Exploration of the potential mechanism of Banxia Xiexin Decoction for the effects on TNBS-induced ulcerative colitis rats with the assistance of network pharmacology analysis

Abstract

Ethnopharmacological relevance

Banxia Xiexin Decoction (BXD), an ancient TCM prescription originating from Treatise on Febrile Diseases (Shang Han Lun) of the Han Dynasty, has been widely used in modern clinical practice, especially for gastrointestinal diseases, including ulcerative colitis (UC). However, the modern decoction method of BXD differs from that of the original method. Thus, an exploration of the influence of the different decoction methods on the pharmacological effects is interesting and significant.

Aim of the study

This study aimed to systematically compare the pharmacological effects of extracts of BXD on TNBS induce UC rats that were prepared by different methods, the ancient method and the modern method. The findings may provide important information for the further mechanical exploration of the classical prescription, contributing to the rational application and enhancing the understanding of BXD in modern applications or scientific research.

Methods

Fifty-four SD rats were randomly divided into the following nine groups at n = 6/group: control group; model group; salicylazosulfapyridine group; BXD ancient extraction method's low-dose group (BXD-AED-L, 3.6 g BXD-AED/kg), medium-dose group (BXD-AED-M, 7.2 g BXD-AED/kg), and high-dose group (BXD-AED-H, 14.4 g BXD-AED/kg); and BXD modern extraction method's low-dose group (BXD-MED-L, 1 g BXD-MED/kg), medium-dose group (BXD-MED-M, 2 g BXD-MED/kg), and high-dose group (BXD-MED-H, 4 g BXD-MED/kg). All the groups, except the control group, were rectally injected with 70 mg/kg ethanol solution containing TNBS (2,4,6-trinitrobenzenesulfonic acid) to establish the UC models. The pharmacological evaluations including disease activity index, colon weight index, macroscopic and histological evaluation of colon damage, and inflammatory cytokine levels (IL-4, IL-10, IL-1β, TNF-α, and IL-6)were measured. In the network pharmacology analysis, the “herbs-components-targets-disease” network was constructed and visually analyzed with which the targets with a strong correlation with UC were screened out.

Results

The results showed that both BXD-AED and BXD-MED might alleviate the severity of UC with different degrees according to the majority of indices that were evaluated. At similar doses, the BXD-AED groups performed better compared with the BXD-MED groups. With the assistance of the network pharmacology analysis, some key active components (quercetin, baicalein, wogonin, and baicalin) related to the anti-UC/inflammation were screened out. The contents of the components in BXD-AED were higher than those in BXD-MED. The joint results of the study indicated that BXD, an ancient TCM compound prescription, is an effective drug candidate for the modern treatment of UC.

Introduction

Ulcerative colitis (UC), an inflammatory bowel disease with unknown etiology, mainly invades the rectum and colon mucosa and submucosa. Traditionally, UC has been viewed as a Western disease. The incidence and prevalence of UC has stabilized in Western Europe and North America (affecting 0.2% of the population), and the incidence continues to rise in newly industrialized countries. The highest incidence of ulcerative colitis is in Northern Europe (24.3 per 100,000), Canada (19.2 per 100,000) and Australia (17.4 per 100,000). The countries with the highest prevalence rates are Europe (505 per 100,000), Canada (248 per 100,000) and the United States (214 per 100,000) (Ungaro et al., 2017). In addition, epidemiological data from the last four decades have shown 1.5-fold to almost 20-fold increases in the incidence and prevalence of UC in some Asian countries, although prevalence remains generally lower than in the West (Wei et al., 2021). Apart from affecting the quality of life and work efficiency, UC also has the risk of causing colorectal cancer. And there are many risks that could be induced in the drug treatment on moderate to severe UC which may lead to serious opportunistic infections and malignant tumors. Surgical treatment may cause serious complications as well (Singh et al., 2020).

The main clinical manifestation of UC is gastrointestinal symptoms, such as diarrhea, abdominal pain, and mucopurulent bloody stool. Long-term inflammation can cause many complications, and colorectal cancer entails the most serious consequences. Therefore, UC is considered to be one of the precancerous lesions of colon cancer (Yashiro, 2014). The current treatment of UC mainly includes drug and surgical treatments (Xue et al., 2017). In the clinical treatment of UC, aminosalicylic acid and glucocorticoid drugs, such as mesalazine (Yorulmaz et al., 2019), budesonide (Abdalla and Herfarth, 2016) are mostly used. Many new drugs have been developed and applied to treat UC (Alasmary et al., 2018), but most of them can hardly cure the disease. As the mechanism of the disease remains unclear and no cure has been determined for UC, this disease has been listed by WHO as one of the “refractory diseases in the world.” As a matter of fact, although chemical medicines have a quick effect on UC, more side effects and incomplete treatments are rampant (Gilca et al., 2017; Huang et al., 2018).

In recent years, an increasing number of traditional Chinese medicines (TCMs) have been proven to offer various benefits, such as anti-inflammatory, anti-oxidant, and anti-tumor effects, with relatively high safety and less side effects. A large number of studies have involved the treatment of UC with TCM, in which Pinelliae Decoction for Purging Stomach-Fire (called Banxia Xiexin Decoction in Chinese), is a typical example. Banxia Xiexin Decoction (BXD), originally recorded in “Treatise on Febrile Diseases” (Shang Han Lun), is a classical TCM prescription composed of seven medicinal herbs, including Pinelliae Rhizoma (Ban Xia), Coptidis Rhizoma (Huang Lian), Scutellariae Radix (Huang Qin), Zingiberis Rhizoma (Gan Jiang), Ginseng Radix (Ren Shen), Jujubae Fructus (Da Zao) and Glycyrrhizae Radix (Gan Cao). In TCM theory, the composition of BXD represents the harmony between acrid-opening and bitter down-bearing features. Previous studies have shown that BXD has anti-inflammatory and antioxidant effects (Chen et al., 2015), and has a protective effect on mice with UC (Wang et al., 2014). Clinically, BXD has also been widely used in treating patients with UC (Zhang, 2016; Zhu et al., 2016), with positive effects and high safety, suggesting that BXD can relieve the pain of UC patients and effectively improve their physical and mental conditions. However, the decoction method in modern clinical practice has commonly been used differently from the ancient ones recorded in the original document (Shang Han Lun). Thus, investigating the difference in the pharmacological effects brought by different decoction methods is an interesting endeavor, which could provide a reference for the modern application of traditional TCM classical prescription.

Network pharmacology is a novel method for exploring the therapeutic effects, targets of Chinese medicines (medicinal herbs or compound prescriptions) and bioactive compounds. Its concept of “multi-targets, multi-components” is most suitable for exploring the therapeutic effects of Chinese medicines at the molecular level (Lv et al., 2020; Wang et al., 2020). Network pharmacology has facilitated the development of evidence-based medicine and herbal-based drug discovery, which differs greatly from the traditional research approach. In recent years, network pharmacology analyses have been increasingly employed to reveal the potential action mechanism of single-component or compounds of Chinese medicinal preparations, including Ganghuo Kanggan Decoction (Lai et al., 2020), Toujie Quwen Granules (Ye et al., 2020), and even the effective prescriptions against COVID-19, such as Maxing Shigan Decoction (Li et al., 2020) and Lianhua Qingwen capsule (Xia et al., 2020).

On the basis of the clinical practice in China, we investigated BXD's in-vivo pharmacological effects on experimental TNBS-induced UC rats, with the extracts prepared using the ancient extraction method and modern extraction method. Then, network pharmacology analysis was used to investigate the interaction between the active components of BXD, their potential targets and UC targets. The results of the combined in-vivo experiments and virtual network pharmacology analysis were used as basis to determine the key components and possible mechanisms related to UC.