Ramie leaf Extract Alleviates Bone Loss in Ovariectomized Rats-The Involvement of ROS and Its Associated Signalings

Area of Science:

• Pharmacology and Traditional Medicine
• Bone Biology and Osteoporosis Research

Background:

• Ramie leaf (Boehmeria nivea L.) is traditionally used for gynecological and bone disorders.
• Osteoporosis, characterized by bone mass loss, is a significant health concern, particularly after menopause.

Purpose of the Study:

• To investigate the efficacy of Ramie leaf extracts (RLE) in preventing bone loss in an ovariectomized (OVX) rat model of osteoporosis.
• To elucidate the mechanisms underlying RLE's effects on bone metabolism and oxidative stress.

Main Methods:

• Female Sprague-Dawley rats underwent bilateral ovariectomy (OVX) or sham surgery.
• OVX rats were treated with varying doses of RLE (0.25, 0.5, 1 g/kg/day) or vehicle for 12 weeks.
• Bone mineral density (BMD), bone microstructure, osteoclast activity (TRAP), reactive oxygen species (ROS), and osteoclastogenesis in vitro (RAW264.7 cells) were assessed.

Main Results:

• RLE treatment significantly increased bone density and improved femur bone microstructure in OVX rats compared to controls.
• RLE administration reduced tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts and intracellular reactive oxygen species (ROS) levels in bone tissues.
• In vitro, RLE inhibited RANKL-induced osteoclast differentiation and the expression of key osteoclastogenesis genes (Cal-R, MMP-9, cathepsin K, TRAP).
• RLE lowered intracellular ROS by downregulating NADPH oxidase 1 (NOX-1) and 4-hydroxynonenal (4HNE).

Conclusions:

• Ramie leaf extract effectively alleviates bone mass loss in OVX rats, suggesting a therapeutic potential for osteoporosis.
• RLE's anti-osteoporotic effects are mediated by the inhibition of osteoclastogenesis and reduction of oxidative stress pathways.