Epiberberine

The concentrated granules (with a concentrate to dried herb ratio of 10:0.9) of four component herbs of BTWT, R. pulsatilla, R. coptidis, C. phellodendri, and C. fraxini (lot numbers 8055671, 9010401, 1612619, and 7122571, respectively), were purchased from Guangdong Yifang Pharmaceutical Co., Ltd (Foshan, China). The structures of representative components from the four herbs are shown in Fig. 1. AB4, AA3, 23-HA, aesculin, aesculetin, palmatine, jatrorrhizine, coptisine, epiberberine, and phellodendrine were purchased from Yuanye Bio-Technology Co., Ltd at the highest available purity (98%) (Shanghai, China). Berberine hydrochloride was purchased from Shenzhen ChemStrong Scientific Co., Ltd (Shenzhen, China) at the highest available purity (95%). DSS was purchased from MP Biomedicals (MW; 36,000 − 50,000, Solon, OH, USA). The stool bleeding test kit was purchased from BaSO Bio-Technology Co., Ltd (Zhuhai, China). Lipopolysaccharide (LPS) was purchased from Sigma-Aldrich. Deionized water was purified using a Millipore water purification system (Millipore, Milford, MA, USA). All other reagents used were of analytical grade.Fig. 1

The label components of the four component herbs of BTWT

Carbamazepine (CAS No.: 298–46-4), berberine (CAS No.: 2086-83-1), coptisine (CAS No.: 6020-18-4), epiberberine (CAS No.: 6873-09-2), palmatine (CAS No.: 3486-67-7), jatrorrhizine (CAS No.: 3621-38-3), columbamine (CAS No.: 483–34-1), evodiamine (CAS No.: 518–17-2) and rutaecarpine (CAS No.: 20575–76-2), all > 98% purity, were purchased from Shanghai Yuanye Bio-Technology Company. Acetonitrile and methanol (LC grade) were purchased from Fisher Chemical, USA. Formaldehyde (AR) was purchased from Beijing Tong Guang Fine Chemicals Company. Isoflurane was provided by HARVEYBIO Company.
TAZF was provided by the State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University. The concentrations of the compounds in TAZF were measured using high-performance liquid chromatography (HPLC), with berberine accounting for the majority of TAZF at a ratio of 14.73% (g/g), followed by palmatine (3.14%), coptisine (2.52%), evodiamine (1.41%), epiberberine (1.30%), rutaecarpine (1.27%), columbamine (0.90%) and jatrorrhizine (0.47%).