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®® was determined by agar dilution method. The killing rate studies of the plant extract and Nystatin® 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® also demonstrated plausible activity against the isolates with MICs ranging from 0.3125 – 25 mg/ml. Candida albicans strain 2 was the most sensitive to both extract and Nystatin® 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® respectively. The killing rate values for the extract ranged from -0.029 to -0.091 min-1 and that of Nystatin® ranged from -0.076 to –0.11216 min-1.Conclusions: The results indicate that the methanolic extract of Cleistopholis patens is a promising clinical alternative besides Nystatin® in the treatment of infections caused by Candida species in stage II HIV patients.Keywords: Anti-candidal activity, Cleistopholis patens, Candida, HIV Patients

Prevalence and Susceptibility Patterns of Clinical Isolates of Escherichia coli to Various Antimicrobials in A Clinical Microbiology Laboratory in South-South Nigeria

The purpose of this study is to determine the prevalence of Escherichia coli as an aetiologic agent in bacterial infections and its antimicrobial susceptibility patterns to ciprofloxacin, ofloxacin, norfloxacin, perfloxacin, gentamycin and cotrimoxazole as a guide for empiric therapy. A retrospective study was carried out using a clinical microbiology laboratory in Nigeria. Data retrieved include number of E. coli isolates, sources of the isolates and their antimicrobial susceptibility to various fluoroquinolones, gentamycin and cotrimoxazole between 2005 and 2009. Statistical analysis was carried out using SPSS version 14, Chicago IL. Out of a total of 906 bacterial isolates, E. coli accounted for 23 % (211) of the isolates. Thirty-eight percent (38.39 %) was isolated from urine samples, 27.96 % from high vaginal swab samples, 24.17 % from stool samples, 0.95% from urethra swabs, 1.9% from wound swabs and 6.6% from semen samples. There was poor level of susceptibility to norfloxacin (2.2%) and cotrimoxazole (23.7%), susceptibility to ofloxacin, ciprofloxacin and pefloxacin were 51.1%, 54.7% and 52.5% respectively, that of gentamycin was 51.8%. The trends across the years showed a significant increase in susceptibility to ciprofloxacin, pefloxacin and ofloxacin in 2007 after which it started reducing, while norfloxacin’s susceptibility was low across the five years with maximum susceptibility at 9.1% in 2006. There was an increase in susceptibility to gentamycin as the susceptibility levels of the  fluoroquinolones were reducing. There should be continuous surveillance of antimicrobial susceptibility patterns and empiric treatment with fluoroquinolones discouraged, especially for non urinary tract infections.KEYWORDS: Antimicrobial susceptibility, Nigeria, Escherichia coli, fluoroquinolones, gentamyci

Susceptibility-resistance profile of micro-organisms isolated from herbal medicine products sold in Nigeria

In order to evaluate the susceptibility and resistance pattern of bacteria and fungal isolates obtained from herbal medicine products (HMPs) marketed in Nigeria to conventional antibiotics, a total ofseventy-five (75) bacteria and fifty-two (52) fungi isolated from the HMPs were screened for susceptibility to conventional antibiotics using the disc diffusion method. Most of the bacteria isolateswere sensitive to the fluoroquinolones (ciprofloxacin, 85.3%, norfloxacin 93.3%) and the aminoglycosides (streptomycin 90%, gentamycin 89.3%). However, the isolates demonstratedsignificant resistance to common antibiotics like penicillins (augmentin [amoxycillin-cavulanic acid combination] 80%, cloxacillin 88.3%, ampicillin 56%), cephalosporins (rocephine [ceftriaxone] 65%,ceporex [cephalexin] 80%, cefuroxime 100%), chloramphenicol (66.7%), nitrofurantoin (100%) and cotrimoxazole (93.3%). Most of the fungal isolates were resistant to griseofulvin (67.3%) but susceptible to nystatin (73.1%), ketoconazole (98.1%), tioconazole (100%), clotrimazole (78.9%) and miconazole (88.5%). A significant proportion of bacteria and fungi isolated from these HMPs demonstratedresistance to conventional antibiotics. The present study therefore reveals that HMPs may represent novel routes of spread of antibiotic-resistant genes especially in developing countries. Efforts shouldtherefore be geared at standardizing the quality of HMPs via strict adherence to Good Manufacturing Practice (GMP)

In vitro evaluation of the interaction between tea extracts and penicillin G against staphylococcus aureus

The herb-drug interaction between tea (Carmelia sinensis) extract and penicillin G (Pen G) was investigated against three strains of Staphylococcus aureus using pair combinations in an in vitro decimal assay for additivity test. Results showed that the interactions between penicillin G and teaextracts were mainly additive against the three strains of S. aureus. This suggests that the concomitant administration of tea and Pen G may not impair the antimicrobial activity of Pen G

Antibacterial Interaction of Crude Methanol Extract of Garcinia kola Seed with Gatifloxacin

Purpose: Concurrent use of orthodox and herbal medicines is likely to precipitate an overall effect which may or may not be beneficial to the patient. The objective of this study was to evaluate the antimicrobial interaction between the methanol extract of Garcinia kola seed (GKS) which is chewed habitually as a masticatory in many rural communities in Africa and gatifloxacin (GAT), a fourth generation fluoroquinolone. Method: The antimicrobial interaction between these two agents was evaluated by a modification of the checkerboard technique using Bacillus subtilis and Staphylococcus aureus as the test organisms. Result: Results obtained showed that the minimum inhibitory concentration (MIC) of gatifloxacin against both organisms was 1.0 μg/ml while the MICs of the G. kola seed extract were evaluated to be 1.562 mg/ml and 3.125 mg/ml respectively against B. subtilis and S. aureus. Upon combination, synergism was manifested serially against B. subtilis in ratios of 9(GAT):1(GKS) down to 6(GAT) :4(GKS) after which additivity, indifference and antagonism, in that order, were manifested as the ratio of GKS increased in the combination. Against S. aureus, the combined interaction showed a somewhat irregular pattern of effect, including synergism at GAT:GKS ratios of 9:1, 2:8 and 1:9 , antagonism at ratios of 8:2, 5:5 and 4:6 and indifference at GAT:GKS ratios of 7:3, 6:4 and 3:7. Conclusion: The results from this study suggest that the effect of combination of the methanol extract of GKS with gatifloxacin was dependent not only on the ratio of combination but also on the test organism employed for the evaluation. Overall, the combined antimicrobial effect of the interaction between GKS and gatifloxacin was predominantly synergistic against B.subtilis. Keywords: Garcinia kola seed, antibacterial interaction, checkerboard technique, Bacillus subtilis, Staphylococcus aureus, gatifloxacinTropical Journal of Pharmaceutical Research Vol. 7(4) 2008: pp. 1159-116

Extracts of Moringa oleifera Lam. showing inhibitory activity against early steps in the infectivity of HIV-1 lentiviral particles in a viral vector-based screening

Moringa oleifera Lam. (Moringaceae) is one of the many medicinal plants employed by herbalist to treat or manage people living with HIV/AIDS (PLWHA) in African Traditional Medicine (ATM) and there are many claims to the fact that it improves quality of life and reverses the course of the HIV/AIDS disease progression. This practice and the claims of efficacy spurred the present study in which the inhibitory activities of three different extracts of M. oleifera on lentiviral vector infectivity were studied on HeLA cells by measuring the expression of green fluorescent protein (GFP) transgene in the vector using flow cytometry. An infectious VSV-G-pseudotyped, human immunodeficiency virus type 1-based, selfinactivating lentiviral vector particles were generated by transient co-transfection of the vector plasmid (pHIV-1 CSCG) with packaging plasmids encoding tat, rev, gag-pol (pCMVΔR8.2), a VSV-G expression plasmid (pHIT-G), a secretory alkaline phosphate expression plasmid (pSEAP) which are all necessary for viral infectivity. The extracts studied were obtained by solvent extraction of the leaf powder of M. oleifera with ethyl ether (EM), methanol (MM) and water (AM). All the extracts (EM, MM, and AM) were active against the HIV-1 lentiviral vector and inhibited the early events of the viral replication cycle on HeLa cells in a concentration-dependent manner with IC50 of 7.59 μg EM/ml, 7.72 μg MM/ml and 7.17 μg AM/ml, respectively. Cytotoxicity of the extracts evaluated in parallel on HeLA cells by the MTT assay method showed TC50 values of 32.33 μg EM/ml, 38.88 μg MM/ml and 41.58 μg AM/ml with selectivity indices (SI) of 4.26, 5.04 and 5.8, respectively. In this study, M. oleifera leaf extracts showed potent and selective inhibition of early steps in HIV-1 infectivity and could serve as source of antiretroviral lead molecules. The outcome of this investigation could partly explain the benefits and improvement in quality of life claimed by PLWHA in the use of this medicinal plant as supplement.Keywords: Antiviral activity, antiviral screening, lentiviral vector particles, Moringa oleifera, HIV-1, viral vectorbased assay.African Journal of Biotechnology Vol. 12(30), pp. 4866-487

Comparative Adsorption of Spiramycin on Veegum®, Activated Charcoal and Garcinia kola Heckel (Guttiferea) Seed

Purpose: To investigate the adsorptive interaction of Garcinia kola with spiramycin, since the kola is widely chewed as a tonic and spiramycin attains high concentrations in saliva.Methods: Spiramycin solutions of different concentration were added to a fixed mass of Garcinia kola (200 mg), activated charcoal or Veegum®. Shaking was carried out at room temperature after which the dispersion was filtered and the filtrate assayed for residual drug concentration. The process was repeated under different equilibrium conditions of pH and ionic strength. The adsorption data obtained for the three adsorbents were analyzed using Langmuir and Freundlich’s plots.Results: At neutral pH, drug adsorprtion by Garcinia kola, activated charcoal and Veegum® were 67, 54 and 71 %, respectively; differences in adsorption was not significant (p = 0.09). However, the other two adsorbents exhibited adverse adsorption characteristics in terms of negative adsorption capacity (-5.78 mol.kg-1) and constant (-1141 mol-1L). For each of the adsorbents, pH and ionic strength affected the extent of adsorption, due to their effect on adsorbent surface charge. Correlation with Langmuir and Freundlich relationships were poor, the correlation coefficient for the latter being 0.97, 0.894 and 0.351 for Garcinia kola, Veegum® and activated charcoal, respectively.Conclusion: The study reveals that Garcinia kola significantly adsorbs spiramycin under alkaline conditions comparable to salivary pH, and therefore should not be taken concurrently with the drug in order to minimize reduction in drug levels.Keywords: Garcinia kola, Spiramycin, Adsorption, Antidote, Interaction, Langmuir plot, Freundlich’s plo

In vitro study of the interaction between some fluoroquinolones and extracts of kola nitida seed

The cup diffusion method (CD) was used to evaluate the in vitro interaction of some fluoroquinolones (ciprofloxacin, pefloxacin and levofloxacin) with extracts of Kola nitida seed (KNS) against a clinical isolate of Escherichia coli. Minimum inhibitory concentration (MIC) of the drugs was determinedseparately and in combination with KNS extract in ratios of 0:5, 1:4, 2:3, 3:2, 4:1 and 5:0 against E. coli. The result of the study revealed that the MIC of the drugs decreased when combined with KNS extract. In other words, KNS extract potentiated the effects of the fluoroquinolones against E. coli

A study of the in vitro interaction of cotrimoxazole and ampicillin using the checkerboard method

In this study, the in vitro interaction of two standard antibiotics – cotrimoxazole and ampicillin trihydrate were studied by the checkerboard technique, using clinical isolates of P. aeruginosa, Staphylococcus aureus and Salmonella typhi. The organisms were exposed to the individual antibiotics as well as different combination ratios of the same, and the zones of inhibition as well as the minimum inhibitory concentrations (MICs) measured. Synergistic interactions were recorded by the antibiotics against Staph. aureus and S. typhi while indifferent interaction occurred with P. aeruginosa. P. aeruginosa however, showed resistance to the two antibiotics when they were used alone. The implication is that cotrimoxazole and ampicillin can be used in combination as a superior treatment of infections caused by Staph. aureus and S. typhi

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. © 2013 Obitte et al.; licensee BioMed Central Ltd