In addition to the factory made Perilla products, several other methods for Perilla preparation are available in the folklore of China and Japan (). The application of home made Perilla extract is also used for the treatment of allergy. However, the removal from the extract of agricultural chemicals and perillaldehyde, which might be allergens to some individuals is important ().
Administration of Perilla Leaf Extract
Dr. Oyanagi et al. reported their experiences in treating allergy patients with Perilla products (). According to the different symptoms and the condition of the patients administration may be singly or combined ().
For the concentrated products of Perilla extract, the dose was 0.3-2 ml/50—100 ml water or other drink, 2-3 times daily dependent on the age. With home made or diluted extract, the dosage varied with the concentration and methods of preparation.
To relieve the symptoms of an itching or running nose, the Perilla extract was applied inside the nostrils using a cotton bud.
Topical application of Perilla extract
Application to the skin was helpful in relieving the itching and redness.
Topical use of Perilla cream and soap
For some atopic dermatitis, Perilla cream and soap were recommended ().
Following treatment with Perilla, some patients experienced effects just after use, others after some days to one week, or in some cases up to three months. A therapy period usually occupied three months. In some cases, at the beginning of the treatment, the symptoms seemed to be more serious than before. This reflects an action of Perilla. Usually after one week, the symptoms are less and thereafter the patient continues to improve. Only a small number of patients (about 2-3%) will experience worse symptom even after ten days. For these, the Perilla extract is discontinued ().
Evaluation of Usefulness of Perilla Leaf Extracts
Perilla leaf extract has been available as a “health product” rather than as a medicine. There are no published reports of controlled clinical trials. Even so, there are many reports of open (uncontrolled) studies from physicians and from patients-completed questionnaires, to support the beneficial use of Perilla leaf extract in the treatment of allergy. Rigorous double-blind placebo-controlled trials are doubtlessly needed before Perilla leaf extract can be accepted as an antiallergy medicine in the West.
Out-patients evaluated by physicians
Dr. Oyanagi reported his results of open studies in the treatment of more than one hundred allergy cases of children with atopic dermatitis. After three months of therapy using a Perilla extract cream formulation, 80% of the patients showed varying degrees of improvement in the degree of itching, skin lesion, and eruption (). No side effects were observed in any of the cases.
Dr. Takiguchi () reported from his open studies that 20 allergic patients, using Perilla cream topically and Perilla extract orally, after two months, showed an improvement in 90% of the patients. Among these, 30% of the patients got significant benefit, 25% of the patients got some benefit and the rest got little benefit. All these patients ceased other medicine while using the Perilla products. Dr. Takiguchi concluded that Perilla is effective for allergy treatment without side effects.
Self evaluation by patients
In the Japanese magazines “My Health” (No. 9,156—168, 1992; No. 8, 142-145, 1993; No. 3, 192—206, 1993; No. 2, 145-149, 1994), “Anshin” ( No. 7, 171 -191,1992; No. 7 139-155,1993; No, 7,258-267, 1994) several special issues about the evaluation, of the use of Perilla extract for allergy were published. Many allergic patients reported their satisfying results after using Perilla leaf extracts or its products such as Perilla cream, Perilla soap and Perilla drink. From these the following data is derived.
Seventy eight cases reported effective benefit after using Perilla extract. Two thirds of them were female and one third of them were male. They included various age groups, but nearly 50% were under the age of twenty. The allergy history of these cases, varied from months to thirty years. A strong familial tendency could be seen. Among these 78 cases, 36 cases were included in 14 families and heredity was implicated. Among the cases, about half suffered from pollinosis or allergic rhinitis, and half had atopic dermatitis. Only one case was an asthma sufferer (). Those were allergic to pollen had allergy in Spring and Summer, and some also in Autumn. With Perilla treatment all these patients got some relief from their allergy symptoms and their quality of life was significantly improved.
Few cases suffering from asthma benefited from using Perilla extract. This might be attributed to the fact that plasma TNF-α concentration in bronchial asthma cases was not increased or only slightly increased (). Whereas the action of Perilla extract was mainly due to its inhibition of TNF overproduction ().
Since 1990 Perilla extract has been widely recommended for the treatment of allergy and some details are given from case studies:
A lady aged 30 years, had allergic reaction since infancy. Every spring when the trees were budding or in late summer when some plants were in bloom, she would have allergic rhinitis, recurrent sneezing, watery nose and eye, itching nose and eye. At that time her medication was ineffective, and she was also concerned about the side effects of the medication. Her child, aged 6, also suffered from allergic rhinitis and atopic dermatitis. After using Perilla extract only a few times, her allergic symptoms were reduced significantly. Her child was also treated topically with Perilla extract for his eczema and obtained as good results as his mother. Since Perilla extract has no side effects, they took Perilla extract as a drink (5-6 drops in a cup of water) twice daily, in order to prevent their symptoms ().
Another lady, aged 42 years, and a beautician, could not work very well due to pollinosis. Her history of allergy was short but the symptoms were serious with recurrent sneezing, nasal itching, face and eye itching, and running nose requiring a full box of tissues every day. After using Perilla extract for one week the running nose stopped and her quality of life was markedly improved ().
A man, aged 62 years, suffered from allergic rhinitis, associated with change in the weather, such as rain or strong wind. After using Perilla extract for three months, his allergic symptoms were much reduced ().
In Finland, Perilla extract was launched on the market in 1993. Investigation of the usefulness of Perilla products for allergy was carried out by self-completed questionnaires. These included age, gender, allergy history, symptoms, specific allergen, time of allergy, medicines used before, dosage, and evaluation of the effectiveness. The latter was self-evaluated according to the reduction of symptoms and the quality of life. The investigation is continuing in some other European countries. In one group in Helsinki city forty cases had accepted questionnaires, among them female 50 %, male 50 %. Investigation showed all the cases were allergic to pollens, about half of the cases were also allergic to some foods or animal pets. All the cases had allergy in spring time and about 40% of the cases, had the trouble all year round. Of the allergy cases investigated, 30% reported Perilla products were highly effective, 35% reported effective, 20% less effective and 15% ineffective.
One example: A young man was allergic to dogs and cats experiencing eye itching and running nose. He took Perilla capsules, 2 or 3 capsules daily, for two weeks before his friend arrived with his dog to spend holiday with him and he had no allergic reaction during their stay ().
Selections from the book: “Perilla: The Genus Perilla”. Edited by He-Ci Yu, Kenichi Kosuna, and Megumi Haga. Series “Medicinal and aromatic plants – industrial profiles”. 1997.