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 (63.930.11) to (95.366.08) 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/100 g. 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 infections.

Antibacterial activity of various honey types of Algeria against Staphylococcus aureus and Streptococcus pyogenes

OBJECTIVE@#To assess the in vitro antibacterial activity of honey from different geographical location on Gram negative organisms.@*METHODS@#Different concentrations (Undiluted honey, 10 %, 30%, 50% and 70% wt/vol) of honey were studied in vitro using Staphylococcus aureus (S. aureus) and Streptococcus pyogenes (S. pyogenes), briefly, two-fold dilutions of honey solutions were tested to determine the minimum inhibitory concentration (MIC) against each type of microorganism, followed by more assays within a narrower dilution range to obtain more precise MIC values. MICs were determined by both visual inspection and spectrophotometric assay at 620 nm. These honey samples were compared with standard antibiotics like ampicillin, penicillin G, amoxicillin, gentamycin, tobramycin, erythromycin and chloramphenicol was determined by the disc diffusion method.@*RESULTS@#The diameter of zone of the inhibition (ZDI) of honey has various concentrations tested for the isolates ranged 0-46 mm for S. aureus, 0-44 mm for S. pyogenes. While the MIC (%) ranged 12%-95%, 25%-73% respectively.@*CONCLUSIONS@#Algeria honey, in-vitro, possess antibacterial activity.

Antifungal activity of four honeys of different types from Algeria against pathogenic yeast:Candida albicans and Rhodotorula sp

Objective: To evaluate the antifungal activity of four honeys of different types from Algeria against pathogenic yeast i.e. Candida albicans (C. albicans) and Rhodotorula sp. Methods:Four Algeria honeys of different botanical origin were analyzed to test antifungal effect against C. albicans, and Rhodotorula sp. Different concentrations (undiluted, 10%, 30%, 50%and 70%w/v) of honey were studied in vitro for their antifugal activity using C. albicans and Rhodotorula sp. as fungal strains. Results:The range of the diameter of zone of inhibition of various concentrations of tested honeys was (7-23 mm) for Rhodotorula sp., while C. albicans showed clearly resistance towards all concentrations used. The MICs of tested honey concentrations against C. albicans and Rhodotorula sp. were (70.09-93.48)%and (4.90-99.70)%v/v, respectively. Conclusions:This study demonstrates that, in vitro, these natural products have clearly an antifungal activity against Rhodotorula sp. and C. albicans.

Additive potential of ginger starch on antifungal potency of honey against Candida albicans

Objective: To evaluate the additive action of ginger starch on the antifungal activity of honey against Candida albicans (C. albicans). Methods: C. albicans was used to determine the minimum inhibitory concentration (MIC) of four varieties of Algerian honey. Lower concentrations of honey than the MIC were incubated with a set of concentrations of starch and then added to media to determine the minimum additive inhibitory concentration (MAIC). Results: The MIC for the four varieties of honey without starch against C. albicans ranged between 38% and 42% (v/v). When starch was incubated with honey and then added to media, a MIC drop was noticed with each variety. MAIC of the four varieties ranged between 32% honey (v/v) with 4% starch and 36% honey (v/v) with 2% starch. Conclusions: The use of ginger starch allows honey benefit and will constitute an alternative way against the resistance to antifungal agents.

Synergistic action of starch and honey against Pseudomonas aeruginosa in correlation with diastase number.

To evaluate the synergistic action of starch on the antibacterial activity of honey against Pseudomonas aeruginosa, a comparative method of adding honey with and without starch to culture media was used. P. aeruginosa (ATCC 27853) was used to determine the minimum inhibitory concentration (MIC) of five varieties of honey. In a second step, lower concentrations of honey than the MIC were incubated with a set of concentrations of starch and then added to media to determine the minimum synergistic inhibitory concentration. The MIC for the five varieties of honey without starch against P. aeruginosa ranged between 15% and 26% (vol/vol). When starch was incubated with honey and then added to media, a significant MIC drop has been noticed with each variety and it ranged between 30.7% and 46.6%. No significant correlation has been established between the MIC drop and the diastase number.