Establishment of Anti-inflammatory Activity Evaluation Method of Qingjin Huatantang Based on Phosphodiesterase Inhibitory Activity / 中国实验方剂学杂志

ObjectiveBased on the inhibitory activity of phosphodiesterase （PDE）， a method for determining the anti-inflammatory activity of Qingjin Huatantang was established to supplement and improve the quality control system of this famous classical formula. MethodHigh performance liquid chromatography （HPLC） was used to determine the activity of PDE， and the dose-effect relationship of inhibiting PDE activity of Qingjin Huatantang was investigated. The mobile phase consisted of methanol-0.5% acetic acid aqueous solution （5∶95）， and the detection wavelength was 254 nm. By measuring the PDE inhibition rate of multiple batches of Qingjin Huatantang water extract lyophilized powder， biological activity was marked with the activity of the neutralizing enzyme in the international unit U. ResultWhen the concentration of reaction substrate （cyclic adenosine monophosphate） was 50 μmol·L-1 and the reaction time was 60 min， the enzymatic reaction was stable with 4 U·mL-1 of PDE. In this reaction system， when the concentration of Qingjin Huatantang water extract lyophilized powder was 0.11-3.0 g·L-1， the inhibitory effect of PDE showed a concentration-dependent relationship. It was determined that the concentration of Qingjin Huatantang water extract lyophilized powder to be tested was 1 g·L-1， which showed a significant and stable inhibitory effect on PDE， and the inhibitory rate was >45%， that is， 1 mg of Qingjin Huatantang water extract lyophilized powder could neutralize the activity of 1.8 U PDE at least. ConclusionThis study establishes a biological activity evaluation method of Qingjin Huatantang based on the inhibitory activity of PDE， and the anti-inflammatory activity of Qingjin Huatantang is characterized by international unit U of PDE activity， which can provide a new method for the determination of biological activity of traditional Chinese medicine compounds.

A Case of Central Serous Chorioretinopathy after Tadalafil Treatment

PURPOSE: To describe a patient who presented with central serous chorioretinopathy after 2 months of tadalafil administration without any other underlying disease or medication. CASE SUMMARY: A 49-year-old male patient was transferred from a local clinic with metamorphopsia and decreased visual acuity in the right eye. His visual acuity was 6/20 in the right eye and 18/20 in the left eye. The fundus examination showed a large serous detachment between the superior and inferior blood vessel arcades in the right retina. In his medical history, he used tadalafil three times a week for 2 months. His medication was then stopped, and a follow-up examination was scheduled. After 2 months, a fundus examination showed resolution of the subretinal fluid, and his corrected visual acuity recovered to 20/20. CONCLUSIONS: Tadalafil (Cialis®) is a phosphodiesterase (PDE)-5 inhibitor and predominantly prescribed for the treatment of erectile dysfunction. PDE–5 inhibitors may be potent vasodilators in the retina and choroid, and may induce choroidal vessel engorgement leading to leakage across the retinal pigment epithelium and accumulation of subretinal fluid in selected patients. When making a diagnosis as central serous chorioretinopathy, the physician should confirm the causative drugs that are easy to miss, by performing a thorough review of the patient's medical history and promptly terminating the causative drugs.

Antifibrotic Effects of Phosphodiesterase (PDE) Inhibitor in Experimental Interstitial Fibrosis induced by Unilateral Ureteral Obstruction

PURPOSE: Phosphodiesterase (PDE) inhibitor increases the cellular content of cAMP, and cAMP suppresses connective tissue growth factor (CTGF) expression induced by TGF-beta1. Therefore, we investigated whether PDE inhibitor suppresses renal fibrosis without suppression of TGF-beta. MATERIALS AND METHODS: Renal interstitial fibrosis was produced by ligation of left ureter in Sprague-Dawley rats. Cilostazol, a selective PDE3 inhibitor, and dipyridamole, a hybrid PDE5, PDE6, and PDE8 inhibitor, were provided in drinking water for 7 days. In addition to the Masson-trichrome score of renal tissue, the concentration of fibronectin and TGF-beta1 in renal tissue-conditioned media was measured by ELISA. RESULTS: Masson-trichrome score and fibronectin concentration were significantly lower in cilostazol-treated group compared to the control group (P<0.05). Though dipyridamole treatment seemed to suppress the Masson-trichrome score and fibronectin concentration too, the decrements were not statistically significant. There was no difference in TGF-beta1 concentration among the groups. CONCLUSION: A selective PDE3 inhibitor cilostazol suppresses renal fibrosis without alteration of TGF-beta expression.

Phosphodiesterase 3:new targets for drug development / 中国临床药理学与治疗学

Phosphodiesterase(PDE) is hydrolase of 3',5'-cyclic adenosine monophosphate(cAMP) and 3',5'-cyclic guanosine monophosphate(cGMP).PDE3 are composed of two genes and distributed widely in vivo.Its inhibitors have been applied in antiplatelet aggregation and vasodilation.It has been reported that PDE3 inhibitors have neuroprotective effects on cerebral ischemia,which may provide new methods to prevention and therapy of cerebral ischemia.

Activation of Caspase-3 During Photoreceptor Degeneration in rd Mouse Retina

Retinal degeneration caused by a hereditary defect in the genome is reported in a few animals and it leads to blindness. rd mouse is one of the well studied animal models for retinal degeneration. The retinal degeneration of rd mouse is caused by a mutation on cGMP-phosphodiesterase(PDE). Caspase activation has been implicated for apoptosis. In this study, we examined the activation of caspase-3 during photoreceptor degeneration in rdmouse. Photoreceptor degeneration of rd mouse occured at PD 9 and disappeared at PD 21.In addition, we observed the active form of caspase-3 in the retinal degeneration of rd mouse. In conclusion, the cell death pattern of photoreceptor degeneration in rd mouse seemed to be an apoptosis rather than necrosis.