灯台树种子萌发特性的研究

目的 研究灯台树种子萌发的最适宜条件和储藏时间，为大量人工繁殖灯台树苗木提供借鉴。方法 不同温度，不同光照时间，不同光质及不同储藏时间，测量灯台树种子的萌发率。结果 灯台树种子萌发的适宜温度为30℃～40℃，适宜的光照时间为8h，适宜的光质为黄光和日光，储藏时间为5个月以内最好。结论 灯台树种子是高温萌发型。     

In vivo anti-plasmodial activities and toxic impacts of lime extract of a combination of Picralima nitida,Alstonia boonei and Gongronema latifolium in mice infected with Chloroquine-sensitive Plasmodium berghei

Background

Lime extracts of powdered combination of seeds of Picralima nitida, stem bark of Alstonia boonei and leaves of Gongronema latifolium is a common remedy used in the treatment of malaria in South Western Nigeria.

Objective

To determine the antiplasmodial activities of the combined herbal extracts and its impact on the haematological, hepatological and renological parameters in mice.

Methods

The 4-day suppressive and curative tests were used to assess the antiplasmodial activities of the extract in mice infected with chloroquine-sensitive Plasmodium berghei at concentration of 200mg/kg, 400mg/kg and 800mg/kg body weight. The haematological parameters including red blood cells, white blood cells, packed cell volume and haemoglobin count were analysed with an auto analyser. The activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were determined, while urea, protein and creatinine were analysed by standard procedural methods.

Results

The 4-day suppressive test revealed that the test extract achieved percentage suppression of 39.0%, 41.6% and 54.68% for the 200mg/kg, 400mg/kg and 800mg/kg concentration respectively. Additionally, the curative test achieved a high percentage suppression of 80.97%, 83.84% and 86.16% at the 200mg/kg, 400mg/kg and 800mg/kg concentration respectively. The extracts did not induce significant change on haematological parameters (P>0.05), while significant elevation in the values of the ALT and AST (P<0.05) was observed and elevation of creatinine (P<0.05) at 800mg/kg.

Conclusions

The results support the traditional use of the herbal combination in the treatment of malaria, however the liver cells were impacted by the extracts in bioassay conducted with mice.     

Protective effect of Alstonia scholaris Linn. R. Br. against Bleomycin induced chromosomal damage in cultured human lymphocytes,in vitro

It is both interesting and necessary to identify and develop nontoxic radioprotective compounds. Bleomycin (BLM), a known radiomimetic drug was used as a clastogen in the present study. The possible protective effects against BLM (15?μg/ml) induced clastogenicity by aqueous and methanolic extracts from Alstonia scholaris bark, stem and leaves were compared. The treatment of bark extracts significantly (p?2 assay was performed. Lymphocyte cultures from 12 healthy volunteers were exposed to aqueous (50?μg/ml) and methanolic (50?μg/ml) extracts of A. scholaris bark alone as well as in combination with Bleomycin under two different growth phases, G₀ and G₂. There was a statistically significant reduction (p?2 phase as compared to respective cultures exposed at G₀ phase. The highest level (p?2 phase than those at G₀ phase. This indicated that there could be certain compound(s) present in aqueous bark extracts which enhance DNA repair capacity. Therefore, the bark of A. scholaris could be further utilized to identify and bring out front line radio protective agents in the market with effective formulations.     

云南傣族药物灯台叶中黄酮类成分

目的:研究云南傣族传统药物灯台叶Alstonia scholaris中黄酮类化学成分.方法:用色谱分离,用理化性质和波谱鉴定化学结构.结果:分离鉴定了山柰酚(1),槲皮素(2),异鼠李素(3),山柰酚-3-O-β-D-半乳糖苷(4),槲皮素_3-O-β-D-半乳糖苷(5),异鼠李素-3-O-β-D-半乳糖苷(6),山柰酚-3-O-β-D-半乳糖-(2→1)-O-β-D-木糖苷(7),槲皮素-3-O-β-D-半乳糖-(2→1)-O-β-D-木糖苷(8)共8个黄酮类成分.结论:化合物1-7为首次从傣药灯台叶分离得到.     

Effect of Alstonia scholaris bark extract on testicular function of Wistar rats

Abstract Aim: To evaluate the antifertility effect ofAlstonia scholaris bark extract in male rats. Methods: In male Wistar rats Alstonia scholaris bark extract was given by oral route at a dose of 200 mg/day for 60 days. The fertility and testicular function were assessed by mating tests, sperm motility, sperm concentration, biochemical indices and testicular cell population dynamics. Results: Oral feeding with the extract at a dose of 200 mg/day for the period of 60 days did not cause body weight loss, while the weights of testes, epididymides, seminal vesicle and ventral prostate were significantly reduced. The production of step-19 spermatids was reduced by 79.6% in treated rats. The population of preleptotene and pachytene spermatocytes were decreased by 61.9% and 60.1%, respectively. Spermatogonia and Sertoli cell population were also affected. The seminiferous tubule and Leydig cell nuclear area were reduced significantly (P<0.01) when compared to the controls. Reduced sperm count and motility res     

Antidiarrhoeal and spasmolytic activities of the methanolic crude extract of Alstonia scholaris L. are mediated through calcium channel blockade

This study was aimed to provide a pharmacological basis to the medicinal use of Alstonia scholaris as an antidiarrhoeal and antispasmodic by using in vivo and in vitro techniques. In the in vivo study the crude extract of Alstonia scholaris (As.Cr), which tested positive for the presence of alkaloids, provided 31–84% protection against castor oil‐induced diarrhoea in mice at 100–1000 mg/kg doses, similar to loperamide. In isolated rabbit jejunum preparation, the As.Cr caused inhibition of spontaneous and high K⁺ (80 mm )‐induced contractions, with respective EC₅₀ values of 1.04 (0.73–1.48) and 1.02 mg/mL (0.56–1.84; 95% CI), thus showing spasmolytic activity mediated possibly through calcium channel blockade (CCB). The CCB activity was further confirmed when pretreatment of the tissue with the As.Cr (0.3–1 mg/mL) caused a rightward shift in the Ca⁺⁺ concentration‐response curves similar to verapamil, a standard calcium channel blocker. Loperamide also inhibited spontaneous and high K⁺ precontractions as well as shifted the Ca⁺⁺ CRCs to the right. These results indicate that the crude extract of Alstonia scholaris possesses antidiarrhoeal and spasmolytic effects, mediated possibly through the presence of CCB‐like constituent(s) and this study provides a mechanistic base for its medicinal use in diarrhoea and colic. Copyright © 2009 John Wiley & Sons, Ltd.     

HPLC法测定面条树中的鸭脚树叶碱

目的:建立面条树中鸭脚树叶碱的HPLC含量测定法.方法:色谱柱为Thermo Gold C18(250 mm×4.60 mm,5 μm),检测波长为287 nm,流动相为甲醇-水-三乙胺(47:53:0.005,V/V),流速为1.0 ml·min-1,柱温为35℃.结果:鸭脚树叶碱在0.14～14.00 μg范围内呈良好的线性关系,r=0.999 9;平均回收率为96.98%,RSD=0.9%(n=9).结论:该法简便、准确,可用于面条树的质量控制研究.     

Potential of a Khaya ivorensis -Alstonia boonei extract combination as antimalarial prophylactic remedy

Ethnopharmacological relevance

The decoction of the combined stem barks of Khaya ivorensis A. Chev. (Meliaceae) and Alstonia boonei De Wild (Apocynaceae) has a history of use in traditional medicine of central Cameroon for malaria treatment but also for the prevention of the disease.

Aim of the study

The purpose of this investigation was to determine the antiplasmodial activity of Khaya ivorensis (K) and Alstonia boonei (A) preparations in the murine malaria model Plasmodium berghei/Anopheles stephensi, to estimate their prophylactic potential and to assess acute and sub-acute toxicity of the formulations prepared according to the traditional recipes.

Materials and methods

Aqueous extracts from the stem-bark of the two plants were prepared and tested separately and in combination. BALB/c mice were treated for 9 days and challenged on day 3 by exposure to mosquitoes infected with Plasmodium berghei. Treatment doses ranged between 200 and 400 mg/kg/day, corresponding approximately to the dosage applied by traditional healers to cure malaria patients or prevent the disease. Parasitemia reduction in treated animals was calculated from Giemsa smear counts, of two replicate experiments. To estimate acute toxicity in terms of median lethal dose (LD50), geometrically increasing doses were administered to mice. Sub-acute toxicity of the herbal combination (KA) was investigated by administering the same doses as in the antiplasmodial activity test for a period of 14 days, followed by 14 days of recovery observation. Locomotor activity (Open Field Test), body weight, liver and kidney morphology were monitored.

Results

The combination KA was found to exhibit antiplasmodial activity in the murine malaria model. In mice treated with the combination remedy at a dosage of 200 mg/kg/day, parasitemia values of 6.2% ± 1.7 and 6.5% ± 0.8 were recorded, compared to 10.8% ± 1.3 and 12.0% ± 4.0 in controls (p < 0.01). Doubling the dosage of the extracts did not significantly increase parasite suppression. When extracts of K and A were administered separately at a dosage of 400 mg/kg, a reduction in parasitemia was still obtained, but it did not reach statistical significance. Toxicity studies yielded comforting results: the LD50 was estimated to be greater than 2779.5 mg/kg. Moreover, mice exposed to the fourteen-day repeated-dose toxicity test (sub-acute toxicity test) did not display weight loss, liver or kidney morphological modifications, significant alterations in locomotor activity or any other sign of illness.

Conclusion

The antiplasmodial activity and the wide dose interval between the therapeutic dosage and the toxic dosage exhibited by the KA herbal combination in the murine malaria model argue in favor of its use as an antimalarial prophylactic remedy. It remains to be demonstrated by human clinical trials whether the combination remedy, when taken by inhabitants during malaria transmission season, can reduce parasite density and lead to a reduction of malaria episodes in the community.     

灯台叶醇提物对H22肝癌移植小鼠免疫和抗氧化功能的影响

目的探讨灯台叶醇提物抗肿瘤作用及其机制。方法以移植H22荷瘤小鼠为模型,设置阴性组、灯台叶醇提物低中高剂量组（0.2,1.0,5.0 g/kg）,阳性药环磷酰胺组,检测其抑瘤效果、碳廓清能力、耳肿胀度、血清中GR、GSH-PX、CAT、SOD和MDA含量。结果灯台叶醇提物高剂量能够明显抑制小鼠H22实体瘤生长（P〈0.05）,其抑瘤率为61.7%;高剂量组对小鼠耳肿胀度无明显影响,但增强其碳廓清能力,与阴性对照组比较,差异有统计学意义（P〈0.05）;高剂量组中血浆MDA含量水平明显降低（P〈0.05）,GR、GSH-PX、CAT、SOD活性水平比阴性对照组明显升高,还能够降低移植瘤细胞中活性氧ROS（P〈0.05）。结论灯台叶醇提物能够增强小鼠的免疫功能;清除自由基,减轻活性氧带来的损伤,从而起到抗肿瘤作用。     

Antiprotozoal screening and cytotoxicity of extracts and fractions from the leaves,stem bark and root bark of Alstonia congensis

Ethnopharmacological relevance

To evaluate the antiprotozoal activity and cytotoxicity of extracts and fractions from the leaves, root bark and stem bark of Alstonia congensis (Apocynaceae), used in traditional medicine against parasitic diseases.

Materials and methods

The aqueous and 80% MeOH extracts, and a series of fractions and subfractions from the leaves, stem and root bark of Alstonia congensis were tested in vitro for their antiprotozoal activity against Trypanosoma brucei brucei, Trypanosoma cruzi, Lesihamania infantum and the chloroquine and pyrimethamine-resistant K1 strain of Plasmodium falciparum. Their cytotoxicity on MRC-5 cells (human lung fibroblasts) was evaluated as well.

Results

The aqueous and 80% MeOH extracts and a series of subfractions of each plant part exhibited pronounced antiprotozoal activity against the K1 strain of Plasmodium falciparum with IC₅₀ values ranging from 2 to 5 µg/ml, and good activity against Trypanosoma brucei brucei and Trypanosoma cruzi with IC₅₀ values ranging between 5 and 10 µg/ml. The residual 80% MeOH extract from the leaves, and the total alkaloid extract from stem and root bark were the only subfractions active against Leishmania infantum with IC₅₀ values <10 µg/ml. None of the samples from the root bark was cytotoxic against MRC-cell lines (CC₅₀>64 µg/ml). In general, the aqueous extract (traditional decoction) showed the highest selectivity, especially against Plasmodium falciparum.

Conclusion

These results can partly support and justify the traditional use of these plant parts of Alstonina congensis as raw materials for the preparation of traditional remedies to treat parasitic diseases such as malaria and trypanosomiasis.