Analgesic Effect of the Kampo Formula Yokukansan via the Suppression of Substance P in an Experimental Rat Model of Hunner-Type Interstitial Cystitis

INTRODUCTION

Yokukansan (YKS), a Kampo formula used in traditional Japanese medicine, has an analgesic effect, and is used for various pain disorders. This study investigated its analgesic effects on Hunner-type interstitial cystitis (HIC) and its mechanism of action in animal models.   Methods: Rats with toll-like receptor-7 agonist (loxoribine)-induced HIC were used. Eight-week-old female Wistar rats were divided into three groups: control, HIC, and HIC-administered YKS (YKS + HIC). Bladder pain was assessed based on escape behavior using the von Frey test. Three days after HIC induction, the bladder and spinal cord were excised, and the expression of substance P (SP) was examined.   Results: The pain threshold decreased significantly in the HIC group compared to that in the control group, but this decrease was suppressed by further YKS administration. The expression of SP in the bladder wall and spinal cord increased significantly in the HIC group compared to that in the control group; however, this increase was suppressed by YKS administration.

CONCLUSION

SP is involved in the onset of bladder pain via neurokinin 1 receptors in bladder tissue. YKS may be useful for managing HIC-induced pain, and the suppression of SP secretion is one of its mechanisms of action.

Risk Factors for Pseudoaldosteronism with Yokukansan Use: Analysis Using the Japanese Adverse Drug Report (JADER) Database

Yokukansan is a Kampo formula that is commonly used by the elderly because it is expected to improve peripheral symptoms of dementia and delirium. However, side effects from its use are frequently reported in the elderly. In particular, pseudoaldosteronism caused by the licorice contained in yokukansan leads to hypertension, hypokalemia, and muscle weakness, which may result in death. This study aimed to identify the risk factors of pseudoaldosteronism with yokukansan use. Using cases reported in the Japanese Adverse Drug Report (JADER) database, the reporting odds ratio (ROR) was calculated and compared to assess the risk of pseudoaldosteronism for each licorice-containing Kampo formula. We also analyzed the risk factors for pseudoaldosteronism in patients taking yokukansan. Yokukansan (ROR 2.4, 95% confidence interval (CI) 1.9-2.8; p < 0.001) had a higher risk of pseudoaldosteronism than that of other licorice-containing Kampo formulas. Furthermore, the results of a logistic regression analysis in patients taking yokukansan showed that the licorice dose (OR 1.5, 95% CI 1.2-2.0; p < 0.01), older age (<70 years, OR 5.9, 95% CI 1.8-20; p < 0.01), dementia (OR 2.8, 95% CI 1.6-4.9; p < 0.001), low body weight (<50 kg, OR 2.2, 95% CI 1.1-3.5; p = 0.034) were risk factors for pseudoaldosteronism, Although not significant, treatment with loop diuretics (OR 1.8, 95% CI 0.98-3.5; p = 0.059) tended to increase the risk of pseudoaldosteronism. In summary, patients must understand the risk factors when considering taking yokukansan and reduce the licorice dose they consume.

Kampo (Traditional Japanese Herbal) Formulae for Treatment of Stomatitis and Oral Mucositis

Stomatitis is occasionally multiple, recurrent, and refractory. Currently, mucositis induced by chemotherapy and radiation therapy in patients with cancer has become a significant clinical problem. Effective treatments have not been established and the treatment of numerous cases remains a challenge for physicians. Traditional Japanese herbal medicines termed Kampo formulae (i.e., Hangeshashinto, Orengedokuto, Inchinkoto, Orento, Byakkokaninjinto, Juzentaihoto, Hochuekkito, and Shosaikoto) are used for treating various types of stomatitis and mucositis. Its use has been based on the Kampo medical theories—empirical rules established over thousands of years. However, recently, clinical and basic research studies investigating these formulae have been conducted to obtain scientific evidence. Clinical studies investigating efficacies of Shosaikoto and Orento for the treatment of cryptogenic stomatitis and acute aphthous stomatitis and those investigating the effects of Hangeshashinto, Orengedokuto, and Juzentaihoto on chemotherapy- or radiotherapy-induced mucositis have been conducted. The Kampo formulae comprise several crude drugs, whose mechanisms of action are gradually being clarified. Most of these drugs that are used for the treatment of stomatitis possess anti-inflammatory, analgesic, and antioxidative properties. In this review, we introduce the clinical applications and summarize the available evidence on the Kampo formulae for the treatment of stomatitis and oral mucositis.

Integration of a Kampo medicine, Nijutsuto, and Western medical treatment in the treatment of long-term frozen shoulder refractory to Western medical treatment: a case series

OBJECTIVE

Frozen shoulder is a common disorder in general orthopedic practice, characterized by spontaneous onset of pain in the shoulder and accompanied by limitation of glenohumeral movement. Treatments for frozen shoulder include shoulder exercise, manual therapy, corticosteroid injection, manipulation under anesthesia, and arthroscopic capsular release. Several patients suffer from some degree of pain and range of motion limitation for up to 10 years even when these treatments are applied. Kampo, a traditional Japanese herbal medicine based on traditional Chinese herbal medicine, has been used for the treatment of pain in Japan. Nijutsuto has been a Kampo formula used to effectively treat frozen shoulder.

METHODS

Thirteen patients suffering from long-term frozen shoulder refractory to Western medical treatment were administered Nijututo.

RESULTS

Almost all patients experienced sound pain relief after Nijutsuto admnistration. There were no severe side effects reported.

CONCLUSION

Nijutsuto combined with an exercise program improved pain intensity in 13 patients with long-term frozen shoulder.