Curcumin powder

Curcumin powder (from Curcuma longa, turmeric plant) and lecithin (in the form of l-α-phosphatidylcholine from egg yolk) were purchased from Sigma-Aldrich (St. Louis, MO, USA). The organic solvents, toluene (anhydrous, 99.8%) and dichloromethane (DCM, 99.9%), were obtained from Sigma-Aldrich (St. Louis, MO, USA) and Acros Organics (Janssen Pharmaceuticals, Geel, Belgium), respectively. All other chemicals and reagents were analytical grade.

Complex particles based on gellan/carrageenan/chitosan with curcumin immobilized were previously obtained [3 (link)]. Curcumin powder (extracted from Curcuma Longa), Tween 20, bovine serum albumin (BSA), dimethyl sulfoxide (DMSO), hydrochloric acid (37%), 2,2-diphenyl-1-picrylhydrazyl (DPPH), Folin-Ciocalteu reactive, double tartrate of sodium, and potassium were purchased from Sigma Aldrich, Hamburg, Germany Sodium nitrite (NaNO₂), Aluminum chloride (AlCl₃)_, Sodium carbonate (Na₂CO₃), Sodium hydroxide (NaOH), Copper sulfate (CuSO₄ × 5H₂O), ethanol were provided by the Chemical Company (Iași, Romania).

Both drugs were administered intra-peritoneally (IP) after dissolution in Tween 80 and dilution in normal saline [22 ]. Curcuma longa -derived pure curcumin powder was purchased from Sigma-Aldrich, USA, assay: ≥ 65% curcumin (HPLC), [CAS: 458-37-7; MW: 368.38 g/mol; C21H20O6]. Each mouse received a daily dose of 150 mg/kg [23 (link)]. Albendazole powder (Sigma pharmaceutical industries – Egypt) was given at a daily dose of 50 mg/kg [24 –28 (link)].

Fifteen milligrams of powder of silica nanoparticles (Nano Sadra Company, Isfahan, Iran) and 0.75 mg of curcumin powder (Sigma Aldrich, Burlington, MA, USA) were added to 10 mL of cyclohexane. The prepared suspension was sonicated, stirred overnight, and washed with cyclohexane, and the silica particles containing curcumin were vacuum dried [30 (link)]. The nanoparticles were stored at −18 °C for further investigations.

All animal procedures were approved by the Institutional Animal Care and Use Committee (IACUC) of Korea University (Seoul, Republic of Korea; Approval No: KUIACUC-2021-0078). Eight-week-old C57BL/6N male mice were purchased from RaonBio, Inc. (Gyeonggi-do, Republic of Korea). Mice were housed in cages at room temperature and maintained at 23 ± 1 °C at a relative humidity of 55 ± 5% with a 12 h light/dark cycle. The animals were allowed at least one week to adapt to their laboratory housing environment, and food and water were available ad libitum. ERM-CZ100 fine dust (similar to PM10) (European Commission Joint Research Centre, Geel, Belgium) was purchased through Sigma. This substance contained approximately 0.5 g of fine dust and was processed similarly to PM10, and its main components were PAHs, including benzo[a]anthracene, indeno [1,2,3-c,d]pyrene, and benzo[b]fluoranthene. Curcumin powder, polyethylene glycol 400, and NF-κB SN50 were purchased from Sigma-Aldrich (St. Louis, MO, USA). N-methyl-L-arginine (L-NMMA) was purchased from Thermo Fisher Scientific (Waltham, MA, USA).

Curcumin powder, low-molecular weight chitosan (75–85% deacetylated), Tween 80, sodium tripolyphosphate (TPP), sucrose, and sodium hydroxide (NaOH) were purchased from Sigma-Aldrich (St Louis, MO, USA). Acetic acid, ethyl acetate, and methanol were purchased from AMRESCO (Radnor, PA, USA). Absolute ethanol was purchased from Scharlau (Barcelona, Spain). All reagents utilised in this study were of analytical grade, except methanol, which was high-performance liquid chromatography (HPLC) grade. CrFK cells and FIPV strain WSU 79-1146 were purchased from ATCC (Manassas, VA, USA). Minimum essential medium (MEM) containing Earle's salts and L-glutamine, foetal bovine serum, nonessential amino acid (NEAA), penicillin (100 U/mL), streptomycin (100 μg/mL), phosphate-buffered saline (PBS), TryPLE™, trypan blue, dimethyl sulfoxide (DMSO), and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) were purchased from Thermo Fisher Scientific (Waltham, MA, USA).

Chitosan high molecular weight Mw 310,000–375,000 Da, deacetylation degree ~85%, 800–2000 cP, acetic acid, ethanol, sodium hydroxide, and curcumin powder (99.8% pure and anhydrous) was purchased from Sigma-Aldrich (Taufkirchen, Germany). Silver nitrate (AgNO₃) we purchased from Merck.