Xiaoke Pill () and anti-diabetic drugs: A review on clinical evidence of possible herb-drug interactions

A comprehensive review of ethnopharmacology, phytochemistry, pharmacology, and pharmacokinetics of Schisandra chinensis (Turcz.) Baill. and Schisandra sphenanthera Rehd. et Wils

ETHNOPHARMACOLOGICAL RELEVANCE

Schisandra chinensis (called bei-wuweizi in Chinese, S. chinensis) and Schisandra sphenanthera (called nan-wuweizi in Chinese, S. sphenanthera) are two highly similar plants in the Magnoliaceae family. Their dried ripe fruits are commonly used as traditional Chinese medicine in the treatment of coughs, palpitation, spermatorrhea, and insomnia. They also are traditionally used as tonics in Russia, Japan, and Korea.

AIM OF THE REVIEW

S. chinensis and S. sphenanthera are similar in appearance, traditional applications, ingredient compositions, and therapeutic effects. This review, therefore, aims to provide a systematic insight into the botanical background, ethnopharmacology, phytochemistry, pharmacology, pharmacokinetics, quality control, and toxicology of S. chinensis and S. sphenanthera, and to explore and present the similarities and differences between S. chinensis and S. sphenanthera.

MATERIALS AND METHODS

A comprehensive literature search regarding S. chinensis and S. sphenanthera was collected by using electronic databases including PubMed, SciFinder, Science Direct, Web of Science, CNKI, and the online ethnobotanical database.

RESULTS

In the 2020 Edition of Chinese Pharmacopoeia (ChP), there were 100 prescriptions containing S. chinensis, while only 11 contained S. sphenanthera. Totally, 306 and 238 compounds have been isolated and identified from S. chinensis and S. sphenanthera, respectively. Among these compounds, lignans, triterpenoids, essential oils, phenolic acid, flavonoids, phytosterols are the major composition. Through investigation of pharmacological activities, S. chinensis and S. sphenanthera have similar therapeutic effects including hepatoprotection, neuroprotection, cardioprotection, anticancer, antioxidation, anti-inflammation, and hypoglycemic effect. Besides, S. chinensis turns out to have more effects including reproductive regulation and immunomodulatory, antimicrobial, antitussive and antiasthmatic, anti-fatigue, antiarthritic, and bone remodeling effects. Both S. chinensis and S. sphenanthera have inhibitory effects on CYP3A and P-gp, which can mediate metabolism or efflux of substrates, and therefore interact with many drugs.

CONCLUSIONS

S. chinensis and S. sphenanthera have great similarities. Dibenzocyclooctadiene lignans are regarded to contribute to most of the bioactivities. Schisandrin A-C, schisandrol A-B, and schisantherin A, existing in both S. chinensis and S. sphenanthera but differing in the amount, are the main active components, which may contribute to the similarities and differences. Study corresponding to the traditional use is needed to reveal the deep connotation of the use of S. chinensis and S. sphenanthera as traditional Chinese medicine. In addition, a joint study of S. chinensis and S. sphenanthera can better show the difference between them, which can provide a reference for clinical application. It is worth mentioning that the inhibition of S. chinensis and S. sphenanthera on CYP3A and P-gp may lead to undesirable drug-drug interactions.

Cost-Effectiveness of Oral Antidiabetic Drugs: A Prospective Multicenter Study of Real-World Patients

This real-world, multicenter, prospective study aims to analyze the cost-effectiveness of prevalent oral antidiabetic drugs, including traditional Chinese medicine and its compounds, used in China. Type 2 diabetes patients initiated on one or several of the most prevalent antidiabetic drugs were recruited on the baseline and followed up over one year with no restriction on drug discontinuation, switching, and add-on. Different drugs were evaluated on their efficacy, adverse effect (AE), health-related quality of life (HRQoL), and cost. Treatments were defined as the intent-to-treat in the primary analysis and on-treatment in the sensitivity analyses. A rich set of patients' baseline characteristics was collected and controlled using the multivariate linear model in the primary analysis and inverse probability weighting and double selection—a machine learning algorithm—in the sensitivity analyses. Estimates of “raw” outcomes, which are not adjusted by covariates and calculated as subgroup means, show that the use of Xiaoke Pill alone and in combination is among the most effective therapies with 50% and 54% of patients reaching the control target of HbA1c < 6.5%. In terms of cost, Xiaoke Pill and gliclazide, which cost participants 4,350 and 5,150 RMB per year on average, are among the least costly therapies. After adjusting patient characteristics, monotherapy and combination therapy using the Xiaoke Pill again display the best control rates, of 45% and 43% against 33% of metformin. Regarding cost, the Xiaoke Pill costs a patient 5,340 RMB per year, in sharp contrast with 8,550 RMB for metformin and 10,330 RMB for acarbose. Our study suggests that the use of Xiaoke Pill—alone or in combination—is associated with better glycemic control and lower cost than some allopathic medications such as metformin or acarbose and shows a similar incidence of hypoglycemia.