| Abstract |
Discovery and identification of novel safe drugs, without severe side effects, is
an important goal of research in cancer chemotherapy. Cell growth regulation is a key
objective in anticancer research. On the other hand, the enhancement of host immune
system through the regulation of cytokines in the cytokine network as defense
mechanisms, as well as expression of MHC class II molecules have been recognized as
possible pathways of inhibiting tumor growth without harming the host. Chili plays
multiple roles in pharmacological and biological functions as a well-known folk
medicine and also a spice. Preliminary observations had detected an anti-proliferative
effect of chili extracts which placed this preparation in the anti-cancer therapeutic
products. In order to evaluate the functional activity of dietary red sweet and hot
peppers, this study was conducted to assess cell proliferating and immunomodulating
activity of aqueous extracts from sweet and hot chili peppers in vitro on murine spleen
cells (BALB/c) with particular focus on the proliferative state of spleen primary cells
and specific cell populations (macrophages, T- and B lymphocytes), cytokine
production, expression of MHC class II molecules and apoptotic status of cells upon the
application of extracts. In addition, significant effort was given on the identification of
the active molecules in the extracts which would be responsible for the above effects. It
was found that extracts from sweet pepper reduced cell growth, while hot extracts
increased cell proliferation. Interestingly, hot extract stimulated the growth of B
lymphocytes and suppressed proliferation of macrophages while sweet extract, on the
contrary, stimulated macrophages. Both extracts suppressed the proliferation of T
lymphocytes. A significant increase in IFN-gamma, IL-2 and TNF-alpha production was
observed upon exposure of spleen cells to all extracts. Both sweet and hot extracts
stimulated biosynthesis of MHC class II molecules. Neither apoptosis nor necrosis was
detected in spleen cells upon administration of either extracts. Subsequent fractionation
by DEAE-Sephacel ionic chromatography revealed certain fractions with significant
proliferative and anti-proliferative activities, both highly active in cytokine production.
High amounts of active components, such as polyamines, proteins, carbohydrates and
carotenoids were found in the extracts, while the fractions derived from the extracts
contained lower amounts of these compounds. Based on these results, the aqueous
extracts from sweet and hot peppers could be proposed as a potential source of food
material for a novel anticancer activity. However, further studies are necessary to assess
wide scale potential of extracts. The identification of the active member(s) in these
extracts will provide new insight in the up- or down-regulation of immune response by
natural products.
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The immunomodulating activity of Capsicum L. Variants : emphasis on proliferation, cytokine production and class II MHC antigen expression
