Perilla 489
perilladehyde) type. The sleep prolongation principle in the PP genotype was later
identified as dillapiole and myristicin, the former was four times more active than the
latter. In the PA type the potentiality factor was identified as perillaldelyde-stigmasterol
in combination (Tabata, 1997).
Promotion of intestinal propulsion
Koezuko et al. (1985) investigated the effects of Perilla leaves on excretory activity.
Only the leaves of the PK (perillaketone) type were found to promote intestinal
propulsion. The active principle was identified as perillaketone. This compound
stimulates the motility of the circular muscles of the intestine.
Toxicity
Perillaketone causes serious lung edema in cattle grazing wild perilla plants. This
toxicity was reported to be due to perillaketone. This validates the non-use of the PK
type in traditional medicines. Further studies have confirmed that perillaketone is a
pulmonary-edema inducing agent (Wilson et al., 1977). In traditional medicine only
the PA type is used.
Allergic contact dermatitis
Contact dermatitis due to prolonged contact with Perilla is well known in the growing
countries. The symptoms include vesicular eruption, diffuse erythrema, mild edema
and marked hyperkeratosis with eruptions on fingers. The chemical constituent
responsible for the malady is perillaldehyde. However the symptoms can be treated
easily with corticosteroid creams.
Antitumour activity
Samaru et al. (1993) reported that administration of Perilla leaf significantly prolonged
the lifespan of mice inoculated with the MM 2 ascites tumour. Perilla seed oil, which
is rich in n-3-polyenoic fatty acids, inhibits carcinogenecity in the large intestine of
rats (Narisawa et al., 1990). Hori et al. (1987) reported the effect of Perilla seed oil
on the pulmonary metastasis of ascites tumour cells in rats.
Yonekura and Sato (1989) showed that Perilla seed oil protects rats from induced
breast cancer. Narisawa et al. (1990) reported the inhibition of MNU (methyl nitrosourea)
induced cancer in the large intestine, and inhibition of induced colon cancer was
reported by Park et al. (1993).
Inhibition of TNF-a over production
Tumour necrosis factor-a (TNF-a), a protein secreted by macrophages shows a
strong necrotic activity on tumour cells. However, the over production of TNF-a
causes damage to tissues, aggravating inflammation. Ueda and Yamakasi (1993)
found that Perilla leaf extract from var. acuta, reduces the TNF in mice treated with
TNF-triggering agents. The reduction is about 86%. This reduction in TNF and
subsequent reduction of inflammation could be behind the use of Perilla in asthma,
allergy, bronchitis, etc. The extract is now used in various products such as foods,
cosmetics and other items. Perillaldehyde face cream applied to the skin has been
shown to be beneficial in the treatment of contact dermatitis.
Influence of Perilla seed oil in lipid metabolism
The seed oil of Perilla has attracted considerable attention in recent years as an ideal
health food, because it is rich in unsaturated fatty acids, in particular linolenic acid,