Genipin is active via modulating monoaminergic transmission and levels of brain-derived neurotrophic factor (BDNF) in rat model of depression.

Genipin, an important bioactive component from Gardenia jasminoides Eills, was demonstrated to possess antidepressant-like effects in a previous study. However, the molecular mechanism of antidepressant-like effects on genipin was not clear. The present study aimed to investigate the possible mechanism of antidepressant-like effects on genipin with a chronic unpredictable mild stress (CUMS)-induced depression model in rats. In CUMS-induced depressive rats, bodyweight and 1% sucrose consumption decreased significantly compared with the normal control group. Furthermore, these changes could be significantly reversed by genipin application. The levels of 5-hydroxytryptamine (5-HT), norepinephrine (NE) in the hippocampus decreased and the level of 5-hydroxyindole acetic acid (5-HIAA) increased in the CUMS-induced depressive rats. However, pre-treatments with genipin significantly increased the levels of 5-HT, NE and decreased the level of 5-HIAA in the hippocampus. The concentration of cAMP in the hippocampus was increased by genipin compared to the CUMS-exposed model group. The mRNA expressions of 5-hydroxytryptamine 1A receptor (5-HT1AR), cAMP response element binding protein (CREB) and brain-derived neurotrophic factor (BDNF) in rats were decreased exposed to CUMS, which were reversed by genipin-treated rats exposed to CUMS. Compared to the CUMS-exposed model group, the mRNA expression of 5-hydroxytryptamine 2A receptor (5-HT(2A)R) was decreased significantly by genipin-treated rats. The mRNA and protein expression of CREB, BDNF were increased in genipin-treated rats compared to the CUMS-exposed model group. Moreover, the levels of corticosterone in serum were decreased by genipin-treated compared to the CUMS-exposed model group. These results suggest that the possible mechanism of antidepressant-like effects on genipin, at least in one part, resulted from monoaminergic neurotransmitter system and the potential dysfunctional regulation of the post-receptor signaling pathway, which particularly affected the 5-HT(1A)R, 5-HT(2A)R and BDNF levels in the hippocampus.

Removal of phosphorus and nitrogen from domestic wastewater using a mineralized refuse-based bioreactor.

Municipal solid waste used for landfill becomes stabilized, or aged, some years after placement, and can be safely excavated; the term 'mineralized refuse' is used in this study. The adsorptions of phosphorus, and the nitrification of the mineralized refuse and clay, were investigated by batch incubation. The variation of phosphorus adsorption in the mineralized refuse was fitted to the Freundlich adsorption isotherm equation, giving a maximum phosphorus adsorption capacity of 2310 mg kg(-1). Based on the Langmuir isotherm equation, maximum phosphorus adsorption capacity was calculated to be 1976 mg kg(-1), almost twice that of the clay. The equations for both the mineralized refuse and clay were fitted to zero-order kinetics (R2 > 0.98, P < 0.01, n = 11), giving concentrations of phosphorus as phosphates less than 250 mg L(-1). The K value for the mineralized refuse was about 3.5 times higher than for the clay. The production of nitrogen as nitrates in both the mineralized refuse and the clay after 120 h incubation yielded a first-order reaction kinetics value of 100 mg kg(-1) NH4(+)-N from the initial concentration. The calculated net nitrification as nitrates for the mineralized refuse was 6.3 times higher than for the clay. Domestic wastewater was then treated in a mineralized refuse-based bioreactor for 30 days. The removal rates of COD(cr), total nitrogen and total phosphorus were 73.77 +/- 8.10%, 61.01 +/- 6.75%, and 69.14 +/- 9.25%, respectively. Large accumulations of nitrates occurred in the mineralized refuse-based bioreactor. For the full-scale design, a high column of mineralized refuse is recommended for the denitrification.