A Comparison of Explanation Methods of Encapsulation Efficacy of Hydroquinone in a Liposomal System

     One of the most important parameters describing the liposomal formulation of hydroquinone is encapsulation efficacy. For the efficacy evaluation of hydroquinone trapped in liposomal structure, there is a need to first separate liposome from the matrix surrounding it. There are various separation techniques; however, in this study, the three techniques of centrifuges with and without washing and dialysis were used. From among the laboratory techniques, an appropriate method is the one that offers responses with a high repeatability. The statistical calculations revealed that encapsulation efficacy with a direct method resulted from a separation via the techniques of dialysis and centrifuge without washing had the highest dispersion with SDs of 6.1 and 8.7, respectively, while the SD value in the technique of centrifuge with washing was 5.2. Through an indirect method, hydroquinone encapsulation efficacy showed the best repeatability with SD values of 2.8 and 2.1 by using the two techniques of centrifuge and centrifuge filtration, respectively. It seems that the treatments leading to the dilution of hydroquinone formulation would result in hydroquinone leakage and a reduction of encapsulation efficacy. It seems that measurement of hydroquinone encapsulation efficacy with an indirect method is a better choice; therefore,  a centrifuge technique was utilized to report the mentioned efficacy at a speed of 45000 rcf and duration of 30 min due to having a reasonable price and ease of access.

In vitro evaluation of antibacterial activity of verbascoside, lemon verbena extract and caffeine in combination with gentamicin against drug-resistant Staphylococcus aureus and Escherichia coli clinical isolates

Objective: In recent years, there has been an increasing interest in using herbal products to overcome bacterial resistance. The aim of this study was to investigate the effect of lemon verbena aqueous extract, verbascoside and caffeine in combination with gentamicin against standard and clinical isolates of Staphylococcus aureus and Escherichia coli strains. Materials and Methods: The MIC and MBC values of different antibacterial agents against bacterial strains were determined. The effect of co-administration lemon verbena extract, verbascoside, and caffeine and gentamicin was studied in vitro using a checkerboard method and calculating fraction inhibitory concentration index (FICI). Results: Herbal extract, verbascoside and caffeine alone showed no inhibitory effects on any of the bacterial strains (at doses up to 200 mg/ml). Herbal extract, verbascoside and caffeine were able to decrease the MIC of gentamicin against the standard resistant strains and two clinical isolates. Among these combinations, the co-administration of verbascoside and gentamicin was more effective and synergistic activities (FIC

A modern formulation of traditional medicine: Jujube) Ziziphus jujuba Mill.) fruit syrup

Ziziphus jujuba Mill.,commonly called jujube (Rhamnaceae) has been known for its health benefits and used to cure different diseases such as asthma, cough and anxiety. The aim of this study is a formulation of its syrup and evaluation of physicochemical properties in accelerated stability conditions. The isosbestic point of spinosin (as marker) and its stability kinetic was studied in different buffers (pH range: 3-8). The isosbestic point was 259 nm that was different from max (334 nm). It was found that spinosin was more stable at pH of 7. So, the pH of the syrup was adjusted to 7. The syrup was a brown viscous liquid with jujube fruit flavor. Dry residue, pH, density and viscosity of the syrup were found to be 0.8 g/mL, 7, 1.29 g/mL and 0.14 Pa/s, respectively. During accelerated stability studies no significant changes were observed in physical properties and 3.2% decrease in spinosin content was seen that is acceptable. The preservative effectiveness test showed that the free preservative formulation met the USP criteria. In conclusion, Z. jujuba fruit syrup has a suitable potential to be manufactured on the mass production for traditional herbal medicine markets

The novel effect of cis-2-decenoic acid on biofilm producing Pseudomonas aeruginosa

Microbial biofilms are a main cause of many chronic infections and mortalities, such as dental caries, cystic fibrosis, osteoradionecrosis, urinary tract infections and native valve endocarditis. These polymeric matrices are sessile communities with different rules from those forms via known planktonic bacteria. One of the important biofilm-producing human pathogens is Pseudomonas aeruginosa, which causes death in the majority of people who suffer from cystic fibrosis, AIDS, burns and neutropenic cancer. To find a method for controlling the growth and resistance of P. aeruginosa biofilm, this study investigated the dispersion induction of this microorganism with a diffusible signal factor (DSF), cis-2-decenoic acid (CDA), in combination with Tobramycin as a useful antibiotic. Our findings confirmed that although CDA did not act as a dispersion inducer in this experiment, it did show an antimicrobial effect and decreased the MIC of Tobramycin. These results suggested that research on the probable new effects of DSF molecules will result in advances in the control of biofilm infections

Characterization of Encapsulated Berberine in Yeast Cells of Saccharomyces Cerevisiae

Abstract Berberine was loaded in yeast cells of Saccharomyces cerevisiae as a novel pharmaceutical carrier to improve the treatment of many diseases. The yeast-encapsulated active materials showed high stability and bioavailability due to the enhanced solubility and sustained releasing. In this study, different characteristics of prepared berberine loaded yeast cells (loading capacity, release kinetic order, MIC and stability) were evaluated by different analytical methods (fluorescence spectroscopy, HPLC and SEM).The loading capacity was about 78% ± 0.6%. Berberine release patterns of microcapsules happened in two different stages and followed by zero and first-order kinetic,respectively. About 99% of all active material released during 34 hours. MIC was improved by berberine loaded microcapsules in comparison with berberine powder. The microcapsules were completely stable. Berberine loaded Sac. cerevisiae could be considered as a favorite sustained release drug delivery system. The yeast would be applied as an efficient carrier to improve various properties of different active materials

The osteogenesis of bacterial cellulose scaffold loaded with fisetin

Objective(s): Bacterial cellulose (BC) has applications in medical science, it is easily synthesized, economic and purer compared to plant cellulose. The present study aimed to evaluate BC, a biocompatible natural polymer, as a scaffold for the bone marrow mesenchymal stem cells (BMSCs) loaded with fisetin, a phytoestrogen.Materials and Methods: BC hydrogel scaffold was prepared from Gluconaceter xylinus and characterized through scanning electron microscopy (SEM). Biocompatibility of BC was measured by MTT assay, BMSCs were obtained from femur of rat and the osteogenic potential of the BC scaffold cultured with BMSCs and loaded with fisetin, was investigated by measuring the alkaline phosphatase (ALP) activity, alizarin red staining (ARS) and real-time PCR in terms of osteoblast-specific marker, osteocalcin (OCN) and osteopontin (OPN). Results: Biocompatibility results did not show any toxic effects of BC scaffold on BMSCs, while it increased cell viability. The data showed that BC loaded fisetin differentiated BMSCs into osteoblasts as demonstrated by ALP activity assays and ARS in vitro. Moreover, results from gene expression assay showed the expression of OCN and OPN genes was increased in cells that were seeded on the BC scaffold loaded with fisetin.Conclusion: According to the results of the present study, BC loaded with fisetin is an effective strategy to promote osteogenic differentiation and a proper localized delivery system, which could be a potential candidate in bone tissue engineering

Black cumin (Nigella sativa) and its constituent (thymoquinone): a review on antimicrobial effects

Nigella sativa seeds have wide therapeutic effects and have been reported to have significant effects against many ailments such as skin diseases, jaundice, gastrointestinal problems, anorexia, conjunctivitis, dyspepsia, rheumatism, diabetes, hypertension, intrinsic hemorrhage, paralysis, amenorrhea, anorexia, asthma, cough, bronchitis, headache, fever, influenza and eczema. Thymoquinone (TQ) is one of the most active constituent and has different beneficial properties. Focus on antimicrobial effects, different extracts of N. sativa as well as TQ, have a broad antimicrobial spectrum including Gram-negative, Gram-positive bacteria, viruses, parasites, schistosoma and fungi. The effectiveness of N. sativa seeds and TQ is variable and depends on species of target microorganisms. The present review paper tries to describe all antimicrobial activities that have been carried out by various researchers

Interaction of methylxanthines and gentamicin against Staphylococcus aureus and Pseudomonas aeruginosa: Role of phosphodiesterase inhibition

Previous studies showed that methylxanthines increased the antimicrobial activity of gentamicin against Staphylococcus aureus and Pseudomonas aeruginosa. In this study, the effect of non-selective phosphodiesterase (PDE) inhibitors (methylxanthines: aminophylline and caffeine) and partially selective PDE inhibitors, dipyridamole and sildenafil, was evaluated on the antimicrobial activity of gentamicin using checkerboard method. Aminophylline at concentrations of 0.5 and 1 mg/ml reduced the minimal inhibitory concentration (MIC) of gentamicin (2 μg/ml) 2 and 4 times against S. aureus, and at concentrations of 0.5 and 2 mg/ml reduced the MIC of gentamicin (4 μg/ml) 2 and 4 times, respectively, against P. aeruginosa. Caffeine at concentrations of 1 and 2 mg/ml reduced the MIC of gentamicin (2 μg/ml) 4 and 32 times against S. aureus, and at concentrations of 0.12 and 2 mg/ml reduced the MIC of gentamicin (4 μg/ml) 2 and 4 times, respectively, against P. aeruginosa. However, dipyridamole and sildenafil (32 μg/ml) did not show any effect on MIC of gentamicin against S. aureus and P. aeruginosa. These results suggest that methylxanthines could increase gentamicin effects against S. aureus and P. aeruginosa but this effect is not mediated by inhibition of PDE 5, 6, 8, 10 and 11