Allium fistulosum (Welsh onion) and Portulaca oleracea increase longitudinal bone growth in weanling rats possibly by promoting TGF-β and IGF-1 signaling

[Display omitted] •Welsh onion (WO-H) and Portulaca oleracea (PO-H) increased femur and tibia lengths compared to the control in young rats.•The proliferative and hypertrophic zones of the growth plate were greater in the legs of WO-H and PO-H rats.•WO-H and PO-H reduced insulin resistance and PO-H had a better effect on it than the growth hormone injection.•WO-H and PO-H potentiated IGF-1 (pIRS-2 → pAkt) and TGF-β signaling in osteoblasts.•Longitudinal bone growth is associated with the improvement of insulin sensitivity. Longitudinal bone growth mainly occurs during adolescence and can be enhanced by growth hormones. We hypothesized that water extracts from roots of Allium fistulosum L. (Welsh onion, WO; 15 or 45 mg/kg bw/day) and Portulaca oleracea L. (PO; 15 or 45 mg/kg bw/day) can stimulate longitudinal bone growth in weanling male rats for 4 weeks. Femur and tibia lengths were higher in the WO-H and PO-H groups than in the control. The proliferative and hypertrophic zones of the growth plate were greater in the legs of WO-H and PO-H rats than in the control; a similar increase was observed in the positive-control (growth hormone, 20 μg/kg bw/day). WO-H and PO-H treatments were found to potentiate insulin-like growth factor-1 (IGF-1) signaling (pIRS-2 → pAkt) in MG-63 osteoblasts compared to control. WO-H and PO increased cell proliferation possibly by activating transforming growth factor (TGF)-β signaling via elevated BMP-2 and Smad4 expression in MG-63 cells. In conclusion, WO and PO are potential to promote the proliferation of the leg growth plate similar to growth hormone.