Antimicrobial potential of chitosan

Promising In Vitro Anti-Toxoplasma gondii Effects of Commercial Chitosan

CDATA[Background: Toxoplasmosis is a disease that results from infection with an obligate intracellular T. gondii parasite, one of the world's most common parasites. Considering the complications of chemical drugs and the need for an appropriate drug combination for treatment of toxoplasmosis and considering the antimicrobial potential of chitosan, as a natural source, this study was aimed to evaluate in vitro activity of commercial chitosan (CC) on T. gondii.

METHODS

In this experimental study, the tachyzoites of T. gondii were collected from the peritoneal exudates from infected Balb/c mice. The tachyzoites were diluted in phosphate buffer saline (PBS) solution. Chitosan with low molecular weight was commercially purchased. Then, at concentrations of 10, 50, 100, and 200 μg/mL and after 30, 60, 120, and 180 minutes, the viability of tachyzoites was determined by using trypan blue 0.1%. Anti-T.gondii activity of CC in all concentrations was significantly higher than pyrimethamine as the control group (P=0.05).

RESULTS

The concentration of 200 μg/mL of CC had the highest effects and killed 30.5, 52, 59, and 81.5% of tachyzoites after 30, 60, 120, and 180 minutes. Moreover, IC50 values of CC were 515, 171, 12.5, and <10 μg/mL in comparison with pyrimethamine as 58.82 μg/mL for 30, 60, 120, and 180 min of exposure time.

CONCLUSION

Our results indicate that chitosan in low molecular weight had potent activity against T. gondii tachyzoites and could be an appropriate candidate for the treatment of at least acute toxoplasmosis, certainly, after complementary in vivo experiments.

Lactoferrin, chitosan and Melaleuca alternifolia-natural products that show promise in candidiasis treatment

The evolution of microorganisms resistant to many medicines has become a major challenge for the scientific community around the world. Motivated by the gravity of such a situation, the World Health Organization released a report in 2014 with the aim of providing updated information on this critical scenario. Among the most worrying microorganisms, species from the genus Candida have exhibited a high rate of resistance to antifungal drugs. Therefore, the objective of this review is to show that the use of natural products (extracts or isolated biomolecules), along with conventional antifungal therapy, can be a very promising strategy to overcome microbial multiresistance. Some promising alternatives are essential oils of Melaleuca alternifolia (mainly composed of terpinen-4-ol, a type of monoterpene), lactoferrin (a peptide isolated from milk) and chitosan (a copolymer from chitin). Such products have great potential to increase antifungal therapy efficacy, mitigate side effects and provide a wide range of action in antifungal therapy.

Synthesis and screening of N-acyl thiolated chitosans for antibacterial applications

Low-molecular weight chitosan-thioglycolic acid has shown significant antibacterial properties against different microorganisms. In order to explore the potential and structure-activity relationships of newly synthesized alkyl thiomers, chitosan has been functionalized with a series of thio-acids with increasing alkyl chain length. All thiomers were characterized with special emphasis on the determination of their degree of deacetylation and substitution, as well as on their molecular weight and amount of thiol groups. The pre-screened chitosan-thiomers were further investigated with plate counting on Pseudomonas aeruginosa, Streptococcus sobrinus and Streptococcus mutans. Furthermore, LIVE/DEAD assays supported the efficiency of chitosan-thiomers against the above microorganisms. All fully characterized chitosan-thiomers showed comparable or enhanced antimicrobial activity compared to pristine chitosan. Our comprehensive approach paves the way to detailed explorations of much sought-after structure activity relationships in the complex chitosan parameter room, starting from correlations between alkyl chain length and antimicrobial activity.