Chemopreventive activity of Azadirachta indica on two‐stage skin carcinogenesis in murine model

The present study reports the chemopreventive activity of aqueous Azadirachta indica leaf extract (AAILE) in a murine two‐stage skin carcinogenesis model. Skin tumors were induced by topical application of 7,12‐dimethylbenz(a)anthracene (DMBA) (500 nmol/100 µL for 2 weeks) followed by 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) (1.7 nmol/100 µL of acetone, twice weekly) as a promoter. Male LACA mice were divided into four groups: control, DMBA/TPA, AAILE and AAILE + DMBA/TPA. AAILE was administered orally at a dose level of 300 mg/kg body weight thrice a week for 20 weeks. 100% tumor incidence was observed in the DMBA/TPA treated animals, whereas the AAILE + DMBA treated animals exhibited a tumor incidence of 58.3% only. A significant reduction in the mean tumor burden (54.5%) and mean tumor volume (45.6%) was observed in the mice that received AAILE along with DMBA/TPA. Topical application of DMBA/TPA to the skin resulted in well‐developed carcinomas associated with decreased expression of pro‐apoptotic protein such as caspase 3 and enhanced expression of antiapoptotic protein such as bcl‐2 when compared with the control counterparts. However, adminstration of AAILE inhibited skin carcinogenesis with induction of pro‐apoptotic proteins such as bax, caspase 3, caspase 9 and inhibition of antiapoptotic proteins such as bcl‐2. These results suggest that the induction of apoptosis may be one of the mechanisms underlying the chemopreventive effects of A. indica. Copyright © 2010 John Wiley & Sons, Ltd.     

Antiproliferative effect on human cancer cell lines after treatment with nimbolide extracted from an edible part of the neem tree (Azadirachta indica)

Nimbolide, a triterpenoid extracted from the flowers of the neem tree (Azadirachta indica), was found to have antiproliferative activity against some cancer cell lines. Treatment of cells with 0.5-5.0 microm concentrations of nimbolide resulted in moderate to very strong growth inhibition in U937, HL-60, THP1 and B16 cell lines. Flow cytometric analysis of U937 cells showed that nimbolide treatment (1-2.5 microm) resulted in cell cycle disruption by decreasing the number of cells in G0/G1 phase, with initial increases in S and G2/M phases. Cells exposed to a higher dose of nimbolide for a longer period displayed a severely damaged DNA profile, resulting in a remarkable increase in the number of cells in the sub-G1 fraction, with a reciprocal decrease of cells in all phases. Quantification of the expression of phosphatidylserine in the outer cell membrane showed that doses of nimbolide higher than 0.4 microm exerted remarkable lethality, with over 60% of cells exhibiting apoptotic features after exposure to 1.2 microm nimbolide. The antiproliferative effect of nimbolide and its apoptosis-inducing property raise hope for its use in anticancer therapy by enhancing the effectiveness of cell cycle disruption.     

Antifertility Effects of Aqueous and Steroidal Extracts of Neem Leaf (Azadirachta indica) in Male Wistar Rats

The antifertility efficacy of both aqueous and steroidal extracts of neem ( Azadirachta indica A. Juss) leaves was studied in male Wistar rats. Intraperitoneal injections of the steroidal extract at a dose of 100 mg/kg body weight, twice a week for 10 weeks resulted in impaired spermiogenesis, increased the number of headless spermatozoa and significantly decreased ( p <0.01) motility of cauda spermatozoa, leading to a decline in the fertility index. Feeding of a 0.8% (w/v) aqueous neem leaf extract in drinking water for 7 weeks decreased serum testosterone ( p <0.01) but no effect was observed in the fertility index. © 1997 by John Wiley & Sons, Ltd.     

Concurrent administration of aqueous Azadirachta indica (neem) leaf extract with DOCA-salt prevents the development of hypertension and accompanying electrocardiogram changes in the rat

The effect of concurrent administration of Azadirachta indica leaf extract with DOCA-salt was investigated in the development of hypertension.Over 5-6 week old, inbred male Wistar rats with a starting weight of 190 g were given either: (1) twice weekly subcutaneous (s.c.) injections of vehicle (soyabean oil, 0.25 mL per animal) for the first 2 weeks, plus normal drinking water (controls); (2) twice weekly (s.c.) injections (weeks 1 and 2 only) of 15 mg/kg DOCA dissolved in vehicle, plus drinking water containing 1.0% NaCl and 0.03% KCl (DOCA-salt group); or (3) 20 mg/kg of aqueous neem extract daily, in addition to the DOCA-salt treatment (DOCA-salt-neem group). All groups (8-12 animals) received normal rat pellets ad libitum and their BP was measured weekly. Terminally, the animals were anaesthetized and ECGs recorded using s.c. pins in a lead II configuration.The mean arterial pressure was significantly lower (p < 0.05) in the control (97 +/- 3.7 mmHg) and DOCA-salt-neem (87 +/- 3.4 mm Hg) groups than in the DOCA-salt group (115 +/- 7.1 mm Hg). PR and RR intervals and the duration of the QRS complex were shorter (p < 0.05) in the DOCA-salt group than in the control and DOCA-salt-neem groups. Amplitude of the QRS complex was increased (p < 0.05) in the DOCA-salt group compared with both the DOCA-salt-neem and the control groups.Daily administration of 20 mg/kg neem-leaf extract concurrently with DOCA-salt for 5 weeks, prevents the development of hypertension and the accompanying alterations in the ECG patterns seen in DOCA-salt treated rats.     

Evaluation of the antimalarial properties and standardization of tablets of Azadirachta indica (Meliaceae) in mice

The antimalarial activities of the tablet suspension of the bark and leaf of Azadirachta indica were evaluated on Plasmodium yoelli nigeriensis infected mice. The tablet suspensions exhibited high prophylactic, mode-rate suppressive and a very minimal curative schizonticidal effect. No animal was cured of the infection in the curative test and there was not much increase in the survival time of the animals compared with the control. The tablet suspensions from the leaf and bark at a concentration of 800 mg/kg and chloroquine at a concentration of 62.5 mg/kg body weight produced average percentage (%) parasitaemia of 79.6%, 68.2% and 99.5% for leaf, bark and chloroquine, respectively, in chemosuppression. Also in the prophylactic treatment, the tablet suspensions at 800 mg/kg and pyrimethamine at a concentration of 0.35 mg/kg gave an average parasitaemia reduction of 75.3%, 65.6% and 98.3% for the leaf, bark and pyrimethamine, respectively. There was a clear indication that both tablet suspensions from the leaf and bark possess antimalarial activity and a suspension from the former is relatively more effective than the bark. Extrapolation of the results from the antimalarial activity of the tablet suspension of the crude plant parts showed that an adult human would need to ingest a minimum of 48 g of the powdered plant material per day, an amount that is impracticable. A survival index value of 0.33 was obtained with the 800 mg/kg dose level, indicating that the tablet suspension has some moderate beneficial effect.     

醋酸型胃溃疡大鼠PGE2变化及不同针刺手法的调节效应

目的 :探讨慢性胃溃疡时胃粘膜组织和血浆前列腺素E2 的变化及不同针刺手法的调节效应。方法 :①采用改良“醋酸浸渍法”造成大鼠慢性胃溃疡模型 ;②按照GUTH等方法改进评定溃疡指数 ;③采用放射免疫分析法测定血浆及胃窦粘膜组织PGE2 含量。结果 :与对照组比较 ,模型组动物血浆PGE2 显著升高 (P <0 0 1) ;与模型组比较 ,热补组溃疡指数和血浆PGE2 含量显著降低 (P <0 0 1) ,捻补组溃疡指数显著降低 (P <0 0 5 ) ,血浆PGE2 有降低趋势但无统计学意义 (P >0 0 5 ) ;热补针法降低血浆PGE2 和溃疡指数较捻补针法显著 (P <0 0 5 ) ,各组动物胃窦粘膜组织PGE2 含量无明显差异 (P >0 0 5 )。结论 :胃窦粘膜PGE2 在大鼠胃溃疡发病中意义不大 ,针刺对其无明显调节作用 ;而血浆PGE2 含量在某种程度上可能反映胃粘膜损伤程度 ,针刺可降低血浆PGE2 使其趋于恢复正常 ,热补针法降低血浆PGE2 的作用明显优于捻转补法。     

Preventive effects of Azadirachta indica on benzo(a)pyrene-DNA adduct formation in murine forestomach and hepatic tissues

In the present investigation, the effects of aqueous Azadirachta indica leaf extract (AAILE) on (3)H-benzo(a)pyrene-DNA [(3)H-B(a)P-DNA] adduct formation, the status of biotransformation enzymes and reduced glutathione (GSH) content were evaluated in the forestomach and liver of Balb/c mice. Two weeks of AAILE treatment reduced the (3)H-B(a)P-DNA adduct levels by 31.6% in forestomach tissue. Similarly, (3)H-B(a)P-DNA adduct levels were decreased by 34.7% in the liver of AAILE treated mice compared with their control counterparts. After AAILE treatment, the cytochrome P450 content decreased, whereas the GSH content increased significantly in the hepatic tissue. In the forestomach as well as in the liver, the cytochrome b5 content declined, whereas an increase in glutathione-S-transferase (GST) activity was observed in both tissues. These observations suggested that AAILE may have reduced the metabolic activation of (3)H-B(a)P with enhanced detoxification of its active metabolites, hence the observed decrease in the levels of (3)H-B(a)P-DNA adducts. These molecular and biochemical modulations observed at the initiation phase of carcinogenesis seems to be significant and could be correlated with the chemopreventive effects of A. indica against B(a)P induced forestomach tumorigenesis.     

注射Azadirachta indica水提物对大鼠血红蛋白和血糖含量的影响(英文)

Presently, there is a growing interest in herbal remedies. Neem (Azadirachta indica) has been used in traditional medicine over centuries. In the present study, the effects of water extracts of Azadirachta indica seeds, stems, flowers and bark on the changes of hemoglobin content (Hb) and glucose levels in the blood of Rattus norvegicus were investigated. Different doses of A. indica water extracts of seeds, stems, flowers and bark were injected to the tested animals every 48 h for 14 days. Significant decrease in both hemoglobin content and glucose levels in the blood samples in all groups of injected rats were compared to control group. However, in all groups higher decrease was shown in the rats injected with 1 g·mL-1 of A. indica water extracts. In addition, the present study showed no significant relationship between decreased hemoglobin content and glucose levels in blood samples, and increased doses injected. In conclusion, A. indica has the potential to decrease both hemoglobin content and blood glucose levels.     

Cytotoxic and apoptosis-inducing activities of limonoids from the seeds of Azadirachta indica (neem)

Thirty-five limonoids, including 15 of the azadiradione type (1-15), five of the gedunin type (16-20), four of the azadirachtin type (21-24), nine of the nimbin type (25-33), and two degraded limonoids (34, 35), isolated from Azadirachta indica seed extracts, were evaluated for their cytotoxic activities against five human cancer cell lines. Seven compounds (3, 6, 7, 16, 18, 28, and 29) exhibited cytotoxic activity against one or more cell lines. Among these compounds, 7-deacetyl-7-benzoylepoxyazadiradione (7), 7-deacetyl-7-benzoylgeduin (18), and 28-deoxonimbolide (28) exhibited potent cytotoxic activity against HL60 leukemia cells with IC(50) values in the range 2.7-3.1 μM. Compounds 7, 18, and 28 induced early apoptosis in HL60 cells, observed by flow cytometry. Western blot analysis showed that compounds 7, 18, and 28 activated caspases-3, -8, and -9 in HL60 cells. This suggested that compounds 7, 18, and 28 induced apoptotic cell death in HL60 cells via both the mitochondrial- and the death receptor-mediated pathways. Futhermore, compound 7 was shown to possess high selective cytotoxicity for leukemia cells since it exhibited only weak cytotoxicity against a normal lymphocyte cell line (RPMI 1788).     

复方血立停对4种实验性胃溃疡模型的影响

本研究观察了复方血立停对大鼠应激性，组织胺性，水杨酸性和小鼠利血平性胃溃疡模型的影响，结果表明，每天口服复方血立停１次（０．２１４～０．８５６ｇ／ｋｇ），共５天对４种溃疡模型的抑制率分别为４０％～６３％，４８％～８５％，６８％～８７％和２７％～６５％，其中对水杨酸性溃疡模型的作用较为明显。提示复方血立停对实验性胃溃疡具有保护作用。     

Relaxant Effects of Ethanol Extracts of Boussingaultia gracilis in the Rat Isolated Gastric Fundus

The inhibitory effect of ethanol extracts of Boussingaultia gracilis (EBG) has been studied in muscle strips from the rat gastric fundus. When tone was raised by administration of carbachol, EBG concentration dependently relaxed the strips. The inhibitory effects of EBG were markedly reduced by pretreatment with propranolol; pretreatment with phentolamine slightly reduced the effects of EBG. The relaxant effect of EBG was not affected by pretreatment with hexamethonium, α-chymotrypsin, L-N^G-nitro-arginine-methyl-ester or methylene blue. These results indicated that EBG relaxed the gastric fundus mainly mediated via a β-adrenoceptors.     

干姜、炮姜对大鼠实验性胃溃疡的影响

报告了干姜、炮姜水煎液按4.5g/kg灌胃对大鼠4种实验性胃溃疡模型的影响,结果表明:炮姜除消炎痛模型外,对其他3种溃疡模型均呈明显的抑制倾向,干姜则无此作用。急性毒性试验显示:炮姜LD₅₀为170.6±1.1g/kg,干姜250g/kg以上未见死亡。提示:干姜经砂炒炮制后的炮姜,水溶性成分发生了变化。     

复方蜥蜴散不同微粒组合剂对大鼠急性胃黏膜损伤修复作用的实验研究

目的：观察复方蜥蜴散不同微粒组合剂对急性酒精性胃黏膜损伤模型大鼠血清PGE2及胃黏膜组织NOS水平的影响,探讨其保护胃黏膜损伤的作用机制。方法：用无水乙醇诱导的急性胃黏膜损伤大鼠模型,在造模前分别灌胃给予生理盐水、复方蜥蜴散不同微粒组合剂及铝碳酸镁等不同药物干预,用ELISA和硝酸还原酶法分别测定血清PGE2及胃黏膜组织NOS的水平。结果：预防治疗组大鼠血清PGE2及胃黏膜组织NOS的水平明显高于模型组（P〈0．01）,且胃黏膜病理组织学损伤有明显改善。结论：复方蜥蜴散不同微粒组合剂对急性胃黏膜损伤有预防保护作用。     

树舌多糖对胃黏膜损伤大鼠胃黏膜PGE2含量及血流量和黏液分泌的影响

目的:研究树舌多糖对大鼠胃黏膜损伤的保护作用及其机制.方法:采用醋酸法和幽门结扎法复制大鼠胃溃疡模型,分别测定胃黏膜PGE2含量和胃黏膜血流量及胃黏液分泌.结果:与模型对照组比较,多次灌服树舌多糖250～1 000mg·kg-1可明显增加大鼠胃黏膜PGE2含量和胃黏膜血流量,对大鼠胃内游离黏液和胃壁黏液的分泌也具有显著的增加作用,且有明显量效关系.结论:树舌多糖通过提高胃黏膜PGE2含量和胃黏膜血流量及胃黏液分泌来加强胃黏膜屏障,这是其保护胃粘膜损伤的作用机制之一.     

Endothelium‐Independent Vasorelaxation Effects of Sigesbeckia glabrescens (Makino) Makino on Isolated Rat Thoracic Aorta

The present study aimed to investigate the vasorelaxant effect of the methanol extract of Sigesbeckia glabrescens (Makino) Makino (MESG) on rat aortic rings and mechanism of action. MESG inhibited both noradrenaline bitartrate (NA)‐ and potassium chloride (KCl)‐induced contraction of endothelium‐intact aortic rings in a concentration‐dependent manner. Removal of the endothelium did not influence the effect of MESG on NA‐precontracted aortic rings. Pretreatment with MESG (250 µg/mL) inhibited calcium chloride‐induced vasocontraction of NA‐ or KCl‐precontracted endothelium‐denuded aortic rings. It also relaxed phorbol‐12‐myristate‐13‐acetate‐induced contraction of aortic rings in a concentration‐dependent manner. In addition, Bay K8644 (an L ‐type calcium channel opener) vasocontracted in MESG pretreated aortic rings. On the other hand, the inositol 1,4,5‐triphosphate receptor, the ryanodine receptor, the Rho‐kinase inhibitor (Y‐27632), a soluble guanylyl cyclase blocker (1‐H‐[1,2,4]‐oxadiazolo‐[4,3a]‐quinoxalin‐1‐one), and K⁺ channel blockers (glybenclamide, tetraethylammonium, and 4‐aminopyridine) did not affect the effect of MESG. These results suggested that the mechanism underlying the vasorelaxant effect of MESG is mediated by endothelium‐independent pathways. This specifically refers to blockade of the influx of extracellular Ca²⁺ via receptor‐operative Ca²⁺ channels and voltage‐dependent Ca²⁺ channels and inhibition of a protein kinase C‐mediated cellular pathway. Copyright © 2012 John Wiley & Sons, Ltd.     

维胃方对实验性大鼠胃溃疡血清NO和NOS的影响

目的:观察维胃方对实验性大鼠胃溃疡血清一氧化氮(NO)和一氧化氮合酶(NOS)的影响,探讨维胃方修复胃黏膜损伤的可能机制。方法:采用冰醋酸烧灼法,建立胃溃疡模型。以PH试纸检测胃酸变化,用公式S=π.d1/2.d2/2计算溃疡面积,比色法测定血清NO和NOS含量,并观察胃黏膜组织病理学变化。结果:与模型组比较,维胃方能明显修复腺泡,促进胃酸分泌,恢复胃液PH值(P<0.01),其中高、中剂量组接近正常组水平;维胃方高、中剂量组与模型组比较可显著降低大鼠血清中NO含量(P<0.01),抑制iNOS活性(P<0.01),增强cNOS活力(P<0.05);维胃方能不同程度减小胃黏膜损伤(P<0.01),其中以维胃方中剂量效果最优,与雷尼替丁组存在着显著性差异(P<0.05),高、低剂量组与雷尼替丁组无差异性(P>0.05);自愈组溃疡面积与模型组无显著性差异(P>0.05)。结论:维胃方对实验性胃溃疡具有明显的保护作用,其机制可能是通过降低大鼠血清中异常升高的NO水平和iNOS活性,进而减轻炎症介质对胃黏膜的损伤。     

Pretreatment with neem (Azadirachta indica) leaf preparation in Swiss mice diminishes leukopenia and enhances the antitumor activity of cyclophosphamide

Cancer chemotherapy is associated with several life threatening complications, including bone marrow suppression and leucopenia. To overcome this problem, colony stimulating factor (CSF), granulocyte colony stimulating factor (GCSF) and granulocyte macrophage colony stimulating factor (GMCSF), can be used, however, these therapeutics are expensive and have several disadvantages, including tumor growth promoting activities. This study attempted to use an immunostimulatory neem (Azadirachta indica) leaf preparation (NLP) to prevent the cyclophosphamide (CYP) induced reduction in the WBC count. Pretreatment of mice with NLP reduced the extent of leucopenia and neutropenia in normal and tumor bearing CYP treated mice. NLP pretreatment enhanced in vitro tumor cell cytotoxicity by peripheral blood mononuclear cells (PBMC) from CYP treated mice in either normal or tumor bearing conditions. Similarly, NLP pretreatment of mice enhanced the CYP mediated in vivo tumor growth inhibition and survivability of the host. Based on these observations, it is concluded that NLP would be an effective tool to reduce CYP-induced hematological complications.     

Studies on the effects of Pluchea indica less root extract on gastroduodenal ulcer models in rats and guineapigs

The methanolic fraction of P. indica root extract was found to possess significant antiulcer activity in different experimental animal models. In preventive antiulcer tests, significant protective actions in acetylsalicylic acid, serotonin and indomethacin-induced gastric lesions were observed in experimental rats. The extract also afforded significant protection to chemically-induced duodenal lesion in guineapigs. Significant enhancement of healing process in acetic acid-induced chronic gastric lesions were also observed in the extract-treated animals.     

鲜山药提取物对实验性胃溃疡大鼠血清表皮生长因子的影响

目的：研究鲜山药提取物对乙酸致大鼠胃溃疡黏膜的保护作用及可能机制。方法：采用放射免疫法观察鲜山药提取物对实验性大鼠胃溃疡愈合时血清表皮生长因子（EGF）的影响。结果：与模型组比较,鲜山药提取物高、中剂量组和施维舒组均可提高血清表皮生长因子含量（P〈0.01）;提取物高剂量组与施维舒组比较无显著性差异（P〉0.05）,但从数值上看,提取物高剂量组比施维舒组高。结论：鲜山药提取物抗溃疡作用可能通过提高粘液层质量和提高血清EGF含量相关。     

健脾清热化瘀中药对胃溃疡愈合质量影响的实验研究

目的:探讨健脾清热化瘀中药对大鼠乙酸性胃溃疡愈合质量的影响。方法:采用冰醋酸注射法制备大鼠胃溃疡模型,随机分为模型组、雷尼替丁组(西药组)、健脾中药组、清热中药组、化瘀中药组、健脾清热化瘀中药组(合用组)和正常对照组(空白组)。于给药14d后在光镜下观察溃疡指数(UI)、再生黏膜厚度、黏膜肌层缺损宽度及囊状扩张腺体数量,应用ELISA法检测血清表皮生长因子(EGF)及6-酮-前列腺素F1α(6-keto-PGF_1α)含量,免疫组化法检测胃黏膜表皮生长因子受体(EGFR)的表达。结果:健脾、清热、化瘀中药及其合方都能使再生黏膜厚度增加,黏膜肌层缺损宽度及囊状扩张腺体数量减少,与模型组比较P<0.01,中药合方组疗效明显优于西药组(P<0.05或P<0.01)。健脾清热化瘀中药可明显提高血清6-keto-PGF_1α含量,与模型组比较P<0.01,接近空白组水平,明显高于雷尼替丁组(P<0.05)。中药各组及西药组血清EGF含量较模型组及空白组升高(P<0.01),且可明显增强胃溃疡黏膜EGFR的表达(P<0.05或P<0.01),尤以中药合方组疗效最为明显(P<0.01)。结论:健脾清热化瘀中药通过改善胃溃疡再生黏膜组织学成熟度和功能成熟度,可明显改善实验性胃溃疡愈合质量,有效减少复发。