Effect of ginsenoside Rb1 on long-term potentiation in the dentate gyrus of anaesthetized rats

Ginsenosides are the major principles of Panax ginseng and have various pharmacological actions on the central nervous system. In this report, we investigated whether ginsenoside Rb1 (10, 100 nmol l^-1, icv) could increase the population spike (PS) amplitude in a dose-dependent manner, and accelerate the maintenance phase of long-term potentiation (LTP) induced by high frequency stimulation (HFS) in the dentate gyrus of anaesthetized rats. However, it had no effect on basic synaptic responses evoked by test stimulation. Comparatively, ginsenoside Rb1 (10, 100 nmol l^-1, icv) inhibited the induction phase of LTP induced by HFS in a dose-dependent manner. This may be one of the mechanisms of action of ginsenoside Rb1 on synaptic transmission. The details of the mechanism need further investigation.     

Ginsenoside RB<Subscript>1</Subscript> the anti-ulcer constituent from the head of<Emphasis Type="Italic">Panax ginseng</Emphasis>

We previously reported that the butanol (BuOH) fraction of the head of Panax ginseng exhibited gastroprotective activity in peptic and chronic ulcer models. In order to identify the active constituent, an activity-guided isolation of the BuOH faction was conducted with a HCl x ethanol-induced gastric lesion model. The BuOH fraction was passed through a silica-gel column using a chloroform-methanol gradient solvent system, and six fractions (frs. 1-6) were obtained. The active fr. 5 was further separated by silica-gel column, to yield 6 subfractions (subfrs. a-f). Subfr. d was composed of ginsenosides Re, Rc and Rb1. The most active constituent was ginsenoside Rb1 (GRb1), a protopanaxadiol glycoside, which was investigated for its anti-ulcer effect. Gastric injury induced by HCl x ethanol, indomethacin and pyloric ligation (Shay ulcer) was apparently reduced with oral GRb1 doses of 150 and 300 mg/kg. GRb1 at these dosage significantly increased the amount of mucus secretion in an ethanol-induced model. The anti-ulcer effects were consistent with the result of histological examination. These results suggest that the major active constituent in the head of Panax ginseng is GRb1, and that anti-ulcer effect is produced through an increase in mucus secretion.     

人参皂苷Re促进自然衰老大鼠学习记忆作用及其机理的研究

目的研究人参皂苷Re对自然衰老大鼠学习记忆功能的影响,并初步探讨其作用机制。方法采用Morris水迷宫法观察人参皂苷Re对大鼠学习记忆功能的影响,同时采用电生理学方法观察人参皂苷Re对大鼠突触长时程增强(LTP)的作用。结果人参皂苷Re能显著对抗自然衰老引起的记忆获得障碍,对麻醉大鼠海马齿状回基础突触传递有增强作用,且能形成突触长时程增强形象。结论人参皂苷Re有改善大鼠学习记忆障碍的作用,该作用可能与其增强基础突触传递、促进LTP形成有关。     

人参皂甙Rg3联合三氧化二砷对人肝癌细胞增殖性的影响

目的探讨人参皂甙Rg3联合三氧化二砷对肝癌裸鼠移植瘤模型的治疗作用,观察其对移植瘤肝癌细胞增殖性的影响。方法采用人肝癌细胞株Bel-7402细胞,种植于32只雄性裸鼠皮下,随机分成联合用药组、Rg3组(5mg/kg、10mg/kg、20mg/kg)、三氧化二砷组及对照组。实验自肿瘤接种第3天开始,人参皂甙Rg3(3个剂量),隔日灌胃,共20次;三氧化二砷40μg.kg-1.d-1,每日腹腔内注射,连续28d;对照组为生理盐水。停药1周后,脱颈处死,完整取出瘤块,检测肿瘤的重量,计算抑瘤率。采用免疫组织化学法检测增殖细胞核抗原(PCNA)在裸鼠肝癌移植瘤组织中的表达情况。结果三氧化二砷组抑瘤率(55.25%)高于Rg3组(5mg/kg亚组为32.24%、10mg/kg亚组为45.10%,20mg/kg亚组为50.00%),但随着Rg3浓度的升高,二者之间的差异明显减小;联合用药组中,5mg/kg亚组平均瘤重(0.58±0.15)g,抑瘤率61.84%;10mg/kg亚组平均瘤重(0.54±0.11)g,抑瘤率64.47%;20mg/kg亚组平均瘤重(0.49±0.12)g,抑瘤率67.76%,其抑瘤作用高于三氧化二砷组,差异有统计学意义(P<0.05)。三氧化二砷组抑制肝癌细胞增殖作用(PI值:38.3±5.3)强于Rg3组(PI值:5mg/kg亚组58.1±2.4;10mg/kg亚组51.8±5.3;20mg/kg亚组41.9±6.5),联合用药组(PI值:5mg/kg亚组38.6±8.4;10mg/kg亚组30.9±3.2;20mg/kg亚组23.3±3.3)作用最强(P<0.05),可以明显抑制移植瘤肝癌细胞增殖性。结论三氧化二砷对裸鼠肝癌移植瘤生长的抑制作用可能是通过抑制PCNA蛋白的表达。人参皂甙Rg3与三氧化二砷联合用药对移植瘤肝癌细胞增殖性的抑制有协同作用。     

人参皂甙Rg3对免疫功能的影响

对人参皂甙Ｒｇ３的免疫功能进行了实验研究,结果表明：人参皂甙Ｒｇ３能明显提高小鼠碳粒廓清速率、免疫器官重量、血清溶血素含量、脾淋巴细胞转化和ＮＫ活性,其结果均具有显著性差异（Ｐ＜０．０５）,表明人参皂甙Ｒｇ３具有提高免疫功能的作用。     

吉林人参花蕾的化学研究(4)——人参皂甙Ro、Rb_1、Rf、Rg_1的分离与鉴定

继前文[1,2]报道从吉林人参(Panax ginseng C.A.Meyer)的花蕾中分离鉴定了七种人参皂甙(ginsenoside-Rb_2、-Rb_3、-Rc、-Rd、-Re、-Rg_2和20—glC—Rf)之后,又从中分离出五种人参皂甙(甙Ⅷ—Ⅻ)。通过测定其理化常数、IR、′H—NMR、~3C—NMR、EI—MS、FD—MS,制备衍生物,并与标准品对照鉴定了其中四种,甙Ⅷ、~1Ⅸ、Ⅸ、Ⅻ分别为ginsenoside-Ro、-Rb_1、-Rf和-Rg_1,另一种在鉴定中。ginsenoside-Ro(Ⅷ)和-Rf(Ⅻ)从人参花蕾中分离鉴定为首次报道。     

不同浓度人参皂甙Rd对次声性脑损害的保护

目的观察次声对大鼠记忆功能的影响及不同剂量人参皂甙Rd对其脑损害的治疗作用。方法通过Y型电迷宫训练将成绩相近的SD大鼠随机分为5个组，除正常对照组以外均接受16Hz 130dB的次声作用gh／d。3个药物组在次声作用前3d开始分别给予不同剂量（30mg／kg、10mg／kg、2mg／kg）的人参皂甙Rd。次声作用7d后再次评定每组大鼠的迷宫成绩，并用单链DNA（Single-stranded DNA，ssDNA）免疫标记法检测海马内ssDNA（凋亡细胞）数。结果与正常对照组相比单纯次声组大鼠学习记忆功能下降、标记的ssDNA阳细胞数明显增多（P〈0．05）；与单纯次声组相比人参皂甙（30mg/kg、10mg／kg组）有明显的保护作用，减轻了学习记忆功能下降，ssDNA阳性细胞数明显减少（P〈0．05）。结论16Hz 130dB次声可引发大鼠海马损伤、细胞凋亡、记忆功能减退，人参皂甙可明显减轻这些损害。     

Inhibitory Effects of Ginsenoside Rh2 on Tumor Growth in Nude Mice Bearing Human Ovarian Cancer Cells

Ginsenoside Rh₂ (Rh₂), isolated from an ethanol extract of the processed root of Panax ginseng CA Meyer, inhibits the growth of B16 melanoma cells. This study was designed to evaluate the ability of Rh₂ to inhibit growth of human ovarian cancer cells (HRA) in vitro and in nude mouse. Rh₂ inhibited proliferations of various established human ovarian cancer cell lines in a dose-dependent manner between 10 and 60 μM in vitro and induced apoptosis at around the IC₅₀ dose. When HRA cells were inoculated s.c. into the right flank of nude mice, all mice formed a palpable tumor within 14 days. Although i.p. administration of Rh₂ alone hardly inhibited the tumor growth, when Rh₂ was combined with cis-diamminedichloroplatinum(II) (CDDP) the tumor growth was significantly inhibited, compared to treatment with CDDP alone. When mice were treated p.o. with Rh₂ daily (but not weekly), the tumor growth was significantly (P<0.01) inhibited, compared to CDDP treatment alone. When Rh₂ was combined with CDDP, the degree of tumor growth retardation was not potentiated. The survival time was significantly (P<, we examined whether p.o. administration of Rh₂ has a dose-dependent inhibitory effect on the tumor growth. I.p. and weekly administration of CDDP had more potent antitumor activity in the order of 1 mg/kg, 2 mg/kg and 4 mg/kg, whereas p.o. and daily administration of Rh₂ (0.4 to 1.6 mg/kg) not only had antitumor activity comparable to that of 4 mg/kg CDDP, but also resulted in a significant increase of the survival. Doses of Rh₂ used in this study did not result in any adverse side-effects as confirmed by monitoring hematocrit values and body weight, unlike 4 mg/kg CDDP, which had severe side-effects. It is noteworthy that p.o. but not i.p. treatment with Rh₂ resulted in induction of apoptotic cells in the tumor in addition to augmentation of the natural killer activity in spleen cells from tumor-bearing nude mice. Thus, particularly in view of the toxicity of CDDP, Rh₂ alone would seem to warrant further evaluation for treatment of recurrent or refractory ovarian tumor.     

人参皂甙对中分子物质抑制红细胞ATP酶活性作用的影响

目的探讨人参皂甙对中分子物质(MiddleMolecularSubstance,MMS)抑制红细胞ATP酶活性作用的影响.方法采用健康SD大鼠红细胞体外孵育,在孵育体系中分别加入MMSⅢ和不同浓度的人参皂甙,观察人参皂甙对受MMSⅢ影响的红细胞Na+、K+-ATP酶、Ca2+-ATP酶的作用.结果人参皂甙可增强受MMSⅢ抑制的红细胞Ca2+-ATP酶活性(P<0.01),但对Na+、K+-ATP酶活性未发现有明显作用(P>0.05).结论人参皂甙可通过改善Ca2+-ATP酶活性抑制MMSⅢ对红系细胞的损伤作用.     

人参皂甙Rgl对帕金森病小鼠神经保护作用初探

目的 研究人参皂甙Rg1在对帕金森病(PD)黑质多巴胺能神经元凋亡的可能机制及其神经保护作用. 方法 采用神经毒素1-甲基4-苯基-1,2,3,6-四氢吡啶(MPTP)制备PD小鼠模型,免疫组织化学法与蛋白印迹法观察各组小鼠黑质酪氨酸羟化酶(TH)和促凋亡基因Caspase-3表达变化;原位末端标记法(TUNEL)观察黑质细胞凋亡数量变化. 结果 人参皂甙Rg1干预组黑质TH阳性神经元细胞丢失明显减轻(31% vs.55%)(P相似文献