Alzheimer’s disease (AD) is the most common form of dementia and is ranked as the 6th leading cause of death in the US. The prevalence of AD and dementia is steadily increasing and expected cases in USA is 14.8 million by 2050. Neuroinflammation and gradual neurodegeneration occurs in Alzheimer’s disease. However, existing medications has limitation to completely abolish, delay, or prevent disease progression. Phosphodiesterases (PDEs) are large family of enzymes to hydrolyze the 3’-phosphodiester links in cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) in signal-transduction pathways for generation of 5’-cyclic nucleotides. It plays vital role to orchestrate several pharmacological activities for proper cell functioning and regulating the levels of cAMP and cGMP. Several evidence has suggested that abnormal cAMP signaling is linked to cognitive problems in neurodegenerative disorders like AD. Therefore, the PDE family has become a widely accepted and multipotential therapeutic target for neurodegenerative diseases. Notably, modulation of cAMP/cGMP by phytonutrients has a huge potential for the management of AD. Natural compounds have been known to inhibit phosphodiesterase by targeting key enzymes of cGMP synthesis pathway, however, the mechanism of action and their therapeutic efficacy has not been explored extensively. Currently, few PDE inhibitors such as Vinpocetine and Nicergoline have been used for treatment of central nervous system (CNS) disorders. Considering the role of flavonoids to inhibit PDE, this review discussed the therapeutic potential of natural compounds with PDE inhibitory activity for the treatment of AD and related dementia.

Bladder tumor is characterized by recurrent recurrence and distant metastasis, which determines the difficulty of completely curing bladder tumor. In recent years, the number of patients with bladder cancer is increasing, and the treatment of bladder cancer has become an important direction of clinical research. It is difficult to control bladder tumor by traditional therapy. Photodynamic therapy (PDT), as a new optical therapy, has gradually become the main method in clinical treatment of bladder tumor combined with transurethral resection of bladder tumor. In this paper, a patient with superficial recurrent bladder tumor was treated by photodynamic therapy combined with transurethral resection of bladder tumor. The advantages of photodynamic therapy in the treatment of bladder tumor and the selection of photosensitizer in the process of photodynamic therapy were discussed. After two recurrences, the patients chose photodynamic therapy. The tumors were resected one by one, and the wound was coagulated by roller electrode. After the drug was retained for 20 minutes, the bladder was empty. The spherical optical fiber was implanted into the bladder. The photodynamic energy was adjusted (light power 1.8 W, light time 1302 s). There was no recurrence after operation.Most bladder tumors are superficial tumors, and bladder is a cavity organ, which determines that bladder is an ideal organ for photodynamic therapy. As a targeted drug, photosensitizer is only absorbed by bladder tumor after being perfused into bladder. The photosensitizer forms reactive oxygen species through oxygen and kills tumor cells. Clinical practice has proved that PDT has its unique advantages for superficial and recurrent bladder tumors. As the first generation photosensitizer, xipofen also has selectivity in the treatment of bladder cancer.

Background and Study Aims: To observe the efficacy of photodynamic therapy in patients with advanced gastric cancer and analyze the reasons affecting the efficacy. Methods: In this paper, a patient with advanced gastric cancer in our hospital was selected.HoPorfin is used as a photosensitizer and photodynamic therapy was performed 48 hours and 72 hours later. Results: One month after the photodynamic treatment, the patient came to our hospital to reexamine the gastroscope. Through the comparison of gastroscopy before and after the photodynamic treatment, the gastric cancer lesion of the patient after the photodynamic treatment was not significantly smaller than before, and the effect of photodynamic treatment was not ideal. Conclusion: The four reasons for the unsatisfactory effect: individual differences of patients, photosensitizer, light source and oxygen.