Kudzu root: traditional uses and potential medicinal benefits in diabetes and cardiovascular diseases

Kudzu root (Gegen in Chinese) is the dried root of Pueraria lobata (Willd.) Ohwi, a semi-woody, perennial and leguminous vine native to South East Asia. It is often used interchangeably in traditional Chinese medicine with thomson kudzu root (Fengen in Chinese), the dried root of P. thomsonii, although the Chinese Pharmacopoeia has separated them into two monographs since the 2005 edition. For more than 2000 years, kudzu root has been used as a herbal medicine for the treatment of fever, acute dysentery, diarrhoea, diabetes and cardiovascular diseases. Both English and Chinese literatures on the traditional applications, phytochemistry, pharmacological activities, toxicology, quality control and potential interactions with conventional drugs of both species have been included in the present review. Over seventy phytochemicals have been identified in kudzu root, with isoflavonoids and triterpenoids as the major constituents. Isoflavonoids, in particular puerarin, have been used in most of the pharmacological studies. Animal and cellular studies have provided support for the traditional uses of kudzu root on cardiovascular, cerebrovascular and endocrine systems, including diabetes and its complications. Further studies to define the active phytochemical compositions, quality standards and clinical efficacy are warranted. Strong interdisciplinary collaboration to bridge the gap between traditional medicine and modern biomedical medicine is therefore needed for the development of kudzu root as an effective medicine for the management of diabetes and cardiovascular diseases.     

Utility of frozen cell lines in medium throughput electrophysiology screening of hERG and NaV1.5 blockade

Introduction

The development of drug candidates must take into account that many compounds have off-target activity against voltage-gated ion channels (VGIC) which may prevent their progression to market. Of particular concern are hERG and hNa_V1.5. Screening against these ion channels is necessary but expensive, partially due to maintenance of constantly cultured cell lines. Here, we show that frozen HEK-293 cells can be maintained indefinitely, reducing variability in cell performance, time and expense of cell culture.

Methods

Cells, constantly cultured or frozen, were assayed on the PatchXpress 7000A using tool compounds.

Results

Amitriptyline, quinidine, compound A, fluoxetine and imipramine inhibited hERG with IC₅₀s (paired values denote constantly cultured and frozen, respectively) of 4.8 ± 0.4 and 5.1 ± 0.4, 1.4 ± 0.1 and 1.1 ± 0.1, 24.4 ± 2.4 and 21.9 ± 1.8, 2.1 ± 0.4 and 2.1 ± 0.1, 5.2 ± 0.4 and 4.0 ± 0.2 μM. Quinidine, flecainide, mexiletine and amitriptyline inhibited hNa_V1.5 with IC₅₀s of 46.6 ± 4.3 and 28.0 ± 2.3, 7.6 ± 0.7 and 6.2 ± 0.5, 153.5 ± 13.0 and 106.0 ± 4.7, 5.5 ± 0.5 and 4.8 ± 0.2 μM. Voltage dependences of activation (V_1/2) for hERG were statistically identical, 0.4 ± 0.8 mV and 2.5 ± 0.5 mV. In hNa_V1.5, the V_1/2 of inactivation and activation were statistically identical, −82.7 ± 0.1 mV versus − 84.9 ± 0.3 mV, −47.5 ± 0.3 mV versus − 45.0 ± 0.6 mV. Current density in both conditions in hERG experiments was similar, 47.0 ± 4.1 pA versus 42.3 ± 6.0 pA/pF.

Discussion

hERG and hNa_V1.5 screens run using frozen cells have statistically identical IC₅₀s, voltage dependence of activation, IV relationships and current density to screens using continuously cultured cells. Frozen cells have more constant performance and allow rapid switching between experiments on several cell lines without sacrificing data quality.     

小鼠Stra8基因慢病毒表达载体的构建与鉴定

目的探讨GV341质粒构建小鼠Stra8基因的慢病毒表达载体的方法。方法应用PCR技术扩增目的基因,将扩增产物插入慢病毒质粒GV341,通过PCR筛选及测序对阳性克隆进行鉴定。将慢病毒表达载体转染至293T细胞后,提取转染细胞的总蛋白,用Western Blot法检测细胞中Stra8蛋白的表达情况。结果成功构建了GV341-Stra8慢病毒表达载体。结论 Stra8慢病毒表达载体的构建为体外研究Stra8基因的功能奠定了基础。     

Comparative potencies of 3,4-methylenedioxymethamphetamine (MDMA) analogues as inhibitors of [3H]noradrenaline and [3H]5-HT transport in mammalian cell lines

BACKGROUND AND PURPOSE: Illegal 'ecstasy' tablets frequently contain 3,4-methylenedioxymethamphetamine (MDMA)-like compounds of unknown pharmacological activity. Since monoamine transporters are one of the primary targets of MDMA action in the brain, a number of MDMA analogues have been tested for their ability to inhibit [3H]noradrenaline uptake into rat PC12 cells expressing the noradrenaline transporter (NET) and [3H]5-HT uptake into HEK293 cells stably transfected with the 5-HT transporter (SERT). EXPERIMENTAL APPROACH: Concentration-response curves for the following compounds at both NET and SERT were determined under saturating substrate conditions: 4-hydroxy-3-methoxyamphetamine (HMA), 4-hydroxy-3-methoxymethamphetamine (HMMA), 3,4-methylenedioxy-N-hydroxyamphetamine (MDOH), 2,5-dimethoxy-4-bromophenylethylamine (2CB), 3,4-dimethoxymethamphetamine (DMMA), 3,4-methylenedioxyphenyl-2-butanamine (BDB), 3,4-methylenedioxyphenyl-N-methyl-2-butanamine (MBDB) and 2,3-methylenedioxymethamphetamine (2,3-MDMA). KEY RESULTS: 2,3-MDMA was significantly less potent than MDMA at SERT, but equipotent with MDMA at NET. 2CB and BDB were both significantly less potent than MDMA at NET, but equipotent with MDMA at SERT. MBDB, DMMA, MDOH and the MDMA metabolites HMA and HMMA, were all significantly less potent than MDMA at both NET and SERT. CONCLUSIONS AND IMPLICATIONS: This study provides an important insight into the structural requirements of MDMA analogue affinity at both NET and SERT. It is anticipated that these results will facilitate understanding of the likely pharmacological actions of structural analogues of MDMA.     

PAX2慢病毒表达载体的制备及鉴定

目的 构建大鼠PAX2慢病毒表达载体,以期在大鼠肾脏中高效、稳定表达.方法 设计引物引入Age I酶切位点,使用PCR方法从质粒pcDNA3.1-PAX2中扩增小鼠PAX2基因的编码区序列,对所扩增出的目的片段回收纯化.用In-Fusion技术将Age Ⅰ内切酶消化后目的片段交换连接入Age Ⅰ酶切的pGC-FU载体,构建PAX2慢病毒表达载体pGC-FU-PAX2.酶切验证并测序正确后,将质粒pGC-FU-PAX2与慢病毒辅助包装载体共转染293T细胞,Western-blot验证PAX2在转染293T细胞中表达.结果 通过PCR扩增获得了PAX2基因,将PAX2克隆到慢病毒转移质粒pGC-FU中,并在293T细胞中包装产生慢病毒颗粒.结论 成功构建了PAX2慢病毒表达载体,为进一步从分子水平探讨PAX2功能奠定了基础.     

G418抗性HEK293细胞的培育

目的　培育具有G418抗性的HEK2 93细胞 ,用于建立猪内源性反转录病毒感染人HEK2 93细胞的模型。方法　通过脂质体转染的方法 ,将含有neo基因的质粒pIRESneo导入HEK2 93细胞中 ,利用G418的选择特性 ,对转染细胞进行压力筛选 ,并对其进行了PCR鉴定。结果　经 6 0 0 μg ml的G418压力筛选后 ,获得了抗性细胞克隆。抗性细胞的形态和生长速度与筛选前细胞没有差异 ,特异性核苷酸引物检测抗性细胞基因组DNA ,可以扩增出对应的核苷酸片段。结论　成功地培育了G418抗性HEK2 93细胞 ,为建立猪内源性反转录病毒感染人HEK2 93细胞的模型奠定了基础。     

载报告基因壳聚糖纳米粒制剂体外转染活性考察

目的 考察壳聚糖纳米粒体外基因转染活性及壳聚糖纳米粒经表面修饰的体外转染活性变化。方法 用复凝聚法制备纳米粒，透射电镜观察粒子形态，体外基因转染实验评价纳米粒的体外转染活性，用倒置荧光显微镜观察和流式细胞仪测定转染结果。通过考察递送不同剂量的基因和转染后不同时间的转染效率，寻找本递送系统较好的转染条件。用纳米粒表面连接PEG以及半乳糖基白蛋白，对纳米粒进行修饰，通过体外转染实验，评价表面修饰对其转染活性的影响。结果 未经表面修饰的载基因纳米粒能够转染人胚胎肾细胞(HEK293)和肝癌细胞(HepG2)，但转染效率仍不如脂质体转染试剂，且在转染实验后约72h较高，递送基因较佳的剂量是4μg，在以上两种细胞中，转染效率也不同。经PEG表面修饰的纳米粒仍保持纳米粒的体外转染活性。连接半乳糖基牛血清白蛋白的纳米粒转染活性却反而略有下降。结论 壳聚糖纳米粒能将基因递送到细胞内，并且报告基因能在细胞内表达。因此，可以用作基因递送的载体系统，值得进一步研究。经PEG表面修饰和冷冻干燥处理,保持生物活性．为基因药物制剂化的可能性提供了证据。对于靶向配基的选择．宜继续进行筛选。     

β-胡萝卜素对病毒转化细胞的影响

目的　探讨β-胡萝卜素 (β- C)对病毒转化细胞的抑制作用 .方法　体外培养人腺病毒转化的 2 93细胞和 EB病毒转化的 Raji细胞 ,培养时添加 0 ,10 ,5 0和 10 0 μmol· L- 1的β- C作用 2 4,48和 72 h后 ,进行细胞计数 ,测定细胞生长抑制率 ;EL ISA-结晶紫方法测定 A值 ,计算细胞存活量 ;采用快速 CPE(细胞病变 )方法测定复制缺陷型腺病毒在 2 93细胞上的病毒滴度 .结果　 10～ 10 0μmol· L- 1 的β- C对 2 93细胞和 Raji细胞均有抑制作用 ,细胞存活量减少 ,抑制率分别是15 .6 % ,10 .1% (10 μm ol· L- 1 ) ;19.7% ,2 2 .4% (5 0 μmol· L- 1 )和 33.6 % ,2 9.3% (10 0μmol· L- 1 ) ,P<0 .0 5 .快速CPE结果显示加入 β- C后 ,复制缺陷型腺病毒在其辅助细胞 -2 93细胞上的复制增殖能力明显下降 ,病毒滴度降低 ,空斑形成单位 (× 10 9pfu· L- 1 )分别为 98± 41(10μmol· L- 1 ) ,75± 2 9(5 0 μmol· L- 1 )和 6 3± 31(10 0 μmol· L- 1 ) ,与对照组 185±2 5 (0 μmol· L- 1 )相比 ,P<0 .0 5 .结论　 β- C对病毒转化的2 93细胞和 Raji细胞的生长增殖具有明显的抑制作用 ,对 2 93细胞内整合的腺病毒早期基因 E1的表达具有下调作用     

负载人microRNA-149的复制缺陷型腺病毒对人肝癌细胞株增殖的影响

目的 包装负载人microRNA-149的复制缺陷型腺病毒(Ad-miR149),并检测其对人肝癌细胞株增殖的影响.方法 全基因合成microRNA-149前体核苷酸序列,插入腺病毒穿梭质粒的多克隆位点,随后与包装质粒共转染人胚肾293细胞,包装负载microRNA-149的复制缺陷型腺病毒;采用MMT方法检测Ad-miR149对人肝癌细胞株增殖的影响.结果 成功包装负载人microRNA-149的复制缺陷型腺病毒,采用倍比稀释法检测病毒滴度为5× 109 pfu/ml.采用电子显微镜技术,观察到HEK293细胞中大量包装病毒颗粒.采用PCR扩增,Ad-miR149可获得腺病毒及microRNA-149特异片段,而对照Ad-LacZ只能扩增出腺病毒特异片段;采用MTT方法发现,Ad-miR149可显著抑制肝癌细胞株增殖.结论 成功包装负载人microRNA-149的复制缺陷型腺病毒并初步证实其对肝癌细胞增殖的抑制作用.