Pharmacological effects of Hachi-mi-jio-gan extract (Harncare) on the contractile response and on pharmacologically relevant receptors in the rat bladder.

Hachi-mi-jio-gan extract (Harncare; HE), a galenical produced from the traditional Chinese herbal mixture Ba-Wei-Die-Huang-Wan, has been reported to improve lower urinary tract symptoms (LUTS) in patients. The present study was undertaken to clarify the pharmacological effects of HE on smooth muscle contraction and on pharmacologically relevant (muscarinic, 1,4-DHP and purinergic) receptors in the rat bladder. Additionally, the effects of repeated oral treatment with HE on the hepatic cytochrome P-450 (CYP) and on blood biochemical values in rats were examined. HE (10 mg/ml) inhibited significantly the acetylcholine-induced contraction of isolated rat bladder strips. The pD(2) value in the absence and presence of HE (10 mg/ml) was 5.14+/-0.16 and 3.99+/-0.17, respectively. HE (0.1 to 10 mg/ml) inhibited the specific binding of [N-methyl-(3)H]scopolamine methyl chloride ([(3)H]NMS), (+)-[(3)H]PN 200-110 and alphabeta-methylene ATP [2,8-(3)H]tetrasodium salt ([(3)H]alphabeta-MeATP) in the rat bladder in a concentration-dependent manner. The respective IC(50) values were 6.85+/-0.94, 7.08+/-0.72 and 1.34+/-0.23 mg/ml. Based on IC(50) values, the binding activity of HE for purinergic receptors was shown to be significantly (about 7 times) greater than that for muscarinic and 1,4-DHP receptors. Repeated oral administration of HE (10, 30 and 100 mg/kg/day) for 4 weeks had little or no effect on the level and activity of hepatic CYP or on blood biochemical values in rats. In conclusion, the present study has shown that HE exerts significant binding activity for pharmacologically relevant receptors in the rat bladder and a relaxant effect on the acetylcholine-induced contraction of isolated muscle strips. HE seemed to exhibit little pharmacokinetic interaction with drugs.

The in vitro real-time oscillation monitoring system identifies potential entrainment factors for circadian clocks.

BACKGROUND: Circadian rhythms are endogenous, self-sustained oscillations with approximately 24-hr rhythmicity that are manifested in various physiological and metabolic processes. The circadian organization of these processes in mammals is governed by the master oscillator within the suprachiasmatic nuclei (SCN) of the hypothalamus. Recent findings revealed that circadian oscillators exist in most organs, tissues, and even in immortalized cells, and that the oscillators in peripheral tissues are likely to be coordinated by SCN, the master oscillator. Some candidates for endogenous entrainment factors have sporadically been reported, however, their details remain mainly obscure. RESULTS: We developed the in vitro real-time oscillation monitoring system (IV-ROMS) by measuring the activity of luciferase coupled to the oscillatory gene promoter using photomultiplier tubes and applied this system to screen and identify factors able to influence circadian rhythmicity. Using this IV-ROMS as the primary screening of entrainment factors for circadian clocks, we identified 12 candidates as the potential entrainment factor in a total of 299 peptides and bioactive lipids. Among them, four candidates (endothelin-1, all-trans retinoic acid, 9-cis retinoic acid, and 13-cis retinoic acid) have already been reported as the entrainment factors in vivo and in vitro. We demonstrated that one of the novel candidates, 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2), a natural ligand of the peroxisome proliferator-activated receptor-gamma (PPAR-gamma), triggers the rhythmic expression of endogenous clock genes in NIH3T3 cells. Furthermore, we showed that 15d-PGJ2 transiently induces Cry1, Cry2, and Roralpha mRNA expressions and that 15d-PGJ2-induced entrainment signaling pathway is PPAR-gamma--and MAPKs (ERK, JNK, p38MAPK)-independent. CONCLUSION: Here, we identified 15d-PGJ2 as an entrainment factor in vitro. Using our developed IV-ROMS to screen 299 compounds, we found eight novel and four known molecules to be potential entrainment factors for circadian clocks, indicating that this assay system is a powerful and useful tool in initial screenings.

Effects of saw palmetto extract on micturition reflex of rats and its autonomic receptor binding activity.

PURPOSE: We examined the effects of saw palmetto extract (SPE) on the rat micturition reflex and on autonomic receptors in the lower urinary tract. MATERIALS AND METHODS: The effect of SPE was examined on cystometrograms of anesthetized rats induced by intravesical infusion of saline or 0.1% acetic acid. SHR/NDmc-cp (cp/cp) rats received repeat oral administration of SPE and nighttime urodynamic function was determined. The autonomic receptor binding activity of SPE in the rat bladder and prostate was examined by radioligand binding assay. RESULTS: Intraduodenal administration of SPE (60 mg/kg) in anesthetized rat cystometry caused a significant increase in the micturition interval, micturition volume and bladder capacity during intravesical saline infusion. Also, similar administration of SPE at doses of 12 and 20 mg/kg significantly reversed the shortened micturition interval as well as the decreased micturition volume and bladder capacity due to 0.1% acetic acid infusion in a dose dependent manner. In conscious SHR/NDmc-cp (cp/cp) rats repeat oral administration of SPE (6 mg/kg daily) constantly increased the micturition interval and concomitantly decreased voiding frequency. SPE inhibited specific binding of [H]NMS ([N-methyl-H]scopolamine methyl chloride) (bladder) and [H]prazosin (prostate) with IC50 values of 46.1 and 183 microg/ml, respectively. CONCLUSIONS: SPE significantly alleviates urodynamic symptoms in hyperactive rat bladders by increasing bladder capacity and subsequently prolonging the micturition interval. Our data may support the clinical efficacy of SPE for the treatment of lower urinary tract symptoms.