Litchi induced liver inflammation: Investigating litchi thaumatin-like protein metabolic kinetics in mice

Pro-inflammatory activity of litchi thaumatin-like protein (LcTLP) contributed to adverse response after overdoing litchi consumption. Less caring about metabolic process of LcTLP severely limited the elucidation of mechanism of action. Metabolic kinetics of fluorescein isothiocyanate labeled LcTLP (F-LcTLP) and reason for LcTLP-induced hepatic inflammation were investigated in mice. The imaging results indicated part of F-LcTLP accumulation in liver vias small intestinal, the rest reaching large intestinal, with the peak at 2 h (1.3 × 10¹⁰), 2 h (1.1 × 10¹²), and 3 h (6.4 × 10¹¹), respectively. Liver was the exclusive accumulation organ. With increased gavage dose, viscera other than liver were also observed with significant fluorescence intensity with maximal hepatic clearance to F-LcTLP between 100 and 200 mg/kg. Moreover, mice without intestinal flora exhibited elevated secretion levels of proinflammatory factors and transaminase activity in liver. These findings offered novel insights to settle the adverse reaction induced by LcTLP.