Euphlyctis Cyanophlyctis Schneider, 1799 (Amphibia: Dicroglossidae) in district Lower Dir, Pakistan

Euphlyctis cyanophlyctis (the skittering frog) is one of the most widespread species in Pakistan. Present study was aimed to know the presence of Euphlyctis cyanophlyctis in urban and rural areas of Lower Dir, the North-western Pakistan. A total of 33 frogs were collected, including 15 from rural and 18 from urban areas. The frogs were caught by hands covered with gloves instead of using nets. The collection was managed from August to October 2016 and from April to May 2018. Morphometric analysis, coloration as well as photographs of the frogs have been provided in detail. Skittering frogs were seen frequent in swampy areas near the water bodies. These frogs were mostly seen after sunset.

Quorum-quenching activity of some Iranian medicinal plants

Anti-quorum sensing (QS) or quorum quenching (QQ) is known as a new anti-bacterial strategy to combat bacterial infection. One of the best candidates for this strategy is a natural plant or traditional herbal medicine. This review aimed to summarize and introduce Iranian medicinal plants with anti-QS properties. Biomedical databases (PubMed, Scopus, Google Scholar and Web of sciences) were investigated to retrieve all related manuscripts published in English and Persian. Out of 65 documents, 47 papers were published during 2010–2020. We categorized and summarized 19 papers that particularly presented the anti-QS activity of Iranian medicinal plants. Based on our results, different studies have been completed on the QQ effects of medicinal plants. We identified 106 plant species with different properties in medicine that have been evaluated for anti-QS activities in Iran. The QQ effects of herbal extracts were identified through different in vitro examinations on biosensor and clinical bacterial strains. Only 35 medicinal plants have shown these effects at sub-MICs. Our review summarizes Iranian medicinal plants with anti-QS properties. Some of these herbal extracts showed anti-QS activity against biosensors, standard and clinical bacterial strains. This result is very important because QS systems can be considered as a new target for the development of new remedial strategies and it is a good opportunity to perform QQ studies to effectively combat bacterial infections in the future.

Antibacterial activity and mechanism of action of chitosan nanofibers against toxigenic Clostridioides (Clostridium) difficile Isolates

BACKGROUND

Clostridioides difficile a Gram-positive, obliged anaerobic, rod-shaped spore-former bacterium, causes a wide spectrum of diseases, ranging from mild, self-limiting diarrhoea to serious diarrhea. Chitosan, a natural polysaccharide, is largely known for its activity against a wide range of microorganisms. Chitosan, in the form of nanofibrils (nanofibrilated chitosan), consists of separated fibers which can be suspended easily in aqueous media.

STUDY DESIGN

This paper, for the first time, aims to evaluate the antimicrobial activity of chitosan nanofibers against C. difficile isolates.

METHODS

Chitosan nanofibers were characterized through scanning electron microscopy and atomic force microscopy. Minimum inhibitory concentration and minimum bactericidal concentration of chitosan nanofibers against toxigenic C. difficile isolates (with resistance gene: ermB, tetM and tetW) was determined by the standard broth microdilution method.

RESULTS

The Miniumum Inhibitory Concentration of chitosan nanofibers for two toxigenic isolates with resistance genes ermB, tetM and tetW, two toxigenic isolates ermB+ tetM+ and the standard strain ATCC 700057 was similar and equal to 0.25 mg/mL. The minimum bactericidal concentration for all isolates was 0.5 mg/mL.

CONCLUSIONS

The results demonstrated that chitosan nanofibers exhibit potent antimicrobial activities against multiple toxigenic C. difficile isolates, and the antibacterial effect of chitosan nanofibers against C. difficile isolates with ermB, tetM and tetW resistance genes indicates that interfering with the synthesis of proteins is not the mechanism of action of chitosan nanofibers.

The physicochemical, sensory evaluation and glycemic load of stingless bee honey and honeybee honey

Honey is a widely consumed functional food which has a valued place in traditional medicine. The purpose of this study was to compare the physicochemical properties, sensory evaluation, and glycemic load of honeybee honey and stingless bee honey. Physicochemical parameters include moisture, ash, pH, free acidity, electrical conductivity and sugar content which were determined by following the International Honey Commission methods. Ten subjects were selected for glycemic index study. For oral glucose tolerance test (OGTT), about 50 g of pure glucose in 250 mL of water was given to subject while 25 g of pure glucose in 250 ml water as a reference food. The blood glucose response was measured based on the incremental area under curve (IAUC) and compared to that of 25 g of available carbohydrate from glucose. Results indicated that the moisture content (29.5% vs 28.0%), free acidity (84.5 vs 73.5) and total carbohydrate (64.33 vs 50.35) of honeybee honey was significantly (all p<0.05) higher as compared to stingless bee honey, with no significant differences in ash content, pH and electrical conductivity between both honey (p>0.05). Their ash content is closely similar, which might be due to a similar geographical source, namely the Marang area. In terms of sensory evaluation, honeybee honey is more preferred, as the overall scores (5.5 vs 4.8) including colour (4.5 vs 3.5), odour (5.2 vs 4.0) and sweetness (6.0 vs 3.5) were significantly higher than stingless bee honey, even though the aftertaste (5.8 vs 4.8) is also higher. Furthermore, stingless bee honey has lower GI and GL (81.76, 5.27) as compared to honeybee honey (97.86, 6.96), respectively. It is suggested that the serving in term of odd or even numbers might affect the outcomes of the study as honeybee honey represents four spoons vs five spoons of stingless bee honey.

Characterization and antibiotic resistance pattern of diffusely adherent Escherichia coli (DAEC), isolated from paediatric diarrhoea in Shiraz, southern Iran

Diarrhoea is a major health concern, especially in developing countries. Research has implicated diffusely adherent Escherichia coli (DAEC) strains as a cause of diarrhoea. In this study, we investigated the prevalence, adherence assay, virulence gene profiles and antimicrobial resistance of DAEC at a hospital in southern Iran. In this cross-sectional study, 309 infants and children under the age of 13 years with diarrhoea who had been referred to Shahid Dastgheib Hospital, Shiraz between October 2018 and May 2019 were recruited. Microbiological methods, PCR, HEp-2 adherence assay and antimicrobial susceptibility test were used. Of the 309 stool samples, 207 (66.9%) were found to contain E. coli by biochemical tests and culture. Molecular analysis of Afa/Dr and AIDA-I adhesin-encoding genes showed that 14 (6.7%) out of 207 E. coli isolates were DAEC. All DAEC isolates in HEp-2 cells showed a diffusely adherent pattern. The virulence genes sat, pet, sigA, pic, astA and fimH were found in 50%, 0%, 14.2%, 14.2%, 21.4% and 100% of DAEC isolates, respectively. The most effective antibiotic against the DAEC isolates was imipenem (92.8%) and the least effective was ampicillin (0%). Our findings expand the knowledge on DAEC prevalence and its characteristics in Iran. It also explains the role of virulence genes in DAEC pathogenesis. The results showed that although the prevalence of DAEC is low, these strains exhibit a high rate of antimicrobial resistance as well as high frequency for carrying virulence genes.

Evaluation of quorum-sensing inhibitory effects of extracts of three traditional medicine plants with known antibacterial properties

Today an alternative approach to control bacterial infections is the use of natural and traditional plant compounds to interfere with their quorum-sensing (QS) systems. In this study, antibacterial and anti-QS sensing activity of Syzygium aromaticum, Dionysia revoluta Boiss. and Eucalyptus camaldulensis Dehnh. were evaluated. These plants are local to the Middle East region and have since ancient times been used for their antibacterial activity. Plant compounds were extracted with n-hexane, methanol and 96% ethanol mixed solvent. Antibacterial activity of this herbal extracts against five Gram-negative and Gram-positive bacteria were assessed. The effective sub–minimum inhibitory concentration (MIC) of this extract on bacterial QS systems were investigated by a violacein quantification assay in the Chromobacterium violaceum CV026 biosensor strain, inhibition of exogenously QS signal molecules in Aeromonas veronii bv. Sobria strain BC88 and Pseudomonas aeruginosa isolated from a patient with cystic fibrosis in vitro. Results found that Syzygium aromaticum 0.39 to 0.048 mg/mL, Dionysia revoluta Boiss. 3.1 to 0.39 mg/mL and E. camaldulensis 0.78 to 0.097 mg/mL showed anti-QS activities by reducing the violacein formation depletion of QS signals produced in A. veronii and P. aeruginosa at sub-MICs. Regarding the anti-QS effects of these herbal extracts, their effective components may be candidates for use in combating bacterial infections at sub-MICs.

Bacterial etiology and antibiotic resistance pattern of septicemia in HIV and non-HIV patients admitted to tertiary care hospitals, Shiraz, South of Iran

The present study aimed to determine the bacteriological etiology and antibiotic susceptibility pattern of sepsis in HIV infected and HIV uninfected patients, and related risk factors to introduce an appropriate therapy. This cross-sectional study was conducted from January 2014 to January of 2015 enrolling patients with sepsis associated with or without HIV infection admitted to Shiraz teaching hospitals, South of Iran. Blood and urine cultures were performed and standard microbiological methods were followed for isolation and identification of the bacteria. HIV antibody testing and CD4+ lymphocyte count were done for HIV-infected patients. Antimicrobial susceptibility tests were performed using the disk diffusion method in accordance with CLSI recommendations. Totally, 140 patients with sepsis including 30 HIV-positive, and 110 HIV-negative were enrolled. Our finding showed 26.7% and 20% blood and urine culture positivity in HIV-positive and 20.9% and 14.5% positivity in HIV-negative patients. Staphylococcus aureus, Salmonella spp. and coagulase-negative staphylococci (CoNS) each with frequency of 25% were detected as the most prevalent isolates in samples of HIV patients. In contrast, the main etiology for sepsis in HIV-negative patients was CoNS (47.8%), followed by Escherichia coli (17.4%). The median of CD4+ lymphocyte count and viral load in HIV patients were estimated 10.15 cells/mm3 and 68019.48 copies/mL, respectively. The results of the present study revealed that the main cause of sepsis in the studied hospitals was nosocomial pathogens. These findings highlighted the importance of infection control policies for preventing the emergence and spread of nosocomial infections.

Green tea polyphenol EGCG suppresses cigarette smoke condensate-induced NF-kappaB activation in normal human bronchial epithelial cells

Cigarette smoke is a powerful inducer of inflammatory responses resulting in disruption of major cellular pathways with transcriptional and genomic alterations driving the cells towards carcinogenesis. Cell culture and animal model studies indicate that (-)-epigallocatechin-3-gallate (EGCG), the major polyphenol present in green tea, possesses potent anti-inflammatory and antiproliferative activity capable of selectively inhibiting cell growth and inducing apoptosis in cancer cells without adversely affecting normal cells. Here, we demonstrate that EGCG pretreatment (20-80 microM) of normal human bronchial epithelial cells (NHBE) resulted in significant inhibition of cigarette smoke condensate (CSC)-induced cell proliferation. Nuclear factor-kappaB (NF-kappaB) controls the transcription of genes involved in immune and inflammatory responses. In most cells, NF-kappaB prevents apoptosis by mediating cell survival signals. Pretreatment of NHBE cells with EGCG suppressed CSC-induced phosphorylation of IkappaBalpha, and activation and nuclear translocation of NF-kappaB/p65. NHBE cells transfected with a luciferase reporter plasmid containing an NF-kappaB-inducible promoter sequence showed an increased reporter activity after CSC exposure that was specifically inhibited by EGCG pretreatment. Immunoblot analysis showed that pretreatment of NHBE cells with EGCG resulted in a significant downregulation of NF-kappaB-regulated proteins cyclin D1, MMP-9, IL-8 and iNOS. EGCG pretreatment further inhibited CSC-induced phosphorylation of ERK1/2, JNK and p38 MAPKs and resulted in a decreased expression of PI3K, AKT and mTOR signaling molecules. Taken together, our data indicate that EGCG can suppress NF-kappaB activation as well as other pro-survival pathways such as PI3K/AKT/mTOR and MAPKs in NHBE cells, which may contribute to its ability to suppress inflammation, proliferation and angiogenesis induced by cigarette smoke.

Prooxidant property of green tea polyphenols epicatechin and epigallocatechin-3-gallate: implications for anticancer properties

It is believed that anticancer and apoptosis inducing properties of green tea are mediated by it's polyphenolic constituents particularly catechins. A number of reports have shown that green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) is among the most effective chemopreventive and apoptosis-inducing agents present in the beverage. Plant polyphenols are naturally occurring antioxidants but they also exhibit prooxidant properties. Over the last several years we have shown that various classes of plant polyphenols including flavonoids, curcuminoids and tannins are capable of catalyzing oxidative DNA cleavage particularly in the presence of transition metal ions such as copper and iron. With a view to understand the chemical basis of various pharmacological properties of green tea, in this paper we have compared the prooxidant properties of green tea polyphenols--EGCG and EC ((-)-epicatechin). The rate of oxidative DNA degradation as well as hydroxyl radical and superoxide anion formation was found to be greater in the case of EGCG as compared with EC. It was also shown that copper mediated oxidation of EC and EGCG possibly leads to the formation of polymerized polyphenols. Further, it was indicated that copper oxidized catechins were more efficient prooxidants as compared with their unoxidized forms. These results correlate with the observation by others that EGCG is the most effective apoptosis inducing polyphenol present in green tea. They are also in support of our hypothesis that prooxidant action of plant polyphenols may be an important mechanism of their anticancer properties. A model for binding of Cu(II) to EC has been presented where the formation of quinone and a quinone methide has been proposed.

Influence of GSTT1 null genotype on the offspring sex ratio of gasoline filling station workers

The aim of this study was to investigate whether the occupational exposure to gasoline of men employed at filling stations affects the sex of their children. Altogether 115 offspring (47 males, 68 females) were identified within families of 49 men working in filling stations in Shiraz (Fars province, south of Iran) and 345 offspring (178 males, 167 females) from 147 families of unexposed persons from the general population of Shiraz, which were matched by age of fathers (+/-2 years) and number of children as a control group. The offspring sex ratio at birth (male proportion) in the filling station workers was significantly lower than the ratio in control group (OR = 0.65; 95% confidence intervals (CI) 0.42 to 0.99). Genotypes of glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) were investigated on extracted genomic DNA of 37 exposed workers using the polymerase chain reaction based method. In exposed group with active GSTM1 and GSTT1 genes, offspring sex ratio was the same as the ratio in the control group (OR = 0.66; 95% CI 0.34 to 1.28). However, in the exposed group with active GSTM1 and null genotype of GSTT1, the offspring sex ratio statistically decreased (OR = 0.45; 95% CI = 0.21 to 0.96). It seems that the GSTT1 null genotype has an effect on offspring sex ratio in the filling station workers.

The biflavonoid, amentoflavone degrades DNA in the presence of copper ions

Previous reports from this laboratory have shown that flavonoids including apigenin are capable of inducing oxidative DNA cleavage in the presence of copper ions. In the present report, we have examined the ability of amentoflavone, a biflavonoid which is a dimer of apigenin, to catalyze the degradation of DNA. Amentoflavone was found to degrade calf thymus DNA in the presence of Cu(II) at a rate almost twice that of apigenin. Amentoflavone was also shown to reduce Cu(II) to Cu(I) and to generate hydroxyl radicals in the presence of copper ions. In the presence of Cu(II), the absorption spectrum of amentoflavone undergoes a shift and a quenching effect indicating that the biflavonoid is capable of binding to copper ions. Amentoflavone and apigenin were isolated from Cycas rumphii and Trifolium alexandrinum, respectively. The results are discussed in relation to the putative chemopreventive mechanism of amentoflavone.

Serotonin-Cu(II)-mediated DNA cleavage: mechanism of copper binding by serotonin

It has been proposed that considerable DNA damage may be caused by endogenous metabolites produced during the body's normal metabolic processes. 5-hydroxytryptamine (serotonin) is an important neurotransmitter in brain and spinal cord. We have previously shown that serotonin induces oxidative cleavage of DNA strands in the presence of copper ions. In the present paper we have examined the mechanism of copper binding by serotonin using absorption spectroscopy, Cu(II)-mediated lipid peroxidation and by determining the oxidation of the serotonin molecule. Addition of increasing concentrations of Cu(II) to serotonin leads to a progressive enhancement in the absorption band and is accompanied by a shift towards a lower wavelength indicative of the formation of an oxidised species of serotonin. Studies with the structurally related molecules tryptophan and melatonin showed that only serotonin is able to reduce Cu(II) to Cu(I). Similarly, only serotonin was found to be able to abolish the copper-mediated peroxidation of mitochondria. These results suggested the involvement of the phenolic group in copper binding. Further, it was also shown that the binding of copper to serotonin leads to the formation of a quinone in the absence of molecular oxygen. Based on these results, a model has been proposed in which serotonin reduces two molar equivalents of Cu(II) to Cu(I) through a reaction involving two electron oxidation of the phenolic ring to a quinone methide.

Assessment of a breast cancer screening programme in Shiraz, Islamic Republic of Iran

A breast cancer screening programme was evaluated for approximately 10, 000 women aged 35 years and older. There were 67 cases of breast cancer. Highest rates of attendance were seen among younger women [35-44 years] and middle socioeconomic groups. Lowest rates were among those aged over 65 years and low socioeconomic groups. The rate of detection by self-examination was similar to that by health personnel examination. At all stages of screening, positive findings were most common among the high socioeconomic class. Attendance decreased steadily from first to last stages of serial screening. Although mammography is the most sensitive method of detection, because of its high cost we suggest establishing breast self-examination education programmes and encouraging women to self-examine.

Assessment of a breast cancer screening programme in Shiraz, Islamic Republic of Iran

A breast cancer screening programme was evaluated for approximately 10,000 women aged 35 years and older. There were 67 cases of breast cancer. Highest rates of attendance were seen among younger women (35-44 years) and middle socioeconomic groups. Lowest rates were among those aged over 65 years and low socioeconomic groups. The rate of detection by self-examination was similar to that by health personnel examination. At all stages of screening, positive findings were most common among the high socioeconomic class. Attendance decreased steadily from first to last stages of serial screening. Although mammography is the most sensitive method of detection, because of its high cost we suggest establishing breast self-examination education programmes and encouraging women to self-examine.

Strand scission in DNA induced by 5-hydroxytryptamine (serotonin) in the presence of copper ions

It has been proposed that considerable DNA damage may be caused by endogenous metabolites produced during the body's normal metabolic processes. Several metabolites including L-3,4-dihydroxyphenylalanine and dopamine have been previously shown to lead to oxidative DNA breakage in the presence of copper ions. 5-hydroxytryptamine or serotonin is an important neurotransmitter in brain and spinal cord and is involved in the control of sleep and consciousness, aggression and mood. In this paper we show that serotonin is also capable of causing strand cleavage in DNA in the presence of Cu(II) through an oxidative mechanism. Serotonin reduces Cu(II) to Cu(I) which is accompanied by the generation of hydroxyl radical. Spectroscopic data indicate that serotonin is able to bind to DNA and copper ions. Relative DNA cleavage efficiency and copper binding ability of serotonin and structurally related molecules tryptophan and melatonin indicates that the phenolic group in serotonin is required for strand cleavage activity.