Traditional Chinese medicine (TCM) as a source of new anticancer drugs

Covering: up to July 2020Drugs derived from traditional Chinese medicine (TCM) include both single chemical entities and multi-component preparations. Drugs of both types play a significant role in the healthcare system in China, but are not well-known outside China. The research and development process, the molecular mechanisms of action, and the clinical evaluation associated with some exemplificative anticancer drugs based on TCM are discussed, along with their potential of integration in western medicine.

Cancer Biomarkers for Integrative Oncology

PURPOSE OF REVIEW

There has been an increasing interest in using complementary and alternative medicine (CAM) approaches to treat cancer. It is therefore relevant and timely to determine if CAM biomarkers can be identified and developed to guide cancer diagnosis and treatment. Herein, we review the status of cancer biomarkers in CAM research and treatment to stimulate further research in this area.

RECENT FINDINGS

Studies on promising anti-cancer natural products, such as PHY906, honokiol, bryostatin-1, and sulforaphane have demonstrated the existence of potential cancer biomarker(s). Additional studies are required to further develop and ultimately validate these biomarkers that can predict clinical activity of the anti-cancer natural products used alone or in combination with chemotherapeutic agents. A systematic approach is needed to identify and develop CAM treatment associated biomarkers and to define their role in facilitating clinical decision-making. The expectation is to use these biomarkers in determining potential options for CAM treatment, examining treatment effects and toxicity and/or clinical efficacy in patients with cancer.

Metabolic and toxicological considerations of botanicals in anticancer therapy

INTRODUCTION

Cancer is a complex disease, characterized by redundant aberrant signaling pathways as a result of genetic perturbations at different levels. Botanicals consist of a complex mixture of constituents and exhibit pharmacological effects by the interaction of many phytochemicals. The multitarget nature of botanicals could, therefore, be a relevant strategy to address the biological complexity that characterizes tumors.

AREAS COVERED

This article reviews the current status of botanicals in the oncological field and the challenges associated with their complex nature.

EXPERT OPINION

Botanicals are an important new pharmacological strategy, which are potentially exploitable in the oncological area but are characterized by a number of problems still unresolved. Content variation of products is one of the primary problems with botanicals and, consequently, there is a concern about the therapeutic consistency in marketed batches. Furthermore, metabolic interactions with antineoplastic drugs and the genotoxic potential of botanicals need to be properly addressed throughout the various phases of botanical drug development. These issues not only pose a serious problem to the approvability of those botanical products as new drugs but also present as a limitation to their post-approval clinical use.

Old formula, new Rx: the journey of PHY906 as cancer adjuvant therapy

ETHNOPHARMACOLOGICAL RELEVANCE

PHY906, is a decoction of a mixture of the four herbs Scutellaria baicalensis Geori, Glycyrrhiza uralensis Fisch, Paeonia lactiflora Pall, and Ziziphus jujuba Mill. A combination of these four herbs has been in continuous use in traditional Chinese medicine for over 1800 years for treating a variety of gastrointestinal distress such as diarrhea, cramps, nausea, vomiting etc.

AIM OF THE STUDY

Preclinical and clinical studies to find PHY906 enhances the therapeutic indices of a broad spectrum of anticancer agents.

MATERIALS AND METHODS

Using various mouse tumor xenograft and allograft models, PHY906 has been shown to enhance the chemotherapeutic efficacy of a variety of anticancer agents in various cancers. The PHY906 clinical program consists of five trials in three different types of cancers in both the United States and Taiwan. To date, approximately 150 subjects have received PHY906 in combination with chemotherapy in these five clinical studies.

RESULTS

Preclinical studies have shown that PHY906 enhances the therapeutic indices of a broad spectrum of anticancer agents. These findings have been examined in clinical studies for colorectal, liver, and pancreatic cancers when PHY906 is used as an adjuvant to chemotherapy and the results were promising; i.e. PHY906 could reduce chemotherapy-induced toxicities and/or increase chemotherapeutic efficacy. Furthermore, PHY906 did not affect the pharmacokinetics of the chemotherapeutic agents used. Some information has been obtained regarding the mechanism of action of PHY906 in preclinical studies. A comprehensive platform, PhytomicsQC that integrates chemical and biological fingerprints together with a novel biostatistical methodology has been developed to assess the quality of different batches of PHY906.

CONCLUSIONS

Over a ten-year period, the multiplex technology "PhytomicsQC" has been used to show batch-to-batch consistency of PHY906 production. Advanced clinical trials are ongoing to demonstrate the effectiveness of PHY906 as adjuvant therapy for cancer patients undergoing chemotherapy.

Are herbal medicines ripe for the cancer clinic?

The use of complementary and alternative medicine (CAM) has become a core component of the daily challenges faced when treating cancer patients. PHY906 is a formulation of four herbal compounds traditionally used to treat nausea, vomiting, cramping, and diarrhea. Diarrhea is one of the major side effects of the cancer drug irinotecan. In this issue of Science Translational Medicine, Lam and colleagues report that administration of PHY906 with irinotecan in a mouse model of colon cancer resulted in a synergistic reduction in tumor burden, maintenance of body weight, and stem cell regeneration in the intestinal mucosa. Yet when considering CAM use in the treatment of cancer patients, one must take into account reproducibility of preclinical findings in clinical practice, quality assurance of herbal products, and potential toxicities associated with alternative therapies.