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

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

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.  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 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

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

Microbiological safety assessment of food handlers in Wudil Local Government Area of Kano State, Nigeria

This study was conducted to investigate the bacteriological safety levels of food handlers in Wudil Local Government Area (LGA) of Kano State, Nigeria. A total of 200 hand-swab samples were collected from different male [100 (50%)] and female [100 (50%)] food handlers/peddlers in the study area. From these samples, 200 non-duplicate bacterial isolates consisting of strains of Salmonella typhi [60 (30%)], Salmonella choleraesuis [52 (26%)], Proteus mirabilis [10 (5%)], Morganella morganii [10 (5%)], Pseudomonas aeruginosa [10 (5%)], Escherichia coli [18 (9%)] and Staphylococcus aureus [40 (20%)] were isolated. A significant proportion (33.3%) of the food handlers sampled was children within the age range of 8-12 years. In addition, only 33.5% of the food handlers had basic level of primary education and a majority (96.5%) of the food handlers displayed poor levels of personal hygiene, especially with regards to safe food handling. S. typhi, S. cholaeresius and S. aureus were found to be the common bacterial species that colonized the hands of food handlers/peddlers in Wudil LGA, Kano State. This highlights a lack of food safety and the resulting risk of spreading foodborne diseases in the area. In addition, low literacy levels and lack of safe food handling practices contribute to the prevalence of these pathogens among the food handlers. It is important for food handlers to obtain training on safe food practices, undergo periodic health checks and practice proper hand hygiene. DOI: http://dx.doi.org/10.5281/zenodo.381334

Evaluation of Antioxidant, Anti-inflammatory and Antimicrobial Activities of the Leaf Extracts of Luffa cylindrica

Introduction: Luffa cylindrica have been used traditionally in the treatment and management of several disease conditions. This study aimed to evaluate the antioxidant, anti-inflammatory and antimicrobial properties of leaf extracts of the plant, and identifying some of its phytoconstituents. Methods: The crude ethanol and ethyl acetate extracts were evaluated for antioxidant and anti-inflammatory activities using the 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) and paw-fluid displacement methods, respectively. The extracts were tested for antimicrobial activity using the agar well diffusion and agar dilution methods. The ethyl acetate leaf extract of the plant was further subjected to high-performance liquid chromatography-diode-array detection (HPLC-DAD) analysis for the identification of the bioactive compounds. Results: The ethanol and ethyl acetate extracts of L. cylindrica showed average antioxidant properties at 100 µg/mL, with inhibitions of 53.31% and 54.73% respectively. The ethanol extract displayed significant anti-inflammatory activity at 50 mg/Kg with an inhibition of 31.1% compared to 39.7% recorded for the control (diclofenac). The ethyl acetate extract produced an inhibition of 15%. In the antimicrobial evaluation, the ethanol and ethyl acetate extracts showed moderate antibacterial activity against S. aureus, S. Typhi and B. subtilis. The ethyl acetate extract exhibited considerable antimicrobial activity against the test isolates compared to the ethanol extract. HPLC-DAD analysis of the ethyl acetate extract suggested the presence of two flavonoid compounds - luteolin and apigenin as key components of the leaf extract of L. cylindrica. These compounds are known to possess anti-inflammatory, antioxidant and antimicrobial activities. Conclusions: The results of this study showed that the leaf extracts of L. cylindrica possess antioxidant, anti-inflammatory and antimicrobial properties

UV-mediated enhancement of antibacterial secondary metabolites in endophytic Lasiodiplodia theobromae

In the science of drug discovery, ultraviolet (UV) irradiation has been applied to induce mutagenesis in fungi to provide possibilities for the stimulation or enhancement of fungal biosynthetic capabilities. This study was carried out to evaluate the effect of UV radiation on the biosynthesis of antibacterial secondary metabolites in an endophytic Lasiodiplodia theobromae. Using standard methods, the fungus was isolated from healthy leaves of Cola acuminata and identified based on PCR amplification and genomic sequencing of the internal transcribed spacer (ITS) region. Cultures of L. theobromae were exposed to UV radiation at different time intervals of 1, 2 and 5 min. The fungus was subjected to solid-state fermentation in rice medium before and after UV treatments. The fungal secondary metabolites were extracted and tested for antibacterial activity using the agar diffusion method. Compounds present in the obtained extracts were identified by HPLC and GC-MS analysis. At a concentration of 1 mg/ml, the extract of the wild type L. theobromae (untreated) was observed to only inhibit Staphylococcus aureus, with an IZD of 12 mm. However, the extract of UV-treated L. theobromae (2 min) inhibited S. aureus, Escherichia coli and Pseudomonas aeruginosa with an IZD of 10 and 4 mm respectively. A wide array of compounds in the phenolics, fatty acids, alkaloids and alkanes classes were identified in the UV-treated and untreated fungal extracts. Overall, UV treatments of L. theobromae stimulated the production of seventeen (17) new compounds that were not detected in the untreated strain. The study confirms UV irradiation as an effective method for stimulating microbial biosynthesis of new bioactive compounds, indicating a promising and potentially abundant source of new drug compounds from microorganisms

Differential role of residual metabolic tumor volume in inoperable stage III NSCLC after chemoradiotherapy ± immune checkpoint inhibition

BACKGROUND The PET-derived metabolic tumor volume (MTV) is an independent prognosticator in non-small cell lung cancer (NSCLC) patients. We analyzed the prognostic value of residual MTV (rMTV) after completion of chemoradiotherapy (CRT) in inoperable stage III NSCLC patients with and without immune checkpoint inhibition (ICI). METHODS Fifty-six inoperable stage III NSCLC patients (16 female, median 65.0~years) underwent 18F-FDG PET/CT after completion of standard CRT. rMTV was delineated on 18F-FDG PET/CT using a standard threshold (liver SUVmean + 2 × standard deviation). 21/56 patients underwent additional ICI (CRT-IO, 21/56 patients) thereafter. Patients were divided in volumetric subgroups using median split dichotomization (MTV ≤ 4.3~ml vs. > 4.3~ml). rMTV, clinical features, and ICI-application were correlated with clinical outcome parameters (progression-free survival (PFS), local PFS (LPFS), and overall survival (OS). RESULTS Overall, median follow-up was 52.0~months. Smaller rMTV was associated with longer median PFS (29.3 vs. 10.5~months, p = 0.015), LPFS (49.9 vs. 13.5~months, p = 0.001), and OS (63.0 vs. 23.0~months, p = 0.003). CRT-IO patients compared to CRT patients showed significantly longer median PFS (29.3 vs. 11.2~months, p = 0.034), LPFS (median not reached vs. 14.0~months, p = 0.016), and OS (median not reached vs. 25.2~months, p = 0.007). In the CRT subgroup, smaller rMTV was associated with longer median PFS (33.5 vs. 8.6~months, p = 0.001), LPFS (49.9 vs. 10.1~months, p = 0.001), and OS (63.0 vs. 16.3~months, p = 0.004). In the CRT-IO subgroup, neither PFS, LPFS, nor OS were associated with MTV (p > 0.05 each). The findings were confirmed in subsequent multivariate analyses. CONCLUSION In stage III NSCLC, smaller rMTV is highly associated with superior clinical outcome, especially in patients undergoing CRT without ICI. Patients with CRT-IO show significantly improved outcome compared to CRT patients. Of note, clinical outcome in CRT-IO patients is independent of residual MTV. Hence, even patients with large rMTV might profit from ICI despite extensive tumor load

Sphingomyelinase inhibitory and free radical scavenging potential of selected Nigerian medicinal plant extracts

Ceramides from sphingolipid breakdown, and other sphingolipid metabolites, mediate cellular signalling in infectious and other diseases. Therefore, inhibitors of sphingomyelinases (SMases), hold promise as prospective therapeutic agents. Considering the potential therapeutic utility, this in vitro study explored the sphingomyelinase inhibitory, and free radical scavenging potential of five Nigerian medicinal plant leaf extracts, purported to have efficacy against diseases, including HIV/AIDS. The extracts\u2019 sphingomyelinase inhibitory potencies were assessed colorimetrically and theirfree radical scavenging capabilities were assayed by the ability to quench 2,2\u2010diphenyl\u20101\u2010picrylhydrazyl (DPPH) radical and superoxide anion (O2.\u2010) radical. Considering their IC50 (\u3bcg/ml) values, the extracts inhibited the biochemical activity of sphingomyelinase in a dose-dependent manner, relative to imipramine the standard inhibitor (IC50 38.5 \ub1 2.4 \u3bcg/ml). With Aloe vera as least inhibitory, inhibition increased as follows: Aloe vera (Asphodelaceae) (1132 \ub1 10.8) < Senna siamea (Fabaceae) (992.2 \ub1 11.2) < Azadirachta indica (Meliaceae) (984 \ub1 7.4) < Landolphia owariensis (Apocynaceae) (146.3 \ub1 9.4) < Stachytarpheta angustifolia (Verbenacae) (100.3 \ub1 8.7). DPPH radical scavenging relative to ascorbic acid standard increased as: A. indica < A. vera < S. siamea < S. angustifolia < L. owariensis; and superoxide anion quenching, relative to standard rutin increased as: A. vera < S. angustifolia < L. owariensis < S. siamea < A. indica.These results showed thatthe most potent SMase inhibitor was S. angustifolia; whereas, for DPPH radical scavenging and superoxide inhibition, the most potent of the five extracts were L. owariensis and A. indica respectively.These extracts deserve further investigation into their biological effects

Systematic review with meta-analysis of the epidemiological evidence relating smoking to COPD, chronic bronchitis and emphysema

<p>Abstract</p> <p>Background</p> <p>Smoking is a known cause of the outcomes COPD, chronic bronchitis (CB) and emphysema, but no previous systematic review exists. We summarize evidence for various smoking indices.</p> <p>Methods</p> <p>Based on MEDLINE searches and other sources we obtained papers published to 2006 describing epidemiological studies relating incidence or prevalence of these outcomes to smoking. Studies in children or adolescents, or in populations at high respiratory disease risk or with co-existing diseases were excluded. Study-specific data were extracted on design, exposures and outcomes considered, and confounder adjustment. For each outcome RRs/ORs and 95% CIs were extracted for ever, current and ex smoking and various dose response indices, and meta-analyses and meta-regressions conducted to determine how relationships were modified by various study and RR characteristics.</p> <p>Results</p> <p>Of 218 studies identified, 133 provide data for COPD, 101 for CB and 28 for emphysema. RR estimates are markedly heterogeneous. Based on random-effects meta-analyses of most-adjusted RR/ORs, estimates are elevated for ever smoking (COPD 2.89, CI 2.63-3.17, n = 129 RRs; CB 2.69, 2.50-2.90, n = 114; emphysema 4.51, 3.38-6.02, n = 28), current smoking (COPD 3.51, 3.08-3.99; CB 3.41, 3.13-3.72; emphysema 4.87, 2.83-8.41) and ex smoking (COPD 2.35, 2.11-2.63; CB 1.63, 1.50-1.78; emphysema 3.52, 2.51-4.94). For COPD, RRs are higher for males, for studies conducted in North America, for cigarette smoking rather than any product smoking, and where the unexposed base is never smoking any product, and are markedly lower when asthma is included in the COPD definition. Variations by sex, continent, smoking product and unexposed group are in the same direction for CB, but less clearly demonstrated. For all outcomes RRs are higher when based on mortality, and for COPD are markedly lower when based on lung function. For all outcomes, risk increases with amount smoked and pack-years. Limited data show risk decreases with increasing starting age for COPD and CB and with increasing quitting duration for COPD. No clear relationship is seen with duration of smoking.</p> <p>Conclusions</p> <p>The results confirm and quantify the causal relationships with smoking.</p