Improving Oral Bioavailability of Luteolin Nanocrystals by Surface Modification of Sodium Dodecyl Sulfate

Luteolin suffers from drawbacks like low solubility and bioavailability, thus hindering its application in the clinic. In this study, we employed sodium dodecyl sulfate (SDS), an efficient tight junction opening agent, to modify the surface of luteolin nanocrystals, aiming to enhance the bioavailability of luteolin (LUT) and luteolin nanocrystals (LNC). The particle sizes of SDS-modified luteolin nanocrystals (SLNC) were slightly larger than that of LNC, and the zeta potential of LNC and SLNC was -25.0 ± 0.7 mV and -43.5 ± 0.4 mV, respectively. Both LNC and SLNC exhibited enhanced saturation solubility and high stability in the liquid state. In the cellular study, we found that SDS has cytotoxicity on caco-2 cells and could open the tight junction of the caco-2 monolayer, which could lead to an enhanced transport of luteolin across the intestinal membrane. The bioavailability of luteolin was enhanced for 1.90-fold by luteolin nanocrystals, and after modification with SDS, the bioavailability was enhanced to 3.48-fold. Our experiments demonstrated that SDS could efficiently open the tight junction and enhance the bioavailability of luteolin thereafter, revealing the construction of SDS-modified nanocrystals is a good strategy for enhancing the oral bioavailability of poorly soluble drugs like luteolin.