The in vitro susceptibility of Campylobacter spp. to the antibacterial effect of manuka honey

Biological Efficacy of Compounds from Stingless Honey and Sting Honey against Two Pathogenic Bacteria: An In Vitro and In Silico Study

Honey inhibits bacterial growth due to the high sugar concentration, hydrogen peroxide generation, and proteinaceous compounds present in it. In this study, the antibacterial activity of stingless and sting honey against foodborne pathogenic bacteria isolated from spoiled milk samples was examined. The isolated bacterial strains were confirmed as Bacillus cereus and Listeriamonocytogenes through morphological, biochemical, and 16 s RNA analysis. Physiochemical characterizations of the honey samples revealed that both of the honey samples had an acidic pH, low water content, moderate reducing sugar content, and higher proline content. Through the disc diffusion method, the antibacterial activities of the samples were assayed and better results were observed for the 50 mg/disc honey. Both stingless and sting honey showed the most positive efficacy against Bacillus cereus. Therefore, an in silico study was conducted against this bacterium with some common compounds of honey. From several retrieved constituents of stingless and sting honey, 2,4-dihydroxy-2,5-dimethyl 3(2H)-furan-3-one (furan) and 4H-pyran-4-one,2,3-dihydro of both samples and beta.-D-glucopyranose from the stingless revealed high ligand-protein binding efficiencies for the target protein (6d5z, hemolysin II). The root-mean-square deviation, solvent-accessible surface area, the radius of gyration, root-mean-square fluctuations, and hydrogen bonds were used to ensure the binding stability of the docked complexes in the atomistic simulation and confirmed their stability. The combined effort of wet and dry lab-based work support, to some extent, that the antimicrobial properties of honey have great potential for application in medicine as well as in the food industries.

The Potential of Honey as a Prebiotic Food to Re-engineer the Gut Microbiome Toward a Healthy State

Honey has a long history of use for the treatment of digestive ailments. Certain honey types have well-established bioactive properties including antibacterial and anti-inflammatory activities. In addition, honey contains non-digestible carbohydrates in the form of oligosaccharides, and there is increasing evidence from in vitro, animal, and pilot human studies that some kinds of honey have prebiotic activity. Prebiotics are foods or compounds, such as non-digestible carbohydrates, that are used to promote specific, favorable changes in the composition and function of the gut microbiota. The gut microbiota plays a critical role in human health and well-being, with disturbances to the balance of these organisms linked to gut inflammation and the development and progression of numerous conditions, such as colon cancer, irritable bowel syndrome, obesity, and mental health issues. Consequently, there is increasing interest in manipulating the gut microbiota to a more favorable balance as a way of improving health by dietary means. Current research suggests that certain kinds of honey can reduce the presence of infection-causing bacteria in the gut including Salmonella, Escherichia coli, and Clostridiodes difficile, while simultaneously stimulating the growth of potentially beneficial species, such as Lactobacillus and Bifidobacteria. In this paper, we review the current and growing evidence that shows the prebiotic potential of honey to promote healthy gut function, regulate the microbial communities in the gut, and reduce infection and inflammation. We outline gaps in knowledge and explore the potential of honey as a viable option to promote or re-engineer a healthy gut microbiome.

Investigating Possible Synergism in the Antioxidant and Antibacterial Actions of Honey and Propolis from the Greek Island of Samothrace through Their Combined Application

Several honeybee products are known for their functional properties, including important antioxidant and antimicrobial actions. The present study examines the antioxidant activity (AA), total polyphenolic content (TPC), and antibacterial action of honey and propolis samples collected from the Greek island of Samothrace, which were applied in vitro either individually or in combination in selected concentrations. To accomplish this, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and the Folin-Ciocalteu assays were employed to determine the AA and TPC, respectively, while the antibacterial action was investigated against each one of four important pathogenic bacterial species causing foodborne diseases (i.e., Salmonella enterica, Yersinia enterocolitica, Staphylococcus aureus, and Listeria monocytogenes) using the agar well diffusion assay. Compared to honey, propolis presented significantly higher AA and TPC, while its combined application with honey (at ratios of 1:1, 3:1, and 1:3) did not increase these values. Concerning the antibacterial action, Y. enterocolitica was proven to be the most resistant of all the tested bacteria, with none of the samples being able to inhibit its growth. S. enterica was susceptible only to the honey samples, whereas L. monocytogenes only to the propolis samples. The growth of S. aureus was inhibited by both honey and propolis, with honey samples presenting significantly higher efficacy than those of propolis. Νo synergism in the antibacterial actions was observed against any of the tested pathogens. Results obtained increase our knowledge of some of the medicinal properties of honey and propolis and may contribute to their further exploitation for health promotion and/or food-related applications (e.g., as preservatives to delay the growth of pathogenic bacteria).

Bee Venom, Honey, and Royal Jelly in the Treatment of Bacterial Infections of the Oral Cavity: A Review

Oral diseases affect a very large number of people, and the applied pharmacological methods of treatment and/or prevention have serious side effects. Therefore, it is necessary to search for new, safer methods of treatment. Natural bee products, such as honey, royal jelly, and bee venom, can be a promising alternative in the treatment of oral cavity bacterial infections. Thus, we performed an extensive literature search to find and summarize all articles about the antibacterial activity of honey, royal jelly, and bee venom. Our analysis showed that these bee products have strong activity against the bacterial strains causing caries, periodontitis, gingivitis, pharyngitis, recurrent aphthous ulcers, supragingival, and subgingival plaque. An analysis of average MIC values showed that honey and royal jelly have the highest antimicrobial activity against Porphyromonas gingivalis and Fusobacterium nucleatum. In turn, bee venom has an antibacterial effect against Streptococcus mutans. Streptococcus sobrinus and Streptoccus pyogenes were the most resistant species to different types of honey, and royal jelly, respectively. Moreover, these products are safer in comparison to the chemical compounds used in the treatment of oral cavity bacterial infections. Since the antimicrobial activity of bee products depends on their chemical composition, more research is needed to standardize the composition of these compounds before they could be used in the treatment of oral cavity bacterial infections.

Beehive Products as Antibacterial Agents: A Review

Honeybees are one of the most marvelous and economically beneficial insects. As pollinators, they play a vital role in every aspect of the ecosystem. Beehive products have been used for thousands of years in many cultures for the treatment of various diseases. Their healing properties have been documented in many religious texts like the Noble Quran and the Holy Bible. Honey, bee venom, propolis, pollen and royal jelly all demonstrated a richness in their bioactive compounds which make them effective against a variety of bacterial strains. Furthermore, many studies showed that honey and bee venom work as powerful antibacterial agents against a wide range of bacteria including life-threatening bacteria. Several reports documented the biological activities of honeybee products but none of them emphasized on the antibacterial activity of all beehive products. Therefore, this review aims to highlight the antibacterial activity of honey, bee venom, propolis, pollen and royal jelly, that are produced by honeybees.

Antimicrobial activity of honey in periodontal disease: a systematic review

BACKGROUND

Honey has shown positive antimicrobial and anti-inflammatory actions in several dermatological studies; however, it is unclear if it could be effective in the treatment of periodontal disease.

OBJECTIVES

To answer the question: Does honey have antimicrobial activity against periodontopathogens?

METHODS

Six electronic databases were screened from initiation to 31 January 2019 for randomized clinical trials (RCTs) and controlled in vitro studies exploring the antimicrobial effect of honey against periodontopathogens. Honey's botanical origin, periopathogens that showed microbial susceptibility to honey, MICs, microbial growth conditions, control product and clinical follow-up were the main investigated outcomes. The risk of bias (RoB) of included RCTs was assessed using the Cochrane Collaboration RoB tool. The RoB of in vitro studies was evaluated based on the Sarkis-Onofre judgement model adapted to the context of honey.

RESULTS

A total of 1448 publications were found as search results in the screened databases. Sixteen eligible papers were included based on predetermined inclusion criteria. Retained studies included 5 RCTs and 11 in vitro controlled trials. Manuka and multifloral honeys were the most studied varieties. The tested honeys showed a significant antimicrobial action, with different MICs, against eight periopathogens. Four of the five RCTs showed a high RoB, while 4 of the 11 retained in vitro studies showed a medium RoB.

CONCLUSIONS

Honey showed a significant antimicrobial activity against all targeted periopathogens. Additional experiments are required to explore the entire antimicrobial spectrum of honey towards all pathogens involved in periodontal disease.

Antibacterial Potency of Honey

Despite the developments in controlling infectious disease around the world, they are still the second biggest cause of morbidity and mortality due in part to the increase in drug resistance among large numbers of the bacterial strains. This means that new strategies are needed to prevent and treat infectious disease. As a result, several ancient methods have been re-evaluated and the substances/procedures employed historically to cure diseases are now attracting renewed scientific attention. Honey is one such product that used to be widely used to combat bacteria. This review covers the antibacterial activity of honey, its use in the treatment of infection and diseases, and the features that are relevant to its activity.

Methylglyoxal, the Major Antibacterial Factor in Manuka Honey: An Alternative to Preserve Natural Cosmetics?

Microbial safety is an essential prerequisite of cosmetics, and preservatives are required to prevent product spoilage and damage to consumers’ health. Consumer concern about the safety of some cosmetic ingredients and the increasing demand for more natural beauty products has driven cosmetic industries and formulators to find natural alternatives to replace synthetic preservatives currently used. In this study, methylglyoxal (MGO, the main factor responsible for the antimicrobial activity of manuka honey) was tested for antimicrobial activity against a panel of selected bacteria and mycetes by using conventional microbiological techniques (determination of M.I.C., time-kill assay), and its potential preservative in an O/W emulsion was investigated (challenge test). MGO showed a remarkable and fast antibacterial activity (M.I.C. values 0.150–0.310 mg/mL), while the inhibitory activity against fungi was less marked (M.I.C. values 1.25–10 mg/mL); chitosan has proven to be a synergist of antimicrobial effectiveness of MGO. Results of the challenge test showed that the addition of MGO to a cream formulation was efficient against microbial contamination. On the basis of our results, MGO appears to be a good candidate as a cosmetic preservative of natural origin; further studies are needed to confirm its applicability and its safety.

Manuka Honey: A Potent Cariostatic Agent- An in vitro Study

Aim

The aim of the study was to test the antibacterial activity of manuka honey and compare its efficacy with another commercially available honey (Dabur honey) on the cariogenic bacteria on Streptococcus mutans and Lactobacillus.

Materials and methods

An in vitro study was carried out on 40 agar specimens; the samples were divided into two groups of 20 samples consisting of S. mutans and Lactobacil-lus respectively. The 20 samples in each group were further subdivided into four groups of five each, which were tested with 25% manuka honey, 100% manuka honey, 25% Dabur honey, and 100% Dabur honey for both Lactobacillus and S. mutans groups. The antibacterial activity was tested using the agar well diffusion method against S. mutans and Lacto-bacillus. Antibacterial activity was assessed by measuring the diameter of inhibition of zones surrounding the wells. The results obtained were statistically analyzed (one-way analysis of variance test, p-value).

Results

The results showed that 25% of manuka honey has statistically significant (p ≤ 0.001) antibacterial effect than 25% of Dabur honey on both Streptococcus and Lactobacillus species, and manuka honey with 100% concentration showed a statistically significant (p ≤ 0.001) antibacterial effect than 100% Dabur honey on the same species of bacteria. 100% of both the honeys showed statistically significant (p ≤ 0.001) antibacterial effect than 25% concentrations of the same on S. mutans and Lactobacillus.

Conclusion

Manuka honey had more antibacterial activity than Dabur honey on S. mutans and Lactobacillus bacteria in the in vitro study. This effect was dependent on the concentration of honey used.

How to cite this article: Beena JP, Sahoo P, Konde S, Raj SN, Kumar NC, Agarwal M. Manuka Honey: A Potent Cariostatic Agent—An in vitro Study. Int J Clin Pediatr Dent 2018;11(2):105-109.

Separation and Identification of Four New Compounds with Antibacterial Activity from Portulaca oleracea L

The Portulaca oleracea L. (P. oleracea) has been used to treat bacillary dysentery for thousands of years in China. Pharmacology studies on P. oleracea have also showed its significant antibacterial effects on the enteropathogenic bacteria, which might reveal the treatment of P. oleracea in cases of bacillary dysentery to some extent. To date, however, the therapeutic basis of P. oleracea treating on bacillary dysentery remains unknown. We determined the antibacterial effective fraction of P. oleracea in a previous study. The current study, which is based on our previous study, was first designed to isolate, identify and screen antibacterial active constituents from P. oleracea. As a result, four new compounds (1–4), portulacerebroside B (1), portulacerebroside C (2), portulacerebroside D (3) and portulaceramide A (4) along with five known compounds (5–9) were isolated, and structures were established by their physico-chemical constants and spectroscopic analysis. The antibacterial activities against common enteropathogenic bacteria were evaluated for all compounds and the new compounds 1–4 showed significant antibacterial effect on enteropathogenic bacteria in vitro, which might contribute to revealing the treatment of P. oleracea in cases of bacillary dysentery.

Antimicrobial properties of honey

Honey has been widely accepted as food and medicine by all generations, traditions, and civilizations, both ancient and modern. For at least 2700 years, honey has been used by humans to treat a variety of ailments through topical application, but only recently have the antiseptic and antimicrobial properties of honey been discovered. Honey has been reported to be effective in a number of human pathologies. Clinical studies have demonstrated that application of honey to severely infected cutaneous wounds rapidly clears infection from the wound and improves tissue healing. A large number of in vitro and limited clinical studies have confirmed the broad-spectrum antimicrobial (antibacterial, antifungal, antiviral, and antimycobacterial) properties of honey, which may be attributed to the acidity (low pH), osmotic effect, high sugar concentration, presence of bacteriostatic and bactericidal factors (hydrogen peroxide, antioxidants, lysozyme, polyphenols, phenolic acids, flavonoids, methylglyoxal, and bee peptides), and increase in cytokine release, and to immune modulating and anti-inflammatory properties of honey; the antimicrobial action involves several mechanisms. Despite a large amount of data confirming the antimicrobial activity of honey, there are no studies that support the systemic use of honey as an antibacterial agent.

Manuka honey: an emerging natural food with medicinal use

The health value of honey is universally acknowledged from time immemorial. Manuka (Leptospermum scoparium) is a tree, indigenous to New Zealand and South East Australia, and from the myrtle family, Myrtaceae. The honey produced from its flowers is a uni-floral honey largely produced in New Zealand. It is becoming increasingly popular as a functional food, seen in the aisles of health stores as its displays superior nutritional and phytochemistry profile over other varieties of honey. Examining existing research databases revealed its biological properties ranging from anti-oxidant, anti-inflammatory, anti-bacterial, anti-viral, anti-biotic and wound healing to immune-stimulatory properties. Methylglyoxal is the unique compound in the honey responsible for some of its potent anti-microbial properties. Further, propolis another component of honey contains chiefly flavonoids (i.e. galangin, pinocembrin), phenolic acids and their esters that may also contribute to its immuno-stimulant properties. Recent findings of the biological roles have been discussed with emphasis on the underlying mechanisms. The hurdles associated in its development as a functional food and also nutraceutical with future scopes have also been mentioned. Relevant data published in MEDLINE, Cochrane library, and EMBASE in the past decade have been gathered to formulate this review.

Antimicrobial activity of different Finnish monofloral honeys against human pathogenic bacteria

The antimicrobial activity and phenolic compounds of five Finnish honey products against important human pathogens Streptococcus pneumoniae, S. pyogenes, Staphylococcus aureus, and methicillin-resistant S. aureus were analyzed. Microbroth dilution method and HPLC-DAD were used in antimicrobial testing and phenolic compound determination, respectively. Significant antimicrobial activity (p < 0.01) against all the tested pathogens was found from willow herb (Epilobium angustifolium), heather (Calluna vulgaris), and buckwheat (Fagopyrum esculentum) honeys. This is the first report on antimicrobial activity of Finnish monofloral honeys against streptococcal and staphylococcal bacteria. To our knowledge this is also the first report on the antimicrobial effect of honey against S. pneumoniae.

Nutraceutical values of natural honey and its contribution to human health and wealth

The use of natural honey (NH) as a nutraceutical agent is associated with nutritional benefits and therapeutic promises. NH is widely accepted as food and medicine by all generations, traditions and civilizations, both ancient and modern. The nutritional profiles, including its use in infant and children feeding reported in different literatures as well as health indices and biomarkers observed by various researchers are illustrated in this manuscript. The review documents folk medicine, experimentation with animal models, and orthodox medical practices shown by clinical trials. This covers virtually all human organs and body systems extensively studied by different workers. The sources and adverse effects of NH contamination, as well as the preventive methods are identified. This could promote the availability of residue free honey and a wholesome natural product for domestic consumption and international market. This could also help to prevent health problems associated with NH poisoning. In addition, apicultural practices and the economic importance of honey are well documented. This report also includes information about a relatively unknown and uncommon South American stingless bee species. We concluded this review by identifying important roles for Ethno-entomologists, other Scientists and Apiculturists in the development of stingless bees to boost honey production, consumption and economic earnings.

Honey and microbial infections: a review supporting the use of honey for microbial control

Honey has been used as a medicine throughout the ages and has recently been reintroduced to modern medical practice. Much of the research to date has addressed honey's antibacterial properties and its effects on wound healing. Laboratory studies and clinical trials have shown that honey is an effective broad-spectrum antibacterial agent. Honey antimicrobial action explains the external and internal uses of honey. Honey has been used to treat adult and neonatal postoperative infection, burns, necrotizing fasciitis, infected and nonhealing wounds and ulcers, boils, pilonidal sinus, venous ulcers, and diabetic foot ulcers. These effects are ascribed to honey's antibacterial action, which is due to acidity, hydrogen peroxide content, osmotic effect, nutritional and antioxidants content, stimulation of immunity, and to unidentified compounds. When ingested, honey also promotes healing and shows antibacterial action by decreasing prostaglandin levels, elevating nitric oxide levels, and exerting prebiotic effects. These factors play a major role in controlling inflammation and promoting microbial control and healing processes. This article reviews data supporting the effectiveness of natural honey in eradicating human pathogens and discusses the mechanism of actions.

Methylglyoxal-a potential risk factor of manuka honey in healing of diabetic ulcers

Honey has been considered as a remedy in wound healing since ancient times. However, as yet, there are inadequate supportive robust randomized trials and experimental data to fully accept honey as an effective medical product in wound care. Manuka honey has been claimed to have therapeutic advantages over other honeys. Recently, it has been documented that the pronounced antibacterial activity of manuka honey is due, at least in part, to reactive methylglyoxal (MG). The concentration of MG in manuka honeys is up to 100-fold higher than in conventional honeys. MG is a potent protein-glycating agent and an important precursor of advanced glycation end products (AGEs). MG and AGEs play a role in the pathogenesis of impaired diabetic wound healing and can modify the structure and function of target molecules. This commentary describes the concern that MG in manuka honey may delay wound healing in diabetic patients. Further detailed research is needed to fully elucidate the participation of honey/derived MG in healing diabetic ulcers. We advocate randomized controlled trials to determine efficacy and safety of manuka honey in this population.

Comparison of the antimicrobial activity of Ulmo honey from Chile and Manuka honey against methicillin-resistant Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa

Background

Honey has previously been shown to have wound healing and antimicrobial properties, but this is dependent on the type of honey, geographical location and flower from which the final product is derived. We tested the antimicrobial activity of a Chilean honey made by Apis mellifera (honeybee) originating from the Ulmo tree (Eucryphia cordifolia), against selected strains of bacteria.

Methods

Ulmo 90 honey was compared with manuka UMF^® 25+ (Comvita^®) honey and a laboratory synthesised (artificial) honey. An agar well diffusion assay and a 96 well minimum inhibitory concentration (MIC) spectrophotometric-based assay were used to assess antimicrobial activity against five strains of methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli and Pseudomonas aeruginosa.

Results

Initial screening with the agar diffusion assay demonstrated that Ulmo 90 honey had greater antibacterial activity against all MRSA isolates tested than manuka honey and similar activity against E. coli and P. aeruginosa. The MIC assay, showed that a lower MIC was observed with Ulmo 90 honey (3.1% - 6.3% v/v) than with manuka honey (12.5% v/v) for all five MRSA isolates. For the E. coli and Pseudomonas strains equivalent MICs were observed (12.5% v/v). The MIC for artificial honey was 50% v/v. The minimum bactericidal concentration for all isolates tested for Ulmo 90 honey was identical to the MIC. Unlike manuka honey, Ulmo 90 honey activity is largely due to hydrogen peroxide production.

Conclusions

Due to its high antimicrobial activity, Ulmo 90 may warrant further investigation as a possible alternative therapy for wound healing.

Traditional medicine in oman: its role in ophthalmology

Aim:

To present three patients with ocular disease who developed a range of complications following use of traditional medications.

Settings and Design:

Case series

Methods:

Three patients who were examined in the Ophthalmic department of a tertiary care teaching hospital in the Sultanate of Oman between 2003 and 2004, seeking care following use of traditional medicines and or healing practices for various ophthalmic problems described below.

Results:

The first patient was a computer professional with a chalazion; the patient used a plant extract from ‘Calotropis procera’ as a part of the treatment. He developed corneal edema with decrease in vision in his left eye following application of the plant extract. Treatment with topical steroids and antibiotics resulted in a complete clinical and visual recovery. The second patient developed a fungal corneal ulcer (dermatophyte - Trichophyton mentagrophyte) after sustaining injury with an animal tail to the right eye and used honey for pain relief prior to presentation. She responded poorly to anti-fungal treatment, underwent a penetrating keratoplasty with recurrence of infection in the graft that resulted in a vascularized corneal scar. The third patient was a five-year-old child who was treated with ‘wasam’ on the occiput for intraocular inflammation following bilateral uncomplicated cataract extraction. Following this treatment the topical steroid was discontinued. The ‘Wasam’ treatment indirectly resulted in exacerbation of the intraocular inflammation and secondary glaucoma and poor vision as well as ‘Wasam ulcers’ on the occiput. Despite treatment of the intraocular inflammation, the visual outcome was poor.

Conclusion:

Traditional medicine in Oman is sought by many for variable reasons. Lack of evidence-based scientific data on its safety or efficacy does not deter the Omanis from flocking the traditional healers. However, when applied in the treatment of ocular diseases, traditional medicine and healing practices seem to cause more harm than benefit for the patient.