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.     

Antinociceptive and antidiarrhoeal activity of Zanthoxylum rhetsa

The methanolic extract of the Zanthoxylum rhetsa Roxb. stem bark, given by oral route to mice at doses of 250 and 500 mg/kg, significantly reduced the abdominal contraction induced by acetic acid and the diarrhoeal episodes induced by castor oil in mice.     

The effect of Mangifera indica stem bark and Pluchea ovalis roots on tracheal smooth muscle in vitro

Aqueous extract of the stem bark of Mangifera indica and ethanolic extract of the roots of Pluchea ovalis has been studied on rat tracheal smooth muscle in vitro. The extract of M. indica at 1, 2 and 4 mg/ml and that of P. ovalis at 0.25, 0.5 and 1 mg/ml relaxed, dose-dependently, the rat tracheal smooth muscle strip previously contracted by acetylcholine at 0.055 mmol/l.     

夹竹桃提取物对松材线虫致死性的研究

用夹竹桃的树皮和树叶的酒精提取物和水提取物对松材线虫有很强的毒性,尤其是叶片的水提取物对松材线虫的杀伤性极强。这对利用植物提取液来毒杀松材线虫提供了一个初步的结论。     

Anthelmintic activities of three medicinal plants from Nigeria

Aqueous extracts of the leaf, stem bark and root bark from Canna bidentata, Spondias mombin and Commiphora africana were examined for anthelmintic activity against earthworm. All the extracts demonstrated a concentration-dependent activity at tested concentrations of 10-80 mg/ml. Higher activities were observed at the higher concentrations, 40-80 mg/ml for all the plant extracts. C. bidentata with a paralysis time of 3-5 min and death time of 5-18 min at these concentrations for the stem bark, and S. mombin which exhibited comparatively higher efficacy (34-44 min paralysis time and 105 min death time for the leaf) at lower concentrations of 10-20 mg/ml were adjudged the outstanding anthelmintics of plant origin accordingly.     

Antinociceptive activity of Ceriops decandra leaf and pneumatophore

The ethanol extract of Ceriops decandra leaf and pneumatophore, at the oral doses of 250 and 500 mg/kg, showed a dose-dependent and significant inhibition of acetic acid-induced writhing in mice. On the contrary, the bark extract was devoid of any significant activity.     

Constituents and cytotoxicity of Zanthoxylum rhesta stem bark

3,5-Dimethoxy-4-geranyloxycinnamyl alcohol (1), 8-methoxy-N-methylflindersine (2), xanthyletin and sesamin have been isolated from petroleum ether extract of the stem bark of Zanthoxylum rhesta. The petroleum ether extract and 8-methoxy-N-methylflindersine showed cytotoxicity on brine shrimp nauplii.     

Antimicrobial activity of Hymenodictyon parvifolium

Methanol extract of the stem bark of Hymenodictyon parvifolium was tested for its antifungal and antibacterial activity. The extract was found to have inhibitory effect against all the pathogens tested.     

Effect of Mahonia aquifolium stem bark crude extract and one of its polysaccharide components on production of IL-8.

The crude hydroalcoholic extract of Mahonia aquifolium stem bark and a polysaccharide isolated from the extract were tested for their activity on interleukin-8 (IL-8) production by human monocytic cell line THP-1. The crude extract partly inhibited the IL-8 spontaneous production after 48-h treatment of the cells, while the polysaccharide was found to be a potent inducer of IL-8 production.     

Antibacterial and antifungal activities of Breynia cernua

The Breynia cernua leaves, stem and root barks and heart-woods extracted with petrol, dichloromethane, ethyl acetate, butanol and methanol gave fractions with varied level of antimicrobial activity. The best activity was exhibited by the methanol extract of the root bark followed by its butanol fraction. These were the only fractions exhibiting a good level of antifungal activity as compared to the standard. The dichloromethane fraction of the stem bark also demonstrated good activity.     

巨桉幼树器官组织中养分元素的分布与积累特点

通过对造林1 a~3 a巨桉幼树的器官生物量调查、器官组织中大量元素N、P、K、Ca、Mg和微量元素Fe、Zn的含量测定及其积累量的分析结果表明:大量元素总含量在各器官中的分布为干韧皮部、叶枝、根干木质部,微量元素主要富集于叶和根器官中;单株木器官中大量元素的累积量排序为叶枝干韧皮部根或干木质部干木质部或根,各养分元素积累量的规律不受林龄的影响,大量营养元素依次为CaNKMgP;微量元素累积量FeZn;林龄1 a~3 a巨桉平均单株木大量元素累积总量分别是12.45 g·株-1、136.19 g·株-1和420.23g·株-1;各养分元素的年净积累量以Ca为最大,N、K养分元素次之,Mg元素较少,P元素最小。     

Comparative evaluation of successive extracts of leaf and stem bark of Albizzia lebbeck for mast cell stabilization activity

Successive chloroform, methanol and water extracts of bark and leaves of Albizzia lebbeck were tested for its in vitro mast cell stabilizing effect against compound 48/80. Methanolic extract of leaf and methanolic and water extracts of bark have shown maximum activity comparable to that of disodium chromoglycate.     

Antibacterial activity of Piliostigma thonningii stem bark

Piliostigma thonningii stem bark 60% methanolic extract exhibited activity against six out of eight bacterial isolates at a concentration of 20 mg/ml.     

Antibacterial activity and cytotoxicity of Miliusa velutina.

Goniothalamusin and two mixtures, acetogenins-A and acetogenins-B, isolated from a petroleum ether extract of the stem bark of Miliusa velutina exhibited significant antibacterial and cytotoxic activities.     

Investigation of in vitro anthelmintic activities of Pycnanthus angolensis and Sphenocentrum jollyanum

Extracts from Pycnanthus angolensis stem bark, and fruits and seeds of Sphenocentrum jollyanum, when tested in vitro, showed potent anthelmintic activity on the earthworm, Eudrilus eugeniae. Methanolic extract of P. angolensis was more active than its chloroform extract (P<0.001), while fruit ethanolic extract of S. jollyanum was also more potent than the seed extract. When compared with other worms, S. jollyanum fruit extract showed the greatest activity on wireworms when tested at 80 mg/ml.     

Dynamics of water storage in mature subalpine Picea abies: temporal and spatial patterns of change in stem radius

Internal water reserves in bark and foliage of trees contribute to transpiration (T) and play an essential role in optimizing water transport by buffering extreme peaks of water consumption. We examined patterns of stem shrinkage and their relationship to tree water dynamics. We measured fluctuations in root radius and stem radius at different stem heights, T of twigs at the top of the crown and sap flow velocities in stem sections of mature subalpine Norway spruce (Picea abies (L.) Karst.) trees over 2 years. The output of each sensor was coupled by physical functions to a mechanistic flow and storage model of tree water relations. The data verified the model-predicted lag in water storage depletion in response to the onset of transpiration and the lag increased with increasing distance from the crown periphery. Between the crown and stem base, the delay ranged from a few minutes to several hours, depending on microclimatic conditions and tree water status. Stem volume changes were proportional to the amount of water exchanged between the elastic tissues of the bark and the rigid xylem, indicating that the "peristaltic" wave of stem contraction along the flow path represented depletion of water stored in bark. On a daily basis, stems lost between 0.2 and 0.5% of their volume as a result of bark dehydration, corresponding to about 2 to 5 l of water. This water contributed directly to T. According to the model based on hydraulic principles, there are three main components underlying the dynamics of water storage depletion: flow resistance, storage capacities of needles and bark, and T of each tree section. The resistances and capacities were proportional to the response delay, whereas T in the lower parts of the tree was inversely proportional. The pattern of T within the crown depended on water intercepted by the branches. Because of these weather-dependent factors, there was no time constant for the response delay along the flow path. Nevertheless, the upper crown and the root section tended to have longer response delays per meter of flow path than the stem. The diurnal course of stem radius fluctuations represents the sum of all external and internal conditions affecting tree water relations; stem radius fluctuations, therefore, provide a sensitive measure of tree water status.     

Cytotoxic activity of Ozoroa insignis from Zimbabwe

The crude methanol bark extract of the Zimbabwean medicinal plant, Ozoroa insignis, showed in-vitro cytotoxic activity against Hep-G2 (human hepatocellular carcinoma), MDA-MB-231 (human mammary adenocarcinoma), and 5637 (human primary bladder carcinoma). Bioactivity-directed chromatographic separation led to isolation of anacardic acid and ginkgoic acid as the cytotoxic components.     

Antimicrobial activity of Newtonia hildebrandtii

Successive petroleum ether, dichloromethane and methanol extracts of Newtonia hildebrandtii stem bark were tested in vitro for their antifungal and antibacterial activity. The methanol extract was found to be the most effective against the tested pathogens.     

Antimicrobial activity of Micrechites novoguineensis

The methanol extracts of Micrechites novoguineensis, leaves and stem bark were partitioned (petrol, ethyl acetate, methanol). All obtained fractions showed a broad spectrum of antibacterial activity, while only the leaf ethyl acetate fraction showed activity against moulds.     

桂西南米老排人工林单株生物量回归模型

通过对桂西南大青山林区28a生米老排(Mytilaria laosensis)人工林林分进行每木检尺和生物量的测定,建立了米老排各器官生物量与胸径、树高和胸径平方乘树高(D2 H)的相关关系;分别选用幂函数等5种模型,用回归分析方法对米老排人工林单株生物量模型进行了拟合。结果表明:树叶和树根生物量分别与胸径和树高的相关关系最显著,而树干、树枝、树皮和全株的生物量都与D2 H的相关关系最为显著。胸径、树高和D2 H与各器官生物量拟合的模型中,全株、树干和树皮的拟合效果最好,树叶和树根的拟合效果中等,树枝的拟合效果较差。除树皮外,各器官均以幂指数模型的拟合效果最好。