg/kg） was administered intragastrically every day for 6 months in the DM ＋ EGb high-dose group and DM ＋ EGb low-dose group, respectively. The DM group and control group were administered distilled water intragastrically every day for 6 months. Drugs were administered once every morning. （2） Experimental evaluation： Six month after intervention, learning and memory of diabetic rats was tested by Morris water maze. Rats were allowed to train for 4 days, and the escape latency and platform-searching score were measured at days 5 and 8. Changes in hippocampal APP mRNA expression were measured with RT-PCR. MAIN OUTCOME MEASURES： Morris water maze performances and hippocampal APP mRNA expression in rats. RESULTS： A total of 70 Wistar rats were included in the final analysis, without any loss. （1） Learning and memory dysfunction of diabetic rats： After 4 days of Morris water maze training, escape latency was longer in the DM group on days 5 and 8, and the platform-searching score was lower in the DM group compared to the control group. In the DM ＋ EGb group, the escape latency score was shorter and platform-searching score was significantly increased compared to the DM group. （2） APP mRNA expression： in the hippocampus of diabetic rats, a 340 bp mRNA product was amplified, which is comparable to the APP mRNA amplification length of design. The expression of APP mRNA from the hippocampus of diabetic rats with learning and memory dysfunctions was significantly increased. EGb extract significantly inhibited the APP mRNA expression in these rats. CONCLUSION： EGb not only ameliorated the learning and memory dysfunctions in diabetic rats, but also significantly inhibited APP mRNA expression. Results from this study led to the hypothesis that diabetes could be one of the risk factors for AD.展开更多
The feasibility of gingko (Gingo Biloba) foliage as a passive bio-monitor for organochlorine pesticides in air was explored. The accumulation patterns of hexachlorocyclohexanes (HCHs), dichlorodiphenyl- trichloroethan...The feasibility of gingko (Gingo Biloba) foliage as a passive bio-monitor for organochlorine pesticides in air was explored. The accumulation patterns of hexachlorocyclohexanes (HCHs), dichlorodiphenyl- trichloroethanes (DDTs) and hexachlorobenzene (HCB) in gingko foliage were similar; the amounts of HCHs, DDTs and HCB increased with foliage growth in spring and decreased thereafter. This accumu-lation pattern is likely related to the growing process of the gingko foliage, which was observed for the first time in our work, giving a piece of evidence for the "bud burst effect" in plants. Compared with those in pine needles in 1980's, the residual levels of HCHs and DDTs have declined obviously in Bei-jing, indicating that the ban on the production and use of organochlorine pesticides (OCPs) in our country is effective; however, the amount of HCB has increased, indicating great progress of chemical industry in Beijing. The analysis for the source of OCPs in the gingko foliage showed that the technical HCHs and DDTs were used largely in history, but were not used in recent years. A little lidane has been used and there was a new input of o,p′-DDT in recent years; dicofol usage may be the main source of o,p′-DDT. Concentrations of HCHs, DDTs and HCB in gingko foliages were similar to those in pine nee-dles in the corresponding period and there is a strong positive correlation between the OCPs concen-tration data obtained from these two kinds of trees. It presents no difference in the accumulation style between these two kinds of trees. The level of OCPs in the gingko foliage reflects the pollution status of OCP in air. The result of this work shows that the gingko foliage can be used as a bio-monitor of OCPs in air.展开更多
白果活性蛋白(GAP)是华中农业大学天然产物化学实验室首次从白果中分离得到的一种以清蛋白为主的且具有显著生物活性的蛋白,为扩大该蛋白在食品中的用途,提高其生物活性,研究了酶法水解制备白果肽段的方法及其抗氧化活性的变化。通过单...白果活性蛋白(GAP)是华中农业大学天然产物化学实验室首次从白果中分离得到的一种以清蛋白为主的且具有显著生物活性的蛋白,为扩大该蛋白在食品中的用途,提高其生物活性,研究了酶法水解制备白果肽段的方法及其抗氧化活性的变化。通过单因素分析、正交试验以及对试验结果的分析,确定了2709碱性蛋白酶水解白果活性蛋白的最佳水解条件为:底物浓度1%,pH值8.5,水解温度45℃,酶浓度7000 U/g,反应时间6 h。以F en ton体系和邻苯三酚体系检验其抗氧化活性,结果表明白果肽段较酶解前的活性蛋白,抗氧化活性有不同程度的提高,但两者均具有较强的抗氧化活性。展开更多
基金the Natural Science Foundation of Guangxi Science and Technology Bureau, No.0542073
文摘BACKGROUND： The mechanisms of brain injury Following diabetes could be related to amyloid precursor protein （APP） mRNA overexpression. Studies have shown that Gingko biloba leaf extract （EGb） is effective in promoting functional recovery of the brain after traumatic injury. EGb is also effective in improving central nervous system plasticity and learning and memory functions of the elderly. OBJECTIVE： To study the effects of EGb on learning and memory, as well as hippocampal APP mRNA expression in the brains of diabetic rats, using Morris water maze behavioral testing and reverse transcription polymerase chain reaction （RT-PCR）, respectively. DESIGN： Complete random design, controlled experimental study. SETTING： Department of Pharmacology, Pharmaceutical School, Guangxi Medical University. MATERIALS： A total of 70 male Wistar rats （180-220 g）, 8 weeks old and specific pathogen free, were used for this study. GbE （containing 24.8% flavone glycosides and 6.2% diterpene lactone） was purchased from Guilin Sitejia Natural Plants Pharmaceutical Factory （Guangxi Province, Lot NO. 200405）. Streptozotocin was purchased from Sigma （USA）. Protamine zinc insulin injection was purchased from WANBANG Biochemical Pharmaceutical Co., Ltd. （Xuzhou Jiangsu, China）. METHODS： The experiment was performed in the Experimental Center of Guangxi Medical University from March to October 2005.（1） Experimental intervention： 70 rats were divided randomly into normal control group, diabetic model group （DM group）, diabetic model ＋10 μ g/kg insulin group （DM ＋ Ins group）, diabetic model ＋ 100 mg/kg ginkgo leaf extract group （DM ＋ EGb high-dose group）, and diabetic model ＋ 50 mg/kg ginkgo leaf extract group （DM ＋ EGb low-dose group）; there were 14 rats in each group. Rats with an intraperitoneal （i.p.） injection of citrate buffer solution （pH 4.4） served as the control group. To establish the diabetes model, rats were treated with i.p. injection of 55 mg/kg streptozotocin. Insulin （10 U/kg） was injected subcutaneously （s.c.） every day for 6 months in the DM group. EGb （100 mg/kg） and EGb （50 mg/kg） was administered intragastrically every day for 6 months in the DM ＋ EGb high-dose group and DM ＋ EGb low-dose group, respectively. The DM group and control group were administered distilled water intragastrically every day for 6 months. Drugs were administered once every morning. （2） Experimental evaluation： Six month after intervention, learning and memory of diabetic rats was tested by Morris water maze. Rats were allowed to train for 4 days, and the escape latency and platform-searching score were measured at days 5 and 8. Changes in hippocampal APP mRNA expression were measured with RT-PCR. MAIN OUTCOME MEASURES： Morris water maze performances and hippocampal APP mRNA expression in rats. RESULTS： A total of 70 Wistar rats were included in the final analysis, without any loss. （1） Learning and memory dysfunction of diabetic rats： After 4 days of Morris water maze training, escape latency was longer in the DM group on days 5 and 8, and the platform-searching score was lower in the DM group compared to the control group. In the DM ＋ EGb group, the escape latency score was shorter and platform-searching score was significantly increased compared to the DM group. （2） APP mRNA expression： in the hippocampus of diabetic rats, a 340 bp mRNA product was amplified, which is comparable to the APP mRNA amplification length of design. The expression of APP mRNA from the hippocampus of diabetic rats with learning and memory dysfunctions was significantly increased. EGb extract significantly inhibited the APP mRNA expression in these rats. CONCLUSION： EGb not only ameliorated the learning and memory dysfunctions in diabetic rats, but also significantly inhibited APP mRNA expression. Results from this study led to the hypothesis that diabetes could be one of the risk factors for AD.
基金the State Key Development Program for Basic Research of China (Grant No. 2003CB415003)
文摘The feasibility of gingko (Gingo Biloba) foliage as a passive bio-monitor for organochlorine pesticides in air was explored. The accumulation patterns of hexachlorocyclohexanes (HCHs), dichlorodiphenyl- trichloroethanes (DDTs) and hexachlorobenzene (HCB) in gingko foliage were similar; the amounts of HCHs, DDTs and HCB increased with foliage growth in spring and decreased thereafter. This accumu-lation pattern is likely related to the growing process of the gingko foliage, which was observed for the first time in our work, giving a piece of evidence for the "bud burst effect" in plants. Compared with those in pine needles in 1980's, the residual levels of HCHs and DDTs have declined obviously in Bei-jing, indicating that the ban on the production and use of organochlorine pesticides (OCPs) in our country is effective; however, the amount of HCB has increased, indicating great progress of chemical industry in Beijing. The analysis for the source of OCPs in the gingko foliage showed that the technical HCHs and DDTs were used largely in history, but were not used in recent years. A little lidane has been used and there was a new input of o,p′-DDT in recent years; dicofol usage may be the main source of o,p′-DDT. Concentrations of HCHs, DDTs and HCB in gingko foliages were similar to those in pine nee-dles in the corresponding period and there is a strong positive correlation between the OCPs concen-tration data obtained from these two kinds of trees. It presents no difference in the accumulation style between these two kinds of trees. The level of OCPs in the gingko foliage reflects the pollution status of OCP in air. The result of this work shows that the gingko foliage can be used as a bio-monitor of OCPs in air.
文摘白果活性蛋白(GAP)是华中农业大学天然产物化学实验室首次从白果中分离得到的一种以清蛋白为主的且具有显著生物活性的蛋白,为扩大该蛋白在食品中的用途,提高其生物活性,研究了酶法水解制备白果肽段的方法及其抗氧化活性的变化。通过单因素分析、正交试验以及对试验结果的分析,确定了2709碱性蛋白酶水解白果活性蛋白的最佳水解条件为:底物浓度1%,pH值8.5,水解温度45℃,酶浓度7000 U/g,反应时间6 h。以F en ton体系和邻苯三酚体系检验其抗氧化活性,结果表明白果肽段较酶解前的活性蛋白,抗氧化活性有不同程度的提高,但两者均具有较强的抗氧化活性。
