Dietary Supplementation of Curcumin Alleviates NF-κB-dependent Skeletal Muscle Wasting in Rat.
BACKGROUND
Activation of the nuclear factor-kappa β (NF-κB) signaling results in releasing of a variety of inflammatory cytokines that can induce skeletal muscle wasting (MW) in mammals. Curcumin is a natural product from spice turmeric that can block biological events in which NF-κB plays a critical role.


OBJECTIVE
The present study was conducted to evaluate the beneficial effects of curcumin on the NF-κB-dependent MW in rats.


METHODS
The MW rats were induced by lipopolysaccharide (LPS) injection and rats were fed 15 g curcumin per kg diet for 16 d.


RESULTS
LPS not only decreased the growth performance of rat, but significantly elevated its serum IL-1 concentration and muscle proteolysis rate. Interestingly, curcumin significantly prevented the muscle proteolysis rate and down-regulated expression levels of two critical muscle-specific ubiquitin ligases (Atrogin-1 and MuRF-1). When muscles from MW rats were incubated with curcumin in vitro, the calpain-, cathepsin L-, and proteasome-dependent muscle proteolysis were significantly decreased. Moreover, the nuclear NF-κB/p65 protein abundance were also decreased by curcumin.


CONCLUSIONS
The results not only suggest a molecular mechanism by which curcumin modulates the inflammatory responses, but also offer a feasible avenue to ameliorate the NF-κB-dependent muscle proteolysis.
Institute of Animal Nutrition, Sichuan Agricultural University, Ya'an, Sichuan 625014, P. R. China.
Jun
J
He
Hongmei
H
Xie
Shan
S
Wu
Curcumin; inflammation; muscle wasting; nutrition; rat; regulation