Formulation and Evaluation of Luteolin-Loaded Nanovesicles: In Vitro Physicochemical Characterization and Viability Assessment

Abstract

Luteolin (LT) is a natural polyphenol water-insoluble compound. LT-loaded nanovesicles (NVs) were prepared by using the solvent evaporation method. LT-NVs were prepared using cholesterol, phosphatidylcholine, span 60, and labrasol in a different composition. The prepared LT-NVs were evaluated for encapsulation efficiency, in vitro drug release, and permeation study. The optimized LT-NVs were further evaluated for antioxidant activity and cytotoxicity using the lung cancer cell line. LT-NVs showed nanometric size (less than 300 nm), an optimum polydispersibility index (less than 0.5), and a negative zeta potential value. The formulations also showed significant variability in the encapsulation efficiency (69.44 ± 0.52 to 83.75 ± 0.35%) depending upon the formulation composition. The in vitro and permeation study results revealed enhanced drug release as well as permeation profile. The formulation LT-NVs (F2) showed the maximum drug release of 88.28 ± 1.13%, while pure LT showed only 20.1 ± 1.21% in 12 h. The release data revealed significant variation (p < 0.001) in the release pattern. The permeation results also depicted significant (p < 0.001) enhancement in the permeation across the membrane. The enhanced permeation from LT-NVs was achieved due to the enhanced solubility of LT in the presence of the surfactant. The antioxidant activity results proved that LT-NVs showed greater activity compared to pure LT. The cytotoxicity study showed lesser IC₅₀ value from LT-NVs than the pure LT. Thus, it can be concluded that LT-NVs are a natural alternative to the synthetic drug in the treatment of lung cancer.

Figure 1

Vesicle size of luteolin-loaded nanovesicles (LT-NVs, F2).

Figure 2

Zeta potential image showing the surface charge of luteolin-loaded nanovesicles (LT-NVs, F2).

Figure 3

Transmission electron microscope image showing the morphology of luteolin-loaded nanovesicles (LT-NVs, F2).

Figure 4

XRD of pure luteolin and luteolin-loaded nanovesicles (LT-NVs, F2).

Figure 5

IR spectra of pure luteolin, excipients (cholesterol, span 60, phosphatidylcholine), and luteolin-loaded nanovesicles (LT-NVs, F2).

Figure 6

Drug release profile of pure luteolin and luteolin-loaded nanovesicles (LT-NVs, F2). The release study was performed in triplicate and data shown as mean ± SD (n = 3).

Figure 7

Antioxidant potential of pure luteolin and luteolin-loaded nanovesicles (LT-NVs, F2). The study was performed in triplicate, and data are shown as mean ± SD (n = 3). Tukey–Kramer multiple comparison test was used to evaluate the statistical significance between two groups. The difference was considered significant if *p < 0.05, ** p < 0.001 when compared with the same concentration of pure LT with LT-NVs (F2).

Figure 8

Cytotoxicity activity of pure luteolin and LT-NVs (F2). Data are depicted in percentage in comparison to control (100%). Tukey–Kramer multiple comparison test was used to evaluate the statistically significant difference between the control and the tested concentrations. The difference was considered significant if p < 0.05. ns = not significant when compared with control; *** p < 0.001 when compared with control; ### p < 0.001 when compared with the same concentration groups of pure luteolin.