Assessment of Nanoencapsulated Syzygium Aromaticum Essential Oil in Chitosan-Alginate Nanocareer as a New Antileishmanial and Antimicrobial System Approach

Syzygium (S.) aromaticum L. (clove) essential oil (EO) has an excellent therapeutic potential including antimicrobial, antiparasitic and antioxidant properties. However, its biological properties can be compromised by its high volatility, toxicity and hydrophobic nature. Nanoencapsulation is a promising approach for enhancing the therapeutic potential of EOs by improving their stability, bioavailability and target delivery. Alginate and chitosan are commonly used natural polymers for nanoencapsulation of EOs due to their biocompatibility, biodegradability and low toxicity. The current study aims to develop and evaluate the biological activity of Syzygium (S.) aromaticum essential oil EO encapsulated into nanometric delivery systems including alginate (AL), chitosan (CS), and the alginate-chitosan complex (AL/CS). The best encapsulation system was selected based on the encapsulation efficiency, biological activity, and cytotoxicity. The developed nanoparticle morphology was determined using SEM and characterized by zeta potential and Fourier transform infrared spectroscopy (FTIR). Results have shown that AL, CS and AL/CS-NPs produced nanoparticles with a nanometric size distribution (526.8 ± 2.34 nm, 641.5 ± 0.31 nm and 849.8 ± 3.57 nm, respectively). They also exhibited high encapsulation efficiency (67.1%, 79.6% and 83.48%, respectively) and a zeta potential of -30 + 0.45mV, + 32.8 ± 0.22mV and + 11.74 ± 0.13mV, respectively. Interestingly, S. aromaticum EO-alginate-chitosan complex nanoparticles exhibited the highest antioxidant, antimicrobial, and antiparasitic potential among the encapsulated nanoparticles. The complex demonstrated the highest antioxidant potential with IC 50 values 30 ± 1.34 and 45 ± 5.36 µg/mL determined by DPPH and FRAP assays and potent antimicrobial activity with MIC values ranged from 125 to 500 µg/mL. It also displayed the greatest antileishmanial activity against L. donovani , L. guyanensis and L. tropica promastigotes, with effective IC 50 values of 6.33 ± 0.16, 8.51 ± 0.23, and 15.66 ± 0.75 µg/mL, respectively. Interestingly, the current study demonstrated that the EO/AL/CS-NPs complex significantly reduced the toxicity and hemolytic potential of S. aromaticum EO by 19.40% and 26.76%, respectively through controlled and sustained release. These findings demonstrate the promising potential of alginate-chitosan encapsulation of S. aromaticum EO in biomedical and pharmaceutical application as a stable, safe, and effective therapeutic alternative to free EO.