Protective effects of tilapia (Oreochromis niloticus) skin gelatin hydrolysates on osteoporosis rats induced by retinoic acid

Abstract

Tilapia skin gelatin hydrolysates (TSGH) were obtained by complex protease hydrolysis. The amino acid sequences of 50 peptides in TSGH were identified, and most of these peptides were found to contain the -Gly-Pro-sequence. The osteoporosis (OP) rat model induced by retinoic acid was prepared, and the effects of different doses of TSGH on OP in vivo were evaluated. Serum calcium (Ca) and phosphate (P), alkaline phosphatase activity, and osteocalcin levels in OP rats were regulated by TSGH. The bone length, dry weight index, maximum load, and Ca content of OP rats significantly increased by treatment TSGH in a dose-dependent manner. Micro-CT images of the femurs and tibias of the rats indicated that the bone mineral density, cortical bone thickness, and cortical/trabecular bone area ratios were recovered and that OP symptoms were improved. Tartrate-resistant acid phosphate and hematoxylin-eosin staining showed that osteoclast numbers and histomorphological changes in the femurs in OP rats could be recovered by TSGH.

Keywords

• Amino acid sequence
• Bone growth
• Micro-CT
• Osteoporosis
• Retinoic acid
• Tilapia skin gelatin hydrolysates