金荞麦根茎乙醇提取物抗氧化和对α-葡萄糖苷酶、α-淀粉酶的抑制作用

目的:研究金荞麦根茎乙醇提取物不同极性部位的体外抗氧化活性和α-葡萄糖苷酶、α-淀粉酶的抑制活性。方法:采用系统溶剂法梯度萃取金荞麦乙醇提取液,以获取不同极性部位的金荞麦提取物;采用DPPH、羟自由基和ABTS自由基清除实验对金荞麦根茎乙醇提取物不同极性部位的抗氧化活性进行研究,并以α-葡萄糖苷酶和α-淀粉酶为药物靶点,4-硝基苯-α-D-吡喃葡萄糖苷和淀粉为底物,阿卡波糖为阳性对照,筛选对α-葡萄糖苷酶和α-淀粉酶具有抑制作用的金荞麦根茎乙醇提取物部位。结果:在0~0.2mg/ml浓度范围内,金荞麦根茎乙醇提取物的乙酸乙酯萃取部位对DPPH、羟自由基和ABTS自由基具有很强的清除作用,但略低于维生素C的清除作用。在25mg/ml相同浓度下,金荞麦根茎乙醇提取物中正丁醇萃取部位、乙酸乙酯萃取部位和氯仿萃取部位对α-葡萄糖苷酶的IC50值均低于阳性对照阿卡波糖的IC50值,且抑制率均大于阿卡波糖的抑制率,乙酸乙酯萃取部位对α-淀粉酶的抑制率大于阿卡波糖的抑制率。在25mg/ml相同浓度下,金荞麦根茎乙醇提取物的5个不同萃取部位中,乙酸乙酯萃取部位对α-葡萄糖苷酶和α-淀粉酶的抑制作用最强(抑制率分别为为87.32%、84.57%)。在0~50mg/ml浓度范围内,金荞麦根茎乙醇提取物的不同萃取部位对α-葡萄糖苷酶和α-淀粉酶的抑制作用均呈剂量依赖关系。结论:金荞麦根茎乙醇提取物的乙酸乙酯萃取部位具有很好的抗氧化作用和α-葡萄糖苷酶、α-淀粉酶的抑制作用。     

甘草中α-葡萄糖苷酶抑制剂的初步研究

目的:从甘草中提取分离α-葡萄糖苷酶抑制剂.方法:将甘草水提取物依次用石油醚、乙酸乙酯、正丁醇萃取,然后测定各部分的酶抑制活性,对活性最强的部分进行酶抑制动力学研究.结果:石油醚部分、乙酸乙酯部分、正丁醇部分与剩余水提物部分的酶活性抑制率分别为68.93%、83.02%、32.17%和10.79%,与综合水提取物的酶活性抑制率69.77%相比,乙酸乙酯部分的活性最强,而且乙酸乙酯部分表现为一种快速的剂量依赖性的竞争性抑制类型,其Ki=34μg/ml.结论:乙酸乙酯部分存在较强的α-葡萄糖苷酶抑制活性成分,对其作进一步分离可望得到α-葡萄糖苷酶抑制单体成分.     

杠板归抗氧化作用及抑制α-葡萄糖苷酶活性

目的:考察杠板归抗氧化及抑制α-葡萄糖苷酶活性作用。方法:通过对ABTS自由基和DPPH自由基的清除能力及FRAP法对杠板归的抗氧化活性进行评价。应用体外α-葡萄糖苷酶筛选模型进行杠板归酶抑制活力的测定。结果:杠板归乙酸乙酯和甲醇提取物具有一定的抗氧化活性,其中甲醇提取物抗氧化活性最好,在ABTS、DPPH和FRAP方法中的Trolox当量分别为701.60±25.35,338.66±11.26,392.52±12.89μmolTE·g-1。杠板归3种提取物均具有很好的抑制α-葡萄糖苷酶活性作用,其中甲醇提取物活性最好,IC50值为16.14 mg·L-1。结论:杠板归甲醇提取物的抗氧化和抑制α-葡萄糖苷酶活性均最好,推测其可以用于糖尿病的治疗。     

西藏绿萝花提取物对α-葡萄糖苷酶的抑制及抗氧化作用

目的:研究西藏绿萝花提取物对α-葡萄糖苷酶的抑制及抗氧化作用.方法:将西藏绿萝花的70%乙醇提取物依次用石油醚、乙酸乙酯、正丁醇萃取,然后测定各部分对α-葡萄糖苷酶的抑制及抗氧化作用.结果:乙酸乙酯的萃取部分对α-葡萄糖苷酶的活性抑制较强,半数抑制浓度IC50为43.63 μg/mL,比阿卡波糖抑制α-葡萄糖苷酶的IC50值250 μg/mL低的多,抵制动力学表明为竞争性抑制,Ki值为21.49 μg/mL;乙酸乙酯及正丁醇萃取部分具有较强抗氧化作用,0.42 μg/mL的乙酸乙酯及正丁醇萃取部分对DPPH·自由基的清除率分别可达到88.5%、93.6%,与0.3 mg/mL的抗坏血酸对DPPH·自由基的清除率96.3%相当;乙酸乙酯萃取部分对氧自由基亦有一定的清除作用,IC50为0.27 mg/mL.结论:西藏绿萝花醇提取物的乙酸乙酯萃取部分有较强的α-葡萄糖苷酶抑制及抗氧化作用;正丁醇萃取部分有较强的抗氧化作用.     

几种灰兜巴提取物配伍对α-葡萄糖苷酶抑制作用的影响

目的研究中药灰兜巴石油醚、乙酸乙酯、正丁醇萃取部分、醇提萃取剩余部分和水提部分5部分对于α-葡萄糖苷酶活性的抑制作用。方法通过高效液相色谱法检测不同灰兜巴提取物单因素及相互配伍后对于α-葡萄糖苷酶活性的抑制作用。结果灰兜巴各部分提取物均表现出良好的α-葡萄糖苷酶抑制活性,不同比例提取物配伍后对于α-葡萄糖苷酶的抑制作用明显升高,通过DPS数据分析可得出,灰兜巴乙酸乙酯部分对于α-葡萄糖苷酶的抑制作用最强,配伍后最优化实验的抑制率可高达98.62%。结论证明灰兜巴具有良好的降糖疗效,且相互配伍有助于增强对于α-葡萄糖苷酶活性的抑制作用。     

琴叶榕根提取物对α-葡萄糖苷酶、α-淀粉酶的抑制作用

目的:研究琴叶榕根2种提取物对α-葡萄糖苷酶和α-淀粉酶活性的抑制作用。方法:采用超声辅助提取法制备琴叶榕根乙醇提取物,回流提取法制备琴叶榕根水提取物。以pNPG (对-硝基苯基-α-D-吡喃葡萄糖苷)和可溶性淀粉为底物分别测定琴叶榕根提取物对α-葡萄糖苷酶(酵母来源和小鼠小肠来源)和α-淀粉酶活性的影响。结果:琴叶榕根乙醇提取物和水提取物均具有较好的α-葡萄糖苷酶和α-淀粉酶抑制活性,其对酵母菌源α-葡萄糖苷酶的半数抑制浓度(IC50值)分别为:(128.13±3.28)、(1923.45±3.24)μg/mL;对小鼠小肠源α-葡萄糖苷酶的半数抑制浓度(IC50值)分别为:(531.04±5.72)、(2232.27±5.76)μg/mL;对α-淀粉酶的半数抑制浓度(IC50值)分别为:(714.25±4.37)、(1141.28±1.23)μg/mL。结论:琴叶榕根乙醇提取物抑制α-葡萄糖苷酶活性和α-淀粉酶均强于水提取物,有作为新型α-葡萄糖苷酶抑制剂开发价值。     

火绒草提取物对α-葡萄糖苷酶和胰岛素的影响

目的通过测定火绒草提取物在体外和糖尿病小鼠体内对ɑ-葡萄糖苷酶活力和胰岛素含量的影响,探讨火绒草降血糖成分的作用机制。方法以对硝基酚α-D吡喃葡萄糖苷(p NPG)为底物,分光光度测定ɑ-葡萄糖苷酶活力。酶联免疫吸附法(ELISA)测定胰岛素含量。结果火绒草的不同溶剂部位对α-葡萄糖苷酶活性均有抑制作用;不同浓度的乙醇洗脱物对α-葡萄糖苷酶活性也具有较强的抑制作用,30%乙醇洗脱物抑制率最高,并能使血清胰岛素含量显著增加。结论 30%乙醇洗脱物在体外和小鼠体内均能显著抑制α-葡萄糖苷酶活性,而且能显著促进小鼠胰岛β细胞分泌胰岛素。     

琴叶榕根提取物对α-葡萄糖苷酶、α-淀粉酶的抑制作用

目的:研究琴叶榕根2种提取物对α-葡萄糖苷酶和α-淀粉酶活性的抑制作用。方法:采用超声辅助提取法制备琴叶榕根乙醇提取物,回流提取法制备琴叶榕根水提取物。以pNPG (对-硝基苯基-α-D-吡喃葡萄糖苷)和可溶性淀粉为底物分别测定琴叶榕根提取物对α-葡萄糖苷酶(酵母来源和小鼠小肠来源)和α-淀粉酶活性的影响。结果:琴叶榕根乙醇提取物和水提取物均具有较好的α-葡萄糖苷酶和α-淀粉酶抑制活性,其对酵母菌源α-葡萄糖苷酶的半数抑制浓度(IC50值)分别为:(128.13±3.28)、(1923.45±3.24)μg/mL;对小鼠小肠源α-葡萄糖苷酶的半数抑制浓度(IC50值)分别为:(531.04±5.72)、(2232.27±5.76)μg/mL;对α-淀粉酶的半数抑制浓度(IC50值)分别为:(714.25±4.37)、(1141.28±1.23)μg/mL。结论:琴叶榕根乙醇提取物抑制α-葡萄糖苷酶活性和α-淀粉酶均强于水提取物,有作为新型α-葡萄糖苷酶抑制剂开发价值。     

虎杖提取物对α-葡萄糖苷酶的抑制作用

目的研究虎杖水溶性提取物对α-葡萄糖苷酶的作用。方法采用大孔吸附树脂柱色谱法进行虎杖水溶性总提取物初步分离,研究其总提取物和不同组分对α-葡萄糖苷酶活性的影响及其抑制反应的类型。结果虎杖总提取物(RRPC)与30%醇洗脱物(RRPCⅡ)对α-葡萄糖苷酶的IC50分别为74、15μg/mL,而蒸馏水(RRPCⅠ)、50%乙醇(RRPCⅢ)、70%乙醇(RRPCⅣ)、95%乙醇(RRPCⅤ)洗脱物的IC50均大于200μg/mL。结论RRPC及RRPCⅡ能显著抑制α-葡萄糖苷酶活性,RRPCⅡ的抑制机制为可逆性的非竞争性抑制。     

滇黄精及其活性成分群对α-糖苷酶活性抑制作用研究

目的:探讨滇黄精及其活性成分群对α-葡萄糖苷酶活性的抑制。方法:以4-硝基酚α-D-吡喃葡萄糖苷(pNPG)为底物,研究滇黄精不同提取成分对α-葡萄糖苷酶活性的抑制作用。结果:滇黄精及其不同提取物对α-葡萄糖苷酶都具有一定的抑制作用,其中小剂量的滇黄精总皂苷抑制率最明显,抑制率为34.2%;滇黄精生水提液次之,抑制率为27.7%;而其制水提液及其总多糖对α-葡萄糖苷酶的抑制作用不明显。结论:滇黄精总皂苷具有明显的α-葡萄糖苷酶抑制活性,可能为滇黄精降糖活性的主要物质基础。     

桑不同药用部位总生物碱对α-葡萄糖苷酶活性的抑制作用

目的:比较桑不同药用部位(桑叶、桑枝、桑白皮)总生物碱对α-葡萄糖苷酶活性的抑制作用。方法:采用采用蒸发光散射检测器(ELSD)-高效液相色谱法(HPLC)测定桑不同药用部位总生物碱中1-脱氧野尻霉素(DNJ)含量;以半数抑制浓度(IC 50)为评价指标,以阿卡波糖为阳性对照,以对-硝基苯基-α-D-吡喃葡萄糖苷为底物,采用体外抑制模型评价桑不同部位总生物碱对α-葡萄糖苷酶活性的抑制作用。结果:桑不同药用部位总生物碱中DNJ质量分数为桑白皮生物碱(30.1%)>桑枝生物碱(25.8%)>桑叶生物碱(21.4%)。桑不同药用部位总生物碱对α-葡萄糖苷酶抑制作用强度为桑枝生物碱>桑叶生物碱>桑白皮生物碱>阿卡波糖。结论:在桑枝、桑叶、桑白皮总生物碱中,以桑枝总生物碱对α-葡萄糖苷酶活性抑制作用最强,为桑资源开发辅助降血糖的药品和保健食品提供依据。     

In vitro studies of Gynura divaricata (L.) DC extracts as inhibitors of key enzymes relevant for type 2 diabetes and hypertension

Aim of the study

To evaluate traditionally used herb, Gynura divaricata (L.) DC (Bai Bei San Qi) as in vitro inhibitors of key enzymes involved in the pathogenesis of hyperglycemia and hypertension. We also determined the distribution of enzyme inhibitory activities in different aqueous and non-aqueous extracts.

Materials and methods

The water extract (extract 1) from the aerial parts of Gynura divaricata (L.) was prepared first and then partitioned sequentially with n-butanol, ethyl acetate, and macroporous adsorptive resin (HPD-40) to yield extracts 2-4; the remaining water phase was named extract 5. Angiotensin-1 converting enzyme (ACE), α-amylase α-glycosidase inhibitory activities of the extracts were determined in vitro and chemical composition including total sugar, protein, flavonoid and total alkaloids in the extract were also evaluated.

Results

The water extract of this herb significantly inhibited (p < 0.05) ACE activity (IC₅₀ = 0.37 mg/ml) and showed a moderate potential hypoglycemic effect via in vitro α-amylase (IC₅₀ = 1.36 mg/ml) and α-glycosidase (IC₅₀ = 2.17 mg/ml) inhibition in dose-dependent manner. Further partitioning of the water extract (extracts 2-4) resulted in higher α-amylase inhibitory activities in extract 2 and 3. For α-glycosidase inhibition, extract 3 gave the highest inhibition. ACE inhibitory activities of the extracts were not improved by partitioning. Sugar, protein, flavonoid and alkaloid were found in water extract but only a small portion was partitioned in the n-butanol extract. However, a large portion of the flavonoids and alkaloids were found in ethyl acetate extract.

Conclusion

The results confirmed potential empirical use of Gynura divaricata (L.) DC for the management of hyperglycemia as well as hypertension. The active compounds for inhibition of α-amylase and α-glycosidase inhibition were flavonoids and alkaloids while ACE inhibition probably resulted from synergic effects of all the herb compounds.     

麸煨肉豆蔻不同提取物对大鼠离体肠平滑肌的影响

目的研究麸煨肉豆蔻不同提取物对大鼠离体肠管自发活动的影响。方法采用RM6240B多道生理信号采集处理系统及大鼠离体十二指肠平滑肌进行实验,观察麸煨肉豆蔻不同提取物对离体肠运动功能的影响。结果麸煨肉豆蔻挥发油、醇提物、醇提物的石油醚提取物及乙酸乙酯提取物对离体大鼠十二指肠自主运动有抑制作用,抑制率分别为51.2%、29.2%、47.8%和59.2%(P<0.01);水提物、正丁醇提取物及醇提取物萃取后的水层无抑制作用。结论麸煨肉豆蔻的挥发油、醇提物的石油醚、乙酸乙酯提取物可能为麸煨肉豆蔻止泻的有效部位。     

不同干燥方式对桑枝提取物物理指纹图谱及其总黄酮含量的影响

目的:考察不同干燥方式对桑枝提取物物理指纹图谱及其总黄酮含量的影响。方法:分别采用常压干燥、减压干燥及冷冻干燥对桑枝浸膏进行干燥,并测定其总黄酮含量,构建以雷达图直观展现的桑枝提取物物理指纹图谱,对3种不同干燥方式所得桑枝提取物物理指纹图谱进行比较,通过可压参数比较不同干燥方式所得桑枝提取物的压缩特性。结果:不同干燥方式所得桑枝提取物对照物理指纹谱相似度77. 8%~87. 3%,一级指标平均值及可压参数的RSD处于0~16. 6%,除均一性及稳定性外,其余RSD均10%。不同干燥方式对桑枝提取物稳定性及均一性影响较大,对其他因素影响较小。结论:不同干燥方式对桑枝提取物物理指纹图谱有一定的影响,而对桑枝总黄酮含量影响较小。     

Cytotoxic, antioxidant and antibacterial activities of Varthemia iphionoides Boiss. extracts

The hexane, ethyl acetate, chloroform, ethanol and water extracts of aerial parts of Varthemia, Varthemia iphionoides, were investigated for cytotoxic activity against human myelocytic leukemia (HL-60) cells; DPPH radical-scavenging activity; antioxidative activity in the linoleic acid system; reducing power; antibacterial activity; the contents of phenolic compounds. A pronounced cytotoxic effect on human leukemia (HL-60) cells was shown in the hexane, chloroform and ethanol extracts, with inhibition of 89.0, 68.4 and 62.3%, respectively, at a concentration of 200 microg extract/ml. High DPPH radical-scavenging activity, antioxidative activity in the linoleic acid system and reducing power were found in the water and ethanol extracts, and were correlated to the contents of phenolic compounds. Antibacterial activity against Staphylococcus aureus, Bacillus subtilis, Micrococcus luteus, Escherichia coli, Bacillus cereus and Salmonella enteritides was shown in the ethyl acetate and chloroform extracts. A compound responsible for the antibacterial activity was isolated from the ethyl acetate extract, and identified as 3-oxocostusic acid.     

木香降血糖有效部位及有效成分研究

目的筛选木香中降血糖活性部位及主要成分。方法制备木香乙醇提取物,乙醇提取物醋酸乙酯部位、正丁醇部位和水提取部位;用HepG2细胞消耗葡萄糖模型和四氧嘧啶致糖尿病小鼠模型测定各提取物的降血糖活性;降血糖活性强的醋酸乙酯部位用柱色谱法继续分离、精制,得2个化合物,经NMR等鉴定化合物结构;并对2个化合物进行降血糖活性研究。结果木香醋酸乙酯部位有较强的降血糖作用,从木香醋酸乙酯部位中分离得到木香烃内酯和去氢木香内酯,且两者均可降低四氧嘧啶所致糖尿病小鼠的血糖,并显示很好的抗氧化作用。结论木香烃内酯和去氢木香内酯可能是木香的降血糖活性成分,抑制氧化应激从而减轻胰岛素抵抗可能是其降血糖机制。     

蒙药材悬钩子木不同溶剂提取物的镇咳祛痰作用比较研究

目的：探讨蒙药材悬钩子木不同方法提取物的镇咳、祛痰作用。方法：悬钩子木水I提取物、乙醇提取物、水Ⅱ提取物、乙醇提取物＋水Ⅱ提取物对小鼠连续灌胃给药,观察浓氨水引咳及气管酚红排泌的作用。结果：水I提取物明显延长氨水所致小鼠咳嗽潜伏期和减少咳嗽次数（P〈0．05）,增加小鼠气管酚红排泌量（P〈0．05）。结论：悬钩子木的水提物的镇咳、祛痰效果最好。     

柿叶不同极性部位对H22腹水瘤及H22,S180实体瘤小鼠的抑瘤作用

目的:研究柿叶不同极性部位对小鼠H22及S180抑瘤作用的影响。方法:柿叶乙醇提取物分别用三氯甲烷、乙酸乙酯、正丁醇萃取,得到相应不同极性部位;乙醇提取后的柿叶晾干后水煮,得水提部位。分别建立H22腹水瘤小鼠模型和H22,S180实体瘤小鼠模型,将荷瘤小鼠随机分为空白组,模型组,环磷酰胺组(0.1 g·kg-1),不同极性部位(柿叶三氯甲烷、柿叶水提、柿叶乙酸乙酯、柿叶正丁醇)高、中、低剂量组,连续ig 10 d。观察各用药组对H22腹水瘤小鼠腹围、腹水抑制率和肝组织病理学形态的影响,以及对H22和S180实体瘤小鼠摄食量、体重、抑瘤率、生命延长率、胸腺和脾脏系数等的影响。结果:与模型组比较,柿叶乙酸乙酯部位、水提部位和正丁醇部位能明显减少H22腹水瘤小鼠的腹水量,不同程度改善肝细胞肿胀、溶解等状况;不影响H22和S180实体瘤小鼠的摄食量,能明显提高荷瘤小鼠的抑瘤率、延长生命延长率,增加胸腺系数和脾脏系数(P<0.01,P<0.05)。结论:柿叶乙酸乙酯部位、水提部位和正丁醇部位对H22和S180荷瘤小鼠有不同程度的抑瘤作用,可为柿叶抑瘤作用的有效部位。柿叶乙酸乙酯部位对肝癌H22小鼠(包括实体瘤和腹水瘤)的影响比对肉瘤S180小鼠更显著。     

Antibacterial, anti-inflammatory, anti-cholinesterase and mutagenic effects of extracts obtained from some trees used in South African traditional medicine

Extracts obtained from 10 trees used in South African traditional medicine were screened for antibacterial, anti-inflammatory (COX-1 and COX-2) and anti-cholinesterase activities and investigated for potential mutagenic effects using the Ames test. Antibacterial activity was detected using the disc-diffusion and micro-dilution assays. The extracts were tested against Gram-positive bacteria: Bacillus subtilis, Staphylococcus aureus, Micrococcus luteus and Gram-negative bacteria: Escherichia coli and Klebsiella pneumoniae. Of the 78 different plant extracts investigated, 80% showed activity against both Gram-positive and Gram-negative bacteria in the disc-diffusion assay. In the micro-dilution assay, 60% of the plant extracts showed minimum inhibitory concentration (MIC) values < or =1.56 mg ml(-1). The lowest MIC value (0.092 mg ml(-1)) was recorded for an ethyl acetate root extract of Acacia sieberiana against Staphylococcus aureus and Escherichia coli. In the anti-inflammatory assay, 70% of the investigated plant extracts (0.25 mg ml(-1)) inhibited both COX-1 and COX-2 activity (>50% and 70% for water and organic solvent extracts, respectively). An ethyl acetate leaf extract of Trichilia dregeana showed selective inhibition of COX-2 (81%). In the acetylcholinesterase inhibitory test, 21% of the plant extracts were active at a concentration < or =1 mg ml(-1) using the micro-dilution assay. The lowest IC(50) value was 0.04 mg ml(-1) obtained with an ethanol bark extract of Combretum kraussii. None of the investigated plants showed any potential mutagenic effects.     

Modulatory effects of Artemisia annua extracts on human complement,neutrophil oxidative burst and proliferation of T lymphocytes

Air-dried aerial parts of Artemisia annua were extracted with petroleum ether, diethyl ether, ethyl acetate, ethanol and water successively. The extracts were screened for their in vitro effects on human complement, proliferation of T lymphocytes, and chemiluminescence by zymosan-stimulated polymorphonuclear leukocytes. All extracts exhibited dose-dependent inhibitory activities in our immunoassays. The highest activity towards the classical pathway of complement was found in ethyl acetate and ethanol extracts, whereas in the chemiluminescence assay, diethyl ether and ethyl acetate extracts showed the most pronounced inhibitory activities. In the T-cell proliferation assay, the diethyl ether extract exhibited the most potent inhibitory effect. Artemisinin showed no immunomodulatory activity in our assays.