Discovery of Natural Products Alleviating Renal Fibrosis with a Viscosity-Responsive Molecular Probe

Renal fibrosis poses a significant threat to individuals suffering from chronic progressive kidney disease. Given the absence of effective medications for treating renal fibrosis, it becomes crucial to assess the extent of fibrosis in real time and explore the development of novel drugs with substantial therapeutic benefits. Due to the accumulation of renal tissue damage and the uncontrolled deposition of fibrotic matrix during the course of the disease, there is an increase in viscosity both intracellularly and extracellularly. Therefore, a viscosity-sensitive near-infrared fluorescence (NIRF) and photoacoustic (PA) imaging probe, BDP-KY, was developed to detect aberrant changes in viscosity during fibrosis. Furthermore, BDP-KY has been applied to screen the effective components of herbal medicine, rhubarb, resulting in the identification of potential antirenal fibrotic compounds such as emodin-8-glucoside and chrysophanol 8-O-glucoside. Ultrasound, PA, and NIRF imaging of a unilateral uretera obstruction mice model show that different concentrations of emodin-8-glucoside and chrysophanol 8-O-glucoside effectively reduce viscosity levels during the renal fibrosis process. The histological results showed a significant decrease in fibrosis factors α-smooth muscle actin and collagen deposition. Combining these findings with their pharmacokinetic characteristics, these compounds have the potential to fill the current market gap for effective antirenal fibrosis drugs. This study demonstrates the potential of BDP-KY in the evaluation of renal fibrosis, and the two identified active components from rhubarb hold great promise for the treatment of renal fibrosis.