The inhibition of baicalein on pancreatic lipase investigated in vitro and in vivo

Abstract

Background

Obesity is increasing seriously worldwide. Inhibiting pancreatic lipase (PL) is an important way to prevent obesity. Baicalein, a dietary flavone, shows various physiological activities and has anti-obesity potential. Therefore, the inhibitory activity of baicalein on PL was investigated in present study.

Results

Baicalein exhibited a significant inhibitory effect on PL with IC₅₀ value of 68 μg/mL. Inhibition kinetics indicated that baicalein was a mixed-type inhibitor of PL. Fluorescence titration showed that baicalein could induce fluorescence quenching of PL. The binding constant (logK_a) and number of binding sites were calculated as 5.40 and 1.11, respectively. In addition, synchronous fluorescence analysis revealed that the quenching ratio of baicalein to tryptophan was greater than that of tyrosine. Circular dichroism (CD) spectrum showed that the binding of baicalein affected the secondary structure of the enzyme protein. Through molecular docking analysis, it confirmed that baicalein could interact with amino acid residues in lipase, thus reducing the enzyme catalytic activity. In vivo studies showed that oral administration of baicalein with a does of 50 mg/kg bwt significantly reduced fat absorption and increased its fecal excretion in rats.

Conclusion

Baicalein showed inhibitory activity on PL in both in vitro and in vivo studies. It may be a safe and effective dietary supplement for obesity prevention.