In Vivo radioprotective effect of Panax ginseng C.A. Meyer and identification of active ginsenosides

This study evaluated the effect of water extracts of Panax ginseng C.A. Meyer (PG), panaxadiol (PD), panaxatriol (PT), ginsenoside Rb(1), Rb(2), Rc, Rd, Re and Rg(1) on jejunal crypt survival, endogenous spleen colony formation and apoptosis in jejunal crypt cells in gamma-irradiated mice. Jejunal crypts were protected by pretreatment with PG, Rc and Rd. Administration of PG, PD, Rd and Re prior to irradiation resulted in an increase in the formation of endogenous spleen colonies. The frequency of radiation-induced apoptosis in intestinal crypt cells was also reduced by pretreatment with PG, PD, Rb(2), Rc, Rd, Re and Rg(1). In experiments on the effects of the individual ginsenosides, the rank order of activity was Rc > Rd > Rg(1) > Rb(2) > Re > Rb(1) on intestinal crypt survival assay, Re > Rb(2) > Rd > Rg(1) > Rb(1) > Rc on the spleen colony formation assay, and Rg(1) > Re > Rd > Rc > Rb(2) > Rb(1) on inhibiting the death of cells caused by apoptosis. The results indicated that Rc, Rd and Re may have a major radioprotective effect in mice irradiated with high and low doses of radiation. When the same experiments were performed using PD and PT, it was observed that most of the inhibitory effects came from PD rather than PT.     

Induction of apoptosis by the ginsenoside Rh2 by internalization of lipid rafts and caveolae and inactivation of Akt

Background and purpose:

Lipid rafts and caveolae are membrane microdomains with important roles in cell survival signalling involving the Akt pathway. Cholesterol is important for the structure and function of these microdomains. The ginsenoside Rh2 exhibits anti-tumour activity. Because Rh2 is structurally similar to cholesterol, we investigated the possibility that Rh2 exerted its anti-tumour effect by modulating rafts and caveolae.

Experimental approach:

A431 cells (human epidermoid carcinoma cell line) were treated with Rh2 and the effects on cell apoptosis, raft localization and Akt activation measured. We also examined the effects of over-expression of Akt and active-Akt on Rh2-induced cell death.

Key results:

Rh2 induced apoptosis concentration- and time-dependently. Rh2 reduced the levels of rafts and caveolae in the plasma membrane and increased their internalization. Furthermore, Akt activity was decreased and consequently, Akt-dependent phosphorylation of Bad, a pro-survival protein, was decreased whereas the pro-apoptotic proteins, Bim and Bax, were increased upon Rh2 treatment. Unlike microdomain internalization induce by cholesterol depletion, Rh2-mediated internalization of rafts and caveolae was not reversed by cholesterol addition. Also, cholesterol addition did not restore Akt activation or rescue cells from Rh2-induced cell death. Rh2-induced cell death was attenuated in MDA-MB-231 cells over-expressing either wild-type or dominant-active Akt.

Conclusions and implications:

Rh2 induced internalization of rafts and caveolae, leading to Akt inactivation, and ultimately apoptosis. Because elevated levels of membrane rafts and caveolae, and Akt activation have been correlated with cancer development, internalization of these microdomains by Rh2 could potentially be used as an anti-cancer therapy.     

HPLC法测定化瘀无糖颗粒中人参皂苷Rg_1、Re含量

目的:建立化瘀无糖颗粒中人参皂苷Rg1、Re含量的HPLC测定方法。方法 :色谱柱:Phenomenex Luna C18(4.6×250 mm,5μm);流动相:乙腈-0.1%磷酸水梯度洗脱;流速:1.0 mL/min;检测波长:203 nm;柱温:25℃。结果:人参皂苷Rg1线性范围为0.326～5.23μg(r=0.999 9),平均回收率99.38%(RSD 0.98%,n=6);人参皂苷Re线性范围为0.118～1.904μg(r=0.999 8),平均回收率99.08%(RSD 1.66%,n=6)。结论:样品处理方法合理,方法学考察符合定量要求,结果准确,可用于化瘀无糖颗粒中人参皂苷Rg1、Re的含量测定。     

人参皂苷Rb1和罗格列酮联合用药对2型糖尿病痴呆小鼠记忆功能的影响及机制

目的: 研究人参皂苷Rb₁和罗格列酮联合用药对2型糖尿病记忆障碍小鼠动物学习记忆能力及胰岛素信号通路的影响. 方法: 雄性10周龄C57BL小鼠16只为正常组(N组),雄性10周龄Kkay小鼠64只为模型组,高糖高脂饲料喂养6周后,检测随机血糖≥13.9 mmol·L^-1后随机分为模型组(M组)、阳性组(P组)、联合给药高、中、低剂量组(C1,C2,C3组).P组每天用马来酸罗格列酮片按3.0 mg·kg^-1灌胃,C组每天用马来酸罗格列酮片(3.0 mg·kg^-1)和人参皂苷Rb₁(60,30,15 mg·kg^-1)灌胃,N组和M组每天用等体积生理盐水灌胃,持续42 d.给药前后分别进行1次Morris水迷宫试验,记录结果并做比较.水迷宫后及时于冰上开颅取海马.采用酶联免疫吸附剂测定(ELISA)小鼠血浆胰岛素水平;半定量反转录-聚合酶链反应(RT-PCR)检测小鼠大脑海马中1-磷脂酰肌醇-3激酶亚基p85(PI-3K/p85)的信使核糖核酸(mRNA)表达水平. 结果: 与正常组相比,模型组在水迷宫试验中寻找平台的时间及错误率明显偏高(P<0.05),血浆胰岛素水平和PI-3K/p85水平均明显升高(P<0.05);与模型组相比,罗格列酮组与之各项指标差异均不明显,复合给药组平台潜伏期均明显降低(P<0.05),血浆胰岛素水平和PI-3K/p85水平均明显降低(P<0.05). 结论: 人参皂苷Rb₁能在改善血浆胰岛素水平的基础上,有效提高胰岛素抵抗型糖尿病记忆障碍小鼠学习、记忆能力,其可能的作用机制为通过降低PI-3K/p85表达水平改善大脑海马胰岛素信号传导通路.     

人参皂苷对创伤后脓毒症大鼠糖皮质激素受体的影响

目的研究人参皂苷对创伤脓毒症后糖皮质激素受体（GR）的影响。方法采用大鼠烫伤面积为30％总体表面积,深度为Ⅲ度,烫伤后12h经腹腔注射内毒素5mg／kg予以“二次打击”,用放射配体法研究人参皂苷对肝胞液GR结合活性和外周血白细胞GR结合容量的影响。结果“二次打击”后大鼠肝胞液GR结合活性和外周血白细胞GR结合容量显著下降,此过程随时间加重,各时相点与对照组比较差异非常显著（P〈0．01）;24、72h人参皂苷组肝胞液GR结合活性和外周血白细胞GR结合容量显著高于脓毒症组（P〈0．01）,但仍显著低于对照组（P〈0．01）。结论烫伤和内毒素“二次打击”后肝胞液GR的结合活性和外周血白细胞GR结合容量显著下降,人参皂苷能提高创伤后脓毒症大鼠肝胞液GR的结合活性和外周血白细胞GR结合容量,拮抗炎症反应。     

基于1H-NMR的人参总皂苷治疗缺血性脑中风的血清代谢组学研究

课题组基于1H-NMR研究人参总皂苷对大脑中动脉闭塞(MCAO)模型大鼠血清代谢组的影响。实验将48只Wistar雄性大鼠随机分为6组:假手术组、模型组、阳性药组(6 mg·kg-1·d-1)和人参总皂苷高、中、低剂量组(200,100,50 mg·kg-1·d-1)。实验采用预给药,造模前连续给药5 d,末次给药后2 h,开始造模,采用改良的Longa线栓法制备大脑中动脉闭塞(MCAO)模型,假手术组只暴露左侧血管不做插线处理,所有大鼠只栓塞左侧大脑中动脉。2 h后轻轻撤出线栓,术后观察大鼠的外观,反应和活动情况,并进行神经症状评分。术后24 h各组眼后静脉丛采血,一定方法处理后采集1H-NMR谱,并用主成分分析方法对其进行分析。与假手术组比较,模型组的乳酸、谷氨酸、牛磺酸、胆碱、葡萄糖、蛋氨酸的含量显著升高(P<0.05),3-羟基丁酸、脂质和磷酸肌酸/肌酸的含量显著性降低(P<0.05)。与模型组比较,人参皂苷组的脂质、3-羟基丁酸酯、磷酸肌酸/肌酸含量显著增加(P<0.05),柠檬酸、胆碱、牛磺酸、葡萄糖和蛋氨酸的含量有变化,但没有显著性差异,乳酸和谷氨酸显著性降低(P<0.01)。结果表明人参总皂苷对大鼠脑缺血再灌注有保护作用,也可以调节代谢紊乱,促进新陈代谢回归表型到正常范围。     

Insights into gastrointestinal microbiota-generated ginsenoside metabolites and their bioactivities

Abstract

The gastrointestinal microbiota and host co-evolve into a complex ‘super-organism,’ and this relationship plays a vital role in many physiological processes, such as drug metabolism. Ginseng is an important medicinal resource and the main ingredients are ginsenosides, which are less polar, difficult to absorb, and have low bioavailability. However, studies have shown that the biological activity of ginsenosides such as compound K (CK), ginsenoside Rg3 (Rg3), ginsenoside Rh2 (Rh2), 20(S)-protopanaxatriol (20(S)-PPT), and 20(S)-protopanaxadiol (20(S)-PPD) is closely related to the gastrointestinal microbiota. In this paper, the metabolic pathway of gastrointestinal microbiota-generated ginsenosides and the main pharmacological effects of these metabolites are discussed. Furthermore, our study provides a new insight into the discovery of novel drugs. Specifically, in new drug screening process, candidates with low biological activity and bioavailability should not be excluded. Because their metabolites may exhibit good pharmacological effects due to the involvement of the gastrointestinal microbiota. In addition, in further research studies to develop probiotics, a combination of agents could exert greater efficacy than single agents. Moreover, differences in lifestyle and diet lead to differences in the gastrointestinal microbiota in the human body. Therefore, administration of the same drug dose to different individuals could elicit different therapeutic effects, owing to the involvement of the gastrointestinal microbiota. Thus, treatment accuracy could be achieved by detecting the gastrointestinal microbiota before drug treatment.

• Highlights

• Gastrointestinal microbiota plays a decisive role in bioactivities of ginsenosides.

• The metabolic pathway and main pharmacological effects of ginsenoside metabolites are discussed.

• It provides new insights into novel drug discovery and further research to find probiotic, combinations to exert greater efficacy.

• Differences in lifestyle and diet, varies the gastrointestinal microbiota in the human body. However, the same dose of a drug producing different therapeutic effects may involve gastrointestinal microbiota.

     

大鼠下丘脑神经元L-型Ca通道特性与Ba浓度关系的研究

目的:研究不同浓度Ba²⁺情况下,新生大鼠下丘脑神经元L-型Ca²⁺通道单通道特性。方法:采用神经元的急性分离技术;用膜片钳细胞贴附式记录方式进行研究。结果:110mmol/LBa²⁺为载流子与10mmol/LBa²⁺为载流子时,单通道活动不同、电导不同,分别为28.6pS和19.1pS,平均开放概率也明显不同。结论:L-型Ca²⁺通道单通道电导、平均开放概率、激活与失活等电生理特性存在明显的Ba²⁺浓度依赖性。     

人参皂苷Rg1调控TLR4/NF-κB信号通路抗重症肺炎大鼠心肌组织损伤的机制探讨

目的　探讨人参皂苷Rg1对重症肺炎大鼠心肌组织损伤的影响及其机制。方法　将40只大鼠以气管注入肺炎克雷伯菌液法构建重症肺炎模型后,将其均分为模型组和低、中、高剂量药物组;另取10只未处理大鼠作为对照组。低、中、高剂量药物组大鼠以2.5、5和10 mg/kg人参皂苷Rg1灌胃,模型组和对照组大鼠以等量生理盐水灌胃,每日1次,持续14 d。苏木精-伊红染色法观察大鼠心肌组织病理形态并行积分统计;采用心脏彩超检测大鼠心功能指标,包括左室舒张压（LVDP）、左室舒张末压（LVEDP）、左室最大舒张速率（-dP/dtmax）和左室最大收缩速率（+dP/dtmax）值;酶联免疫吸附测定（ELISA）法检测血清中B型钠尿肽（BNP）、肌钙蛋白I（cTnI）和肌酸激酶同工酶MB（CK-MB）含量;实时荧光定量PCR（qPCR）法检测心肌组织中白细胞介素（IL）-6、IL-1β和肿瘤坏死因子-α（TNF-α）mRNA表达水平;蛋白免疫印迹法（Western blot）检测心肌组织中凋亡相关蛋白活化的含半胱氨酸的天冬氨酸蛋白酶3（cleaved caspase-3）和非活性态（procaspase-3）、Bcl-2、Bcl-2相关X蛋白（Bax）、Toll样受体4（TLR4）、髓样分化因子88（MyD88）、核因子-κB（NF-κB）p65和磷酸化（p）-NF-κB p65蛋白表达水平。结果　对照组大鼠心肌组织结构正常,模型组大鼠心肌组织中心肌细胞排列紊乱且肿胀变形,肌纤维部分断裂且伴随有炎性细胞浸润;相对模型组,低、中、高剂量药物组大鼠心肌组织中上述细胞形态变化明显改善。与对照组比较,模型组大鼠心肌组织病理积分,LVEDP水平,BNP、cTnI、CK-MB含量和IL-6、IL-1β、TNF-α mRNA水平,cleaved caspase-3/procaspase-3和Bax/Bcl-2比值以及TLR4、MyD88、p-NF-κB p65蛋白表达水平均明显升高,而LVDP、-dP/dtmax和+dP/dtmax水平明显降低（P＜0.05）;以人参皂苷Rg1灌胃干预后可呈剂量依赖性逆转建模引起的上述变化（P＜0.05）。结论　人参皂苷Rg1可通过减轻炎症反应和心肌细胞凋亡保护重症肺炎大鼠心肌组织,其作用机制可能与抑制TLR4/NF-κB信号通路活化有关。     

人参皂苷Rg3对H2O2诱导人卵巢颗粒细胞氧化应激损伤的保护作用#br#

摘要：目的　探讨人参皂苷Rg3对过氧化氢（H2O2）诱导人卵巢颗粒细胞（KGN）损伤的保护作用及其可能的作用机制。方法　体外培养KGN,采用不同剂量H2O2孵育细胞2 h,建立H2O2刺激的KGN损伤模型。人参皂苷Rg3预处理24 h,H2O2刺激KGN后,CCK-8检测细胞活力,筛选有效的干预剂量,随后将KGN分为空白组、H2O2模型组、H2O2+Rg3组和Rg3组,采用DCFH-DA荧光探针检测细胞内活性氧（ROS）水平;AnnexinⅤ/PI双染,流式细胞术检测人参皂苷Rg3对H2O2诱导KGN凋亡的影响;Western blot检测凋亡相关蛋白Bcl-2、BAX及细胞色素C的表达。结果　与空白组相比,H2O2模型组细胞活力下降,凋亡比例升高（P＜0.01）,ROS水平增高,细胞色素C水平显著升高,Bcl-2/BAX降低（均P＜0.05）。与模型组相比,H2O2+Rg3组能够明显提高细胞活力,减少ROS的产生,降低凋亡细胞比例,降低细胞色素C水平,提高Bcl-2/BAX（均P＜0.05）。与空白组相比,Rg3组无明显差异。结论　人参皂苷Rg3预处理对H2O2诱导的KGN氧化损伤具有保护作用,其机制与减缓ROS过量累积以及抑制线粒体凋亡途径有关。