In vitro antibacterial activity of roselle calyx and protocatechuic acid

The in vitro inhibitory effect of roselle calyx and protocatechuic acid, a compound derived from roselle calyx, on the growth of methicillin-resistant Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii was studied. The data from inhibition zone and minimum inhibitory concentration (MIC) values showed that both roselle calyx extract and protocatechuic acid inhibited effectively the growth of all test bacterial pathogens, the antibacterial activity of protocatechuic acid being significantly greater than roselle calyx (p < 0.05). Furthermore, heat treatment did not affect the antibacterial activity of roselle calyx and protocatechuic acid against all test pathogens. The time-kill data from protocatechuic acid showed this agent provided concentration dependent antibacterial activities in broth and human plasma (p < 0.05); however, protocatechuic acid showed less inhibitory activity in human plasma than in broth (p < 0.05). These agents based on their lower MIC values, heat tolerance and concentration dependent antibacterial activity may be useful in clinical infection prevention or therapy.     

In vitro anti‐Helicobacter pylori activity of usnic acid

Eradication of Helicobacter pylori is an important objective in overcoming gastric diseases. Many regimens are currently available but none of them could achieve 100% success in eradication. Medicinal lichen is used in the treatment of gastric ulcer in local folk medicine in Anatolia (Turkey). The present study was performed to assess the in vitro effects of usnic acid from Usnea dasypoga against clinical isolates and standard H. pylori strains and their minimum inhibitory concentrations (MICs). A total of 38 strains was assayed for anti‐H. pylori activity. The agar dilution method was used for the determination of usnic acid and clarithromycin resistance. Six (16.2%) clinical isolates were resistant to usnic acid and five (13.5%) were resistant to clarithromycin. Dual susceptibility to usnic acid and clarithromycin rate was detected as very high (97.3%). Usnic acid has a strong and dose‐dependent activity against H. pylori strains. The synergism between usnic acid and clarithromycin may be effective in the treatment of H. pylori infection. Copyright © 2009 John Wiley & Sons, Ltd.     

In vitro anti-Helicobacter pylori potential of methanol extract of Allium ascalonicum Linn. (Liliaceae) leaf: susceptibility and effect on urease activity

The crude methanol extract of the leaf of Allium ascalonicum was screened in vitro against fi ve strains of Helicobacter pylori (Hp) (ATCC 24376, UCH 97001, UCH 97009, UCH 98026 and UCH 99039) for antibacterial activity by the agar diffusion method in Mueller-Hinton agar supplemented with de fi brinated horse blood. All the strains were inhibited by the extract to varying degrees. The minimum inhibitory concentrations (MICs) of the extract against all the tested strains ranged from 6.25 to 12.5 mg/mL. The effects of increasing concentrations of the extract on the urease activity of three of the Helicobacter pylori strains were investigated further. The results showed that increasing the concentration of the extract decreased the urease activity of all the strains tested. Phytochemical screening of the plant showed that it contains alkaloids, cardiac glycosides and saponins. The anti-Hp activity observed is discussed in relation to the chemical constituents reportedly isolated from these plants and their traditional uses. The result of this work suggests that Allium ascalonicum has some therapeutic potential against Helicobacter pylori infection, which could be explored for patients with gastroduodenal disorders.     

In vitro anti-Helicobacter pylori activity of aqueous extract from Persian Oak testa

Objective: Growing problem of antibiotic resistance in Helicobacter pylori, as a common cause of chronic gastritis and even stomach cancer, demands searching for novel candidates of herbal sources. This study is aimed at assessing the antimicrobial activity of aqueous extract obtained from Quercus brantii var. persica seed coat(Testa) on H. pylori isolated from gastric biopsy specimens.Methods: Such specimens were collected from 100 patients presenting with endoscopic gastroduodenal findings. Testa extracts were prepared from Persian Oak forests in the province of Kohgiluyeh and BoyerAhmad, IRAN. H. pylori isolates were obtained by a series of standard bacteriology tests and cell culture,then were confirmed by PCR. The activity of testa extracts towards 25 H. pylori isolates was assessed by well diffusion method, microdilution assay, and a disk diffusion assay in vitro. Results were analyzed statistically by one-way ANOVA analysis.Results: Aqueous extract of testa demonstrated an antimicrobial activity with zone diameters of inhibition ranged from 0 mm to 40 mm. Its inhibitory activity increased simultaneously with increasing extract concentration. The lowest MIC and MBC were both recorded as 2 μg/m L. Anti-H. pylori activity of testa extract was approximately close to tetracycline and metronidazole and less than amoxicillin. A potent extract of testa possessed significant inhibitory activity(P 0.05).Conclusion: Testa extract is suggested as a natural therapeutic source against the gastric H. pylori infection. However, evaluating the in vivo activity of this extract is necessary too.     

毛细管电色谱测定复方丹参注射液中原儿茶醛和原儿茶酸的含量

 目的 建立毛细管电色谱分离测定复方丹参注射液中原儿茶醛(PAH)和原儿茶酸(PA)的内标定量测定方法。方法 用ODS柱为固定相,甲醇和2 mmol·L^-1磷酸缓冲液(pH 3.0)为流动相,电压为-8kV,流速为10μL·min^-1,压力为6766.59kPa,紫外检测波长为255 nm,4-羟基苯甲酸为内标。结果 原儿茶醛和原儿茶酸的线性范围分别是0.2-2.5ng和0.042-0.52 ng;相关系数分别为0.999 96和0.999 97;加样回收率分别为98.02%(RSD=3.42％)和100.0％(RSD)=0.93％);检测限分别为0.085 ng和0.036 ng;精密度实验RSD分别为0.52％和0.33％;重现性实验RSD分别为0.27％和0.34％;稳定性实验RSD分别为0.37％和0.32％:柱效分别为113246和257901;PA与PAH的分离度为4.854,PAH与4-羟基苯甲酸的分离度为4.620。结论 该方法简便,快速,准确,灵敏度高,重现性好,样品用量少,适用于丹参及含丹参制剂的样品中原儿茶醛和原儿茶酸的分离测定。     

In vitro anti-Helicobacter pylori activity of extracts of selected medicinal plants from North West Cameroon

ETHNOPHARMACOLOGICAL RELEVANCE: Helicobacter pylori, a gram negative microaerophilic bacterium is a major etiological agent in duodenal, peptic and gastric ulcers. The growing problem of antibiotic resistance by the organism demands the search for novel compounds from plant based sources. AIM OF STUDY: The present study is aimed at evaluating the antimicrobial activity of some selected medicinal plants on clinical isolates of H. pylori circulating in Cameroon in a bid to identify potential sources of cheap starting materials for the synthesis of new drugs. MATERIALS AND METHODS: Gastric biopsy samples were obtained from patients presenting with gastroduodenal complications. H. pylori was isolated from the specimens following standard microbiology procedures. The disk diffusion method was used to determine the susceptibility of 15 isolates to ten methanol plant extracts (Ageratum conyzoides, Scleria striatinux, Lycopodium cernua, Acanthus montanus, Eryngium foetidium, Aulutandria kamerunensis, Tapeinachilus ananassae, Euphorbia hirta, Emilia coccinea and Scleria verrucosa). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for the most active plant extracts were also determined by the agar dilution method. Results were analyzed statistically by the Fisher's exact test. RESULTS: All the plants tested demonstrated antimicrobial activity with zone diameters of inhibition ranging from 0-30mm. Of these, A. conyzoides, S. striatinux and L. cernua showed very potent antibacterial activity on the isolates. The lowest MIC and MBC recorded were 0.032mg/mL and 0.098mg/mL respectively. However, the MIC of the extracts ranged from 0.032-1.0mg/mL for S. striatinux; 0.063-0.5mg/mL for L. cernua and 0.063-1.0mg/mL for A. conyzoides. The MBC of the extracts ranged from 0.098-15.0mg/mL for S. striatinux; 0.098-12.5mg/mL for A. conyzoides, and 0.195-12.5mg/mL for L. cernua. The extracts had a wide spectrum of activity. The three most potent extracts possessed significant (P<0.05) inhibitory activities. CONCLUSION: The plant extracts may contain compounds with therapeutic activity.     

原儿茶酸衍生物的合成及活性研究

目的:探讨原儿茶酸(protocatechuic acid,PCA)及其衍生物体外清除DPPH自由基活性及对鸡胚绒毛尿囊膜(chick chorioallantoic membrane,CAM)血管新生的影响.方法:利用苄基保护及苄酯水解等相关反应,得到PCA系列衍生物PCA-1,PCA-2,PCA-3,结构经1H,13C-NMR及MS验证,并采用DPPH自由基体外抗氧模型、CAM对PCA及其衍生物的活性进行筛选.结果:PCA及含有邻二酚羟基的PCA-1的体外清除DPPH自由基活性较强;PCA,PCA-3对新生血管有一定的抑制作用,而PCA-2则能促进血管的新生(P＜0.001).结论:PCA分子结构中的邻二酚羟基为体外清除DPPH自由基的活性部位;不含邻二酚羟基,同时有羧基时能增强其促血管新生活性,但需要进一步的实验验证.     

In vitro inhibition of Helicobacter pylori growth and adherence to gastric mucosal cells by Pycnogenol

The emergence of antibiotic resistant H. pylori strains has necessitated the identification of alternative additive therapies for the treatment of this infection. The study tested whether a specific pine bark extract (Pycnogenol is effective in inhibiting the growth and adherence of H. pylori in vitro. Inhibition of H. pylori growth by Pycnogenol was tested in liquid medium as well as in an in vitro model by using sessile bacteria attached to AGS cells. Adherence was determined by co-incubation of gastric cells with Pycnogenol and H. pylori in vitro. Pycnogenol inhibited H. pylori growth in suspension with an MIC(50) of 12.5 microg/mL. Growth of H. pylori in infected cells was reduced to 10% of the control value by 125 microg/mL Pycnogenol. Adherence of H. pylori to gastric cells was reduced by 70% after 3 h incubation with 125 microg/mL Pycnogenol. The results show a significant, yet limited inhibition of growth and adherence of H. pylori to gastric cells by Pycnogenol. In vivo studies have to demonstrate the clinical relevance of these findings.     

UPLC法同时测定胆木注射液中原儿茶酸、新绿原酸、绿原酸和隐绿原酸

目的 建立同时测定胆木注射液中原儿茶酸、新绿原酸、绿原酸和隐绿原酸的方法.方法 采用UPLC法,色谱柱Waters Acquity UPLC BEH C18 (50mm×2.1mm,1.7 μm),流动相为甲醇(A)-0.1％乙酸水溶液(B),梯度洗脱;检测波长为260 nm(原儿茶酸)和325 nm(新绿原酸、绿原酸和隐绿原酸);体积流量0.4 mL/mim柱温35℃.结果 原儿茶酸、新绿原酸、绿原酸和隐绿原酸分别在3.984～159.400、1.440～57.600、1.204～48.160、1.056～42.240 μg/mL内具有良好的线性关系;平均回收率分别98.66％、96.76％、101.1％、103.6％.结论 UPLC分离效果及重复性好,且快速、准确,可作为胆木注射液的质量控制方法.     

Pterocarpus santalinus: an In Vitro study on its anti-Helicobacter pylori effect

The anti-H. pylori activity of Pterocarpus santalinus (PS), a traditional herb, has been assessed and compared with that of bismuth subcitrate, through in vitro studies employing rat gastric epithelial cell cultures and H. pylori isolates from gastric mucosal biopsy patients. The MIC of PS was found to be 20 microg/mL. H. pylori was co-cultivated with rat gastric epithelial cells in the presence/absence of PS at its MIC. A reduction in the activity of urease, a normal appearance of the epithelial cells on electron microscopic examination, a decrease in lipid peroxidation and lactate dehydrogenase suggests the possible anti-H. pylori activity of PS.     

In vitro susceptibility of Helicobacter pylori to isoquinoline alkaloids from Sanguinaria canadensis and Hydrastis canadensis

Methanol extracts of the rhizomes of Sanguinaria canadensis, and the roots and rhizomes of Hydrastis canadensis, two plants used traditionally for the treatment of gastrointestinal ailments, were screened for in vitro antibacterial activity against 15 strains of Helicobacter pylori. The rhizome extracts, as well as a methanol extract of S. canadensis suspension-cell cultures inhibited the growth of H. pylori in vitro, with a MIC50 range of 12.5-50.0 microg/ml. Three isoquinoline alkaloids were identified in the active fraction. Sanguinarine and chelerythrine, two benzophenanthridine alkaloids, inhibited the growth of the bacterium, with an MIC50 of 50.0 and 100.0 microg/ml, respectively. Protopine, a protopine alkaloid, also inhibited the growth of the bacterium, with a MIC50 of 100 microg/ml. The crude methanol extract of H. canadensis rhizomes was very active, with an MIC50 of 12.5 microg/ml. Two isoquinoline alkaloids, berberine and beta-hydrastine, were identified as the active constituents, and having an MIC50 of 12.5 and 100.0 microg/ml, respectively.     

高效液相色谱法同时测定解风酒中阿魏酸、原儿茶酸和桂皮醛

目的 用HPLC法测定解风酒(当归、狗脊、桂枝等)中阿魏酸、原儿茶酸、桂皮醛.方法 采用kromasil C18柱,以乙腈为流动相A,0.1％冰醋酸溶液为流动相B,线性梯度洗脱(0 ～ 35min,75％B～55％ B),体积流量为1.0 mL/min,柱温30℃,检测波长260 nm.结果 方中阿魏酸、原儿茶酸及桂皮醛分别在0.024 26 ～0.242 6 μg、0.025 02～0.250 2 μg和0.01048～0.104 8 μg范围内与峰面积呈良好的线性关系(r=0.999 9),平均加样回收率分别为98.2％、99.9％、99.2％(n=9),RSD分别为1.52％、0.78％、1.14％.结论 本法操作简单、准确、重复性好,可用于解风酒的质量控制.     

丹参素和原儿茶醛对丹酚酸B降解规律的影响研究

目的建立定量测定多种丹参酚酸的高效液相色谱(HPLC)分析方法,考察丹参素和原儿茶醛对丹酚酸B降解规律的影响。方法应用HPLC技术对丹酚酸B降解样品中的4种酚酸进行定量分析,应用LC-MS技术剖析样品的化学物质基础,对加入丹参素和原儿茶醛前后的丹酚酸B样品进行研究。结果丹酚酸B降解产物主要有9种,包括丹参素、原儿茶醛、丹酚酸B的多种异构体、紫草酸以及多种紫草酸异构体。加入相同质量浓度的丹参素和原儿茶醛,原儿茶醛对丹酚酸B降解的保护作用更明显,紫草酸异构体I和II的峰面积随着初始原儿茶醛质量浓度的增大而有所增加。结论原儿茶醛对丹酚酸B降解的保护作用可能是依赖于其弱酸性,紫草酸异构体I和II的峰面积受原儿茶醛初始质量浓度的影响可能与反应平衡改变有关。     

In vitro susceptibility of Helicobacter pylori to botanical extracts used traditionally for the treatment of gastrointestinal disorders

The gram-negative bacterium Helicobacter pylori (HP), identified in 1982, is now recognized as the primary etiological factor associated with the development of gastritis and peptic ulcer disease. In addition, HP infections are also associated with chronic gastritis, gastric carcinoma and primary gastric B-cell lymphoma. For centuries, herbals have been used in traditional medicine to treat a wide range of ailments, including gastrointestinal (GI) disorders such as dyspepsia, gastritis and peptic ulcer disease (PUD). However, the mechanism of action by which these botanicals exert their therapeutic effects has not been completely elucidated. As part of an ongoing screening program, the study assessed the in vitro susceptibility of 15 HP strains to botanical extracts, which have a history of traditional use in the treatment of GI disorders. Methanol extracts of Myristica fragrans (seed) had a MIC of 12.5 microg/mL; Zingiber officinale (ginger rhizome/root) and Rosmarinus officinalis (rosemary leaf) had an MIC of 25 microg/mL. Methanol extracts of botanicals with a MIC of 50 microg/mL included Achillea millefolium, Foeniculum vulgare (seed), Passiflora incarnata (herb), Origanum majorana (herb) and a (1:1) combination of Curcuma longa (root) and ginger rhizome. Botanical extracts with a MIC of 100 microg/mL included Carum carvi (seed), Elettaria cardamomum (seed), Gentiana lutea (roots), Juniper communis (berry), Lavandula angustifolia (flowers), Melissa officinalis (leaves), Mentha piperita (leaves) and Pimpinella anisum (seed). Methanol extracts of Matricaria recutita (flowers) and Ginkgo biloba (leaves) had a MIC > 100 microg/mL.     

HPLC法同时测定透骨灵橡胶膏中槲皮素、原儿茶酸和乌头碱

目的建立同时测定透骨灵橡胶膏(透骨草、天南星、鸡血藤等)中槲皮素,原儿茶酸和乌头碱的测定方法。方法采用反向高效液相色谱法,色谱柱为Agilent C18色谱柱(150 mm×4.6 mm,5μm),流动相为乙腈-0.2%磷酸(梯度洗脱),检测波长为250 nm,体积流量为1 mL/min。结果槲皮素在0.158 8～2.540 8μg,原儿茶酸在0.177 6～2.841 6μg/mL,乌头碱在0.212 8～3.404 8μg/mL与峰面积呈良好的线性关系。加样回收率分别为98.6%、100.8%、97.7%,RSD分别为1.66%、2.58%、1.09%。结论能准确分析透骨灵橡胶膏中3种主要成分,灵敏度高,重复性好,可用来控制透骨灵橡胶膏的质量。     

Aged garlic extract, garlic powder extract, S-allylcysteine, diallyl sulfide and diallyl disulfide do not interfere with the antibiotic activity of gentamicin

It was shown that aged garlic extract (AGE), garlic powder and the following garlic-derived compounds: S-allylcysteine (SAC), diallyl sulfide (DAS) and diallyl disulfide (DADS), ameliorate gentamicin (GM)-induced nephrotoxicity in rats. However, it was not established if the above mentioned extracts and compounds of garlic could interfere with the antibiotic action of GM. To address this point, AGE, garlic powder extract (GPE), SAC, DAS and DADS were assessed for their ability to interfere with the in vitro antibiotic activity of GM in Escherichia coli cultures. It was found that the above mentioned extracts and compounds of garlic were unable to decrease the antibiotic capacity of GM and even SAC, DAS and DADS alone inhibited the growth of Escherichia coli and enhanced the antibiotic effect of GM. Our data show that SAC, DAS and DADS are antibacterial compounds against E. coli and suggest that AGE, GPE, SAC, DAS and[sol ]or DADS may be administered along with GM-treatment to ameliorate GM-induced nephrotoxicity without interfering with its antibiotic activity.     

Antibacterial activity of Chamomilla recutita oil extract against Helicobacter pylori

The antibacterial activity of an oil extract of Chamomilla recutita flowers against Helicobacter pylori (H. pylori) was evaluated by the agar dilution method using Colombia agar with 10% sheep blood, an inoculum of McFarland 0.5 and incubation in an anaerobic atmosphere at 37 degrees C for 3 days. The oil extract was prepared by olive oil extraction of Chamomilla recutita flowers using rotary pulsation. The MIC(90) (minimal inhibitory concentration) and MIC(50) were 125 mg/mL and 62.5 mg/mL, respectively. It was shown that the Chamomilla recutita oil extract inhibited the production of urease by H. pylori. In addition, it was found that the morphological and fermentative properties of H. pylori were affected by application of the Chamomilla recutita oil extract.     

In vitro anti‐adhesive activity of green tea extract against pathogen adhesion

Camellia sinensis polysaccharide has been reported to possess anti‐adhesive activity against pathogens. The present study was designed to investigate whether hot water extracts obtained from green tea leaves might inhibit pathogen adhesion to human or mouse cell lines. Green tea extract‐4 (CSI‐4) with the maximum yield of 4% (w/v) is composed of a major proportion of carbohydrates containing 40% uronic acids, but lack of catechins. It showed strong inhibitory activities against hemagglutination mediated by pathogens Helicobacter pylori, Propionibacterium acnes and Staphylococcus aureus with the minimum inhibitory concentrations of 0.01‐0.5 mg/mL. CSI‐4 further demonstrated an inhibitory effect on the adhesion of these pathogens to host cell lines with the IC₅₀ values (50% inhibition of adhesion) of 0.14–2.3 mg/mL. It exhibited the highest activity against P. acnes, but no inhibitory effects were observed against Lactobacillus acidophilus, Bifidobacterium bifidum, Escherichia coli, or Staphylococcus epidermidis. Our results suggest that CSI‐4 may exert a selective anti‐adhesive effect against certain pathogenic bacteria with no adverse effects against beneficial or commensal bacteria. Copyright © 2008 John Wiley & Sons, Ltd.     

RP-HPLC测定双丹口服液中丹酚酸B、丹参素和原儿茶醛的含量

目的:建立双丹口服液(丹参、牡丹皮)中有效成分丹酚酸B、丹参素和原儿茶醛的HPLC含量测定方法。方法:采用Phenomenex LunaC18柱(4.6mm×150mm,5μm),甲醇-乙腈-甲酸-水(30:10:1:59)为流动相,检测波长:286nm,流速:1.0mL/min,测定丹酚酸B;甲醇-乙腈-2(v/v)甲酸溶液(9:4:87)为流动相,检测波长:281nm,流速:1.0mL/min,测定丹参素和原儿茶醛。结果:丹酚酸B平均回收率为98.6,RSD=1.91(n=6);丹参素平均回收率为99.2,RSD=2.2(n=6);原儿茶醛平均回收率为97.3,RSD=2.5(n=6)。结论:6批样品测定结果表明,该方法简便、准确,可用于双丹口服液丹酚酸B等3种有效成分含量测定。     

Antimicrobial activity of an Amazon medicinal plant (Chancapiedra) (Phyllanthus niruri L.) against Helicobacter pylori and lactic acid bacteria

The potential of water extracts of the Amazon medicinal plant Chancapiedra (Phyllanthus niruri L.) from Ecuador and Peru for antimicrobial activity against Helicobacter pylori and different strains of lactic acid bacteria such as Lactobacillus acidophilus, Lactobacillus casei and Lactobacillus plantarum was investigated. H. pylori was inhibited by both water extracts in a dose dependent manner, whereas lactic acid bacterial growth was not affected. Both extracts contained ellagic acid and hydroxycinnamic acid derivatives and exhibited high free radical scavenging linked-antioxidant activities (89%). However, gallic acid was detected only in the Ecuadorian extract. Preliminary studies on the mode of action of Chancapiedra against H. pylori revealed that inhibition may not involve proline dehydrogenase-based oxidative phosphorylation inhibition associated with simple mono-phenolics and could involve ellagitannins or other non-phenolic compounds through a yet unknown mechanism. This study provides evidence about the potential of Chancapiedra for H. pylori inhibition without affecting beneficial lactic acid bacteria.