Effect Of Bovine Lactoferrin On The Bone Metabolism And Cytokine In Ovariectomized Rats

Objective :1.To observe the effect of lactoferrin on the bone mineral density in ovariectomized rats;2. To investigate the effect of lactoferrin on the the bone metabolism biochemical indicators osteocalcin (BGP),bone alkaline phosphatase(BALP),β-CrossLaps(β-CTx),collagen type I N-telopeptide(NTX)and cytokines interleukin-6(IL-6),tumor necrosis factor-α(TNF-α) in ovariectomized rats, confirming bovine lactoferrin has preventive and therapeutic effect on postmenopausal osteoporosis.Method: Seventy 6-month-old female Sprague Dawley(SD) rats of clean degree were selected and randomly divided into two groups :10 sham-operated group(sham group)and 60 ovariectomized group. 60 ovariectomized rats were randomly divided into six groups: OVX group (each rat was orally intubated with a 0.9% physiological saline at a dose of 2ml), LF-1 group(lactoferrin at 0.01g/kg body weight),LF-2 group(lactoferrin at 0.1g/kg body weight),LF-3 group(lactoferrin at 1g/kg body weight), LF -4 group(lactoferrin at 2g/kg body weight)and E2 group(intramuscular injection estradiol at 10 mg/kg body weight every week),ten rats in each group. after 3 month of treatment,survey the bone mineral density, collect the blood of each rat and then measure the serum estradiol,BGP,BALP,β-CTx,NTX and IL-6,TNF-α.Results:1. Compared to the Sham group, the level of serum estradiol was decreased in OVX group and lactoferrin groups by four different concentration. the level of serum estradiol in E2 group was similar to Sham group. Bone mineral density of OVX group was significantly decreased compared to the Sham group. Bone mineral density was dose-dependently increase in lactoferrin groups by four different concentration compared to the osteoporosis group, Bone mineral density was significantly increased in lactoferrin groups by 1g/kg body weight and 2g/kg body weight than the osteoporosis group, and they are the same as the Sham group and E2 group.2. The level of serum BGP,BALP,β-CTx,NTX in OVX group was increased compared to the Sham group, butβ-CTx and NTX was observably increased than BGP and BALP. The level of serum BGP,BALP,β-CTx,NTX was raised by 17.9%,14.0%,47.7%,31.7%, respectively. Compared to the OVX group, the level of serum BGP and BALP in lactoferrin groups by four different concentration was increased, it was significantly increased in lactoferrin groups by 1g/kg body weight and 2g/kg body weight, but the level of serumβ-CTx and NTX was decreased, it was significantly decreased in lactoferrin groups by 1g/kg body weight and 2g/kg body weight. The level of serum BGP,BALP,β-CTx and NTX was similar in between E2 and Sham group.3. The level of serum IL-6 and TNF-αin OVX group was increased than that in Shan group. Compared to the OVX group, The level of serum IL-6 and TNF-αwas decreased in E2 group and lactoferrin groups by four different concentration. The level of serum IL-6 and TNF-αin E2 group and lactoferrin groups by 0.1g/kg body weight ,1g/kg body weight and 2g/kg body weight was the same as the Sham group.Conclusion:1. The replication animal model of osteoporosis was successful.2. Lactoferrin can increase Bone mineral density of ovariectomized rats, it may raise the biochemical marker of bone formation and reduce that of bone resorption, decrease the bone mass loss. It is a potential prevent and therapeutic role in osteoporosis.3. Lactoferrin inhibited osteoclastogenesis, proliferation and differentiation via attenuating the Spontaneous Production of IL-6 and TNF-α, the activity of the osteoclast was decreased, thus, Lactoferrin promote bone formation and inhibit bone resorption.