ABSTRACT
BACKGROUND: Isoflavone isolated from Trifolium pratense L. has been found to be able to effectively inhibit bone resorption, reduce bone turnover rate, improve osteocyte activity and bone mineral density by enhancing the effect of estrogen, which is helpful for the prevention and treatment of osteoporosis. OBJECTIVE: To investigate the effect of Trifolium pratense L. extracts on the bone resorption and differentiation of osteoclasts.METHODS: Rat bone marrow cells were extracted, isolated by lymphocyte separation and cultured for 5 hours; then, the non-adherent cells were selected followed by induced by 30 μg/L macrophage colony stimulating factor and 75 μg/L RANKL (control groups), or different concentrations of Trifolium pratense L. extracts (0.3, 0.6 and 1.2 g/L) to observe their effect on the osteoclast differentiation and bone resorption. The levels of osteoclast differentiation-associated proteins c-fos and NFATcl were determined by western blot assay. RESULTS AND CONCLUSION: Compared with the control group, different concentrations of Trifolium pratense L. extracts could suppress osteoclast differentiation and bone resorption to different degrees. Tartrate-resistant acid phosphatase staining showed that Trifolium pratense L. extracts could significantly reduce the number of osteoclasts. Western blot assay results suggest that Trifolium pratense L. extracts significantly inhibited the expression levels of c-fos and NFATcl. These results reveal that Trifolium pratense L. extracts can inhibit osteoclast differentiation and bone resorption.
ABSTRACT
Objective To explore the effects of gross saponins of Tribulus terrestris L.on inflammatory reaction and permeability of blood-brain barrier in rats following cerebral ischemia-reperfusion injury and their potential mechanisms. Methods Sixty SD rats were divided into sham operation group,model control group,gross saponins of Tribulus terrestris L.at low-dose (10 mg?kg-1 )and high-dose groups(30 mg?kg-1 ).Cerebral ischemia -reperfusion model was established with suture emboli method in middle cerebral artery of rats.Neural injury scores,the contents of Evans blue ( EB) and myeloperoxidase( MPO) activities in rat brain were measured 24 hours after the cerebral reperfusion post 2 h ischemia.Content of tumor necrosis factor-α (TNF-α) in rat brain was detected by ELISA; expression levels of matrix metalloproteinase-9(MMP-9) in rat brain was determined by Western blot. Results Compared to the model control group,the neurological deficit scores were significantly decreased(P<0.05),MPO activities and EB contents decreased(P< 0.05 or P< 0.01) in the treatment groups.The expression levels of TNF-α were significantly lower in the treatment groups(0.760±0.110) mg?g-1 and (0.670±0.073) mg?g-1 compared to (0.920±0.128) mg?g-1 in the model control group ( P< 0.05 or P< 0.01). The MMP-9 expression levels were (1.770± 0.181)% and(1.480±0.146)%,significantly lower than(2.200±0.186)% in the model control group(P<0.01). Conclusion Gross saponins of Tribulus terrestris L. exert neuroprotective effects on cerebral ischemia-reperfusion injury in rats through inhibiting the inflammatory reaction and decreasing the permeability of blood-brain barrier,which may be associated with the decrease of the TNF-α content and downregulation of the MMP-9 expression.
ABSTRACT
Objective To investigate the protective effct of Panax quinquefolium saponins from steams and leaves(PQS)on focal cerebral ischemia injury in rats and its mechanisms. Methods Wistar rats were randomly divided into sham operation group,model control group,nimodipine group and two PQS groups,in which PQS of 100 and 50 mg/kg was intragastrically administered. Focal cerebral ischemia model was established by middle cerebral artery occlusion (MCAO)in rats, via string ligation of artetia carotis interna. The content of malondicldehy de(MDA) was determined by thibabituric acid ( TBA ) test, the activity of lactate dehydrogenase ( LDH ), superoxide dismutase (SOD)and the content of lactic acid(LA) were detected by chemical colorimetry test in cerebral tissues. Results PQS( 100,50mg/kg)could significantly decrease the content of LA、MDA and increase the activity of LDH、SOD. Conclusion The protective mechanism of PQS on focal cerebral ischemia injury may be related to reduce acidosis, anti-free radical and resist oxidative damage.