Selective Th2 Upregulation by Crocus sativus: A Neutraceutical Spice

Abstract

The immunomodulatory activity of an Indian neutraceutical spice, saffron (Crocus sativus) was studied on Th(1) and Th(2) limbs of the immune system. Oral administration of alcoholic extract of Crocus sativus (ACS) at graded dose levels from 1.56-50 mg/kg p.o. potentiated the Th(2) response of humoral immunity causing the significant increases in agglutinating antibody titre in mice at a dose of 6.25 mg/kg and an elevation of CD19(+) B cells and IL-4 cytokine, a signature cytokine of Th(2) pathway. Appreciable elevation in levels of IgG-1 and IgM antibodies of the primary and secondary immune response was observed. However, ACS showed no appreciable expression of the Th(1) cytokines IL-2 (growth factor for CD4(+) T cells) and IFN-γ (signature cytokine of Th(1) response). A significant modulation of immune reactivity was observed in all the animal models used. This paper represents the selective upregulation of the Th(2) response of the test material and suggests its use for subsequent selective Th(2) immunomodulation.

Figure 1

Crocus flowers and their reddish-orange stamens which are plucked, then dried.

Figure 2

Cytokine-mediated differentiation of Th1/Th2 cells. Undifferentiated naive T cells secrete specific cytokines after antigenic stimulus that polarizes, first into null T-helper cells (Th0), then into Th1or Th2 cells.

Figure 3

HPLC profile of water extract of ACS at 440 nm.

Figure 4

Schematic representation of experimental procedure.

Figure 5

Effect of ACS on humoral immunity as assessed by PFC assay.

Figure 6

Effect of ACS on T lymphocytes (CD4⁺, CD8⁺, CD3⁺) in normal Balb/c mice.

Figure 7

Effect of ACS on B lymphocytes (CD19⁺) in normal Balb/c mice.

Figure 8

Effect of ACS on Th1 cytokine (IL-2, IFN-gamma) expression in whole blood of normal Balb/c mice.

Figure 9

Effect of ACS on Th2 cytokine (IL- 4) expression in whole blood of normal Balb/c mice.

Figure 10

Flow cytometric representation showing effect of ACS on Ig-G1 and Ig-M. Cells were labeled with Ig-G1 (FITC-conjugated monoclonal antibody) and Ig-M (PE-conjugated monoclonal antibody) and analysed in flowcytometer using cell-quest software.