In vitro activity of natural honey alone and in combination with curcuma starch against Rhodotorula mucilaginosa in correlation with bioactive compounds and diastase activity

Objective:To evaluate the in vitro activity and synergism of the combinations of natural honey and curcuma starch against Rhodotorula mucilaginosa in correlation with total phenolic,flavonoid contents,and diastase activity.Methods:The Folin-Ciocalteu test was used to determine the total polyphenols content and the flavonoid content was analyzed using by the aluminum chloride method.The antifungal activity of the natural honey,determined by an agar well diffusion assay and agar incorporation method.Results:Total phenolic content varied from(63.93±0.11)to(95.36±6.08)mg GAE/100 g honey as gallic acid equivalent.Total flavonoids content varied from(5.41±0.04)to(9.94±0.54)mg CE/100g.Diastase activity values were between(7.3±2.8)and(26±2.8).The zone inhibition diameter for the six honey samples without starch ranged between 6 and 20 mm.When starch was mixed with honey and then added to well,a zone inhibition increase diameter 7 and 21 mm.The percentage increase was noticed with each variety and it ranged between 5%and 62.5%.The minimal inhibitory concentrations for the six varieties of honey without starch against Rhodotorula mucilaginosa ranged between 28%and 36%(v/v).When starch was incubated with honey and then added to media,a minimal inhibitory concentration drop has been noticed with each variety.It ranged between 6.66%and 20%(w/v).No significant correlation was established between diastase activity and bioactive compounds.Conclusions:The mixture of curcuma starch and honey could lead to the development of new combination antibiotics against Rhodotorula

Preliminary study on synergistic combinations of raw honey with gentamicin against Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa of veterinary origin

Objective:To search for further synergistic combinations of gentamicin and raw honey that might have potential in treating wounds.Methods:The antibacterial activity and synergistic interaction of raw honey and gentamicin was assessed by using agar well diffusion method.Two Gram-negative(Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 2154)bacteria were selected for antibacterial activity assay.The cultures of bacteria were maintained in their appropriate agar slants at 4°C throughout the study and used as stock cultures.Results:Raw honey and gentamicin interacted synergistically to inhibit Escherichia coli and Pseudomonas aeruginosa.Conclusions:These results suggest that combinations of raw honey and gentamicin have therapeutic benefits in prophylaxis of infections caused by multidrug-resistant Gram-negative bacilli.

Preliminary comparative study of anti-inlfammatory effect of unheated and heat-treated Sahara honey:In vivo approach

Objective:To investigate the effect of unheated and heat-treated of Sahara honey.Methods:A total of 24 Swiss albino mice weighing 25-35 g were divided into four groups(n=6).Anti-inflammatory effect was assessed at 1,2,3,4,5 and 6 h after subplantar injection of carrageenan(0.5 mL of a 1%solution in normal saline).In addition,total phenolic content was determined by modified Folin-Ciocalteu method.Results:The total phenolic content capacity of the Sahara honey before and after heat treatment was between 72 and 97.9 mg of gallic acid equivalents/100 g of honey respectively.Administration of unheated honey(oral administration)reduced significantly(P<0.05).The carrageenan induced mice paw edema model at 1,3 and 6 h for 21.85%,5.43%and 80.43%,respectively.Administration of heat-treated honey showed insignificant inhibition of carrageenan and induced paw edema at 1 h(31.16%),3 h(0.25%)and 6 h(34.19%).The 50 mg/kg diclofenac exhibited percent reduction in paw volume 16.12%,8.90%and 15.32%after 1 h,3 h and 6 h,respectively,when compared with control animals.No toxicity was identified.Conclusions:Our results suggest that unheated Sahara honey has anti-inflammatory effects by reducing the mice paw edema size while heat-treated Sahara honey decreases the antiinflammatory activity.

Effect of heat treatment on antimycotic activity of Sahara honey

Objective:To evaluate the influence of the temperature on honey colour,polyphenol contents and antimycotic capacity and to evaluate the correlation between these parameters.Methods:Sahara honey were heated up to 25,50,75 and 100℃for 15,30 and 60 min,and their colour intensity,polyphenol contents and antimycotic capacity.The Folin-Ciocalteu test was used to determine the total polyphenol contents(TPC).The antimycotic activity was evaluated both by agar diffusion method and micro wells dilution method against the Candida albicans(C.albicans)and Candida glabrata(C.glabrata).Results:Initial values for TPC in Sahara honey ranged from 0.55 to 1.14 mg of gallic acid per kg of honey,with the average value of 0.78 mg of gallic acid per kg of honey.The TPC values after heat-treatment were 0.54 to 1.54 with the average value of 1.49 mg.The minimal inhibitory concentrations before heat-treatment of Sahara honey against C.albicans and C.glabrata ranged from 3.06%-12.5%and 50%respectively.After heat-treatment the minimal inhibitory concentrations between 12.5%and 50%for C.albicans and C.glabrata,respectively.The diameters of inhibition zones of Sahara honey with 50%concentration varied from(12.67-15.00)mm by C.albicans to(14.33-15.67)mm by C.glabrata.The diameters of inhibition zones after heat-treatment at 25 and 50°C for 15.30 and 60 min ranged from(2.00-18.67)mm by C.albicans to(8.00-16.67)mm by C.glabrata.Statistically significant relations between the TPC and the colour intensity of Sahara honey(r=0.99,P<0.05).Furthermore,the results showed that the TPC and colour is not correlated with the antimycotic capacity.Conclusions:To our knowledge this is the first report on the antimycotic capacity of Sahara honey.