In vitro and in vivo anti-Helicobacter pylori activity of Calophyllum brasiliense Camb.

Aims of the study

Calophyllum brasiliense (Camb.) is a medicinal tree that grows particularly in the hilly and forested regions of Brazil. Preparations from its stem bark are popular remedies for the treatment of chronic ulcers. Since earlier investigations on bark extracts evidenced gastroprotective and gastric acid inhibitory properties, this study evaluated the effects of hydroethanolic extract (HEECb) and the dichloromethanic fraction (DCMF), from Calophyllum brasiliense stem bark, against Helicobacter pylori, in vitro and in vivo.

Materials and methods

The in vitro assays were performed using the disk diffusion and broth microdilution methods to determine the minimum inhibitory concentration (MIC) values. The test substances were evaluated in vivo taking into account the delay in the gastric ulcer healing in Wistar rats, infected with Helicobacter pylori.

Results

DCMF appeared the most active and potent in vitro against Helicobacter pylori growth with an MIC of 31 μg/mL. In the in vivo assays, rats ulcerated by acetic acid, and inoculated with Helicobacter pylori showed a marked delay in ulcer healing. Treatment with HEECb (50, 100 and 200 mg/kg) and DCMF (100 and 200 mg/kg) reduced the ulcerated area in a dose-dependent manner. While DCMF, at 200 mg/kg, increased the prostaglandin E₂ (PGE₂) level, both HEECb and DCMF decreased the number of urease-positive animals, as confirmed by the reduction of Helicobacter pylori presence in histopathological analysis.

Conclusion

The results suggest that the antiulcer activity of Calophyllum brasiliense is due, in part, to its anti-Helicobacter pylori action, validating the popular use of this species.     

射干提取物体内体外抑菌作用的研究

目的:研究射干提取物的体内外抑菌作用。方法:通过测定抑菌圈直径考察射干提取物对不同菌株的敏感性;采用2倍稀释法检测射干提取物的最小抑菌浓度(MIC);通过ip金黄色葡萄球菌观察射干提取物低、中、高(0.46,0.92.1.84g.kg-1)3个剂量ig给药7 d对小鼠的致死保护率。结果:肺炎链球菌、铜绿假单胞菌对射干提取物有较强的敏感性,金黄色葡萄球菌、大肠埃希菌、无乳链球菌、化脓链球菌、痢疾志贺菌对射干提取物中度敏感;射干提取物对金黄色葡萄球菌、肺炎链球菌、大肠埃希菌、铜绿假单胞菌、无乳链球菌、化脓链球菌、痢疾志贺菌的最小抑菌浓度(MIC/g.mL-1)分别为0.062 5,0.015 6,0.250 0,0.031 2,0.015 6,0.015 6,0.062 5;射干提取物低、中、高3个剂量组均显著降低金黄色葡萄球菌酵母悬液引起的小鼠死亡率,死亡率分别为45%,35%,30%,与模型对照组死亡率100%比较差异有统计学意义(P<0.05或P<0.01)。结论:射干提取物体内体外对所试菌株均有抑菌作用。     

雄黄致体内外染色体畸变

目的:用仓鼠体内染色体畸变试验和中国仓鼠肺细胞CHL细胞染色体畸变试验评价雄黄的遗传毒性.方法:体内染色体畸变试验用毛足属仓鼠连续ig5 d给予33.25,66.5,133 mg·kg-1剂量雄黄悬浊液,处死前2 h ip秋水仙素.处死后取骨髓细胞制备染色体.油镜下观察每只动物骨髓细胞的有丝分裂指数和100个中期分裂相细胞的畸变类型.CHL细胞染色体畸变试验用雄黄浸出液终质量浓度为0.15,0.3,0.6g.L-1作用于CHL细胞,培养24 h或48 h,终止培养前4h加入秋水仙素.收获细胞,制备染色体,油镜下观察CHL细胞有丝分裂指数和200个中期分裂相细胞的畸变类型.结果:①雄黄265.0 mg· kg -1组和雄黄530.0 mg·kg-1组ig给药和雄黄浸出液(1.2,2.4g·L-1)作用于CHL细胞显示有明显的抑制有丝分裂作用.②与阴性对照组比较,雄黄ig给药仓鼠体内染色体畸变率和雄黄体外给药CHL细胞染色体畸变率均显著升高,差异有极显著意义,且有明显的量效关系.但体内试验的畸变率低于体外试验.③雄黄给药后CHL细胞染色体畸变试验中可见较多的染色体断片,而仓鼠体内染色体畸变试验中未发现,这可能与体内外药物作用的方式不同.结论:①雄黄能致体内外细胞染色体畸变,具有遗传毒性.②仓鼠体内染色体畸变试验可作为中药新药遗传毒性评价试验组合的方法之一.     

交泰丸有效部位自微乳系统的体内外评价

目的:对交泰丸有效部位自微乳化释药系统质量及大鼠在体肠吸收进行评价。方法:考察交泰丸有效部位自微乳液的外观、自微乳化后微乳粒径分布、外观、形态、类型、自乳化时间、药物含量及自微乳、微乳化后的稳定性;以黄连总碱为指标,运用大鼠在体肠回流模型,分析比较交泰丸有效部位制备自微乳前后对大鼠在体肠吸收的改善。结果:交泰丸有效部位自微乳化后微乳平均粒径为34.12 nm,可在3 min内基本乳化完全;自微乳液在室温下放置3个月较稳定;自微乳化后的微乳液在37℃下0.1 mol.L-1HCl溶液中放置8 h,交泰丸有效部位自微乳液与有效部位溶液剂比较,黄连总碱在体肠灌流液中的相对剩余百分含量(T)和表观吸收速率常数(Ka)值均获得明显提高(P0.01),前者的Ka是后者的152.6%。结论:自微乳化给药系统能显著改善交泰丸有效部位中黄连总碱大鼠小肠吸收,增加肉桂油在制剂中的稳定性。适合难溶性和难吸收药物的口服吸收,提高其生物利用度,是具有良好应用前景的中药制剂新剂型。     

三七总皂苷肠溶微丸的体内外相关性

目的:考察三七总皂苷(Panax Notoginseng Saponins,PNS)肠溶微丸在Beagle犬体内的释药行为及其体内外相关性。方法:采用双周期交叉试验设计,6只健康Beagle犬口服自制PNS普通胶囊或自制PNS肠溶微丸(胶囊型)后,用HPLC测定血药浓度,计算2种制剂的药动学参数,进行生物利用度比较,并对体外累积释度和体内累积吸收率进行线性回归。结果:自制PNS肠溶微丸对PNS普通胶囊的相对生物利用度为三七皂苷R1 520.56%,人参皂苷Rb1 367.70%,人参皂苷Rg1251.66%,上述3成分在体内的平均滞留时间均延长;R1,Rb1,Rg1的体内外相关系数分别为0.784 9,0.877 2,0.691 2。结论:自制PNS肠溶微丸与PNS普通胶囊相比生物利用度更高,在pH 6.8的缓冲液中R1,Rb1,Rg1的体内外相关性较差。     

基于UPLC-PDA-MS/MS技术的四逆散水煎液体内外物质基础研究

目的:采用液质联用技术,分析四逆散水煎液体外化学成分及血中移行成分,对其体内外物质基础进行研究。方法:采用ACQUITY UPLCTMBEH C18柱(2.1 mm×100 mm,1.7μm),以乙腈-2 mmol.L-1醋酸铵水溶液为流动相进行梯度洗脱,流速0.2 mL.min-1,柱温35℃;质谱采用ESI源,正负离子同时检测,在m/z 100～1 000进行扫描,并对特征离子进行2次裂解,获得二级质谱数据。结果:在四逆散水煎液中,检测到芍药苷、甘草酸、柴胡皂苷a及柚皮苷等20种化学成分。在体内样品中,发现芍药苷、柚皮苷、橙皮苷等8种成分以原型入血;同时还检测到6种代谢物,包括葡萄糖醛酸结合物、硫酸酯结合物及葡萄糖醛酸硫酸酯结合物等。结论:采用UPLC-PDA-MS/MS技术分析四逆散水煎液的体内外化学成分,能比较全面、快速地反映四逆散水煎液的体内外物质基础,为进一步研究四逆散的药效物质基础提供依据。     

喘平缓释片体外释放与人体内吸收的相关性研究

目的: 研究喘平缓释片体外释放与人体内吸收的相关性。 方法: 以麻黄碱、伪麻黄碱为指标成分,体外采用转篮法结合HPLC测定喘平缓释片在不同pH介质中的累积溶出率;体内采用尿药法结合HPLC测定尿液中的药物浓度;应用Wagner-Nelson法评价喘平缓释片体内外相关性。 结果: 喘平缓释片人体内不同时间点的吸收百分数F与体外累积溶出率f的线性回归方程分别为F_麻黄碱=1.572 5f-20.729(R²=0.974 5),F_伪麻黄碱=1.237f-0.147 6(R²=0.959 5)。 结论: 喘平缓释片体内-体外相关性良好,体外释放度测定方法可用于控制喘平缓释片内在质量和预测其生物利用度。     

In vitro and in vivo hepatoprotective and antioxidant activity of ethanolic extract from Meconopsis integrifolia (Maxim.) Franch

Ethnopharmacological relevance

Meconopsis integrifolia (Maxim.) Franch is a high mountain endemic species used as a traditional Tibetan and Mongolian herb to treat hepatitis, pneumonia, and edema. This study aims to investigate the hepatoprotective and antioxidant effects of Meconopsis integrifolia ethanolic extract (MIE) in vitro and in vivo.

Materials and methods

The in vitro antioxidant property of MIE was investigated by employing various established systems. Rats with carbon tetrachloride (CCl₄)-induced liver injury were used to assess the hepatoprotective and antioxidant effect of MIE in vivo. The level or activity of alkaline phosphatase (ALP), glutamate pyruvate transaminase (ALT), aspartate aminotransferase (AST), and total bilirubin (TB) in the blood serum and thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) in the liver and kidney of the rats were assayed using standard procedures.

Results

MIE exhibited strong antioxidant ability in vitro. In the rats with CCl₄-induced liver injury, the groups treated with MIE and silymarin showed significantly lower levels of ALT, AST, ALP, and TB. MIE demonstrated good antioxidant activities in both the liver and kidney of the rats in vivo.

Conclusions

MIE exhibits excellent hepatoprotective effects and antioxidant activities in vitro and in vivo, supporting the traditional use of Meconopsis integrifolia in the treatment of hepatitis.     

In vitro and in vivo safety evaluation of Acer tegmentosum

Ethnopharmacological relevance

Acer tegmentosum, which contains salidroside and tyrosol, has been used for the treatment of hepatic disorders in eastern Asia. However, little is known about its safety.

Aim of the study

To determine the safety of Acer tegmentosum, we evaluated its acute oral toxicity and genotoxicity profiles.

Materials and methods

Salidroside and tyrosol present in Acer tegmentosum were quantified using high-performance liquid chromatography. Acute oral toxicity testing of Acer tegmentosum was performed in rats. Genotoxicity of Acer tegmentosum was assessed by bacterial reverse mutation, chromosomal aberration, and bone marrow micronucleus tests. All the tests were conducted in accordance with the good laboratory practices.

Results

The amounts of salidroside and tyrosol in Acer tegmentosum were found to be 85.01±1.21 mg/g and 3.12±0.04 mg/g, respectively. In the bacterial reverse mutation test, Acer tegmentosum increased the number of revertant Salmonella typhimurium TA98 colonies, regardless of metabolic activation by S9 mixture. In contrast, Acer tegmentosum application did not significantly increase the number of chromosomal aberrations in Chinese hamster ovary (CHO)-K1 cells and micronucleated polychromatic erythrocytes in mice. In the acute oral toxicity test, the median lethal dose (LD₅₀) of Acer tegmentosum was found to be >2000 mg/kg in rats.

Conclusion

Take together, Acer tegmentosum exhibits mutagenicity, which was evident from the bacterial reverse mutation test. Further studies are needed to identify the components responsible for such an effect and the underlying mechanisms.     

柴胡总皂苷提取物体外溶血作用

目的:考察柴胡总皂苷提取物的溶血作用和抗氧化剂对柴胡总皂苷溶血的影响。方法:通过肉眼观察和分光光度法考察不同浓度柴胡皂苷的溶血作用及抗氧化剂对柴胡总皂苷溶血的影响。结果:柴胡总皂苷质量浓度为在0.01,0.02 g.L-1时,其溶血曲线呈S形,溶血当量为0.01 mg,溶血指数为1∶10万,抗氧化剂与柴胡总皂苷组溶血率低于同浓度柴胡总皂苷组。结论:柴胡总皂苷具有一定的溶血作用,且溶血强度与浓度呈剂量依赖性,抗氧化剂的加入能减轻柴胡总皂苷的溶血作用。     

In vitro and in vivo antimalarial activity and cytotoxicity of extracts and fractions from the leaves,root-bark and stem-bark of Triclisia gilletii

Ethnopharmacological Relevance

To evaluate the in vitro antiplasmodial activity and cytotoxicity, and the in vivo activity of extracts and fractions from the leaves, root-bark and stem-bark of Triclisia gilletii (De Wild) Staner (Menispermaceae), used in traditional medicine against malaria.

Materials and Methods

The aqueous and 80% MeOH extracts, and a series of fractions and subfractions from the leaves, stem and root-bark of Triclisia gilletii were tested in vitro for their antiplasmodial activity against a Congolese-sensitive strain of Plasmodium falciparum, against the chloroquine and pyrimethamine-resistant K1 strain of Plasmodium falciparum, for cytotoxicity against MRC-5 cells, and in vivo in mice infected with Plasmodium berghei berghei.

Results

Many samples from the three plant parts exhibited pronounced activity against the Congolese chloroquine-sensitive strain of Plasmodium falciparum with some IC₅₀ values <0.02 µg/ml, and against the K1 strain, with some IC₅₀ <0.25; the selectivity was higher against the Congolese strain. At oral doses of 200 and 400 mg/kg body weight in infected mice, the aqueous, 80% methanol and total alkaloid extracts from the three plant parts produced more than 65% and 75% chemosuppression, respectively. The antiplasmodial activity of these three plant parts of Triclisia gilletii can at least in part be attributed to bisbenzylisoquinoline alkaloids, and supports its use for the treatment of uncomplicated malaria in traditional medicine.     

糙苏素的抗肿瘤活性研究

目的:探讨藏药螃蟹甲中环烯醚萜类成分糙苏素(phlomiol)的抗肿瘤作用.方法:采用MTT法检测糙苏素对体外培养的2种人肿瘤细胞增殖的抑制作用;体内试验采用小鼠实体瘤S180、肝癌H22细胞株接种小鼠,连续给药14 d,计算抑瘤率.采用MTT比色法检测糙苏素对S180荷瘤小鼠NK细胞杀伤活性的影响和对S180荷瘤小鼠T淋巴细胞增殖反应的影响.结果:糙苏素在50～150 mg·L-1对2种肿瘤细胞增殖均有抑制作用,且呈剂量依赖关系(r=0.989,P<0.05);体内试验结果显示小鼠分别灌胃给予2.5,5,10 mg·kg-13个剂量的糙苏素,对接种的实体瘤S180、肝癌H22细胞株的抑瘤率分别为28.5%～65.0%.35.0%～74.5%.同时,糙苏素可显著提高S180荷瘤小鼠淋巴细胞增殖活性(P<0.05),显著增加S180荷瘤小鼠NK细胞的杀伤能力(P<0.05).结论:糙苏素对体外培养的人肿瘤细胞和接种的小鼠肿瘤具有明显抑制作用,能够增强淋巴细胞增殖功能和NK细胞的杀伤能力,具有抗肿瘤和免疫调节功能.     

Aqueous extract of Taxus Chinensis (Pilger) Rehd inhibits lung carcinoma A549 cells through the epidermal growth factor receptor/mitogen-activated protein kinase pathway in vitro and in vivo

Objective

To explore the anticancer mechanism of aqueous extract of Taxus Chinensis (Pilger) Rehd (AETC).

Methods

The serum pharmacological method was used to avoid interference from administration of the crude medicinal herbs. Eight purebred New Zealand rabbits were used for preparation of serum containing various concentrations of AETC. Forty-eight Balb/c-nu mice were used for in vivo experiments. The effects of serum containing AETC on the proliferation of A549 cells and expression levels of the epidermal growth factor receptor/mitogen-activated protein kinase (EGFR/MAPK) pathway-related proteins in vitro were investigated. Additionally, the effects on the growth of A549 xenografts in nude mice, and expression levels of the EGFR/MAPK pathway-related proteins in the xenografts, were investigated.

Results

3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay revealed that the serum containing AETC significantly decreased the viability of A549 cells in a dose-dependent manner. Western blot showed that the serum containing various concentrations of AETC strongly reduced the levels of phospho-Jun N-terminal kinase (p-JNK) and phospho-extracellular signal-regulated kinasel/2 (ERK1/2) while it increased the level of p-p38. However, no significant effects on the expression levels of JNK, ERK1/2, and p38 MAPK were found. In addition, an anticancer effect from AETC was observed in vivo in the Balb/c-nu mice bearing A549 xenografts.

Conclusion

AETC has significant effects on the growth of A549 xenografts and on the activity of the EGFR/MAPK pathway. Therefore, AETC may be beneficial in lung carcinoma treatment.     

川芎嗪眼部植入剂的制备及体内外释药相关性研究

目的:制备川芎嗪(TMPZ)眼部缓释植入剂,考察其体外释放、兔眼玻璃体内药动学行为及体内外相关性.方法:使用微量锥形双螺杆混合机,采用热熔融挤出法,以聚乳酸-羟基乙酸共聚物(PLGA)为基质材料制备川芎嗪眼部植入剂,HPLC测定川芎嗪植入剂植入兔眼后玻璃体的浓度,考察其体内缓释行为,并对体内外相关性进行研究.结果:载药量为10％～ 30％时,可制备得到川芎嗪植入剂,含量均匀度符合2010年版《中国药典》规定.体外释放符合零级释放模型.以PL-GA 5050,2.5A为载体,载药量为30％的川芎嗪植入剂在玻璃体内可缓慢释放药物达到3周以上,体内外释放相关性良好.结论:热熔融挤出法制备川芎嗪眼部植入剂工艺可行,川芎嗪眼部植入剂在兔眼玻璃体内释药平稳,缓释效果良好.     

夏枯草花粉离体萌发观察

选用唇形科植物夏枯草花粉为材料,通过在离体条件下花粉的萌发来探讨夏枯草花粉萌发的最适条件.以10％ H3BO4,30％ Ca(NO3)2,20％ MgSO4,10％ KNO3配制成无机盐溶液为基本培养基,统计不同相对分子质量的PEG,不同浓度的蔗糖,不同pH和不同温度条件以及不同采集时间下花粉萌发率的情况.夏枯草花粉萌发的最适液体培养条件是:10％ H3BO4 +30％ Ca(NO3)2 +20％ MgSO4+10％ KNO3+25％ PEG-4000,pH在6.5左右,刚刚开花时采集的花粉在此条件下花粉萌发率最高.     

Evaluation of behavioral and pharmacological effects of Hedyosmum brasiliense and isolated sesquiterpene lactones in rodents

Ethnopharmacological relevance

Hedyosmum brasiliense Miq. (Chloranthaceae) is an essential Brazilian species largely found in the Atlantic Forest. It is popularly known as “cidrão” and in folk medicine, this aromatic species is widely used as a calmative/tranquilizer and to treat sleep disorders.

Aim of the study

To examine the neurochemical properties of ethanol extract (EEHb), fractions and compounds of fresh leaves of Hedyosmum brasiliense and the antidepressant effect of the isolated sesquiterpene lactones podoandin and 13-hydroxy-8,9-dehydroshizukanolide.

Materials, methods and results

The effects of EEHb were demonstrated by the open field, elevated-plus-maze, forced swimming, pentobarbital-induced sleeping time, PTZ-induced seizure, and inhibitory avoidance tests. EEHb did not show a protective effect against PTZ-induced convulsions. In the plus-maze test, EEHb (100 mg/kg, i.p.) exhibited an anxiolytic effect through the effective enhancement of the frequency and time spent in the open arms of the maze. Conversely, the time spent and the number of entrances to the closed arms were decreased. All these effects were also completely reversed by pre-treatment with flumazenil (2.5 mg/kg, i.p./a benzodiazepine receptor agonist), similar to the results observed with diazepam used as a positive standard. In this test, the anxiolytic effect of EEHb was also totally blocked by pre-treatment with reserpine (2.0 mg/kg, i.p.), a drug known to induce depletion of biogenic amines. In the forced swimming test, the treatment of EEHb (100 mg/kg, i.p. or 100 mg/kg, p.o.) given in acute and chronic form (10, 50 and 100 mg/kg), produced a decrease in immobility time, similar to that of imipramine (10 mg/kg, i.p.), the positive control. The dichloromethane and hexane fractions (100 mg/kg, p.o.) also produced a decrease in immobility time. In addition, the two isolated compounds tested in a single dose (10 mg/kg, i.p.), the antidepressant effect was observed only with the compound podoandin, which also caused a decrease in immobility time. EEHb (10–100 mg/kg) a dose-dependent manner also caused a decrease in barbiturate sleeping time in mice, and in high doses (100 mg/kg), did not interfere in memory consolidation.

Conclusions

The results suggest that EEHb presents psychopharmacological activities, including anxiolytic, antidepressant, and hypnotic effects.     

pH依赖型黄连总生物碱结肠靶向微丸的制备及其体内外释放性能评价

目的:制备用于治疗溃疡性结肠炎的pH依赖型黄连总生物碱靶向微丸并对其体内外释放性能进行评价。方法:采用丙烯酸树脂(eudragit)S100和eudragit L100-55双层包衣制备pH依赖型黄连总生物碱结肠靶向微丸。以盐酸小檗碱为指标进行了体外释放度和大鼠体内释放的初步评价。结果:体外释放度试验表明盐酸小檗碱在人工胃液中2 h累计释放度<0.1%,在人工小肠液中4 h累计释放度<10%,在人工结肠液中3 h累计释放度>90%;体内试验表明在大鼠体内包衣微丸大部分能完整到达盲肠或结肠部,并在上述部位开始崩解释放。结论:pH依赖型黄连总生物碱靶向微丸能够实现结肠的定向释放。     

何首乌不定根的离体诱导及悬浮培养研究

通过离体不定根的高效诱导与悬浮培养,实现何首乌资源的永续利用。在培养基中添加不同浓度的蔗糖和植物生长物质,筛选从幼茎有效诱导不定根的最适培养基;采用正交试验筛选不定根悬浮培养的最适培养基;对悬浮培养的不定根进行继代培养并测定生长曲线,同时对不定根中的主要有效成分进行检测。结果表明,能够从幼茎有效诱导不定根的最适培养基为MS+蔗糖 40 g·L^-1+α-萘乙酸 2.0 mg·L^-1+6-卞基腺嘌呤 0.2 mg·L^-1;不定根悬浮培养的最适培养基为 MS+蔗糖30 g·L^-1+α-萘乙酸 2.0 mg·L^-1+生根粉 0.2 mg·L^-1;经过检测,发现不定根同样含有何首乌药材中的主要有效成分二苯乙烯苷。该实验实现了何首乌不定根的高效诱导与培养,为中药资源的永续利用研究提供了工作基础。     

In vivo and in vitro toxicological evaluation of the hydroalcoholic leaf extract of Ageratum conyzoides L. (Asteraceae)

Ethnopharmacological relevance

In African traditional medicine, Ageratum conyzoides has been used as purgative, febrifuge, anti-ulcer and wound dressing. To date there is no safety information about long term use of Ageratum conyzoides which contains pyrrolizidine alkaloids, a class of hepatotoxic and carcinogenic phytochemicals. This study aims to evaluate the 90 days subchronic toxicity and in vitro toxicity of Ageratum conyzoides.

Materials and methods

Three groups of 8 rats (4 males and 4 females) received distilled water (control), 500 and 1000 mg/kg of the extract daily for 90 consecutive days by oral gavage. The animals were observed daily for abnormal clinical signs and death. Body weight, relative organ weight, haematological and biochemical parameters of blood as well as heart, kidney, liver and spleen tissues histology were evaluated.

Results

After 90 days administration, Ageratum conyzoides increased significantly (p<0.05) the relative weight of the liver, the spleen and kidney as compared to control group. Ageratum conyzoides increased also significantly (p<0.05) ALP, ALT, AST and blood glucose. Furthermore, an increase in the number of platelets associated with a normocytic and normochromic anaemia was observed. The cytotoxicity, determined by the MTT test and neutral red assay, has shown that the cytotoxicity of hydroalcoholic extract of Ageratum conyzoides and its total alkaloids was very close.

Conclusions

Our results have shown that Ageratum conyzoides at 500 and 1000 mg/kg can induce liver, kidney and haematological disorders. These toxics effects can be attributed to its total alkaloids especially to pyrrolizidine alkaloids which are present in this plant.     

Toxicity and potential anti-trypanosomal activity of ethanolic extract of Azadirachta indica (Maliacea) stem bark: An in vivo and in vitro approach using Trypanosoma brucei

Aim of the study

To determine the toxicity and anti-trypanosomal activity of the ethanolic extract of Azadirachta indica (Maliacea) stem bark, through in vivo and in vitro approach using Trypanosoma brucei brucei.

Materials and methods

Graded concentrations (100, 200, 400, 800, 1600 and 3200 mg/kg) of the crude stem bark ethanolic extract of Azadirachta indica, Hochst ex. A. Dc. (Maliacea) was tested for acute toxicity in 35 out bred Swiss (Wister) adult albino rats of both sexes. Secondly, the in vitro activity in test tubes and in vivo activity of the extract in 30 out bred Swiss (Wister) adult albino rats against Trypanosoma brucei brucei strain NITR/14 (Federe) was evaluated in a graded dose manner.

Results

The calculated intra-peritoneal LD₅₀ of the extract was 870 mg/kg and produced toxicity at high doses (>800 mg/kg). Graded concentrations of the ethanolic extract produced remarkable in vitro activity against Trypanosoma brucei brucei within seconds of inoculation. It also suppressed the establishment of parasitaemia at 100 mg/kg when administered simultaneously with infection in vivo. Similarly, at 200 and 400 mg/kg, the extract administered at the onset of parasitaemia for 4 consecutive days reduced parasitaemia, modulated declined packed volume (PCV) changes by day 48 post-infection in vivo.

Conclusion

The results confirm that the folkloric medicinal application of the extract of Azadirachta indica (Maliacea) has a pharmacological basis. Further investigation is however, needed to optimize the effectiveness of the extract.