Antioxidant Properties of Brassica Rapa L. Seeds and Immunostimulant Effect on Immunity Broilers Cells (Gallus Gallus Domesticus)

Abstract

In the past few decades, researchers have focused on finding the benefits of natural substances derived from plants. This study aimed to evaluate the use of Brassica rapa seeds in poultry feed as an antioxidant and immunostimulant of host defenses. We prepared three extracts using ethanol, Ethyl Acetate, and water. Spectrophotometric methods determined the total phenolic and flavonoid content in the three extracts. Antioxidant activity was assessed using 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing/antioxidant power (FRAP), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radicals and β-Carotene bleaching methods. An assessment of their immunostimulant activities in vitro was performed on chicken immunity cell proliferation (splenocytes, thymocytes, and Bursa cells) and IgY production. We prepared three different extracts using ethanol, Ethyl Acetate, and water. The total phenolic and flavonoid content in the three extracts was determined by spectrophotometric methods.Antioxidant activity has been assessed using 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing/antioxidant power (FRAP), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radicals and β-Carotene bleaching methods. Assessment of their immunostimulant activities in vitro was tested on chicken immunity cell proliferation (splenocytes, thymocytes, and Bursa cells) and IgY production The total phenolic contents ranged from 462.5 to 794.8 mg /g of extract, the order of TPC was as follows: EtOAc > EtOH >Water. Flavonoid contents were, 63.7 mg in EtOH extract, 81.2 mg in EtOAc extract, and 108.7 mg/g Extract in aqueous extract. By DPPH, the IC50s of EtOH, EtOAc, and water, were 1.8μg/ml, 2.4μg/ml, and 1.5μg/ml, respectively. Using the Ferric- Reducing Antioxidant Power (FRAP), we remarked that the EtOH and EtOAc extracts have important antioxidant powers. The ABTS assay indicated that EtOH and water had the highest activities with IC50s of 0.19 and 0.07, respectively. Finally, by the β-carotene bleaching test, we observed that the IC50 of the EtOH, EtOAc, and water were 62.1 μg/mL; 72.7 μg/mL, and 45.8 μg/mL, respectively. The results obtained indicate that Brassica aqueous extract stimulates humoral immunity by stimulating splenocyte (B and T-lymphocytes) and Bursa cell (B-lymphocyte) proliferation by more than 200% of response vs control. In addition, the aqueous extract highly stimulated the function of bursa cells by 208% of the reaction. In the same conditions, we recorded a stimulation of cellular immunity mediated by thymocytes by an increase in cell proliferation (352.7% of response) implicated in virus protection. These extracts also possessed an antimicrobial effect against diverse microorganisms such as coliforms and Staphylococcus. The FT-IR spectrum indicated that the hydroxyl group (phenol), hydroxybenzoic acid family, carbohydrate molecules such as glucopyranose, a carbonyl ester group, hydrocarbon chains (alkyls groups)) were present. The total phenolic contents ranged from 462.5 to 794.8 mg /g of Extract, the order of TPC was as follows: EtOAc > EtOH >Water. Flavonoid contents were, 63.7 mg in EtOH extract, 81.2 mg in EtOAc extract, and 108.7 mg/g Extract in aqueous extract.By DPPH, the IC50s of EtOH, EtOAc, and water, were respectively 1.8µg/ml, 2.4µg/ml, and 1.5µg/ml. Using the ferric-reducing antioxidant power (FRAP) we remarked that the EtOH and EtOAc extracts have important antioxidant powers. The ABTS assay indicated that EtOH and water had the highest activities with IC50s of 0.19 and 0.07 respectively. Finally, by the β-carotene bleaching test, we observed that the IC50 of the EtOH, EtOAc, and water were 62.1 µg/mL; 72.7 µg/mL, and 45.8 µg/mL respectively. The results obtained indicate that Brassica aqueous extract stimulates humoral immunity by stimulating splenocyte (B and T-lymphocytes) and Bursa cell (B-lymphocyte) proliferation by more than 200% of response vs control. In addition, the aqueous extract stimulated highly the function of bursa cells by 208% of the response. In the same conditions, we recorded a stimulation of cellular immunity mediated by thymocytes by an increase in cell proliferation (352.7% of response) implicated in virus protection. These extracts possessed also an antimicrobial effect against diverse microorganisms such as coliforms and Staphylococcus. The FT-IR spectrum indicated that the hydroxyl group (phenol), hydroxybenzoic acid family, carbohydrate molecules such as glucopyranose, a carbonyl ester group, hydrocarbon chains (alkyls groups)) were present. This result could have interesting applications in the poultry feed industry to enhance the performance of animal development.