The genus Cinnamomum

272 K.K. Vijayan and R.V. Ajithan Thampuran
Azumi et al. (1997) found that cinnamon bark contained an inhibitor of bacterial
endotoxin. The inhibition of the activity of the bacterial endotoxins (LPS) was caused
by the direct interaction of the LPS and inhibitory molecule. This finding was
significant in the sense that it was the first report of the presence of a plant-derived
bacterial toxin inhibitor. In yet another antimicrobial screening study De et al. (1999)
tested the activity of 35 spices against Bacillus subtilis, E. coli and Saccharomyces cerevisiae
and found that cinnamon had potent activity against both the bacteria and the fungus.
The growth inhibiting potential of spice oils were studied by Chao et al. (2000), who
observed that cinnamon oil was active against four Gram positive bacteria (Bacillus
cereas, Micrococcus luteus, Staphylococcus aures, Enterococcus faecalis) and four Gram negative
bacteria (Alcaligens faecalis, Enterobacter cloacae, E. coli, Pseudomonas aeruginosa). The results
show that cinnamon oil had a broad spectrum of activity and a high degree of inhibition.
The inhibitory effects were shown towards two fungi and on Candida albicans also.
The results of the above investigations show the high potential of cinnamon as an
antibacterial agent. It should be specifically noted that on some beneficial intestinal
flora it does not have any activity. This increases the potential of developing cinnamon
as a therapeutic agent against many of the pathogenic bacteria. The antibacterial studies
described above provide a scientific basis for the age-old practice of using cinnamon as
a food preservative. The spoilage of cooked/processed food occurs because of bacterial
action. Moreover, the use of cinnamon protects food from the effect of harmful bacteria
by inhibiting the growth in storage. Also, the therapeutic use of this herb in the Indian
and Chinese systems of medical practice is scientifically supported.
ShangTzen et al. (2001) recently investigated the antibacterial action of essential oil
of C. osmeophleum. The oil displayed a very good inhibitory effect on bacterial growth.
The minimum inhibitory concentration (MIC) of the native variety of C. osmeophleum
leaf oil is 500 g/ml when tested against seven bacterial species (E. coli, Pseudomonas
aeruginosa, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Methylene
blue resistant Staphylococcus aureus, Vibrio parahaemolyticus).
Yadav and Dubey (1994) studied the effect of the oil on organisms causing ringworm
infection in animals and humans. They found that the minimum inhibitory concentration
(MIC value) for the two fungi Trichophyton mentagrophytes (Tinea infections) and
Microsporum audounil (Tinea ring worm infections) was 500 ppm and was more effective
than the synthetic antifungal agents clotrimazole, griseofulvin or nystatin. Yadav et al.
(1999) extended the study on ringworm infections caused by the two fungi using
ointment prepared from the oil at 500 ppm concentration. They treated the dermatomycosis
of guinea pigs by twice daily applications of 2 ml of ointment in PEG (0.5 ml
oil/50 ml PEG) and obtained good results. The oral toxicity of the oil in mice was
recorded as an LD 50 of 5.36 ml/kg body weight.
Cinnamon-containing creams are found to be useful in fighting ‘acne’ producing
bacteria (such as Propionibacterium acnes). A commercial product, Sepicontrol A5, consisting
of cinnamon bark powder and a lipo-aminoacid (lypoglycine) in a cream formulation
is reported to be very effective in improving the state of oily acne-prone skin situations.
Antifungal activity
Cinnamon is a potent antifungal substance. It is fungistatic or fungicidal against many
species of pathogenic fungi (Table 11.2). The preservative action of cinnamon in food
and food products is partially due to the fungitoxic effect. The growth of all Aspergillus