Toxicity and anthelmintic efficacy of crude aqueous of extract of the bark of Sacoglottis gabonensis

The water extract of the stem bark of Sacoglottis gabonensis was evaluated for its preliminary acute toxicity and anthelmintic efficacy against gastro-intestinal nematodes of small ruminants and mice in both in vitro and in vivo studies. Intra-peritoneal administration of doses ranging from 400 to 3200 mg/kg of the aqueous stem bark extract produced varying degrees of toxicity manifested as depression, drowsiness and unsteady gait, paralysis of the hind limbs, dyspnoea, coma and death. The pathological lesions noted at necropsy were mainly congestion and edema of the lungs, bronchi and bronchioles and hepatomegally with focal necrosis of liver cells. The severity of the clinical symptoms and pathological lesions were dose-related. In the in vitro study, the extract significantly (P<0.05) reduced the hatching of strongyline nematode eggs from naturally infected small ruminants. The 100 mg/ml concentration of the extract produced the highest (94.4%) inhibition on nematode egg hatch and the result was comparable to similar effect produced by either levamisole (100% at 15 mg/ml) or albendazole (99.7% at 6.25 mg/ml). In rats experimentally infected with Heligmosomoides polygyrus, treatment with the S. gabonensis stem bark aqueous extract significantly (P<0.05) reduced adult worm burden and completely inhibited faecal egg output 5 days post treatment.     

Inhibitory effect of Ipomoea aquatica extracts on glucose absorption using a perfused rat intestinal preparation

Investigations were carried out to evaluate the effect of Ipomoea aquatica aqueous and dichloromethane/methanol extracts on the glucose absorption using a rat intestinal preparation in situ. Extracts orally tested at the dose of 160 mg/kg exerted a significant inhibitory effect on glucose absorption when compared with control animals. The most pronounced effect was observed with the aqueous extract. Ouabain used as reference inhibitor strongly inhibited glucose absorption. On the other hand both plant extracts inhibited the gastrointestinal motility suggesting that the inhibition of glucose absorption is not due to the acceleration of intestinal transit.     

Relaxant effect of aqueous extract of Cistus ladaniferus on rodent intestinal contractions

The effects of the aqueous extract of Cistus ladaniferus leaves and stems were studied on the rodent isolated jejunum. The extract produced a reversible concentration dose-dependent (0.1-3 mg/ml) inhibition of the spontaneous motility of the rabbit jejunum. The inhibitory effects of the extract were not affected by pretreatment with the inhibitors of the alpha and beta adrenergic receptors yohimbine, prazosin or propranolol. The extract also inhibited K(+)-induced contractions in rabbit and rat jejunum at a similar concentration range. This result suggests that the antispasmodic action of the extract is mediated through calcium channel blockade. The results confirm the traditional use of C. ladaniferus in treating intestinal ache.     

卷叶黄精根不同极性化感物质的化感作用

化感作用是植物通过淋溶、挥发、残茬降解和根系分泌向环境中释放化学物质,从而对自身或周围其他植物的生长产生影响的现象(孔垂华等,2001;董卓杭等,2001;翟明普等,1993;林文雄等,2001;马茂华等,1999;彭少麟等,2001).化感作用普遍存在于自然界,对其深入研究将有利于复合系统中植物配置、耕作制度和栽培措施的科学化,在植物间加强促进作用,降低抑制作用,促进生物多样性和农业可持续发展.     

天然膨润土吸附Cu2+的动力学、等温线及热力学研究

文章讨论了不同影响因素如接触时间、振荡速度、膨润土用量、初始离子浓度、初始pH、温度等对膨润土吸附性能的影响,研究了Cu2+在天然膨润土上吸附的动力学、等温线和热力学理论。动力学研究数据表明,吸附满足准二级动力学模型,吸附初始阶段受界面扩散控制,45 min后受粒子内扩散控制;吸附满足Freundlich等温线模型;吸附是一个自发的、吸热的过程,而且反应不可逆。     

杜仲叶提取物的抑菌活性研究

为了发现新的抑茵材料,对杜仲叶70％(体积分数)乙醇提取物及其分级组分进行了抑菌试验.结果显示:杜仲叶的乙醇和乙酸乙酯提取物对细菌和真茵都有抑制作用,而且乙酸乙酯提取物对黄曲霉和黑曲霉有特殊的抑制特征;正丁醇和水提取物对细菌有抑制作用,但对真菌几乎没有抑制作用;石油醚提取物几乎对细菌和真茵都没有抑制作用.最大抑茵圈直径超过了10 mm,最小抑茵浓度(MIC)在0.25％～3.0％之间.杜仲叶提取物在抑菌活性方面具有一定的热稳定性,抑茵率随时间而逐渐增加,16 h之后基本保持不变.     

Monitoring the antioxidant activity of extracts originated from various Serratula species and isolation of flavonoids from Serratula coronata

The antioxidant effect of aqueous methanolic herb extracts of Serratula coronata, S. wolffii and S. tinctoria was investigated using both enzyme-dependent and enzyme-independent systems. The extracts displayed concentration-dependent inhibition of lipid peroxidation. Flavonoids and ecdysteroids present in the extracts were evaluated as antioxidant components. The flavonoid-containing fraction of the herb extract of S. coronata was more effective in lipid peroxidation than the ecdysteroid-containing fraction. This paper also reports the isolation of quercetin 3-O-methyl ether, apigenin, luteolin, quercetin, luteolin 4'beta-D-glucoside and quercetin 4'beta-D-glucoside from S. coronata.     

高山栲水提液对云南松种子发芽的化感效应

为了解混交树种高山栲对云南松的化感作用,用高山栲各器官水提液对云南松种子的发芽进行处理。结果表明,高山栲鲜叶、枝干、树皮、树根,枯落叶水提液对云南松种子的发芽和芽的生长均有一定的影响。所有样品的水提液均表现出在高浓度下对云南松种子发芽和芽的生长有明显抑制作用,随着水提液浓度减小,抑制作用减弱、消失甚至转变为促进作用的规律;其中枝干和鲜叶水提液对云南松种子发芽和芽的生长作用强度最大;发芽效果不同指标对高山栲各器官水提液作用的敏感性次序是:鲜重>根长>发芽率>胚轴长。说明在营造云南松和高山栲混交林时,高山栲比例适当减小将有利于云南松的天然更新和生长。     

蓝桉水提液对蓝桉种子发芽的化感效应

分析了蓝桉枯叶、鲜叶、树枝、树皮、树根1∶50、1∶100、1∶200、1∶400的水提液对蓝桉种子发芽的化感效应。结果表明,除蓝桉各器官的水提液对发芽率大多数起促进作用,树根、树枝及树皮的水提液对鲜重的影响均表现为促进作用外;高浓度的水提液对芽及幼苗的生长有明显的抑制作用,表现在幼苗茎严重卷曲和呈倒伏状,且随着水提液浓度减小,抑制作用减弱,有的消失甚至转变为促进作用,继而幼苗生长恢复正常;鲜叶、枯叶水提液对蓝桉幼苗胚根长、总长的抑制作用强度大于其它器官,枯叶和树根水提液对种子发芽率起促进作用的强度比其它器官大,树根水提液对鲜重的促进作用强度比其它器官大。     

Immunomodulatory activities of fractions from hot aqueous extract of wood from Clausena excavata

The effects of fractions from hot aqueous extract, acetone extract and the folklore preparation of Clausena excavata were studied on mouse splenocyte proliferation. The fractions of hot aqueous and acetone extracts were found to be the most active. On the contrary, the fractions from the crude folklore preparation resulted less active. This result could partly explain the popularity of this plant in folk medicine as a remedy for cancer and HIV patients in the eastern part of Thailand.     

Hypoglycemic activity of Abutilon indicum leaf extracts in rats

Alcohol and water extracts of Abutilon indicum leaves (400 mg/kg, p.o.) showed significant hypoglycemic effect in normal rats 4 h after administration (23.10% and 26.95%, respectively).     

Pesticidal Activity of the Leaf and Bark Extracts of Giliricidia sepium on Callosobrucus maculatus

Abstract

The effects of different concentrations of cold and hot aqueous extracts of G. sepium on C. maculatus, the storage pest of cow-pea were examined. The extracts had a killing effect on the weevils. The percentage mortality of the weevils increased with the increase in the extract concentrations. Statistical analyses at 5% level revealed that significant differences abound in the efficacies of the cold and hot aqueous extracts. The hot aqueous leaf and bark extracts tend to have more toxic effect than the cold aqueous extracts. Also, extracts from the bark tend to be more toxic to the weevils than those of the leaves.     

Anthelmintic activity of Swertia chirata against gastrointestinal nematodes of sheep

This paper describes in vitro and in vivo anthelmintic activities of Swertia chirata. In vitro studies revealed that at 25 mg/ml (P>/=0.05) the crude aqueous (CAE) and methanolic extracts (CME) of S. chirata whole plant showed an anthelmintic effect on live Haemonchus contortus. Moreover, in the in vivo study, the whole plant of S. chirata administered as crude powder (CP), CAE and CME at the dose of 3 g/kg to sheep naturally infected with mixed species of gastrointestinal nematodes, showed a significant reduction in egg per gram of faeces.     

A preliminary study on the anti-inflammatory properties of Emilia sonchifolia leaf extracts.

The aqueous and methanolic extracts of Emilia sonchifolia leaves progressively reduced rat paw oedema induced by subplantar injection of albumin, the aqueous extract showing a more pronounced effect than the methanol extract.     

落叶松枯落针叶水浸液对落叶松和云杉种子的萌发影响

研究了长白落叶松未分解和半分解枯落针叶的水浸液处理对红皮云杉种子和长白落叶松种子萌发的不同生物效应。对于长白落叶松种子萌发来说,长白落叶松半分解和未分解枯落针叶水浸液4.0 g/L浓度的处理效果均为最佳;而对于红皮云杉种子萌发来说,10.0 g/L浓度或0.5～1.0 g/L浓度的处理效果为最佳。长白落叶松枯落针叶水浸液处理对长白落叶松自身种子和对红皮云杉种子萌发的作用均有很大的差异,推测这是长白落叶松枯落针叶水浸液中所含的化感物质和营养物质与长白落叶松和红皮云杉萌发过程中种子产生的不同代谢物质之间不同相互作用的反映。     

5种药用植物提取液对杨树灰斑病抑菌活性研究

为筛选出对杨树灰斑病菌具有抑制作用的中草药抑菌活性物质,采用3次浸渍提取法对丁香、肉桂、厚朴、毛茛、兴安白芷5种中草药进行提取,采用生长速率法和孢子萌发法,测定了提取液对菌丝生长和孢子萌发的影响。结果表明,5种药用植物提取液对杨树灰斑病原菌均有不同程度的抑制作用,其中丁香、肉桂、兴安白芷提取物对病原菌的菌丝生长抑制效果较好,丁香提取液浓度在16 mg/mL时,对病菌菌丝生长抑制率可达到98.02%,同样浓度的肉桂、兴安白芷提取液抑制率也可达到91%以上;5种药用植物提取液对孢子萌发抑制作用强于对菌丝生长的抑制作用,其中丁香、毛茛对病原菌的孢子萌发抑制效果最好。说明5种药用植物75%乙醇提取液中含有抗菌成分,为生物防治杨树灰斑病提供参考。     

Allelopathic effects of Lantana camara on germination and growth behavior of some agricultural crops in Bangladesh

An experiment was conducted to understand the growth inhibitory effects of aqueous extracts derived from Lantana camara L. （a globally recognized invasive alien weed） on six popular agricultural crops of Bangladesh. The test was conducted in sterilized petridishes with a photoperiod of 24 hours and an average temperature of 29℃. The effect of different concentrations ofL. camara leaf extracts were recorded and compared with control （i.e., distil water）. Result showed different concentrations of aqueous leaf extracts caused significant inhibitory effect on germination, root and shoot elongation and development of lateral roots of receptor crops. Bioassays also indicated that the inhibitory effect was proportional to the concentrations of the extracts and higher concentration had the stronger inhibitory effect whereas the lower concentration showed stimulatory effect in some cases. The inhibitory effect was much pronounced in root and lateral root development rather than shoot and germination.     

云南蓝果树对种子萌发及幼苗生长的自毒效应

云南蓝果树为中国特有极度濒危一级保护植物,为探讨云南蓝果树濒危机理并进行有效保护,通过野外原位实验和室内受控实验相结合的方法,研究云南蓝果树对种子萌发及幼苗生长是否有自毒效应。结果表明:野外条件下,云南蓝果树的种子萌发受野外枯枝落叶和自身种皮的显著抑制;室内受控实验发现,云南蓝果树的根、茎、叶和种皮浸提液对种子萌发都有不同程度的显著抑制作用,其中,根的抑制作用最强(80.90%),种皮的抑制作用最弱(13.59%),而且云南蓝果树的根、茎、叶浸提液和根际土壤对幼苗生长(株高、叶片数和生物量)也表现出显著的抑制作用。     

Spasmolytic stilbenoids from Maxillaria densa

2,5-dihydroxy-3,4-dimethoxyphenanthrene (1), fimbriol-A (2), nudol (3), gymnopusin (4) and erianthridin (5) isolated from Maxillaria densa provoked a concentration-dependent inhibition of the spontaneous contractions of the rat ileum with potencies comparable to papaverine. In order to establish the mode of action of stilbenoids 1-5, their effect on the contractions induced by different spasmogens (histamine, barium chloride and L-NAME) was investigated. In general, the results suggested that the relaxant activity of the products does not involve a direct nitrergic or antihistaminergic mode of action or an interference with calcium influx into the smooth muscle cells.     

青钱柳叶提取物对Caco-2细胞二糖酶活性的抑制作用

采用Caco-2细胞模型,分析了青钱柳Cyclocarya paliurus叶水提物、醇提后的水提物、95%醇提物、乙酸乙酯萃取物和正丁醇萃取物5种不同提取物对Caco-2细胞活力的影响及对Caco-2细胞上麦芽糖酶、蔗糖酶、乳糖酶3种二糖酶活性的抑制作用。结果表明,5种不同提取物中除95%醇提物对Caco-2细胞活力产生一定影响外,其余4种提取物对Caco-2细胞基本无毒性,在200 mg·L^-1浓度提取物范围内培养24～72 h后细胞仍能保持较高活力;对3种二糖酶活性抑制作用效果最好的为醇提后的水提物,尤其是对蔗糖酶和乳糖酶的抑制作用更为明显,最高的抑制率分别达到76.35%和60.13%,其次为乙酸乙酯萃取物,对乳糖酶的抑制率最高达54.41%。从青钱柳叶不同方法提取物的制备流程说明多糖类或中等极性的黄酮甙类有可能是青钱柳叶中抑制二糖酶活性的主要组成成分。