Antibacterial and antibiofilm efficacy of the preferred fractions and compounds from Euphorbia humifusa (herba euphorbiae humifusae) against Staphylococcus aureus.

ETHNOPHARMACOLOGICAL RELEVANCE: Euphorbia humifusa Willd., known as Di-Jin-Cao in Chinese, has long been utilized as a traditional herb for the treatment of furuncles and carbuncles mainly caused by Staphylococcus aureus infection. Despite extensive chemical and pharmacological studies reported previously for E. humifusa, the antibacterial and antibiofilm activities against S. aureus as well as the related mechanism of action (MoA) remain largely obscure. AIM OF THE STUDY: To investigate the antibacterial and antibiofilm activities of the preferred fractions and compounds from E. humifusa against S. aureus and assess the associated MoA. MATERIALS AND METHODS: The bioactive fractions and compounds were obtained from the 75% ethanol extract of E. humifusa (75%-EEEH) with the assistance of the related antibacterial and antibiofilm screening. Their antibacterial activities were determined using the broth microdilution method, whilst the inhibition of biofilm formation and the disruption of preformed biofilm were assessed by crystal violet staining and confocal laser scanning microscopy (CLSM). To achieve more effective therapies, the combinatory effects of different components were also studied. The biofilm metabolic activities of isolated compounds were evaluated by 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assay. The scanning electron microscopy (SEM) and quantitative real-time polymerase chain reaction (qRT-PCR) were employed to explore the antibiofilm mechanism. RESULTS: Fractions DJC06 and DJC07 collected from the ethyl acetate extract of the 75%-EEEH exhibited antibacterial activity (MIC = 256 µg/mL) against S. aureus and further separation of these two fractions led to the isolation and characterization of 22 compounds. Among the isolates, luteolin (LU), quercetin (QU), and kaempferol (KA) are the verified components associated with the antibacterial and antibiofilm activities by displaying individual or combinational MIC values of 8-128 µg/mL and 70.9-99.7% inhibition for biofilm formation. Importantly, QU and KA can work in synergy with LU to significantly enhance the efficacy via destroying cell integrity, increasing membrane permeability, and down-regulating the biofilm-related gene expression. CONCLUSIONS: The preferred fractions and compounds from E. humifusa exerted desired antibacterial and antibiofilm efficacy against S. aureus via a MoA involving cell morphology disruption and altered genes expression. The findings herein not only support its traditional use in the treatment of furuncles and carbuncles, but reveal E. humifusa is a potential source for producing promising antibiofilm alternatives against S. aureus and highlight the isolated components (LU, QU, KA) that can potentiate the efficacy when used in synergy.

[Separation and regeneration of protoplast from Phellinus igniarius].

OBJECTIVE: To study the conditions on separation and regeneration of protoplast from Phellinus igniarius. METHOD: The effects of enzymolysis conditions of P. igniarius mycelia on yield of protoplast and culturing conditons on regeneration ratio of protoplast were investigated. RESULT: When the 8 days-old mycelia was hydrolysed by 1.5% of lywallzyme adding to driselase of 0. 5% and at 30 degrees C for 3 h and enzymolysis was stablized by sucrose as a stablisher of osmotic pressure, higher yield of P. igniarius protoplast was obtained. If 10 days-old mycelia was used as raw material of enzymolysis and manntol was selected as stablisher of osmotic pressure of enzymolysis, higher regeneration ratio of P. igniarius protoplast also would be obtained in following regeneration step at same time keeping higher yield. For the regeneration processing, it was beneficial for the regeneration of P. igniarius protoplast that PDA plusing mulberry ramulus was used as the culture medium of regeneration and manntol was selected as the osmotic pressure establisher of regeneration culture medium. CONCLUSION: The method and conditions to keep both higher yield and regeneration ratio of P. igniarius protoplast were obtained.

[Study on liver targeted drug delivery system of the effective anticancer component from Bolbstemma paniculatum].

OBJECTIVE: To study the liver targeted drug delivery system of TBMS--the effective anticancer component from Bolbstemma paniculatum, and to discuss the system's function of decreasing toxicity. METHOD: BCA was used as carrier material. The preparation through overall feedback dynamic techniques. The properties of preparation and toxicology were also technology of nanoparticles was optimized studied. Thenanoparticles' targeting in mice vivo was observed with transmission electron microscopy. The function of decreasing toxicity was researched by the XXTX-2000 automatic quantitative analysis management system. RESULT: D50 was 0.68 microm. Drug-loading rate and entrapment rate were 37.3% and 88.6% respectively. The release in vitro accorded with Weibull equation. The reaching release balance time and the t 1/2 extended 26 times and 19 times respectively comparing with injection. Nanoparticles mainly distributed in liver tissue. Their toxicity to lung and liver was evidently lower than injection. Nanoparticles' LD50 exceeded injection's by 13.5% and their stimulus was much lower than injection. CONCLUSION: The TBMS can be targeted to liver by liver targeted drug delivery system. At the same time, the problem about the toxicity hindering clinical application could be solved, which lays the foundation for the further studies on TBMS.