Revaluation of Xihuang Pill on tumor treatment: from ancient literatures to modern studies

Xue Yang, Xiong-Zhi Wu*

1 Huan-Hu-Xi Road, He-Xi District, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China.

Introduction

Xihuang Pill (XHP), also called Xihuang Wan or Xihuang Capsule, is a complementary and alternative medicine used for tumor treatment in traditional Chinese medicine (TCM) since the 18th c entury. XHP was originally developed by Wang Weide and was recorded in the Wai Ke Quan Sheng Ji, which was written according to the combination of 40 years clinical experience and ancestral secret recipe, during the Qing dynasty. XHP consists of Calculus Bovis,Moschus, Olibanum and Myrrha, serving to disintegrate scleroma, detoxify toxic heat, and promote blood circulation. It is recorded that XHP was used to treat breast cancer, heng, scrofula, phlegm node, deep multiple abscess, pulmonary abscess, and small intestinal abscess (Chinese, supplement 1) in Wai Ke Quan Sheng Ji [1].

Nowadays, XHP is approved by China food and drug administration to treat various tumors alone or in combination with chemotherapy and/or radiotherapy.XHP was recorded to have effects on treating lymphomas, breast cancer, liver cancer, intestinal cancer, and brain tumor [2].

Here, we aimed to put forward a new method to revaluating XHP on its application on tumor therapy from ancient literatures to modern studies and from pharmacy to medicine. In this review, we firstly introduced the application of XHP on tumor therapy from ancient literatures. Then, the antitumor studies of XHP in both clinical and basic aspects were summarized and we also discussed the antitumor material basis and mechanisms of Calculus Bovis,Moschus, Olibanum and Myrrha. In addition, with the development of time, the dosage form of XHP, source and dose of herbs and processing methods of Olibanum and Myrrha have been changed and we also evaluated the advantage and disadvantage of these changes of XHP.

Ancient literature

XHP is an old prescription from Wai Ke Quan Sheng Ji in 1740. Since then, XHP was used by many physicians in ancient China to treat various diseases,especially breast cancer and carbuncle. The clinical efficacy of XHP is significant according to recordation in ancient literatures. XHP combined with cooked rhubarb and realgar was recorded to treat acute mastitis and scrofula in Wai Ke Chuan Xin Ji written by Ma Peizhi (Chinese, Supplement 2) [3]. XHP was mainly recorded to treat breast cancer in old literatures. Xu Ming Yi Lei An recorded one medical notes, in which XHP and Wu Tong Wan (Radix Aucklandiae, Herba Ephedrae, Myrrha, Olibanum, Faeces Togopteri) were taken in the morning and evening alternately to treat breast cancer (Chinese, Supplement 3) [4]. In addition,XHP was recorded to combine with Yanghe decoction(Radix Rehmanniae Preparata, Cortex Cinnamomi,Herba Ephedrae, Colla Corni Cervi, Semen Sinapis Albae, charcoal of ginger, Radix Glycyrrhizae) to treat early breast cancer in Yan Fang Xin Bian (Chinese,Supplement 4) [5]. In Wai Ke Zheng Zhi Quan Shu,XHP combined with Shiquan Dabu decoction was used to treat advanced breast cancer (Chinese, Supplement 5)[6]. Moreover, XHP also can be used to relieve cancer pain in Chong Lou Yu Yao (Chinese, Supplement 6)[7].

Table 1 The action mechanisms of XHP on tumor

Modern research

Basic study

XHP, a classical anti-cancer prescription of traditional Chinese medicine, plays a vital role in treating various malignant tumors (Table 1). Modern pharmacological study confirmed that XHP behaves as a metastasis cell line LoVo cells by regulating ZEB1-SCRIB Loop resulting in inhibition of epithelial-mesenchymal matrix damage [8]. Another study indicated that XHP suppressor by means of preventing angiogenesis and suppressed the ability of proliferation, invasion and migration of highly metastatic human colorectal cancer transition (EMT) [9]. Chen et al. reported that XHP could inhibit zebrafish angiogenesis [10]. The extract of artificial musk and myrrh had no effect on zebrafish angiogenesis, while frankincense and artificial Bovis Calculus could inhibit angiogenesis. These results indicated that frankincense and Bovis Calculus were the main herbs in the XH to play anti-tumor angiogenesis role [11]. XHP inhibited L7212 leukemic cells proliferation in vivo, and arrest cells in S stage.Moreover, XHP could relieve the infiltration of leukemic cells in the liver and spleen of L7212 mice and obviously prolong the survival time of the mice[12].

XHP has been shown to affect breast neoplasms.XHP significantly inhibited Walker256 tumor cells growth in vivo, and XH high dose group showed significantly up-regulated IL-2, IFN-gamma, B7-1 level, and increase CD3+CD4+ T cells in peripheral blood, which indicated that the anti-tumor effect of XHP maybe attribute to its immune clearance function[13]. In addition, XHP can affect breast cells viability and cause apoptosis. XHP had growth-inhibitory effects on MCF-7 and MDA-MB231 cells with a half-maximal inhibitory concentration (IC50) of 10.14 mg/mL (MCF-7) and 8.98 mg/mL (MDA-MB231)[14].

Breast hyperplasia, especially of the columnar cells,is the earliest histologically identifiable lesion linked to cancer progression [15]. Aside from the tumor, XH can treat benign lesions such as breast hyperplasia and prevent transformation into malignancies [16].

Calculus bovis

Calculus Bovis, commonly known as Niuhuang in China, is the dried gallstone of Bos taurus domesticus Gmelin and one of the most important and precious traditional Chinese medicines. Calculus bovis has been used in TCM for thousands years to treat high fever,convulsion, inflammation, and tumor [17]. Calculus bovis contains bilirubin, bile acids, amino acids, and other compounds [18]. Bilirubin and bile acids are primary active constituents in Calculus Bovis.

Bile acids

Bile acids, as one of the main active constituents in Calculus bovis, are important indicator for evaluating the quality of Calculus bovis and the substitutes, which have the effects of diminishing inflammation,antianaphylaxis and antidote [19]. Unique biologic activities have been identified for the four different bile acids: cholic acid (CA), deoxycholic acid (DCA),chenodeoxycholic acid (CDCA), and ursodeoxycholic acid (UDCA) (Figure 1). Among four bile acids, DCA is the major active constituent of Calculus bovis. One study suggested that blockade of fMLP receptors may contribute to the anti-inflammatory effects of traditional medicine containing DCA [20].

Different bile acids exhibit distinct biological activities toward tumor cells. CA and UDCA had only minimal cytotoxic effect on ovarian cancer cell lines A2780 and A2780-CP-R (cisplatin-resistant) even at maximum concentrations. In contrast, CDCA and DCA have significant cytotoxic activity in both platinum sensitive and platinum-resistant ovarian cancer cell lines via induction of apoptosis. The mechanism of apoptosis appears to be mediated by alternative kinases distinct from protein kinase C (PKC) [21]. Another study found that incubating cells with CDCA or DCA caused colon cancer cells morphological changes,which were characteristics of apoptosis, whereas incubating cells with UDCA inhibited cell proliferation but did not induce apoptosis. CA had no discernible effect on cells. Notably, the cytotoxicity reported for DCA may be due to its capacity to induce apoptosis via a PKC-dependent signaling pathway [22].

Figure 1 The molecular structure of four different bile acids: cholic acid (CA, A),deoxycholic acid (DCA, B), chenodeoxycholic acid (CDCA, C), and ursodeoxycholic acid(UDCA, D).

Although the ingredients in bile acid exhibit anti-tumor effects, there are studies reporting the opposite directions toward gastrointestinal cancer including colon cancer, esophageal cancer [23-25].More recent reports confirmed that DCA directly stimulates proliferation of human colonic mucosa [26]and human colon cancer cells in culture [27, 28]. It has been reported that exposure to DCA can lead to the induction of a variety of growth regulatory genes including cyclooxygenase-2 [29], as well as stimulate the activity of AP-1 and NF-kB transcription factors[30, 31]. Recent evidence suggests that bile acids promote tumor growth by stimulating several kinase signaling pathways, in part by activating epidermal growth factor receptor (EGFR) signaling pathway [32].The controversial effects of bile acids on gastrointestinal cancer may be related to its concentration. > 100 µmol L–1 DCA induces apoptosis in colon cancer cells, whereas, low-dose DCA stimulates colon cancer cell proliferation by a mechanism that is mediated by PKC [33]. Further studies are needed to clarify the action mechanism of bile acids on gastrointestinal cancer, especially colon cancer.

Taurine

Taurine (Figure 2A), also called 2-aminoethanesulfonate, is ubiquitous and is the most abundant intracellular free amino acids present in mammalian tissues, including those exposed to high concentrations of oxidants, such as heart, retina,skeletal muscle, brain, and leukocytes [34-36]. Taurine has been shown to be tissue-protective in many models of oxidant-induced injury [37]. One study evaluated a possible role of serum taurine level as an early marker for breast cancer patients. The most impressive observation in this work showed significant decreases in serum taurine levels in both breast cancer and high risk groups when compared to normal control group[38]. Taurine was investigated to the enhanced permeability of doxorubicin on the M5076 ovarian sarcoma cells in vitro, which elucidated the novel effect of taurine to increase doxorubicin-induced antitumor activity [39]. In addition, taurine can partly attenuate the harmful actions of bile acids [40].

Figure 2 The molecular structure of taurine (A)and taurolidine (B).

Taurolidine

Taurolidine [bis(1,1-dioxoperhydro-1,2,4-thiadiazinyl-4)-methane (TRD)] (Figure 2B), a derivative of the amino acid taurine, was first described as an anti-bacterial substance [41]. Recently, taurolidine has been shown to possess anti-neoplastic properties in vitro and in vivo against a variety of cancers including colorectal cancer, ovarian cancer, brain tumor and melanoma [42-45]. It has been shown to enhance apoptosis, inhibit angiogenesis, reduce tumor adherence [46]. Previous study reported that TRD selectively inhibited the growth of human ovarian tumor cell lines in vitro through the induction of apoptosis in tumor cells, instead of regulating cell cycle distribution. Furthermore, administration of TRD to nude mice bearing human ovarian tumor xenografts significantly inhibited both tumor formation and growth [43]. Moreover, one study indicated that TRD significantly attenuated murine melanoma tumor growth in vitro and in vivo, which may result from TRD-induced apoptosis by modulation of the Bcl-2 family proteins [45]. Besides, one review reported that TRD additionally inhibited tumor angiogenesis [47].Treatment with TRD inhibited the growth of all ten osteosarcoma cell lines and TRD-induced growth inhibition was found to be associated with a dose dependent increase in the number of apoptotic cells.And apoptosis was shown to be caspase-dependent. In addition to apoptosis induction action, TRD also inhibited adhesion of osteosarcoma cell [48].Subsequent to these experimental observations, TRD has shown encouraging clinical results after intravenous administration in patients with gastrointestinal malignancies and tumors of the central nerve system [47].

Moschus

Moschus, also called Musk, is a rare Chinese medicine,which is dry secretions and origins from mature male moschus deer including Moschus berezovskii Flerov,Moschus sifanicus Przewalski, and Moschus moschiferus Linnaeus [49]. As a highly valued ingredient of Chinese medicinal remedies, musk is used as a detoxification agent and for treating fever,inflammation and swelling, and pain. Mouschus consists of muscone (3-methylcyclopentadecanone-1),androstane alkaloids, androstanoids and cholestanoidsan [50-52]. A small amount of muscopyridine is also found in the secretion from the ventral glands of male musk deer [53].

Recent study indicated that the decoction of Moschus, and Toona sinensis exhibited the strongest anticancer effects, compared to two single decoctions.The combined decoction arrested HeLa cell cycle progression in S-phase and RB pathway is partially responsible for the cell cycle arrest [54].

The antitumor activity was first observed in musks secreted by the mammalian genital gland. These musks consist of low-molecular-weight macrocyclic ketones(MCKs) of low molecular weight (224-250 Da).Carcinostatic activity was detected in diverse natural MCKs by the inhibition of mitochondrial dehydrogenase activity in Ehrlich ascites tumor cells.In addition, MCKs inhibited the invasive action of human fibrosarcoma HT1080 cells even after the short-term exposure of 3 h at 25 µM, without reducing cell viability [55].

Muscone

Muscone (Figure 3A) is believed to be the main active ingredient of Mouschus [53]. Previous study showed that muscone has protective effects on the neural system and cardiac myocytes [56-60]. However, it remains unclear whether muscone is also effective in tumor therapy. Further studies are in urgent need to verify the anti-tumor effects of muscone.

Figure 3 The molecular structure of muscone(A), musk ketone (B), and musk xylene (C).

Synthetic musk

Musk ketone (MK, Figure 3B) and Musk xylene (MX,Figure 3C), two types of synthetic musk, are often used in fragrances and soaps to substitute the natural musk.In China, synthetic musk is not approved in the application of medicine at present. One study explored the effect of MK treatment on breast cancer. MK can significantly inhibit the expression of angiogenic factors, such as VEGF and bFGF in MDA-MB-231 breast tumor tissue, which offers broad prospects for application in inhibition of tumor angiogenesis [61].

Frankincense

Boswellia serrata Roxb. et Colebr. and Boswellia carterii Birdw. (syn. B. sacra) are deciduous trees growing in China, India, the Arab peninsula, and some African countries (Somalia, Ethiopia). The resin gum of these trees is called frankincense or Olibanum and is used not only for religious rituals, but also for medicinal purposes in different civilizations [62].Frankincense is reported to contain 60-85% resins(mixtures of terpenes), 6-30% gums (mixture of polysaccharides) and 5-9% essential oil [63]. It has been used to alleviate pain and inflammation, to invigorate the circulation of blood in China and as an antiarthritic in Ayuredic medicine in India for thousands of years (Boswellic acids: novel, specific,nonredox inhibitors of 5-lipoxygenase [64].

Frankincense essential oil

Frankincense essential oilprepared from hydrodistillation of Boswellia sacra gum resins and is frequently used in aromatherapy practices. According to previous studies, the constituents of frankincense oil vary according to the climate, harvest conditions and geographical sources of the frankincense resin [65].Recent studies indicate that frankincense essential oil has tumor inhibition effects. A review reported that Boswellia essential oil could suppress transformation,proliferation, and metastasis of tumors by regulating cell cycle arrest, apoptosis induction, and various growth signals [66].

Frankincense essential oil elicited selective cancer cell death on human bladder cancer J82 cells via NRF-2-mediated oxidative stress [67]. Microarray and bioinformatics analysis proposed multiple pathways that can be activated by frankincense oil to induce bladder cancer cell death [68]. It also induces human pancreatic cancer cell death in cultures and in a xenograft murine model. The anti-tumor activity of frankincense essential oil on pancreatic cancer cells is mediated through multiple signaling pathways and cell cycle regulators, and is dependent upon caspase pathway mediated apoptosis [69]. In addition,Boswellia sacra essential oil has tumor cell-specific cytotoxicity in multiple breast cancer cell types through suppresses Akt and ERK1/2 activation and G1 phase arrest of cell cycle by suppressing cyclin D1 and cdk4 expression [70].

Boswellic acids

The active compounds of frankincense are the boswellic acids, which are pentacyclic triterpenic acids in Boswellia sacra essential oils. Recent investigations have shown that boswellic acids exert potent anticancer activities through their anti-proliferative and pro-apoptotic effects in multiple human cancer cell lines and in mice [71, 72]. Boswellic acids have anti-proliferation and anti-cancer effects on HepG2 cells. The apoptotic effect is mediated by a pathway dependent on caspase-8 activation [73]. Boswellic acids also induce malignant glioma cells apoptosis at low micromolar concentrations by via a p53-independent pathway [74]. Furthermore, boswellic acids can inhibit glioma growth in vivo and prolong survival time of experimental rats [75].

Figure 4 The molecular structure of four major boswellic acids found in frankincense.

There are four major boswellic acids (Figure 4) found in frankincense: β-boswellic acid (BA),acetyl-β-boswellic acid (ABA), 11-keto-β-boswellic(KBA) acid and 3-O-acetyl-11-Ke-to-β boswellic acid

Table 2 The main action mechanism of four boswellic acids on tumor

(AKBA) [76]. Among these boswellic acids, AKBK is the main anti-tumor active constituent (Table 2).Park and coworkers showed that treatment of pancreatic cancer cells and breast cancer MDA-MB-231 cells with AKBA suppressed the CXCL12-induced invasion of these cells and down-regulated CXCR4. It has also been found that the AKBA-mediated down-regulation of CXCR4 occurred at both the mRNA and protein levels [77].However, another study indicated that prostate cancer cells were most sensitive to boswellic acids, while breast cancer and leukemia cell lines were the most resistant [72]. Consistently, ABA and AKBA inhibit proliferation and elicit cell death in chemoresistant androgen-independent PC-3 prostate cancer cells in vitro and in vivo. At the molecular level, these compounds inhibit constitutively activated NF-kappaB signaling by intercepting the IkappaB kinase (IKK)activity promoting apoptosis of PC-3 prostate cancer cells [78]. Another study also showed that AKBA suppressed tumor growth in the human prostate tumor xenograft mice treated daily (10 mg/kg AKBA). The inhibitory effect of AKBA on tumor growth was well correlated with suppression of angiogenesis. The molecular mechanism of angiogenic inhibition of AKBA induced by VEGFR2 signaling pathways [79].Treatment of meningioma cells by AKBA revealed a potent cytotoxic activity by the inhibition of the Erk signal transduction pathway [80]. Boswellic acids,particularly AKBA and KBA have anti-proliferative and apoptotic effects in human HT-29 cells. The apoptotic effect is mediated via a pathway dependent on caspase-8 activation but independent of Fas/FasL interaction [81]. Besides, the anti-cancer effect of AKBA may in part be due to its ability to demethylate and reactivate methylation-silenced tumor suppressor genes of colorectal cancer cells [82].

In addition to solid tumors, boswellic acid also exerts anti-tumor to hematological malignancies. BA,ABA, KBA and AKBA all inhibited the synthesis of DNA, RNA and protein in human leukemia HL-60 cells in a dose dependent manner and AKBA has the most pronounced inhibitory effects. AKBA significantly inhibited the cellular growth of HL-60 cells, but did not affect cell viability [83]. The inhibition of leukemic cells by AKBA may be due to induction of apoptosis by inhibiting topoisomerase I[84].

One compound, containing alpha- and beta-boswellic acid acetate in 1:1, could induce differentiation of B16F10 mouse melanoma cells,blocked the cell population in G1 phase, inhibited migration and topoisomerase II activity. In addition,this compound induced apoptosis of HT-1080 cells and inhibited the secretion of MMPs from HT-1080 cells[64].

Tetracyclic triterpenes

In addition to boswellic acids, tetracyclic triterpenes such as 3-beta-acetoxy-tirucallic acid and 3-beta-acetoxy-tirucallic acid, also isolated from Boswellia species, showed potent anticancer activity against prostate cancer cells [85].

Myrrha

Myrrha, also called myrrh, is an aromatic gum resin,which was the plant stem resinous exudate of different Commiphora species and has been used for centuries to treat various diseases. Myrrha is used in traditional Chinese medicine for the treatment of trauma, arthritis,fractures and diseases caused by blood stagnation.Myrrha has also been used in the Ayurvedic medical system because of its therapeutic effects against inflammatory diseases, coronary artery diseases,gynecological disease, obesity, etc [85-87]. Especially,Myrrha was a common analgesic and has been used to clean wounds and sores for more than 2000 years, until the European discovered the morphine [88]. Previous study also indicated that the crude aqueous extracts of Myrrha exhibit anti-tumor toward various human and murine cell lines including lung cancer, breast cancer,pancreatic cancer [89]. Myrrha has been found to have cytotoxic and antitumor activity equivalent to that of the standard cytotoxic drug cyclophosphamide [90].

Previous investigations have revealed that the chemical substances from Myrrha contained about 3–8% essential oil, 30–60% water-soluble gum and 25–40% alcohol-soluble resins [91]. Phytochemical investigation of this genus has resulted in identification of more than 300 secondary metabolites which include terpenoids, steroids, flavonoids and ligans, etc. [92].

Myrrha Essential oil

Essential oils are secondary metabolite of plants whose constituents are basically a complex mixture of terpenic hydrocarbons and oxygenated derivatives such as aldehydes, ketones, epoxides, alcohols and esters.Monoterpenes, diterpenes, and even sesquiterpenes constitute the composition of many essential oils. High contents of oxygenated sesquiterpenes (36.1%) and aliphatic acids (22.8%) were found in Commiphora parvifolia Engl., in which caryophyllene oxide (14.2%),beta-eudesmol (7.7%), bulnesol (5.7%), T-cadinol(3.7%) and hexadecanoic acid (18.4%) predominated[93]. Sesquiterpenoids are the primary chemical compositions of the Myrrha essential oil [94].

Sesquiterpenoids

Recent studies have shown that sesquiterpenoids,nonsteroidal compounds, found in myrrh possess anti-tumorigenic effects [87, 95]. Two sesquiterpenoids isolated from myrrh, 1(10)E,2R,4R-2-methoxy-8,12-ep-oxygermacra-1(10),7,11-trien-6-one (ST1) and 2-meth-oxy-5-acetoxy-furanogermacr-1(10)-en-6-one (ST2),inhibited the proliferation of prostate cancer LNCaP and PC3 cells through reduction of AR expression,inhibition of AR translocation into the nucleus,reduction of the expression of ARA70 and SRC-1, and interference with the interaction between AR and ARA70 and SRC-1, leading to the inhibition of AR transactivity [96].

β-bisabolene, a sesquiterpene from the essential oil extract of opoponax (Commiphora guidottii), also exhibits cytotoxicity in mouse and human breast cancer cell lines in vivo and in vitro by inducing apoptosis [97].

α-bisabolol is a small, oily sesquiterpene alcohol with some anti-inflammatory and even anti-microbial properties [98]. Previous studies discovered that α-bisabolol exerts a selective pro-apoptotic action towards human malignant cells, both nonhematological and leukemic. α-bisabolol selectively induced glioma cells apoptosis through an intrinsic pathway, while, the viability of normal rat glial cells was not affected by treatment with alpha-bisabolol at the same concentrations [99]. α-Bisabolol also induces doseand time-dependent apoptosis in HepG2 cells via a Fas- and mitochondrial-related pathway, involves p53 and NFκB [100, 101]. α-bisabolol can suppress the proliferation and survival of pancreatic cancer cells by inhibiting Akt activity and upregulating EGR1 in pancreatic cancer [102]. In an in vitro model of glioblastoma cell lines α-bisabolol induced apoptosis through the mitochondrial pathway, by abolishing the mitochondrial transmembrane potential (DYm) and inducing the release of cytochrome c [99]. In addition,α-bisabolol exerted a pro-apoptotic activity in an ex vivo leukemic model through a similar mechanism[103]. α-bisabolol may induce preferential toxicity against tumor cells because it enters the cells through lipid rafts [104], that are more represented in tumor cells than their normal counterparts [105]. Another study indicated that α-bisabolol may act as a candidate for treatment of BCR-ABL+ leukemias to overcome resistance to TKI alone and to target leukemic cells through BCR-ABL independent pathways [106].

Cycloartane triterpenoids

Cycloartan-24-ene-1α,2α,3β-triol (MY-1), isolated from Commiphora myrrha, has cytotoxic and apoptotic effects of MY-1 on human prostatic cancer PC-3 cells by regulating the expression levels of Bcl-2, Bax, p53 and caspase-3 [107].

Myrrh and frankincense are often used for their combination on clinic in order to obtain a synergistic effect with relieving pain and activating blood circulation, and especially to treat blood stasis syndrome of gynecology diseases, for example dysmenorrhea. According to the traditional Chinese medicinal theory, myrrh and frankincense were commonly used with combination and it was considered that the combination with enhanced effects on clinic [108, 109]. The combination of frankincense and myrrh oils exhibited synergistic effects on Cryptococcus neoformans and Pseudomonas aeruginosa [108]. One study indicated that the MCF-7 and HS-1 cell lines showed increased sensitivity to the myrrh and frankincense essential oils compared with the remaining cell lines. In addition, the anticancer effects of myrrh were markedly increased compared with those of frankincense, however, no significant synergistic effects were identified. The flow cytometry results indicated that apoptosis may be a major contributor to the biological efficacy of MCF-7 cells[110].

Clinical observation research

Previous clinical observation studies reported that XHP have clinical efficacy either in its anti-cancer effects or in adjuvant therapeutic effects. Hong et al. explored the possibility of XHP application in assistant therapy in patients with breast cancer, short- and long-term clinical efficacy were assessed in this study [111]. This study investigated the application of XHP with TEC(taxotere, epirubicin, and cyclophosphamide) in patients with breast cancer and found that XHP could significantly enhance the two-year survival rate and overall response rate in the treatment group. However,XHP did not alter the side effects of TEC. Furthermore,XHP regulated T-lymphocyte subsets and improved the immunity of breast cancer patients taking CEF(cyclophosphamide, epirubicin, and fluorouracil) [112].In addition, XHP has selective effect on estrogen-dependent breast cancer. XHP had synergistic effect on symptoms improvement and quality of life in estrogen-dependent breast cancer patients combined with Letrozole. And the curative effect of XHP group was also better than that of non-estrogen-dependent breast cancer [113]. In addition to breast cancer, XHP can also improve the quality of life (QOL) in patients with advanced primary hepatic cancer, advanced esophageal cancer, and advanced pancreatic cancer[114-116].

Dosage form improvement

With the development of time, some changes of XHP have happened, such as the dosage form of XHP,source and dose of herbs and processing methods of frankincense and myrrh. Here, we aim to describe the reasons of these changes and objectively discuss the influence of these changes on efficacy of XHP.

XHP was recorded to be shaped by yellow rice,which is inconvenient to store. The modern manufacturing method of generating XHP is beta-cyclodextrin inclusion. The period of validity of XHP produced using modern craftsmanship is 48 months.

In addition, as the natural occurrence is very rare,natural Calculus bovis and natural Moschus are difficult to get. Besides, Forest musk deer (Moschus berezovskii), a rare wild medicinal animal, is listed under the category of the state key protected wildlife list of China. Natural Moschus, secreted by the musk glands, is so precious that it is rare in clinical practice and illegally collection of it is criminal behavior in China. Under this circumstance, great attempts have been made to obtain artificial Calculus bovis and artificial Moschus to meet the demand of the medical use.

Substitutes for Calculus Bovis are now available in clinical and medicinal preparations through simply mixing bilirubin, taurine, bile acids and other trace constituents [117]. Two artificial substitutes for Bos Taurus have been introduced in China: artificial Calculus Bovis and in vitro cultured Calculus Bovis.Nowadays, XHP used in clinical practice also take artificial Calculus Bovis or in vitro cultured Calculus Bovis instead of natural Calculus Bovis. By means of comparative pharmacological study, the main pharmacodynamics and toxicity of cultured calculus bovis and natural calculus bovis were compared. The results show that both drugs possess sedative,antispasmodic, antipyretic, anti-inflammatory,cardiotonic and hypotensive effects, the strength of effect and toxicity being similar [118].

Notably, the composition formula of artificial musk remains unknown, because it is national level of confidentiality in China. The artificial Moschus can be used the same as natural Moschus. The use of artificial Calculus bovis and artificial Moschus to replace natural Calculus bovis and natural Moschus is not affect the curative effect of XHP. Besides, the dose of artificial Calculus bovis and artificial Moschus is 3-fold higher in XHP compared to the prescription in Wai Ke Quan Sheng Ji.

Thirdly, processing method of frankincense and myrrh is also different compared to the prescription in Wai Ke Quan Sheng Ji. The essential oil of frankincense and myrrh was removed in Wai Ke Quan Sheng Ji, while, frankincense and myrrh were treated with vinegar and reserved the essential oil. Modern pharmacological research has revealed that essential oils are the primary effective components in xxxxxxxxx frankincense and myrrh oil that exhibit a broad oils are the primary effective components in spectrum of biological activities such as antimicrobial,anti-inflammatory, and antitumor activities [119].Therefore, further studies are needed to clarify these differences.

Grade of references

In the present study, we evaluated the level of references to make our conclusion more objective(Table 3).

Conclusion and perspective

Here, we put forward a new method to revaluate XHP on its application on tumor therapy from ancient literatures to modern studies and from pharmacy to medicine. As a multi-compound medicine, XHP has multiple targets in tumor treatment and it is needed to further study how these compounds work together and whether they have synergistic effects with each other.In addition, the changes in the dosage form of XHP,source and dose of herbs and processing methods of Frankincense and Myrrha also deserve our in-depth study. It is well known that traditional Chinese medicine is based on a set of theories and Zheng(syndrome). Therefore, XHP application may be more effective for certain syndromes according to TCM theory.

Appendix A. Supporting information

Additional supporting information associated with this article can be found in the online version at http://tmrjournal.faisco.cn/nd.jsp?id=41&_np=125_447

Table 3 Hierarchy of evidences

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