Fig. 1
Psoralen mitigated irradiation-induced osteoporosis in a murine model. For the prevention/treatment group, C57BL/6 N mice (n = 5 per group) were administered psoralen (20 mg/Kg) intragastrically every day for 1 week before/after radiation and killed 1 week after radiation. The representative MicroCT data of femur bones at week 1 post-irradiation are shown in a and b. The results of BV/TV, Tb.Sp, Tb.Th, and Tb.N demonstrated that irradiation induced significant destruction of the bone structures, while treatment or prevention with psoralen remarkably alleviated the bone injuries (a and b). In addition, the image of calcein double-labeling analysis and quantitative data of BFR and MAR showed that gastric administration of psoralen promoted new bone formation in irradiated mice (c and d). The HE staining data further demonstrated that psoralen treatment provided protective effects on the bone structures of irradiated mice (e). The ELISA data showed that psoralen treatment reduces the TRAP level in serum of irradiated mice (f). Gene expression analysis of TRAF6 and OCN in femurs also suggested that psoralen inhibited osteoclastogenesis while favoring osteogenesis in irradiated mice (g). Further pathological analysis showed that psoralen partially restored the irradiation induced the reduction of OCN-labeled OBs and the increase of TRAP-labeled OCs in the irradiated mice (h and i). All data are shown as the mean ± SD. **P < 0.01, *P < 0.05. The scale bars represent 2 mm (a and c), 500 μm (e), and 200 μm (h), respectively. IR: irradiation; BV/TV: bone volume per tissue volume; Tb.N: trabecular bone number; Tb.Sp: trabecular separation; Tb.Th: trabecular bone thickness; BFR: bone formation rate; MAR: mineral deposition rate; TRAP: tartrate-resistant acid phosphatase; OCN: osteocalcin; TRAF6: TNF receptor-associated factor 6; Ob.S/B.S: osteoblast surface per bone surface; Ob.N/B.Pm: number of osteoblasts per bone perimeter; Oc.S/B.S: osteoclast surface per bone surface; and Oc.N/B.Pm: number of osteoclasts per bone perimeter