Limonin

Deionized water was used for HPLC-Q-TOF-MS and HPLC-Q-TOF-MS/MS analysis and was purified using a Milli-Q system (Merck Millipore, Billerica, MA, USA). HPLC-grade acetonitrile and formic acid were purchased from Merck (Darmstadt, Germany) and ROE (Newark, New Castle, USA), respectively. Methanol (AR) was purchased from the National Institutes for Food and Drug Control (Beijing, China). The seventeen reference substances (seven flavonol glycosides, three flavonols, two polymethoxyflavonoids, three coumarins, one alkaloid, and one limonin), including synephrine (15), neoeriocitrin (36), poncirin (39), eriocitrin (40), naringin (42), naringenin (43), narirutin (44), neohesperidin (51), hesperidin (56), apigenin (59), hesperitin (61), xanthotoxol (71), scopoletin (76), auraptene (80), limonin (79), nobiletin (85), and tangeretin (87) were purchased from Shanghai Yuanye Bio-Technology Co., Ltd. (Shanghai, China).

All the Chinese herbs were provided by Tongde Hospital of Zhejiang Province (Hangzhou, China). All the chemical standards, including l (+)-arginine, proline, adenine, succinic acid, isoleucine, leucine, gallic acid, phenylalanine, protocatechuic acid, l-tryptophan, protocatechuic aldehyde, neo-mangiferin, chlorogenic acid, caffeic acid, amygdalin, mangiferin, rutin, liquiritin, luteoloside, naringin, berberrubine, baicalin, quercetin, epimedin A, epimedin B, epimedin C, icarrin, isorhamnetin, glycyrrhizic acid, limonin, aaikosaponin A, and 3-N-butyl-4,4-dihydrophthalide, were purchased from Shanghai Yuanye Bio-Technology Co. Ltd (Shanghai, China). Azoxymethane (AOM) was obtained from Sigma-Aldrich (St. Louis, MO, United States) and dextran sodium sulfate (DSS) from MP Biomedicals (Santa Ana, CA United States). TUNEL apoptosis assay kits, radioimmunoprecipitation assay (RIPA) buffer, BCA protein assay kits, and anti-MMP9 antibody (AF5234) were purchased from Beyotime (Beijing, China). Mouse IL-6 and IL-17A ELISA kits were from LiankeBio (Hangzhou, China), and antibodies to p-STAT3 (AF3293), STAT3 (AF6294), NF-κB-p65 (BF8005), Bcl-2 (BF9103), Lamin B (AF5161), and β-actin (T0022) were purchased from Affinity Biosciences (Changzhou, China). Antibodies to IL-17RA (sc-376374) and Bax (sc-20067) were purchased from Santa Cruz Biotechnology (Santa Cruz, CA, United States).

The peach leaf orange was picked from Longmaxi Village, Quyuan Town, Zigui County (Hubei, China) on 3 September 2019; the Qingzhuan tea (loose tea) was provided by Zigui Yihong Tea Co., Ltd. (Hubei, China)
Folin phenol, ninhydrin, methanol, anhydrous ethanol, anthrone, sulfuric acid, potassium dihydrogen phosphate, disodium hydrogen phosphate, sodium carbonate, oxalic acid, ethyl acetate, n-butanol, stannous chloride, Coomassie brilliant blue G250, sodium chloride, and phosphoric acid were all of analytical grade and purchased from China Pharmaceutical (Group) Shanghai Chemical Reagent Company (Shanghai, China). Bovine serum albumin BSA, α-glucosidase, α-glucoside, rutin, limonin, synephrine, hesperidin, and cyclohexanone standard products were purchased from Shanghai Yuanye Biotechnology Co., Ltd. (Shanghai, China). ABTS, FRAP, and DPPH antioxidant kits were purchased from Suzhou Keming Biotechnology Co., Ltd. (Suzhou, Jiangsu, China). α-amylase activity detection reagent cartridges were purchased from Solarbio Co., Ltd. (Beijing, China).