Melatonin effects on hard tissues: bone and tooth.

Melatonin is an endogenous hormone rhythmically produced in the pineal gland under the control of the suprachiasmatic nucleus (SCN) and the light/dark cycle. This indole plays an important role in many physiological processes including circadian entrainment, blood pressure regulation, seasonal reproduction, ovarian physiology, immune function, etc. Recently, the investigation and applications of melatonin in the hard tissues bone and tooth have received great attention. Melatonin has been investigated relative to bone remolding, osteoporosis, osseointegration of dental implants and dentine formation. In the present review, we discuss the large body of published evidence and review data of melatonin effects on hard tissues, specifically, bone and tooth.

WITHDRAWN: Transplantation of bone mesenchymal stem cells containing the nerve growth factor gene in adult rat brain with Fimbria Fornix lesion.

Bone marrow-derived mesenchymal stem cells (BMSCs) are a promising source for cell-based treatment of brain injury, but the therapy of BMSCs is restricted by low cell survival. We examined whether nerve growth factor (NGF) improve BMSCs viability in the brain with Fimbria-Fornix lesion (FF). After transduction of NGF gene via recombinant retroviral vectors, the rat BMSCs were transformed into the NGF-GFP positive BMSCs, nearly 100% of cells expressed NGF. After transplanted into basal forebrain of rat with FF, the NGF-GFP positive BMSCs expressed the exogenous NGF gene in the host brain, and interesting, the survival number of BMSCs in the NGF group was significant more than that of the void plasmid group. Furthermore, the number of choline acetyltransferase (ChAT) immunoreactive neurons of NGF group was also significant higher than those of the void plasmid group (p<0.05) or the PBS group (p<0.01). Performance in the water maze test was improved in these rats in NGF group. These results indicate that NGF increased BMSCs survival in brain with FF, which results in better improvement of brain function than injected with BMSCs alone.

[Pineal mechanism of danggui shaoyao powder on anti-aging].

OBJECTIVE: To study whether Danggui Shaoyao Powder (DSP) is by way of improving pineal function to realize its anti-aging effects. METHODS: Forty aged rats were randomly divided into the sham operated group (A), the pinealectomized group (B), the sham medicated group (C), the pinealectomized and medicated group (D). The medication given was gastric perfusion of DSP for 3 weeks. Learning and memory ability of rats was observed using Morris water maze and the serum melatonin (MLT) concentration of the rats was measured by radio-immunoassay. RESULTS: The average escape latency in Group B was significantly longer than that in other groups (P <0.05). The times of passing through the platform and the percentage of swimming distance in Group C were significantly higher than those in other groups (P <0.05). The serum MLT was higher at daytime than at night in Group C and D (P <0.05); that at daytime in Group C was higher than Group A (P <0.05) and also higher in Group D than Group B; that at daytime was higher in Group C than Group D; that at night markedly decreased in Group D as compared with Group B (P <0.05). CONCLUSION: DSP could increase the melatonin secretion and improve learning and memory ability. Since its effects reduced after pinealectomy, it could be deduced that improving pineal function should be one of the action mechanisms for anti-aging.

Effects of the aqueous extract of the Chinese medicine Danggui-Shaoyao-San on rat pineal melatonin synthesis.

OBJECTIVES: The purpose of this study is to investigate if the aqueous extract of the Chinese medicine Danggui-Shaoyao-San (DSS) can increase the plasma level of melatonin and enhance the function of the pineal gland of naturally aged rats. METHODS: The rats were treated with DSS at doses of 3ml or same volume of distilled water by oral administration at 11 p.m. for three weeks. The plasma level of melatonin were measured by radioimmunoassay. The function of pineal gland were measured through three parameters: pineal beta adrenergic receptor binding investigated by [3H]DHA binding; pineal expression of NAT mRNA detected by real-time RT-PCR; phosphorylation of CREB (P-CREB) and total level of CREB (T-CREB) measured by western blot analysis. RESULTS: DSS significantly increased melatonin level at night after oral administration for 3 weeks. By measurement of pineal [3H]DHA binding, it was found DSS improved the beta-adrenergic receptors binding in pineals. The stimulatory effect of DSS on the expression of NAT mRNA in the old rat pineal gland has been demonstrated in this study. Western blot analysis showed that DSS significantly increased phosphorylation of CREB. CONCLUSIONS: Our results indicate that a downstream pathway for DSS induction of melatonin synthesis in the rat pineal gland acts via cyclic AMP-dependent cascade and transcription mechanism.

[Effects of dahuang zhechong pill on expression and activity of matrix metalloproteinase in rats' hepatic stellate cells].

OBJECTIVE: To observe the effects of Dahuang Zhechong Pill (DZP) on the gene expression of matrix metalloproteinase-1 (MMP-1) in rats' hepatic stellate cells (HSC) and activity of matrix metalloproteinase-2 (MMP-2) that secreted into the culture base. METHODS: HSC were isolated from the liver of normal rats and incubated with DZP-contained drug serum. The expression of MMP-1 in the HSC was detected by quantitative reverse-transcription polymerase chain reaction (RT-PCR). The activity of MMP-2 was examined by zymography. RESULTS: DZP-contained drug serum could obviously promote the gene expression of MMP-1 in HSC. In the meantime, it could obviously increase the content and activity of MMP-2 synthesized by HSC (P < 0.05). CONCLUSION: The anti-fibrosis action of DZP was correlated to the promotion of HSC's gene expression of MMP-1 and increasing of the contents and activity of MMP-2.

[Effect of supplemented danggui shaoyao powder and its disassembled prescriptions on lymphocytes proliferation in aged rats].

OBJECTIVE: To study the effect of supplemented Danggui Shaoyao San (DSS) and its disassembled prescriptions on function of lymphocyte in aged rats. METHODS: Rats aged 18 months were administered with decoction of DSS and its disassembled prescriptions separately in groups for 3 weeks to prepare drug containing serum. Samples of ConA induced rats splenic lymphocytes proliferation was treated respectively with prepared drug serum, for testing their effect on lymphocyte proliferation using methyl thiazolyl tetrazolium (MTT) method, and isoprel (ISO) and propranolol were taken as the controls. RESULTS: The A value of lymphocyte proliferation in the drug serum treated groups was significantly different from that in the control groups (P < 0.01), which could be reduced markedly after treatment with ISO, but could restore to the level before ISO treatment by adding drug serum or propranolol. CONCLUSION: DSS and/or its disassembled prescriptions could raise the lymphocyte proliferation in aged rats significantly, it also shows antagonizing effect against the inhibition of ISO on lymphocyte proliferation.