Evaluation of debridement effects of bromelain-loaded sodium alginate nanoparticles incorporated into chitosan hydrogel in animal models.

OBJECTIVES: Bromelain, a mixture of proteolytic enzymes from pineapple (Ananas comosus) is known as a potential debriding agent in burn treatment. In this research, the debridement efficiency of chitosan hydrogel loaded by sodium alginate-chitosan nanoparticles (NPs) containing bromelain (Br 10%-AG-CS NPs) was evaluated in animal models. MATERIALS AND METHODS: The NPs were prepared using the ionic gelation technique and their properties were identified. Then, the debridement effect of bromelain NPs incorporated into chitosan hydrogel was evaluated 4 hr after wound treatment in animal models. RESULTS: The particle size of positively charged Br-AG-Cs NPs was about 390±25 nm. The encapsulation efficiency of bromelain into AG-CS NPs was about 92%. The in vitro release profile showed that the maximum release of bromelain from NPs occurred during the first 4 hr (70%). The hydrogel structure did not significantly affect the profile release of bromelain in the formulation. After 6 months of storage at 4 and 25 °C, the synthesized NPs indicated no significant changes in bromelain activity. It was found that Br 10%-Ag-Cs NPs-CS hydrogel had the most beneficial effects on reducing necrotic tissues and resulted in re-epithelialization compared with other treated groups (negative and positive control, CS hydrogel, and Br 10%-CS hydrogel). CONCLUSION: Therefore, using this novel formulation can be considered a potential debridement agent.

Evaluation the interaction of ABC multidrug transporter MDR1 with thymoquinone: substrate or inhibitor?

OBJECTIVES: Thymoquinone (TQ) has valuable medical properties like anticancer effects. Development of multidrug resistance (MDR) phenotype is one of the most important factors in failure of cancer chemotherapy. The aim of this study was to evaluate the mode of interaction of TQ and MDR1, a major MDR-related protein in gastric cancer drug resistant EPG85-257RDB cells, and its parental non-resistant EPG85-257 cells. MATERIALS AND METHODS: MTT assay was used to assess the effects of TQ and doxorubicin (DOX) on cell viability of tested cell lines and TQ effect on pump performance. HPLC analyses were used to measure the input and output of TQ in EPG85-257RDB cells. Molecular docking studies were used to identify interactions between TQ and MDR1. RESULTS: TQ inhibited cell viability in a time and concentration-dependent manner. Co-treatment of the cells with TQ and DOX did not significantly affect the amount of cell viability in comparison with DOX treatment alone. The HPLC analyses showed that more than 90% of TQ entered to EPG85-257RDB during 1 hr of treatment with TQ, but it was unable to exit from the cells. Moreover, there was no difference between influx and efflux amount of TQ in cells with inhibited and non-inhibited MDR1 transporters. Molecular docking studies revealed that TQ had a higher inhibitory constant to bind to active site of MDR1 protein as compared to specific inhibitor (verapamil) and substrate (vinblastine) of this transporter. CONCLUSION: These results proposed that TQ does not work as an inhibitor or a substrate of MDR1 transporter.

Topical green tea formulation with anti-hemorrhagic and antibacterial effects.

OBJECTIVES: Potentially preventable death from uncontrolled hemorrhage clearly indicates the importance of simple, fast and efficient ways to achieving hemostasis. The aim of this study was to develop a topical formulation of green tea extract for reducing bleeding that can be helpful in hemorrhage control. MATERIALS AND METHODS: Hydroalcoholic extract of green tea was isolated from Camellia sinensis and formulated in polyvinyl alcohol (PVA) to achieve two concentrations of 2% and 4% v/v. Folin-Ciocalteau assay was used to determine the total amount of tannins in extract. Rheological behavior of solutions was investigated by measuring viscosity at shear rates of 0-200 sec-1. Quantitative and qualitative microbial limit tests and minimum inhibitory concentration (MIC) assay were done. The effect of formulations on bleeding time was evaluated in an animal model. RESULTS: The total amount of tannin in green tea extract was 3.8% w/w and addition of green tea significantly increased the viscosity of PVA. The results of MIC assay showed that PVA could not inhibit the growth of bacteria, while, 716 µg/ml of green tea and 2860 µg/ml of green tea/PVA 4% inhibited the growth of Staphylococcus aureus and Pseudomonas aeruginosa. In an animal study both 2% and 4% formulations were able to stop hemorrhage approximately at an equal time compared with tranexamic acid (TXA) 50 mg/ml as a control and the lowest bleeding time was 6.4±0.51 sec for green tea/PVA 4%. CONCLUSION: Based on our results, the topical formulation of green tea extract in PVA has a great potential for anti-hemorrhage applications.

Crocin Increases Gastric Cancer Cells' Sensitivity to Doxorubicin.

BACKGROUND: Crocin is one of the substantial constituents of saffron extract. It has multiple clinical effects including anti-cancer effects. The development of the multidrug resistance (MDR) phenotype is one of the principal causes of cancer chemotherapy failure. The multidrug resistance protein 1 (MDR1) is one of the MDR-related protein and is often overexpressed in different cancers. In the present study, we aimed to evaluate the influence of crocin on the expression and function of MDR1 protein in EPG85-257 and EPG85-257RDB gastric cancer cell lines. METHODS: The cytotoxicity effect of crocin was evaluated by the MTT assay. The impacts of crocin on the expression and function of MDR1 were assessed by Real-time RT-PCR and MTT assay, respectively. RESULTS: The results demonstrated that crocin decreased cell viability in a dose-dependent manner with higher intensity on the EPG85-257 than the EPG85-257RDB cells. Crocin did not make any significant changes in the MDR1 gene expression level in EPG85-257 and EPG85-257RDB cell lines. In contrast, crocin increased doxorubicin cytotoxicity in drug-resistant cells, which might be induced by reduced MDR1 activity. CONCLUSION: In summary, although crocin did not affect mRNA expression of MDR1, results of MTT assay suggest that it might inhibit the MDR1 function.

Histopathological study of the maternal exposure to the biologically produced silver nanoparticles on different organs of the offspring.

This research for the first time presents the possibility of crossing the biologically produced SNPs through the placenta to different organs of rat offspring. SNPs were produced using Fusarium oxysporum. After adding 1 mmol final concentration of silver nitrate solution to the culture supernatant and 5 min heating, SNPs were produced, and their production was proved using visible spectrum, transmission electron microscope (TEM), and X-ray diffraction (XRD) analyses. SNPs were washed, and their concentration determined using inductively coupled plasma (ICP) instrument. SNPs were used for 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and after determination of their half maximal inhibitory concentration (IC50) dose, their toxic and nontoxic doses were determined and used for in vivo studies. A total of 24 female rats, after detection of their vaginal plugs, were divided into 3 groups each having 8 members. A control group was treated with normal saline. The other two groups were treated by toxic and nontoxic doses of SNPs, respectively. After delivery and breastfeeding, the pups were scarified, and their organs were collected and analyzed using histological examinations. Results showed that SNPs had a maximum absorbance peak around 450 nm, with polygonal and round shapes. XRD results confirmed the presence of SNPs. The concentration of the SNPs after washing was 19 ppm/mL based on the ICP results. MTT assay results showed that SNPs had a dose-dependent toxic effect. Histopathological examination results showed that SNPs could pass through the placenta; both their nontoxic and toxic doses induced somehow mild alternations in the liver, kidney, testis, and ovary and had no effects on the brains of the rat offspring. In conclusions, the use of the biologically produced SNPs should be limited during pregnancy and breastfeeding.

Design, Synthesis, and In Vitro Evaluation of Low Molecular Weight Protamine (LMWP)-Based Amphiphilic Conjugates as Gene Delivery Carriers.

Development of efficient non-viral carriers is one of the major challenges of gene delivery. In the current study, we designed, synthesized, and evaluated the in vitro gene delivery efficiency of novel amphiphilic constructs composed of cholesterol and low molecular weight protamine (LMWP: VSRRRRRRGGRRRR) peptide. Vectors having both hydrophobic and hydrophilic moieties were evaluated in terms of particle size and charge, DNA condensation ability, cytotoxicity, and gene transfection efficiency. The prepared vectors spontaneity self-assembled into the liposome-like particles with a high local positive density. The nano-vehicle A (H5-LMWP-Cholestrol) and nano-vehicle B (LMWP-Cholesterol) could form micelles at concentrations above 50 µg/mL and 65 µg/mL, respectively. The gel retardation assay showed that nano-vehicles A and B could condense pDNA more efficiently than the corresponding unconjugated peptides. The mean of size and zeta potential of complexed nano-vehicle A at N/P ratios of 5, 15, and 30 were 151 nm and 23 mv, and those of nano-vehicle B were 224 nm and 19 mv, respectively. In terms of transfection efficiency, the designed nano-vehicles showed almost two-fold higher gene expression level compared to PEI 25 kDa at optimal N/P ratios, and also exhibited negligible cytotoxicity on a model cancer cell, Neuro 2a. The findings of the present study revealed that these cationic micelles can be promising candidates as non-viral gene delivery vehicles.

Structural and functional aspects of P-glycoprotein and its inhibitors.

P-glycoprotein (P-gp) is a member of ATP-binding cassette (ABC) superfamily which extrudes chemotherapeutic agents out of the cell. Suppression of this efflux activity has been the subject of numerous attempts to develop P-gp inhibitors. The aim of this review is to present up-to-date information on the structural and functional aspects of P-gp and its known inhibitors. The data presented also provide some information on drug discovery approaches for candidate P-gp inhibitors. Nucleotide-binding domains (NBDs) and drug-binding domains (DBDs) have been extensively studied to gain more information about P-gp inhibition and it looks that the ATPase activity of this pump has been the most attractive target for designing inhibitors. Hydrophobic and π-π (aromatic) interactions between P-gp binding domains and inhibitors are dominant intermolecular forces that have been reported in many studies using different methods. Many synthetic and natural products have been found to possess inhibitory or modulatory effects on drug transporter proteins. Log P value is an important factor in studying these inhibitors and has a crucial role on absorption, distribution, metabolism, and excretion (ADME) properties of candidate P-gp inhibitors.

The effects of crocetin, extracted from saffron, in chemotherapy against the incidence of multiple drug resistance phenotype.

OBJECTIVES: Crocetin, one of the main substances of saffron extract, has anti-cancer effects. Drug resistance proteins (e.g. MRP1 and MRP2) are important reasons for the failure of cancer therapy. We intended to investigate the efficacy of crocetin on MRP1 and MRP2 activity in human ovarian cisplatin-resistant carcinoma cell line (A2780-RCIS). MATERIALS AND METHODS: The cytotoxic effect of crocetin was evaluated by the MTT assay. The efficacy of crocetin on MRP1 and MRP2 expression at mRNA level was studied by real-time RT-PCR. The effect of crocetin on the activity of MRP transporters was determined by drug efflux assay. RESULTS: Crocetin decreased cell proliferation in the A2780 (IC50: 183±7 µM) and A2780-RCIS (IC50: 316±9 µM). Crocetin decreased the expression level of MRP1 (22±2 %) and MRP2 (48±8 %) in A2780-RCIS and inhibited MRP pumps function directly in A2780 (44±1 %) and A2780-RCIS (88±10 %) and indirectly in A2780 (32±2 %) and A2780-RCIS (48±15 %) respectively. CONCLUSION: Our findings showed that crocetin could quench drug resistance through modulation of MRP transporters in the drug resistant human ovarian cancer cells.

Crocin suppresses multidrug resistance in MRP overexpressing ovarian cancer cell line.

BACKGROUND: Crocin, one of the main constituents of saffron extract, has numerous biological effects such as anti-cancer effects. Multidrug resistance-associated proteins 1 and 2 (MRP1 and MRP2) are important elements in the failure of cancer chemotherapy. In this study we aimed to evaluate the effects of crocin on MRP1 and MRP2 expression and function in human ovarian cancer cell line A2780 and its cisplatin-resistant derivative A2780/RCIS cells. METHODS: The cytotoxicity of crocin was assessed by the MTT assay. The effects of crocin on the MRP1 and MRP2 mRNA expression and function were assessed by real-time RT-PCR and MTT assays, respectively. RESULTS: Our study indicated that crocin reduced cell proliferation in a dose-dependent manner in which the reduction in proliferation rate was more noticeable in the A2780 cell line compared to A2780/RCIS. Crocin reduced MRP1 and MRP2 gene expression at the mRNA level in A2780/RCIS cells. It increased doxorubicin cytotoxicity on the resistant A2780/RCIS cells in comparison with the drug-sensitive A2780 cells. CONCLUSION: Totally, these results indicated that crocin could suppress drug resistance via down regulation of MRP transporters in the human ovarian cancer resistant cell line.

The effect of temperature on antibacterial activity of biosynthesized silver nanoparticles.

The purpose of this study was the evaluation of two different temperatures on antibacterial activity of the biosynthesized silver nanoparticles. 38 silver nanoparticles-producing bacteria were isolated from soil and identified. Biosynthesis of silver nanoparticles by these bacteria was verified through visible light spectrophotometry. Two strains were relatively active for production of silver nanoparticles. These strains were subjected for molecular identification and recognized as Bacillus sp. and Acinetobacter schindleri. In the present study, the effect of temperatures was evaluated on structure and antimicrobial properties of the silver nanoparrticles by transmission electron microscopy (TEM), X-ray diffraction (XRD) analysis and antimicrobial Agar well diffusion methods. The silver nanoparticles showed antibacterial activity against all the pathogenic bacteria; however, this property was lost after treatment of the silver nanoparticles by high temperatures (100 and 300 °C). TEM images showed that the average sizes of heated silver nanoparticles were >100 nm. However, these were <100 nm for non-heated silver nanoparticles. Although, XRD patterns showed the crystalline structure of heated silver nanoparticles, their antibacterial activities were less. This was possible because of the sizes and accordingly less penetration of the particles into the bacterial cells. In addition, elimination of the capping agents by heat might be considered another reason.