Evaluation of Immunomodulatory Potential of Two Naturally Occurring Bioactive Flavonoids: Luteolin & Apigenin

Abstract

AIM- The aim of the present investigation is to study the Immunomodulatory potential of two naturally occurring bioactive flavonoids: Luteolin & Apigenin. MATERIAL & METHODS- Fresh blood was collected from sheep sacrificed in the local slaughter house. Sheep red blood cells (SRBCs) were washed three times in large volumes of Pyrogen free 0.9% normal saline and adjusted to a concentration of 0.5×109 cells/ml for immunization and challenge. The control group received normal saline solution. Group II was administered with only cyclophosphamide at the dose of 30 mg/kg, i.p. while different group rats received cyclophosphamide with both bioactive flavonoids (50 & 100 mg/kg) and Ocimum sanctum extracts (100  mg/kg) for 10 days. Red blood cell diluted fluid (Hayem’s fluid) – 5g of sodium sulphate, 1g of sodium chloride, 0.5g of mercuric chloride were dissolved in 200ml of distilled water. WBC diluting fluid or Turk’s fluid was used as the diluents which can destroy RBC’S. WBC diluting fluid was prepared by mixing Glacial acetic acid, Gentian violet 1% and Water 95 ml. Haemoglobin is converted into acid haematin by the action of HCl. The acid haematin solution is further diluted with distilled water until its colour matches with exactly that of permanent standard of comparator block. RESULTS- The luteolin and apigenin produced a significant, dose-related increase in DTH reactivity in rats. Increase in DTH reaction in rats in response to cell dependent antigen revealed the stimulatory effect of luteolin and apigenin on T cells. Oral administration of luteolin and apigenin in 50 & 100 mg/kg for 7 days, and 10 min prior to carbon injection exhibited a dose-related increase in the clearance rate of carbon by the cells of the RES. Cyclophosphamide at the dose of 30 mg/kg, i.p. caused a significant reduction in the haemoglobin, RBCs, WBCs and differential leukocyte count. CONCLUSION- Many of the plant products exert some effect on immune system. They either enhance immune response to help body clear undesirable agents from body or suppress immune response to control deterioration in the body. Compounds that alter immune response are considered Immunomodulatory agent.