Antibacterial and phytochemical studies of selected South African honeys on clinical isolates of Helicobacter pylori

Infection with Helicobacter pylori has been associated with the pathogenesis of numerous stomach and gastroduodenal diseases that pose threats to public health. Eradicaftion of this pathogen is a global challenge due to its alarming rate of multidrug resistance. Consequently, to find an alternative treatment, the search is increasingly focused on new antimicrobial product from natural sources including honey. Honey has been used as medicine in several cultures since ancient time due to its enormous biomedical activities. Its beneficial qualities have been endorsed to its antimicrobial, antioxidant, anti-inflammatory properties added to its phytocomponents. In this study, the anti-H. pylori activity of South African honeys and their solvent extracts as well as the phytochemicals present in the two most active honeys were evaluated. Agar well diffusion test was used to investigate the antimicrobial activity of six honey varieties obtained from different locations in the country. Subsequently, the honeys were extracted with four organic solvents viz n-hexane, diethyl ether, chloroform and ethyl acetate employed in order of increasing polarity. The antibacterial activity of the different solvent extracts of each honey was evaluated by agar well diffusion; broth micro dilution and time kill assays. Different chromatographic techniques (Thin layer & column chromatography) were employed to enumerate the phytochemical constituents in the most active solvent extracts of Pure Honey (PH) and Champagne Royal Train (CRT); and were identified by gas-chromatography linked mass-spectrometry. Linalool pure compound was equally evaluated for anti-H. pylori activity in a bid to trace the antibacterial agent among the variety of compounds identified. Data were analyzed by One-way ANOVA test at 95% confidence interval. Crude honeys and their solvent extracts demonstrated potent anti-H. pylori activity with zone diameter that ranged from [16.0mm (crude) to 22.2mm (extract)] and percentage susceptibilities of test isolates between 73.3% (crude) and 93.3% (extract). The chloroform extracts of PH and CRT were most active with MIC50 in the ranges 0.01- viii 10%v/v and 0.625-10%v/v respectively, not significantly different from amoxicillin (P> 0.05); and efficient bactericidal activity (100% bacterial cells killed) at 1/2MIC and 4xMIC over different time intervals, 36-72hrs and 18-72hrs respectively. The appearance of bands on the thin layer chromatography (TLC) chromatogram spotted with the chloroform extracts of PH and CRT; and developed with hexane: ethyl acetate: acetic acid (HEA) and methanol: acetic acid: water (MAAW) solvent systems indicated the presence of compounds. Purification of the compounds contained in these extracts over silica gel column yielded numerous fractions which were evaluated for antibacterial activity and purity. PHF5 was the most active fraction with a mean MIC50 value of 1.25mg/mL. Volatile compounds belonging to different known chemical families in honey were identified in all the active fractions obtained from PH. Conversely, only four compounds were identified in the active fractions obtained from CRT hence the non volatile constituents could be of prime relevance with respect to antibacterial activity of this honey. Of novelty was the presence of thiophene and N-methyl-D3-azirdine compounds, essential precursors used for the synthesis of natural products and pharmaceuticals with vital biomedical properties. Linalool demonstrated potent inhibitory (MIC95, 0.002- 0.0313mg/mL) and bactericidal activity (0.0039-0.313mg/mL) against the test isolates. On the other hand, a significant difference was recorded (P < 0.05) in comparing the activity of linalool compound to the fractions. PH could serve as a good economic source of bioactive compounds which could be employed as template for the synthesis of novel anti-H. pylori drugs. However, further studies are needed to determine the non volatile active ingredients in PH and CRT as well as toxicological testin

Treatment of Helicobacter pylori infections: Mitigating factors and prospective natural remedies

Helicobacter pylori is a Gram-negative, microaerophilic spiral or motile rod that infects about half the world&#8217;s population with a very high prevalence in the developing world. It is an important aetiological factor in the development of gastritis, peptic ulcer disease, gastric atrophy and B cell mucosa associated lymphoid tissue (MALT) lymphoma. H. pylori infection is responsible for a significant cause of morbidity and mortality imposing a major burden on health care systems world wide. The high prevalence of infection in the developing countries has been attributed to poor socioeconomic status and sanitation as well as an increased trend of antibiotic resistance. Antimicrobial chemotherapy (two antibiotics and a proton pump inhibitor) employed for the treatment of H. pylori infections has emerged as the most important means to resolve these infections. However, antimicrobial therapy is fraught with a number of inherent limitations such as resistance, cost of treatment, unavailability of drugs in rural areas and undesirable side effects necessitating the need to search for alternative approaches from natural sources including vegetables, honey and probiotics amongst others. These could form the basis of novel low cost, efficient, large-scale and alternative/complementary solutions with minimal side effects to decrease or eradicate H. pylori infections in the future

Volatile Compounds in Honey: A Review on Their Involvement in Aroma, Botanical Origin Determination and Potential Biomedical Activities

Volatile organic compounds (VOCs) in honey are obtained from diverse biosynthetic pathways and extracted by using various methods associated with varying degrees of selectivity and effectiveness. These compounds are grouped into chemical categories such as aldehyde, ketone, acid, alcohol, hydrocarbon, norisoprenoids, terpenes and benzene compounds and their derivatives, furan and pyran derivatives. They represent a fingerprint of a specific honey and therefore could be used to differentiate between monofloral honeys from different floral sources, thus providing valuable information concerning the honey’s botanical and geographical origin. However, only plant derived compounds and their metabolites (terpenes, norisoprenoids and benzene compounds and their derivatives) must be employed to discriminate among floral origins of honey. Notwithstanding, many authors have reported different floral markers for honey of the same floral origin, consequently sensory analysis, in conjunction with analysis of VOCs could help to clear this ambiguity. Furthermore, VOCs influence honey’s aroma described as sweet, citrus, floral, almond, rancid, etc. Clearly, the contribution of a volatile compound to honey aroma is determined by its odor activity value. Elucidation of the aroma compounds along with floral origins of a particular honey can help to standardize its quality and avoid fraudulent labeling of the product. Although only present in low concentrations, VOCS could contribute to biomedical activities of honey, especially the antioxidant effect due to their natural radical scavenging potential

Honey Supplementation and Exercise: A Systematic Review.

Honey is a natural substance formed primarily of carbohydrates (~80%) which also contains a number of other compounds purported to confer health benefits when consumed. Due to its carbohydrate composition (low glycaemic index, mostly fructose and glucose), honey may theoretically exert positive effects when consumed before, during or after exercise. This review therefore appraised research examining the effects of honey consumption in combination with exercise in humans. Online database (PubMed, MEDLINE, SPORTDiscus) searches were performed, yielding 273 results. Following duplicate removal and application of exclusion criteria, nine articles were reviewed. Large methodological differences existed in terms of exercise stimulus, population, and the nutritional interventions examined. All nine studies reported biochemical variables, with four examining the effects of honey on exercise performance, whilst five described perceptual responses. Acute supplementation around a single exercise session appeared to elicit similar performance, perceptual, and immunological responses compared with other carbohydrate sources, although some performance benefit has been observed relative to carbohydrate-free comparators. When consumed over a number of weeks, honey may dampen immunological perturbations arising from exercise and possibly improve markers of bone formation. More well-controlled research is required to better understand the role for honey in a food-first approach to exercise nutrition

Food processing as a risk factor for antimicrobial resistance spread along the food chain

Documento post-printFarms and food industries rely to a large extent on the use ofbiocides as disinfectants and other antimicrobial agents andpreservatives with antimicrobial properties in order to providefood of high microbiological quality and safe for consumers.However, in the last decades it has become apparent that long-term sub-lethal exposure to these antimicrobial agents canexert a selective pressure leading to the emergence and spreadof microbial strains with a reduced susceptibility to the usedantimicrobials, which can persistently colonize food-processing environments and recurrently contaminate food. Inaddition, it may induce resistance to unrelated and clinicallyrelevant antibiotics, in a phenomenon known as cross-resistance. This review aims to provide insights on howantimicrobial resistance emergence and spread can beaffected by certain food processing activities and to discussrecent research focused on different pathways through whichbiocides and other antimicrobials could co-select for bacteriaresistant to clinically relevant antibiotics.S

Mineral and volatile composition of agua-mel from Portugal

Agua-mel (honey-water) is a typical honey-based product produced by the Portuguese beekeepers, particularly in southern Portugal. Agua-mel was characterized by mineral content and volatiles contents. Mineral content evaluation was performed based on a random sampling of 14 samples from a total of 16 samples provided by local producers. Mineral content showed that potassium predominated in agua-mel samples (1270-4105 mg/kg). The concentration of aluminium in one sample was tenfold higher (5.8 mg/kg) than in the remaining samples (0.3-0.6 mg/kg). Agua-mel volatiles were isolated by hydrodistillation and analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) from a subset of eight samples. Cluster analysis showed two poorly correlated clusters (S (corr) < 0.3). Cluster I only sample was dominated by trans-beta-ocimene (19 %), gamma-terpinene (15 %) and 2-furfural (9 %). Cluster II that included the remaining seven samples showed two moderately correlated subclusters (S (corr) < 0.5). The six samples with high correlation from subcluster IIa were dominated by 2-furfural (18-41 %) and benzene acetaldehyde (12-39 %). n-Nonadecane (14 %), n-heneicosane and 2-furfural (both 13 %) were the main components of subcluster IIb sample. Although the presence of some volatile compounds can help in the correlation between agua-mel and honey botanical source, the final product varies largely according to the preparation process even for the same producer, in different years. Agua-mel detailed characterization may assist in bringing added value to this typical Portuguese honey-based product

Infection, colonization and shedding of Campylobacter and Salmonella in animals and their contribution to human disease: A review

Livestock meat and offal contribute significantly to human nutrition as sources of high‐quality protein and micronutrients. Livestock products are increasingly in demand, particularly in low‐ and middle‐income settings where economies are growing and meat is increasingly seen as an affordable and desirable food item. Demand is also driving intensification of livestock keeping and processing. An unintended consequence of intensification is increased exposure to zoonotic agents, and a contemporary emerging problem is infection with Campylobacter and Salmonella spp. from livestock (avian and mammalian), which can lead to disease, malabsorption and undernutrition through acute and chronic diarrhoea. This can occur at the farm, in households or through the food chain. Direct infection occurs when handling livestock and through bacteria shed into the environment, on food preparation surfaces or around the house and surroundings. This manuscript critically reviews Campylobacter and Salmonella infections in animals, examines the factors affecting colonization and faecal shedding of bacteria of these two genera as well as risk factors for human acquisition of the infection from infected animals or environment and analyses priority areas for preventive actions with a focus on resource‐poor settings

The effects of native and modified clupeine on the structure of gram-negative model membranes

Clupeine, a cationic antimicrobial peptide found in fish, is of interest as a food additive but non-specific binding of the peptide to anionic molecules reduces its antimicrobial activity. The overall positive charge of clupeine can be reduced by blocking 10% of its arginine residues with 1,2-cyclohexanedione (CHD). The modified peptide retains antimicrobial activity but it is not known if its effect on the structure of Gram-negative model membranes is the same as the native peptide. In the presented paper, neutron reflectometry (NR) and X-ray reflectometry were used to investigate the effect of native and modified clupeine on the structure of model monolayer membranes composed of Phosphatidylethanolamine (PE), Phosphatidylglycerol (PG), and Cardiolipin (CL). The effect of the peptides on the structure of 1,2-dipalmitoyl (d62)-sn- glycero-3-phosphocholine (DPPC)/PE:PG:CL bilayers were also examined by NR. In both model systems, modified clupeine demonstrated a greater effect on the lipid structure. Charge reduction in the modified sample also resulted in improved hydrophobicity, and the formation of thicker peptide layers in the membrane models. Some lipid translocation was observed in the inner tail region (~69 ± 0.24% DPPC and ~24 ± 0.02% PE:PG:CL); and in the outer tail region (~24 ± 0.02% DPPC and ~56 ± 0.01% PE:PG:CL). Improved hydrophobicity and electrostatic interactions with lipid head groups, strongly suggests that the modified clupeine may use the carpet mechanisms to exert its effect on model membranes. These findings suggest that changing the charge on the native peptide changes the way in which the modified peptide disrupts Gram-negative model membranes

Volatile Compounds in Honey: A Review on Their Involvement in Aroma, Botanical Origin Determination and Potential Biomedical Activities

Volatile organic compounds (VOCs) in honey are obtained from diverse biosynthetic pathways and extracted by using various methods associated with varying degrees of selectivity and effectiveness. These compounds are grouped into chemical categories such as aldehyde, ketone, acid, alcohol, hydrocarbon, norisoprenoids, terpenes and benzene compounds and their derivatives, furan and pyran derivatives. They represent a fingerprint of a specific honey and therefore could be used to differentiate between monofloral honeys from different floral sources, thus providing valuable information concerning the honey’s botanical and geographical origin. However, only plant derived compounds and their metabolites (terpenes, norisoprenoids and benzene compounds and their derivatives) must be employed to discriminate among floral origins of honey. Notwithstanding, many authors have reported different floral markers for honey of the same floral origin, consequently sensory analysis, in conjunction with analysis of VOCs could help to clear this ambiguity. Furthermore, VOCs influence honey’s aroma described as sweet, citrus, floral, almond, rancid, etc. Clearly, the contribution of a volatile compound to honey aroma is determined by its odor activity value. Elucidation of the aroma compounds along with floral origins of a particular honey can help to standardize its quality and avoid fraudulent labeling of the product. Although only present in low concentrations, VOCS could contribute to biomedical activities of honey, especially the antioxidant effect due to their natural radical scavenging potential

Reduction of Bacterial Pathogens in a Single-Stage Steel Biodigester Co-Digesting Saw Dust and Pig Manure at Psychrophilic Temperature

The experiment was conducted using a single-stage steel biodigester of 75 L working volume, charged with 75% pig manure and 25% pine wood sawdust and operated under batch mode at a psychrophilic temperature range (13.16&ndash;24.69 &deg;C). The total viable count was determined via the spread plate method on selective microbiological media to determine viable numbers of the selected bacterial pathogens in samples collected from the biodigesting chamber every seven or fourteen days over the duration of study. Multiple linear regression models including the log bacterial counts (response) and number of days, pH, and average daily temperature as predictors were developed using Matlab for each bacterium. The reduction (90&ndash;99.9%) in numbers of isolates of E. coli, Salmonella, Yersinia, Campylobacter, and Listeria varied with time (days) from their initial respective counts of 2 &times; 106, 7 &times; 104, 3 &times; 105, 9 &times; 105, and 1 &times; 104 cfu/g to concentrations lower than the detection limit (DL = 102 cfu/g substrate). E. coli demonstrated the least resistance to the environmental conditions in the biodigester and survived only for 77 days, unlike L. monocytogenes that lasted for 175 days and was the most resistant bacterium. From the models, the number of days and temperature were directly and inversely related to log Listeria counts, respectively, contrary to the others. The predictors, number of days, pH, and average daily temperature, were described as either primary or secondary factors based on the bacteria via the reliefF test