Chitosan based encapsulation increased the apoptotic efficacy of thymol on A549 cells and exhibited non toxic response in swiss albino mice

Thymol is a plant-derived natural phenolic compound abundantly present in Thymus vulgaris species. In the present study, we developed a chitosan-based drug delivery system to deliver thymol to A549 cells. The physicochemical properties of thymol-loaded chitosan nanoparticles (thymol-NP) were characterized using polyphasic techniques viz., FTIR, XRD, DLS, and SEM. Thymol-NP exhibited a size of 282.5 nm and encapsulation efficiency of 74.08 ± 0.73%. The IC₅₀ of thymol-NP against A549 cells was 99.57 μg/ml at 24 h, which was lower than that of the pure form. Clear apoptotic features such as cellular morphology, cell shrinkage, and augmentation of dead cells were observed in both the thymol and thymol-NP treated A549 cells. The percentage of apoptotic cells in the thymol-NP IC₅₀ treated cells was >90% which was considerably higher than the group treated with thymol alone. In vivo toxicity study showed that the swiss albino mice treated up to a concentration of 1000 mg/kg of thymol-NP neither showed signs of toxicity nor death up to 14 days. Also, no significant influence was observed on behavior, body weight, organ weight, and organ histology. Overall, the data concluded that thymol-NP can be considered a safe and potent drug candidate against A549 cells.