α-硫辛酸对H9 c2心肌细胞低氧及低氧/复氧损伤的保护作用及其机制探讨

目的：探讨α-硫辛酸(α-LA)对H9c2心肌细胞低氧及低氧/复氧损伤的保护作用及其作用机制。方法研究包括H9 c2心肌细胞低氧实验和低氧/复氧实验两部分,分成常氧组、低氧组或低氧/复氧组、LA组、乙醛脱氢酶抑制剂异黄酮苷(Daidzin)组(Daidzin组)、二甲亚砜(DMSO)溶剂对照组( DMSO组)。采用噻唑蓝( MTT)比色法检测心肌细胞存活率;微量酶标法测定乳酸脱氢酶( LDH)活性;ELISA法检测心肌细胞乙醛脱氢酶2(ALDH2)活性;硫代苯巴比妥酸法检测丙二醛( MDA)水平。结果与常氧组比较,低氧组及低氧/复氧组细胞存活率均下降(P<0．01),LDH活性及MDA含量均升高(P<0．01);与低氧组或低氧/复氧组比较, LA组细胞存活率上升( P <0．01)、ALDH2活性增加( P <0．05)、LDH活性及MDA含量降低(P<0．01);LA组、Daid-zin组、DMSO组3组比较, LA组与DMSO组间存活率、AL-DH2、LDH、MDA比较差异均无统计学意义( P>0．05);Daid-zin组与LA组、DMSO组比较,细胞存活率及ALDH2活性降低(P<0．05),LDH活性及MDA含量升高(P<0．05),差异均有统计学意义( P<0．05)。结论α-LA可通过上调AL-DH2活性并减少过氧化终产物形成,最终减轻心肌细胞低氧及低氧/复氧过程中的氧化损伤。     

葛根提取物治疗酒依赖的研究概况

葛根是巾国传统医学中最具代表性的解洒药物.国内外有关学者埘葛根及其提取物大豆苷和葛根素的抗洒依赖作用进行了深入的约理学研究,本文概述了目前的研究进展.     

培根胶囊的质量标准研究

目的:建立培根胶囊质量标准。方法:采用薄层色谱(TLC)法对大豆异黄酮和淫羊藿进行定性鉴别;用高效液相色谱法测定淫羊藿苷、大豆苷、大豆黄苷、染料木苷的含量。结果:TLC斑点清晰、分离度好,阴性无干扰;淫羊藿苷、大豆苷、大豆黄苷、染料木苷进样量分别在0.04～0.80(r=0.9998)、0.03～0.60(r=0.9998)、0.0076～0.1520(r=0.9996)、0.01～0.20(r=0.9997)μg范围内与其峰面积积分值呈良好的线性关系;淫羊藿苷、大豆苷、大豆黄苷、染料木苷的平均回收率分别为99.22%、97.61%、98.25%、98.46%,RSD分别为0.21%、1.64%、1.00%、1.32%(n均为9)。结论:所建标准可用于培根胶囊的质量控制。     

Suppressive Effects of Dietary Genistin and Daidzin on Rat Prostate Carcinogenesis

High intake of phytoestrogens through soybeans and their products is thought to be associated with low incidences of prostate and/or breast cancer in Asian countries. Possible chemopreventive effects of genistin or daidzin on rat prostate carcinogenesis were therefore investigated. Male F344 rats were given 10 biweekly subcutaneous injections of 3,2'-dimethyl-4-aminobiphenyl (DMAB) and then either genistin or daidzin in the diet at a concentration of 0.1% for 40 weeks. Other groups of rats given DMAB were treated with genistin or daidzin together with a high dose of testosterone propionate (TP). Both genistin and daidzin reduced the numbers of ventral prostate carcinomas (P<0.05), with a tendency for decrease in incidence. Invasive carcinomas which developed in the anterior prostate and seminal vesicles with TP were, however, not influenced by the two isoflavones. Thus, the present data suggest that genistin and daidzin possess anti-cancer effects at relatively early stages of prostate cancer development, providing experimental support for epide-miological findings.     

Mechanisms of the cerebral vasodilator actions of isoflavonoids of Gegen on rat isolated basilar artery

Ethnopharmacological relevance

Gegen (root of Pueraria lobata) is used in traditional Chinese medicine for treatment of cardiovascular diseases. In this study, the relaxant actions of three of its isoflavonoids; puerarin, daidzein, and daidzin, were investigated on rat-isolated cerebral basilar artery.

Materials and methods

Rat basilar artery rings were precontracted with 100 nM U46619. Involvement of endothelium-dependent mechanisms was investigated by mechanical removal of the endothelium and inhibitors of nitric oxide synthase (NOS) and cyclooxygenase (COX) enzymes. Adenylyl cyclase- and guanylyl cyclase-dependent pathways were investigated using their respective inhibitors 9-(tetrahydro-2-furanyl)-9H-purine-6-amine (SQ22536) and 1H-[1,2,4]oxadiazolo [4,3-[alpha]]-quinoxalin-1-one (ODQ). K⁺ channels were investigated by pretreatment of the artery rings with various K⁺ channel inhibitors, and Ca²⁺ channels were investigated in artery rings incubated with Ca²⁺-free buffer and primed with 100 nM U46619 for 5 min prior to adding CaCl₂ to elicit contraction.

Results

Puerarin, daidzein, and daidzin produced concentration-dependent relaxation of the artery rings with concentration that produced 50% inhibition (IC₅₀) of 304 ± 49 μM, 20 ± 7 μM, and 140 ± 21 μM, respectively. Removal of the endothelium produced no change on their vasorelaxant responses except the maximum response (I_max) to puerarin was inhibited by 28%. The NOS inhibitor N^G-nitro-l-arginine methyl ester (L-NAME; 100 μM) also produced 45% inhibition on the puerarin-induced vasorelaxant response, but not the COX inhibitor flurbiprofen (10 μM). SQ22536 (100 μM) and ODQ (100 μM) did not affect the vasodilator responses to puerarin, daidzein and daidzin, but glibenclamide (1 μM), tetraethylammonium (TEA, 100 mM) or a combination of K⁺ channel inhibitors (100 nM iberiotoxin + 1 mM 4-aminopyridine + 100 μM barium chloride + 1 μM glibenclamide + 100 mM TEA) reduced their I_max. The contractile response to CaCl₂ was attenuated by 61% and 34% in the presence of daidzein and daidzin, respectively, whereas, puerarin did not significantly affect the contraction.

Conclusions

The vasorelaxant action of daidzein and daidzin involved opening of K⁺ channels and inhibition of Ca²⁺ influx in the vascular smooth muscle cells. There is no evidence supporting involvement of endothelium-derived relaxing factors (EDRFs) in their actions. In contrast, puerarin produced vasodilatation via an endothelium-dependent mechanism involving nitric oxide production and an endothelium-independent pathway mediated by the opening of K⁺ channels. The cerebral vasodilator activities of all these three isoflavonoids may be beneficial to patients with obstructive cerebrovascular diseases.     

大豆苷及大豆苷元溶解吸收特性差异比较及相互作用研究

目的：考察大豆苷和大豆苷元的溶解吸收特性及两者共存条件下在溶解和吸收方面的相互影响。方法采用溶解度实验技术测定大豆苷和大豆苷元的平衡溶解度;采用大鼠在体单向肠灌流方法研究大豆苷元和大豆苷肠渗透性相互作用。结果在pH＝7.4的K-R试液中,大豆苷的溶解度约为大豆苷元的6倍,两者共存时溶解度均有所增强。大豆苷元在大鼠肠道内的吸收系数约为大豆苷的3倍,大豆苷对大豆苷元的吸收有显著性增强作用,但大豆苷元对大豆苷的吸收有抑制作用。结论大豆苷元的溶解度低于大豆苷,渗透性高于大豆苷。两者合用后大豆苷元的溶解度和渗透性均明显增强,大豆苷的溶解度增强不显著,且渗透性显著降低。     

RP-HPLC法测定药材黑豆中大豆苷的含量

目的：建立RP-HPLC法测定黑豆中大豆苷（Daidzin）的含量。方法色谱柱为cosmosil-C18柱（250mm＆#215;4.6mm,5μm）,流动相为乙腈：0.1%三氟乙酸溶液（12：88,v/v）,检测波长为254nm,柱温为25℃,流速为1.0mL/min。结果大豆苷质量浓度在1.11-88.8μg/mL内线性关系良好（R=0.9999）。大豆苷的平均回收率为99.99%,RSD为1.45%。结论该方法准确,重复性良好,适用于黑豆药材的质量控制。     

Daidzin, an Antioxidant Isoflavonoid, Decreases Blood Alcohol Levels and Shortens Sleep Time Induced by Ethanol Intoxication

The extract from an edible vine, Pueraha lebata has been reported to be efficacious in lessening alcohol intoxication. In this study, we have tested the efficacy of one of the major components, daidzin, from this plant extract. When ethanol (40% solution, 3 g/kg body weight) was given to fasted rats intragastrically, blood alcohol concentration (BAC) peaked at 30 min after alcohol ingestion and reached 1.77 ± 0.14 mg/ml (mean values ±sd , n = 6). If daidzin (30 mg/kg) was mixed with the ethanol solution and given to animals intragastrically, BAC was found to peak at 90 min after alcohol ingestion and reached only 1.20 ± 0.30 mg/ml (n = 6) (p < 0.05 vs. controls). The ability of daidzin to delay and decrease peak BAC level after ethanol ingestion was also observed in fed animals, in both fasted and fed rats given alcohol without daidzin, BAC quickly declined after reaching its peak at 30 min. By contrast, BAC levels receded more slowly if daidzin was also fed to the animals. Daidzin showed a chronic effect. Rats fed daidzin for 7 days before ethanol challenge, but not on the day of challenge, also produced lower and later peak BAC levels. Interestingly, daidzin, whether fed to rats only once or chronically for 7 days, did not significantly alter activities of either alcohol dehydrogenase or mitochondrial aldehyde dehydrogenase in the liver. Further experiments demonstrated that daidzin shortened sleep time for rats receiving ethanol intragastrically (7 g/ kg) but not intraperitoneally (2 g/kg). To test whether daidzin delayed stomach-emptying, [Clpolyethylene glycol was mixed with ethanol and fed to rats. It was found that, 30 min after intragastric feeding, more ethanol and [¹⁴C]polyethylene glycol remained in the stomach if rats were also given daidzin. Because daidzin is an isoflavonoid glucoside that possesses strong antioxidant activity, two other antioxidants (i.e., vitamin E and thioctic acid) were tested. Similar to daidzin, these two antioxidants also delayed and suppressed peak BAC, as well as shortened sleep time induced by alcohol ingestion. We conclude that: (1) daidzin is effective in countering alcohol intoxication; (2) suppression of BAC by daidzin is due mainly to delay of stomach-emptying, but not to accelerated clearance of ethanol in circulation by liver enzymes; and (3) the effect of daidzin may in part be due to its antioxidant activity.     

梯度洗脱高效液相色谱法同时测定大豆异黄酮中大豆苷和黄豆黄苷的含量

目的建立大豆异黄酮中大豆苷和黄豆黄苷的含量测定方法。方法采用高效液相色谱法,色谱柱为Phenomenex Luna C18(4.6 mm×250 mm,5μm),以乙腈、水混合体系为流动相,流速为1.0 mL/min,柱温25℃,检测波长为260 nm。结果大豆苷在49.3～147.9 mg/L浓度范围内、黄豆黄苷在40.1～120.3 mg/L浓度范围内,与峰面积呈良好的线性关系,相关系数分别为0.999 7和0.999 4。方法平均回收率分别为98.7%(RSD=0.38%)和98.9%(RSD=0.60%)。结论该方法简便、准确,重现性好,可作为大豆异黄酮质量控制方法之一。     

RP-HPLC法测定中药白英中大豆苷的含量

目的建立测定白英中大豆苷(Daidzin)含量的RP-HPLC法。方法色谱柱为Diamonsil-C18柱(250 mm×4.6 mm,5μm),流动相为乙腈-水-磷酸(16∶84∶0.1,v/v),检测波长为260 nm,柱温为35℃,流速为1.0 mL/min。结果大豆苷质量浓度在1.0～40.0μg/mL内线性关系良好(r=0.999 7)。大豆苷的平均回收率为100.1%,RSD为1.1%。结论该方法准确,重复性良好,适用于白英药材的质量控制。