Synergistic activity of lawsone methyl ether in combination with some antibiotics and artocarpin against methicillin-resistant Staphylococcus aureus, Candida albicans, and Trychophyton rubrum

Objective: One appealing strategy to overcome and prevent resistant problem is the use of combined two or more antibacterial substances. Lawsone methyl ether(LME) is the naphthoquinone found in the leaves of Impatiens balsamina. The objective of this study is to determine the interaction of LME with some antibiotics(ampicillin, tetracycline, norfloxacin, and clotrimazole) and a natural compound, artocarpin against methicillin-resistant Staphylococcus aureus(MRSA), Candida albicans, and Trychophyton rubrum.Methods: A broth microdilution method was used to determine the minimum inhibition concentration(MIC). Synergistic effects were evaluated at their own MIC using the checkerboard method and time-kill assay.Results: LME showed moderate antibacterial activity against MRSA with MIC value of 15.6 μg/mL, and exhibited strong antifungal activities against T. rubrum and C. albicans with MIC values of 7.8 and 3.9 μg/m L,respectively. The interaction of LME with the natural compound artocarpin against MRSA produced a synergy with fractional inhibitory concentration index(FICI) value of 0.31, while the combination of LME and clotrimazole exhibited synergy against C. albicans and T. rubrum with FICI values of 0.38 and 0.24, respectively. The time-kill assays confirmed that the compounds in combination enhanced their antimicrobial activities against the resistant microorganisms with different degrees.Conclusion: LME in combination with clotrimazole exhibited synergy effect against C. albicans and T.rubrum. In combination with artocarpin, it showed synergy effect against MRSA.     

Preventive and curative effects of curcumin on the development of gastric inflammatory diseases in rats

Preventive and curative effects of curcumin on experimental acute and chronic gastric ulcers were investigated to validate its clinical application on a remedy for peptic ulcer. Intraduodenal administration of curcumin, 5–20 mg/kg, inhibited gastric acid secretion in pylorus-ligated rats, and oral administration prevented ethanol-induced acute gastric mucosal lesions. Curcumin (20–80 mg/kg, p.o.) dose-dependently prevented both serotonin-induced gastric mucosal lesions and compound 48/80-induced gastric mucosal lesions in rats. Furthermore, oral administration of curcumin, 10–80 mg/kg, twice daily for 10 days, significantly accelerated the healing of acetic acid-induced chronic gastric ulcer and promoted mucosal regeneration in the ulcerated portion in a dose-related manner. Cimetidine prevented the formation of ethanol-induced gastric mucosal lesions, but not of serotonin-induced and compound 48/80-induced gastric mucosal lesions. Consecutive administration of cimetidine showed a marked acceleration in the healing of acetic acid-induced ulcer. Aminoguanidine, an inducible nitric oxide synthase (iNOS) inhibitor, showed anti-ulcerogenic effects similar to those oberved for curcumin. The present results indicate that curcumin exhibits gastric cytoprotection in the acute lesion models and ulcer healing promotion in the chronic ulcer model. The preventive and curative effects of curcumin might be due to an increase in the mucosal defensive mechanism through its antioxidant property and inhibition of NO or cytokine-mediated inflammation.     

Effects of curcumin on reflux esophagitis in rats

The preventive effect of curcumin, a compound isolated from the rhizome of Curcuma longa, on experimental reflux esophagitis in rats was investigated in order to validate its potential therapeutic use for gastroesophageal reflux disease. Curcumin (20 mg/kg, i.d.), the antioxidative agent dimethyl sulfoxide (DMSO) (1 ml/kg, i.p.) or the proton pump inhibitor lansoprazole (1 mg/kg, i.d.) inhibited the formation of acute acid reflux esophagitis by 52.5, 61.5 and 70.9% respectively. Curcumin alone was not effective in preventing chronic acid reflux esophagitis, but the combination of curcumin and DMSO reduced the mortality rate and the severity of the esophagitis ulcer index to the same extent (56.5%) as did the lansoprazole (53.9%). Intraduodenal administration of curcumin also markedly prevented the formation of acute mixed reflux esophagitis, together with reducing the incidence or the severity of neutrophil infiltration, when compared to a control group. In contrast, lansoprazole tended to increase the severity of all histopathological changes, when compared to either the control or the curcumin-treated group. Aminoguanidine, a specific inducible nitric oxide synthase inhibitor, had no preventive effect against both types of acute reflux esophagitis models, and increased the mortality in the chronic acid reflux esophagitis model. From these results, it is indicated that curcumin can effectively prevent acute reflux esophagitis formation. Although curcumin is less potent than lansoprazole in inhibiting acid reflux esophagitis, it is superior to lansoprazole in inhibiting mixed reflux esophagitis. The antiulcerogenic mechanisms are considered to be closely associated with its antioxidant nature and antiinflammatory property.     

Anti-allergic and Antioxidative Activities of Some Compounds from Thai Medicinal Plants

Evaluation of the anti-allergic and antioxidative activities of compounds from Thai medicinal plants demonstrated that lawsone methyl ether significantly exhibited the inhibitory effect on degranulation in RBL-2H3 cells with an EC₅₀ of 26.71?µM, while quercetin, a standard control, had an EC₅₀ of 10.02?µM. Other compounds from Thai medicinal plants including lucidin-ω-methyl ether, bergenin, homorapanone, strictosidinic acid and barakol, had no effect on the degranulation assay. In a DPPH radical scavenging assay, strictosidinic acid and barakol were more potent than the positive control, BHT. The EC₅₀ values of strictosidinic acid and barakol were 27.68 and 39.62?µM, respectively. Other tested compounds, including lawsone methyl ether, bergenin, homorapanone and lucidin-ω-methyl ether, had weak antioxidative activities or no activity. In a nitrite assay, only lawsone methyl ether reduced nitrite production with an EC₅₀ of 10.27?µM in RAW 264.7 cells. In conclusion, lawsone methyl ether suppresses degranulation in RBL-2H3 cells and reduces nitrite production in RAW 264.7 cells whereas strictosidinic acid and barakol have an antiradical action against DPPH.     

Topical anti-inflammatory and analgesic activities of standardized pomegranate rind extract in comparison with its marker compound ellagic acid in vivo

Ethnopharmacological relevance

In Chinese traditional medicine, the peels of Punica granatum L. have been used to treat traumatic hemorrhage, burn, and ulcers.

Aims of the study

This study aimed to assess the topical anti-inflammatory and analgesic activities of a standardized pomegranate rind extract (SPRE) of which ellagic acid (EA) was the major antioxidant constituent and the marker compound.

Material and methods

The topical anti-inflammatory effects of SPRE were evaluated against acute models (croton oil-induced mouse ear edema and carrageenan-induced rat paw edema) and chronic model (complete Freund's adjuvant (CFA)-induced polyarthritis). The topical analgesic activities of SPRE were investigated in the rat punctuate mechanical hyperalgesia test and in the mouse formalin test. All studies of SPRE were carried out in parallel with its marker compound EA.

Results

SPRE (5%, 2.5%, and 1%, w/w) and the equivalent EA (0.65%, 0.325%, and 0.13%, w/w) dose-dependently reduced the croton oil-induced mouse ear edema with a maximal inhibition of 86.30% and 80.82%, respectively. SPRE dose-dependently attenuated the inflammatory responses in the carrageenan-induced rat paw edema and in the CFA-induced polyarthritis but the equivalent EA were effective only at the doses of 0.65% and 0.325%. Both SPRE (5%) and EA (0.65%) showed significant topical analgesic activities in the rat punctuate mechanical hyperalgesia test and in the mouse formalin test.

Conclusions

SPRE was more active as an anti-inflammatory agent than EA. The anti-inflammatory and analgesic effects of SPRE were achieved through inhibiting the leukocyte infiltration and modulating the pro-inflammatory cytokines IL-β and TNF-α. These results clearly demonstrated that SPRE is a promising phytomedicine that could find use in the treatment of inflammatory diseases.     

Naphthoquinone Formation in Cell Cultures of Impatiens balsamina

Induction of naphthoquinone formation in Impatiens balsamina cell cultures was achieved by using parent plants yielding high levels of 2-methoxy-1,4-naphthoquinone as initiated explants. The cell culture with red-yellowish color was established in B5 medium supplemented with 0.1 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.0 mg/L 6-benzylaminopurine (BA). The cell cultures were capable of producing two naphthoquinones, lawsone, and an unknown, which was more polar than lawsone. The time-course of growth and lawsone production in I. balsamina cell culture were also established.     

Antifungal activity of lawsone methyl ether in comparison with chlorhexidine

J Oral Pathol Med (2011) 40 : 90–96 Objective: The aim of this study was to determine the antifungal activity of lawsone methyl ether mouthwash (LME) in comparison with chlorhexidine mouthwash (CHX) in vitro and in vivo. Materials and methods: For in vitro study, each mouthwash preparation was added into the inoculum of Candida. The turbidity was recorded after incubation at 37°C for 48 h. Candidal culture was performed and the number of colony of Candida albicans was recorded. For in vivo study, a crossover clinical trial was conducted in 22 HIV‐infected subjects and 32 denture wearers. Clinical examination was performed and oral rinse technique was carried out immediately before and 0, 1, 2 h after using each mouthwash. Allergy and subjective assessment of the mouthwashes were recorded. Statistical analysis was performed using one‐way ANOVA and linear mixed effect modeling. Results: In vitro, antifungal activity of 0.25% LME was significantly greater than that of 0.12% CHX (P < 0.05) and comparable with that of 0.2% CHX. In vivo, antifungal activity up to 2 hours of 0.025% LME mouthwash was evidenced in both groups of subjects, although significantly lower than that of 0.12% CHX. No allergic reaction was reported. LME mouthwash was graded to have less bitter taste than that of CHX. Subjects’ satisfaction on taste and smell of LME mouthwash was significantly greater than that of CHX (P < 0.05). Conclusions: Lawsone methyl ether mouthwash possesses potent antifungal activity both in vitro and in vivo. However, concentration of the mouthwash needs to be adjusted in addition to further clinical trials on long‐term use.     

利用UPLC/Q-TOF-MS/MS主成分分析和T-test探讨生半夏与法半夏有毒成分的差异

目的：从化学成分探讨生半夏与法半夏的差异。方法：制备生半夏和法半夏样品并采用UPLC/Q-TOF-MS/MS测定,通过主成分分析(PCA)和T检验分析研究两组样品之间的差别,并确定相应的化学标记物。UPLC/Q-TOF-MS/MS可准确地测定得到荷质比和MS/MS 的碎片数据,通过参考文献或数据库对照相应数据我们可以鉴别相应化合物。结果：甘草苷、甘草素、溶血磷脂酰胆碱(LPC)是最具特征的化学标记物。由于LPC可导致炎症反应的发生,炮制前后LPC的减少是减毒的原因之一;甘草苷和甘草素有治疗炎症的作用且能减少肝损伤作用,其在炮制后的法半夏中的增加也是减毒的原因。结论：该方法不仅可探索传统中药炮制后减毒的机制还可分别对炮制前后中药的质量进行控制。