Quercetin

Lipopolysaccharides (LPSs) from E. coli 055:B5 were purchased from Solarbio (Cat. No. L8880, Beijing, China) with a purity > 99%. N-Acetyl-l-cysteine (NAC) and vitamin C (VC) were purchased from Beyotime (Cat. No. ST1546; Cat. No. ST1434, Shanghai, China) with a purity > 99%. The standard samples of apigenin, quercetin, chrysin and diosmetin were purchased from CHENGDU MUST Biotechnology CO.,LTD (Cat. No. A0113, A0083, A0292, A0927, MUST, Chengdu, China) with HPLC purity > 99%. Rabbit BRCA1 Polyclonal Antibody was purchased from Beyotime (Cat. No. AF6339, Shanghai, China). BeyoClick EdU 488 kit was purchased from Beyotime (Cat. No. C0071S, Shanghai, China).

Lianqiaoxinside A was isolated by the author from the fruits of F. suspensa. Chlorogenicacid, caffeic acid, forsythiaside B, rutin, hyperoside, forsythiaside A, cynaroside, scutellarin, (+)-pinoresinol-β-d-glucoside, isochlorogenic acid A, baicalein, baicalin, phillyrin, phillygenin, arctiin, quercetin, luteolin (≥98.0%)were purchased from the Chengdu MUST Biotechnology Co., Ltd. (Chengdu, China). HPLC grade acetonitrile (ACN) and formic acid were obtained from Fisher Scientific (Waltham, MA, USA). Purified water was used from a Milli-Q system (Millipore, Bedford, MA, USA). All other reagents were of analytical grade.

BALB/c mice were purchased from Beijing Weitong Lihua Laboratory Animal Technology Co., Ltd. (Beijing, China). (6–8 weeks old, 18–22 g). The animal study was reviewed and approved by the Management Committee of the Experimental Animal Center of Heilongjiang Bayi Agricultural University (DWKJXY2022029). The cp BVDV-1a (strain NADL, No. VR-534) and ncp BVDV-1b (strain NY-1, No. VR-524) were derived from the American Type Culture Collection (ATCC, Manassas, VA, USA). Reactive oxygen species (ROS), total antioxidant capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) were measured by using commercial kits (Nanjing Jiancheng Bioengineering Institute, Nanjing, China). Cell Counting Kit 8 (WST-8/CCK8) was purchased from Abcam (ab228554). Quercetin was purchased from Chengdu Must Bio-Technology Co., Ltd. and was resuspended in DMSO. Hsp70 lentivirus was purchased from Hanbio Technology Co., Ltd. The production of IL-2 and IFN-γ were measured by using commercial ELISA kits (IL-2, SEA073Mu, USCN Life Science, Wuhan, China; IFN-γ, SEA049Mu, USCN Life Science, Wuhan, China).

Both DOF and DDF were collected at the Longling Institute of Dendrobium (98.696°E, 24.593°N) in May 2019. The reference standards with 98% purity including taxifolin, rutin, myricetin, quercetin, luteolin, and kaempferol were obtained from ChengduMust Biotechnology Co, Ltd Company (Chengdu, China). Acetonitrile (ACN) and methanol (MeOH) for high‐performance liquid chromatography (HPLC) analysis and for the ultra‐performance liquid chromatography–tandem mass spectrometry (UPLC‐MS/MS) analysis were purchased from Merck (Darmstadt, Germany). Deionized water was prepared using a Smart‐Q30 purification system (Hitech Instruments Co., Ltd., Shanghai, China). Other reagents were of analytical grade.

The Manzanillo variety of olive trees was cultivated in the commercial olive orchards of Xichang, Sichuan. Olive leaves were collected in April and July, 2017. The leaves were washed and dried at 45 °C, and then ground into powder by a high speed mill (FW177, Taisite Instrument Co., Ltd., Tinjin, China). The powder was stored at −20 °C.
Phenazine methosulfate (PMS), 1,1-diphenyl-2-picrylhydrazyl (DPPH), nicotinamide adenine dinucleotide (NADH), and nitroblue tetrazolium (NBT) were obtained from Sigma Chemical Co. (St. Louis, MO, USA). Fetal bovine serum (FBS) and penicillin–streptomycin were from Gibco/BRL (Burlington, Canada). HPLC-grade apigenin-7-O-β-d-glucosidase, apigenin, quercetin, rutin, luteolin, and luteolin-4’-O-glucoside were purchased from the Chengdu Must Biotechnology Co., LTD (Chengdu, China); acetonitrile was purchased from Acros Organics (Geel, Belgium). All other reagents were analytical grade and obtained from Chengdu Kelong Chemical Factory (Chengdu, China).

Reference standards including chlorogenic acid, caftaric acid, caffeic acid, cichoric acid, luteolin, luteolin-7-O-β-d-glucoside, isochlorogenic acid A, isochlorogenic acid C, apigenin and quercetin were purchased from Chengdu Must Bio-Technology Co., Ltd. (Chengdu, China). DPPH (1,1-Diphenyl-2-picrylhydrazyl), copper (II) chloride, ascorbic acid, sodium acetate trihydrate, iron (III) chloride hexahydrate, TPTZ (2,4,6-Tris(2-pyridyl)-s-triazine), copper (III) chloride, neocuproine, Folin-Ciocalteu reagent, gallic acid, sodium nitrite, and catechin were acquired from Sigma-Aldrich Co. (St. Louis, MO, USA). All other reagents used in this study were of analytical grade.

Analytical grade methanol (purchased from Da Mao Chemical Reagent Co., Ltd., Tianjin, China), chromatography-grade acetonitrile (obtained from Honeywell Trading (Shanghai) Co., Ltd., Shanghai, China), distilled water (from Watsons, Hong Kong, China), rutin, and quercetin (batch numbers: MUST–22022507 and MUST–22042012, respectively, were purchased from Chengdu Must Bio–Technology Co., Ltd., Chengdu, China), isoquercitrin, 1,3–dicaffeoylquinic acid, and chlorogenic acid (batch numbers: ZABH1013, AFBL1284, and AZ22011851, respectively, were obtained from Chengdu Alfa Biotechnology Co., Ltd., Chengdu, China). The purity of all reference compounds exceeded 98%, including ascorbic acid (Guangzhou Chemical Reagent Factory, Guangzhou, China) and 1,1–diphenyl–2–trinitrophenylhydrazine, 2,2–diazo–bis (3–ethylbenzothiazole–6–sulfonic acid) (Alsan Biotechnology Co., Guangzhou, China).