The genus Cinnamomum

266 K.K. Vijayan and R.V. Ajithan Thampuran
that HCA and BCA inhibit lymphoproliferation and T-cell differentiation. However,
Shan et al. (1999) attributed an immunostimulant effect on human lymphocytes
for the extract. They have studied the action of eight medicinal herbs and reported that
the extract of cinnamon stimulated lymphocyte proliferation, enhanced cytotoxic
T-lymphocyte activity, stimulated immunoglobulin production by B-cells and
interleukin (IL-1) production by monocytes. These activities are attributed to the
glycoprotein of MW 100 KDa from the extract. An et al. (1987) studied the hot water
extract of tender stems of Chinese cassia for its immunolomodulatory action and found
that a water soluble polysaccharide isolated from the extract showed a significant
complement system activating effect.
The different investigations reveal that cinnamon shows both immune system
potentiating and inhibiting effects. The macromolecules such as the glycoproteins and
water-soluble polysaccharides are responsible for the potentiating activity, whereas
the diterpenoid moieties and the phenolic molecules give inhibitory properties.
Kaishi-ni-eppi-ichi-to (TJS-664), a Chinese herbal preparation containing cinnamon as
its main constituent, has been shown to exhibit antiviral action against the influenza
A 2 virus. It has been suggested that the antiviral effects of TJS-064 are expressed
through the host’s immune system. This inference is based on the observation that
a 100% survival rate of the virus infected mice was obtained on a treatment with
70 mg/kg p.o. of the drug, whereas the control mice had a mean survival of 11.2 days
and all the mice died in 25 days. In vitro studies did not give any viricidal or viristatic
effects (Ball et al., 1994). In another study Kobayashi et al. (1994) investigated the
effect of TJS-038, another herbal preparation (cinnamon with a combination of four
herbs), which is used as a traditional medicine to treat influenza following rheumatoid
arthritis. TJS-038 at a dose of 50 mg/kg p.o. stimulated the generation of contrasuppressor
T-cells in mice (selective elimination or inactivation of Suppressor T-cells
enhances immune reactions).
Antiallergenic activity
Allergy is a hypersensitivity reaction due to an excessive or inappropriate immunological
response to an antigen (IgE). This occurs when an antigen reacts with antibody
bound to mast cells or basophilic blood cells, leading to disruption of these cells with the
release of vasoactive mediators such as histamine. The antigens that initiate this response
are called the allergens. Compounds, which can inhibit or antagonise this excessive
immunological response and intervene in the multitude of complex reaction sequences
of the immune system, may function as antiallergenic. Cinncassiol C 1, cinncassiol D 4
and its glycosides, which are constituents of cinnamon bark, exhibit anti-allergic
activity (Torhara, 1980). In another investigation, Tanaka et al. (1991) found that
cinnamaldehyde inhibited allergic reactions caused by the release of chemical mediators
from basophils and mast cells. The antigen (allergen) and antibody (IgE) reaction caused
a cell degranulation function. Shichinohe et al. (1996) studied the anti-allergic effect of
a Chinese herbal formulation Moku-boi-to (M-711), which contained cinnamon as the
main constituent. A model dermatitis was created in rats, which when administered with
20 mg/kg B.W of M-711 significantly suppressed the capillary permeability induced
by histamine. The antihistamine effect of 40 mg/kg was equivalent to the optimum
dose of other anti-inflammatory drugs, azelastine and diphenhydramine. Ikwati et al.
(2001) found that the hexane extract of C. massoia bark from Indonesia had a strong