Comparative Evaluation of Three In Vitro Techniques in the Interaction of Ampicillin and Ciprofloxacin against Staphylococcus aureus and Escherichia coli

Purpose: The study was designed to evaluate the consistency of interpretation of results of interaction between ampicillin and ciprofloxacin against S. aureus and E. coli using three in vitro techniques. Methods: The interaction between ampicillin and ciprofloxacin was studied using three in vitro methods- Checkerboard technique, Overlay Inoculum Susceptibility Disc technique (OLISD) and the Decimal Assay for Additivity technique (DAA). Results: In the Checkerboard technique, fractional inhibitory concentration (FIC) indices show that the ampicillin/ciprofloxacin combination is synergistic against the test organisms. In the DAA approach, a target IZD of 15 mm yielded Biological Equivalent Factors (BEF) of 1.35 &#956;g (amp/Staph), 6.74 &#956;g (cipro/Staph), 9.62 &#956;g (ampicillin/E. coli), and 5.45 &#956;g (cipro/E. coli). Statistical analyses show that all decimal combinations of ampicillin and ciprofloxacin were additive (p< 0.05). The overlay inoculum susceptibility disc method shows inhibition zone diameter increments ranging between 36 ± 8.00 % to 69.2 ± 23.08 % for S. aureus and 28.12 ± 3.13 % to 50 ± 12.50 % for E. coli. These increments are consistent with reported criteria for synergism in the OLISD method. Conclusion: The study suggests a possible clinical use for the combination of ampicillin and ciprofloxacin against infections caused by these organisms. Equally, the apparent disagreement between DAA and the other two methods raises questions as to the consistency of inferences drawn on interaction studies when different techniques are used. Keywords: Ampicillin, Ciprofloxacin, Interaction, Decimal Assay, Checkerboard, OLISD method.> Tropical Journal of Pharmaceutical Research Vol. 5 (2) 2006: pp. 605-61

PHARMACOKINETICS, HEMATOLOGICAL AND BIOCHEMICAL EFFECTS OF CIPROFLOXACIN HYDROCHLORIDE-SODIUM CHOLATE COMPLEX

Objective: Ciprofloxacin is a broad spectrum antibiotic widely used in the treatment of infections, but its toxicological effects remains a great challenge. This research emphasized on analyzing the effect of a hydrophobic ion pair complex, involving ciprofloxacin hydrochloride and sodium cholate and also pegylated ciprofloxacin hydrochloride-sodium cholate complex.Methods: The effects of ciprofloxacin-cholate complex and pegylated ciprofloxacin-cholate complex were evaluated. LD50 was determined. The test drugs were orally to twenty-four albino mice, in six groups of four mice, at different doses of 7.14 mg/kg, 14.2 mg/kg and 21.4 mg/kg; and PEG complex, 7.14 and 14.2 mg/kg. Each was administered twice daily for fourteen days. The animal blood samples were subjected to hematological, biochemical tests; and the liver organs were collected. Histopathological examination was carried out on the harvested organs. Pharmacokinetic parameters were determined using the non-compartmental method.Results: The LD50 of the complex was above 5000 mg/kg. The non-significant decrease in PCV and WBC showed the parent drug and its complex are neither anemia inducing nor immunosuppressing; the significant decrease in the average RBCs count in post–treatment of 21.47 mg/kg of the complex could be from physiological changes; the bio-liver makers showed hepatocellular damage. Photomicrograph of the liver sections of mice showed mild areas of hepatocyte degeneration and inflammatory cell infiltrates.Conclusion: The biochemical, hematological and histology results showed complexation did not increase adverse effects of ciprofloxacin. The PEGYlated complex showed higher AUC and Cmax peak than the uncomplexed drug, hence more therapeutic benefits

The utility of self-emulsifying oil formulation to improve the poor solubility of the anti HIV drug CSIC

BACKGROUND: CSIC (5-chloro-3-phenylsulfonylindole-2-carboxamide), a non-nucleoside reverse transcriptase inhibitor (NNRTI) has not been advanced as a therapeutic anti-HIV candidate drug due to its low aqueous solubility and poor bioavailability. OBJECTIVE: The objective of this work was to formulate CSIC into self-emulsifying oil formulations for the purpose of improving its aqueous solubility and evaluating in vitro antiretroviral activity. METHODS: CSIC self-emulsifying oil formulations (SEFs) were formulated and evaluated for droplet size, zeta potential, polydispersity index (PDI), viscosity, emulsification time, stability and bioactivity. RESULTS: Results showed significantly improved solubility of CSIC in the SEFs.The concentration of co-surfactant affected the droplet size, zeta potential and polydispersity index. In vitro bioactivity studies showed that the CSIC SEFs retained full anti-HIV activity. CONCLUSION: The in vitro data from this first attempt to formulate CSIC SEFs suggest that improvement on the aqueous solubility of CSIC through this delivery system may accentuate its antiretroviral effectiveness in vivo via bioavailability enhancement. The formulation is therefore intended as an oral anti-HIV agent for prophylactic and therapeutic uses

Antimicrobial activities of secondary metabolites of endophytic fungi isolated from Catharanthus roseus

Introduction: Recently, several endophytes have been shown to possess the potentials to synthesize novel bioactive compounds that have found use for drug discovery. We isolated endophytic fungi associated with Catharanthus roseus collected from the river banks of Amassoma in Southern Nigeria, and identified some of their bioactive secondary metabolites. Methods: The fungi were subjected to solid-state fermentation on rice medium and the metabolites were extracted using ethyl acetate. The fungal crude extracts were screened for antimicrobial activity and were also subjected to high-performance liquid chromatography-diode-array detection (HPLC-DAD) analysis for the identification of the bioactive compounds. Results: The fungal extracts showed both antibacterial and antifungal activities with minimum inhibitory concentrations ranging from 0.0625 to 1 mg/mL. The HPLC-DAD analysis of the extracts suggested the presence of citreoisocoumarin, citreoisocoumarinol, questinol, hydroxyemodin, acropyrone, methyl 2-(4-hydroxyphenyl) acetate, nigricinol, and cladosporin. Conclusion: The results of this study suggest that endophytic fungi associated with C. roseus could be a promising source of novel bioactive compounds with pharmaceutical and industrial importance

Antimicrobial activities of secondary metabolites of endophytic fungi isolated from Catharanthus roseus

Introduction: Recently, several endophytes have been shown to possess the potentials to synthesize novel bioactive compounds that have found use for drug discovery. We isolated endophytic fungi associated with Catharanthus roseus collected from the river banks of Amassoma in Southern Nigeria, and identified some of their bioactive secondary metabolites. Methods: The fungi were subjected to solid-state fermentation on rice medium and the metabolites were extracted using ethyl acetate. The fungal crude extracts were screened for antimicrobial activity and were also subjected to high-performance liquid chromatography-diode-array detection (HPLC-DAD) analysis for the identification of the bioactive compounds. Results: The fungal extracts showed both antibacterial and antifungal activities with minimum inhibitory concentrations ranging from 0.0625 to 1 mg/mL. The HPLC-DAD analysis of the extracts suggested the presence of citreoisocoumarin, citreoisocoumarinol, questinol, hydroxyemodin, acropyrone, methyl 2-(4-hydroxyphenyl) acetate, nigricinol, and cladosporin. Conclusion: The results of this study suggest that endophytic fungi associated with C. roseus could be a promising source of novel bioactive compounds with pharmaceutical and industrial importance

Sensitivity of Pseudomonas Species Expressing Extended Spectrum Beta Lactamase to Different Solvent Fractions of Milletia Aboensis

The presence of Extended Spectrum Beta Lactamase (ESBL) producing organisms in abattoirs, a non-hospital community was investigated. A total of ten (10) isolates of Pseudomonas species out of twenty-six bacteria isolates expressing ESBL was obtained. The anti-pseudomonal activities of various solvent fractions of Milletia aboensis against the ESBL positive isolates of Pseudomonas species showed varying sensitivity. These results have suggested that Milletia aboensis possess potent anti-pseudomonal agents that could be used to treat infections due to Pseudomonas species expressing ESBL. These anti-pseudomonal metabolites are located in the ethanol, chloroform and methanol fractions but are absent in the ethyl acetate fractions. Keywords: Extended Spectrum Beta Lactamase, Milletia aboensis, Pseudomonas specie

Evaluation of the anti-candidal activity of methanolic leaf extract of cleistopholis patens (fam. Annonaceae) on candida species isolated from stage II HIV patients.

Background: Candida species (sp) is implicated in causing opportunistic disseminated mycotic complications in stage II HIV patients. Cleistopholis patens is a West African medicinal tree reported to have significant antifungal activity against C. albicans. Objectives: This study aimed to determine the anti-candidal activity of methanolic leaf extract of Cleistopholis patens against Candida species isolated from stage II HIV patients. Methods: The minimum inhibitory concentration (MIC) of the extract and Nystatin\uae\uae was determined by agar dilution method. The killing rate studies of the plant extract and Nystatin\uae were also determined. Results: The extract had activity against all Candida isolates, with the MIC against the five isolates ranging from 6.0 - 9.8 mg/ml. Nystatin\uae also demonstrated plausible activity against the isolates with MICs ranging from 0.3125 \u2013 25 mg/ml. Candida albicans strain 2 was the most sensitive to both extract and Nystatin\uae with MIC values of 6 and 0.3125 mg/ml respectively. Candida krusei was the least sensitive with MIC values of 9.8 and 25 mg/ml for the extract and Nystatin\uae respectively. The killing rate values for the extract ranged from -0.029 to -0.091 min-1 and that of Nystatin\uae ranged from -0.076 to \u20130.11216 min-1. Conclusions: The results indicate that the methanolic extract of Cleistopholis patens is a promising clinical alternative besides Nystatin\uae in the treatment of infections caused by Candida species in stage II HIV patients

Biologically active phenolic acids produced by Aspergillus sp., an endophyte of Moringa oleifera

This study investigates the secondary metabolites of an endophytic Aspergillus sp. isolated from leaves of M. oleifera growing in Anambra State, South-Eastern Nigeria. Antimicrobial and antioxidant screening of the fungal extract and isolated compounds, as well as cytotoxicity assay of the extract against cisplatin-sensitive A2780 (sens) and cisplatin-resistant A2780 (cisR) ovarian cancer cell lines were carried out using standard methods. Chemical investigations of the fungal extract involving a combination of different chromato-graphic methods and spectroscopic techniques were carried out to isolate and characterize the constituents of the extract. At a concentration range of 1-4 mg/ml, the crude extract of Aspergillus sp. showed mild antimicrobial activity against Bacillus subtilis, Klebsiella pneumoniae, and Candida albicans. The fungal extract showed good antioxidant activity at 500 µg/ml, with an inhibition of 72.1%. Also, at 100 µg/ml, the extract showed excellent cytotoxic activity against A2780 (sens) and A2780 (cisR), with growth inhibitions of 105.1% and 105.5% respectively. Two known pharmacologically active phenolic compounds (p-hydroxyphenyl acetic acid and ferulic acid) were isolated from the fermentation extract of the endophytic fungus. At 250 µg/ml, ferulic acid exhibited an excellent antioxidant activity with an inhibition of 90.4%, while an inhibition of 35.4% was recorded for p-hydroxyphenyl acetic acid. Ferulic acid also showed a mild antifungal activity at 500 µg/ml against A. niger with an IZD of 2 mm. p-Hydroxyphenyl acetic acid showed no antimicrobial activity. These results further confirm the potentials of endophytic fungi associated with Nigerian plants as source of bioactive compounds with pharmaceutical or industrial applications. DOI: http://dx.doi.org/10.5281/zenodo.140498

Incidence of community acquired ESBL-producing bacteria among asymptomatic University students in Anambra State, Nigeria

This study was conducted to investigate the incidence of community acquired extended-spectrum β-lactamase (ESBL)-producing bacteria among asymptomatic students of Nnamdi Azikiwe University, Awka, Anambra State, South-East Nigeria. A total of 102 non-duplicate strains of Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa were isolated from fecal samples (n=273) collected from the participating students. The isolates were subjected to antimicrobial susceptibility tests to determine their antimicrobial resistance profile. Their multiple antibiotic resistance (MAR) indices were also evaluated.&nbsp; Screening of the isolates for possible ESBL production was carried out by disk diffusion test using cefotaxime and ceftazidime disks. ESBL-production by the resistant strains was confirmed using the double-disk synergy test. Most of the isolates were found to be multi-drug resistant, as all K. pneumoniae and P. aeruginosa strains (100%), and 98.4% of the E. coli strains, had MAR indices ≥0.2. A total of 22 ESBL-producing bacterial species were confirmed, and the frequency of&nbsp;E. coli, K. pneumoniae and P. aeruginosa isolates among the ESBL-producing bacteria were n=20 (90.9%), n=2 (9.1%), and n=0 (0.0%) respectively. The total number of ESBL-producing bacterial strains isolated accounted for 8.1 % of the entire sample population. Although this prevalence rate may not indicate an alarming situation, it is important that the proliferation of ESBL-producing bacteria in the community be contained, since a high incidence of ESBL-producing organisms will create significant therapeutic problems in the near future. There is therefore need to develop strategies to reduce their spread in the community especially through monitoring, surveillance and proper detection protocol. DOI: http://dx.doi.org/10.5281/zenodo.131471

Fluorescent organic cations for human OCT2 transporters screening: uptake in CHO cells stably expressing hOCT2

The aim of this study was to assess the suitability of amiloride, rhodamine 6G and rhodamine 123 as non-radioactive substrates for characterizing hOCT2 using CHO cells. The uptake characteristics of these compounds were compared in wild-type (WT) and human organic cation transporter 2 (hOCT2)-stably transfected Chinese Hamster Ovary (CHO) cells. All the compounds were accumulated by the CHO-hOCT2 cells. Intracellular uptake of the compounds was higher in CHO cells stably-expressing hOCT2 compared to the WT. The uptake was concentration–dependent and saturable (except for rhodamine 123). The affinities of the compounds for the hOCT2 (in descending order) were: amiloride (Km = 72.63 12.02 μM) > rhodamine 6 G (Km = 82.47 29.15 μM). Uptake of amiloride in transfected cells was pH -dependent and significantly inhibited by hOCT2 inhibitors (quinine, verapamil and quinidine). Based on our kinetic data and other considerations, we recommend the use of amiloride for characterizing hOCT2 transporters