**6. Conclusions**

**4.3. Activity against** *Mycobacterium tuberculosis*

226 Honey Analysis

*M. tuberculosis*, being the leading member of the MTB complex (*Mycobacterium tuberculosis complex*), is the main cause of tuberculosis worldwide. Over the recent past years, resistance against antituberculous drugs has emerged rapidly, resulting in MDR (*Multi Drug Resistant*) strains. In vitro activity of Beri honey (from Pakistan) was tested against 21 clinical isolates of MDR-MTB by Hannan and coworkers (2014) [35]. The obtained results clearly demonstrate that Pakistani Beri honey exhibits significant antimycobacterial potential, and three (14%) of the isolates were susceptible at 1% (v/v) honey, while at 2% (v/v) of honey, 18 (86%) isolates were found to be susceptible. All the 21 isolates (*n* = 21) were susceptible at 3% (v/v) of honey [35]. Honey was also proposed for treatment tuberculosis by Avicenna, a known ancient Persian philosopher and physician. At the beginning of twenty-first century, this hypothesis was evaluated by the researchers from Shiraz University of Medical Sciences in Iran [36]. It was demonstrated that the growth of mycobacteria was inhibited by adding 10% honey to the growing media (Lowenstein-Jenson media and L-J media were used). *Mycobacteria* did not grow in culture media containing 10 and 20% honey, while it grew in culture media containing 5, 2.5 and 1% honey. Thus, the obtained results of in vitro tests are quite optimistic [36]. However, future research of in vivo activity of honey against *Mycobacteria* located within the lung tissue would be necessary for fully evaluation of its usefulness in the treatment of tuberculosis. According to the best of our knowledge to date, such studies have not been conducted.

**4.4. Activity against Gram-negative bacteria:** *P. aeruginosa* **and** *E. coli*

**5. Antimicrobial activity of other honeybee products**

The most carried out to date studies revealed that Gram-negative bacteria are a bit less sensitive to the activity of honey in comparison with Gram-positive bacteria. This situation was also observed in the research carried out in our group. The collection of over 30 Polish monofloral honeys was tested, and definitely most of them were less active against *P. aeruginosa* and especially *E. coli* reference strains in comparison with *S. aureus* PCM2051. However, the activity of most of honeys against these pathogens was on satisfactory level, with MIC values in the range of concentrations from 6.25 to 25% (v/v) and from 12.5 to 25% (v/v), respectively [13]. Honey effectively eradicates biofilm formed by *P. aeruginosa* [37]. Activity of this product against this bacterium has been also confirmed in some in vivo studies. The stingless bee honey has been successfully used for treatment of *P. aeruginosa* infected conjunctivitis in Hartley guine pigs [38]. The investigation carried out by the group of Khoo (2010) revealed that Tualang honeytreated rats demonstrated a reduction in bacterial growth in *P. aeruginosa* inoculated wounds [39]. *P. aeruginosa* belongs to the important etiological factors of wound infections. Thus, activity of many potential wound dressing materials containing honey against this bacterium has been carried out. Most of them confirm high therapeutic antimicrobial potential of honey.

In addition, honeybees also produce propolis, wax, pollen, bee bread and royal jelly. All these products exhibit some antibacterial activity. However, from the point of view of possibilities Honey produced from some botanical sources exhibits high antimicrobial activity. Possibilities of application of this product for treatment infections in clinical practice should be the subject of intensive investigations in the near future. Except of high activity, the most important advantages of this product are as follows:


However, it has to be notice that several important problems would have to be solved for more common application of honey for treatment infections.


Summarizing we have no doubt that honey is an interesting and promising alternative to classical antibiotics and should be more seriously considered as therapeutic agents.
