Antioxidant and the Efficacy of Sophora secundiflora and Methoxyisoflavones in the Immune Function of Pigeons Vaccinated against Paramyxovirus Serotype-1

Objective: The present work investigated the effect of oral administration of hydroalcoholic (70% aqueous ethanol) extract (TeE) of Sophora secundiflora leaves and its organic fractions n-hexane (HeE), ethyl acetate (EaE) and n-butanol (BuE) and major isolated methoxyisoflavones 1 and 2, on the cellular and humoral immune responses to live attenuated avian paramyxovirus-1 (APMV-1) vaccines in pigeons. Methods: The structures of six isolated compounds were elucidated on the basis of chromatographic, chemical, and spectroscopic methods. The samples antioxidative and radical scavenging capabilities of 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical cation and ferric reducing power were determined. Total phenolic, tannin and flavonoid contents of EaE extract were evaluated. Results: Six compounds were isolated. Three were the methoxyisoflavones5- 7-dihydroxy-4′-methoxyisoflavone (1), 7-hydroxy-4′methoxyisoflavone (2), 5,4'-dihydroxy-7- methoxy-isoflavone (3), along with isorhamnetin (4) and two quercetin derivatives quercetin 3-glucoside (5) and quercetin 3-rutinoside (6) were isolated. The hydroalcoholic extract, fractions and 4'-methoxyisoflavones showed radical scavenging effect in the order of EaE > TeE > BuE >compound 1>compound 2> HeE. Stimulation of both sero-responses was observed, especially this of EaE. The results showed an increase of macrophage cells, lymphocyte and antibody titers in blood. Conclusion: The presence of 5-hydroxyl group at A-ring may be important to show the immunostimulant and antioxidant activity of compound 1vs compound 2. The present results showed the potential abilities of EaE as antioxidant and immunomodulator agent and these would impart healthy economic benefits in vaccinated birds.