PHY906, a four-herb Chinese medicine formula first described 1800 years ago, decreases gastrointestinal toxicity induced by the chemotherapeutic drug CPT-11 (irinotecan), as shown in a phase I/II clinical study. Similarly, in a murine colon 38 allograft model, PHY906 increased the antitumor activity of CPT-11 while decreasing animal weight loss caused by CPT-11. Here, we have further examined the effect of PHY906 on the intestinal toxicity caused by CPT-11 in mice. PHY906 did not protect against the initial DNA damage and apoptosis triggered by CPT-11 in the intestine, but by 4 days after CPT-11 treatment, PHY906 had restored the intestinal epithelium by promoting the regeneration of intestinal progenitor or stem cells and several Wnt signaling components. PHY906 also potentiated Wnt3a activity in human embryonic kidney-293 cells. Furthermore, PHY906 exhibited anti-inflammatory effects in mice by decreasing the infiltration of neutrophils or macrophages, tumor necrosis factor-alpha expression in the intestine, and proinflammatory cytokine concentrations in plasma. Chemical constituents of PHY906 potently inhibited nuclear factor kappaB, cyclooxygenase-2, and inducible nitric oxide synthase. Our results show that the herbal medicine PHY906 can counteract the toxicity of CPT-11 via several mechanisms that act simultaneously.

PHY906 (KD018) is a four-herb Chinese Medicine Formula. It has been shown to potentially enhance the therapeutic indices of different class anticancer agents in vivo. Here, PHY906 is reported to enhance the anti-tumor activity of Sorafenib in nude mice bearing HepG2 xenografts. Among the four herbal ingredients of PHY906, Scutellaria baicalensis Georgi (S) and Paeonia lactiflora Pall (P) are required; however, S plays a more important role than P in increasing tumor apoptosis induced by Sorafenib with an increase of mouse(m)FasL and human(h)FasR expression. PHY906 may potentiate Sorafenib action by increasing hMCP1 expression and enhancing infiltration of macrophages into tumors with a higher M1/M2 (tumor rejection) signature expression pattern, as well as affect autophagy by increasing AMPKα-P and ULK1-S555-P of tumors. Depletion of macrophage could counteract PHY906 to potentiate the anti-tumor activity of Sorafenib. It was reported that tumor cells with higher levels of ERK1/2-P are more susceptible to Sorafenib, and the S component of PHY906 may increase ERK1/2-P via inhibition of ERK1/2 phosphatase in HepG2 tumors. PHY906 may potentiate the anti-hepatoma activity of Sorafenib by multiple mechanisms targeting on the inflammatory state of microenvironment of tumor tissue through two major ingredients (P and S) of PHY906.

Background -Traditional Chinese Medicine (TCM) has been used for thousands of years to treat or prevent diseases, including cancer. Good manufacturing practices (GMP) and sophisticated product analysis (PhytomicsQC) to ensure consistency are now available allowing the assessment of its utility. Polychemical Medicines, like TCM, include chemicals with distinct tissue-dependent pharmacodynamic properties that result in tissue-specific bioactivity. Determining the mode of action of these mixtures was previously unsatisfactory; however, information rich RNA microarray technologies now allow for thorough mechanistic studies of the effects complex mixtures. PHY906 is a long used four herb TCM formula employed as an adjuvant to relieve the side effects associated with chemotherapy. Animal studies documented a decrease in global toxicity and an increase in therapeutic effectiveness of chemotherapy when combined with PHY906.Methods -Using a systems biology approach, we studied tumor tissue to identify reasons for the enhancement of the antitumor effect of CPT-11 (CPT-11) by PHY906 in a well-characterized pre-clinical model; the administration of PHY906 and CPT-11 to female BDF-1 mice bearing subcutaneous Colon 38 tumors.Results -We observed that 1) individually PHY906 and CPT-11 induce distinct alterations in tumor, liver and spleen; 2) PHY906 alone predominantly induces repression of transcription and immune-suppression in tumors; 3) these effects are reverted in the presence of CPT-11, with prevalent induction of pro-apoptotic and pro-inflammatory pathways that may favor tumor rejection.Conclusions -PHY906 together with CPT-11 triggers unique changes not activated by each one alone suggesting that the combination creates a unique tissue-specific response.

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Background Preclinical studies showed a Chinese botanical formula, PHY906, has synergistic anti-tumor activity with capecitabine. Our phase I study determined maximal tolerated dose of capecitabine 1500mg/m2 BID day 1–7 and PHY906 800mg BID day 1–4 every two weeks. We conducted this phase II study to explore the efficacy of capecitabine and PHY906 in patients with advanced pancreatic cancer who were previously treated with gemcitabine-based regimens. Methods Patients with pancreatic cancer and an ECOG performance status of 0 to 2 received PHY906 and capecitabine. Toxicity was assessed per NCI-CTCAE v3.0 and response per RECIST q 6 wks. Correlative studies of cytokines, chemokines and growth factors were tested using a cytometric bead array. Quality of life was assessed by utilizing Edmonton Symptom Assessment System. The primary objective was overall survival. Results The study enrolled 25 patients. Median progression-free survival (mPFS) was 10.1 weeks (range: 0.4–54.1) and median overall survival (mOS) was 21.6 weeks (range: 0.4–84.1). 18 patients received at least 2 cycles, achieved mPFS of 12.3 weeks and mOS of 28 weeks. Six-month survival rate was 44% (11/25). Unsupervised clustering of patients grouped those with shortened survival together by their cytokine profile showed that only IL-6 had a significant difference (p<.001) between short and long term survivors. Conclusions Capecitabine plus PHY906 provides a safe and feasible salvage therapy after gemcitabine failure for APC. Role of IL-6 in tumor progression and tumor cachexia needs to be investigated with respect to its relation to pathophysiology of pancreatic cancer and development of anti-IL-6 therapeutics.