The “Daido Ruijuho” series to be translated into modern Japanese, and pages showing a prescription by Otomo no Yakamochi (Yuka Nishimoto)

YOKOHAMA--Academics here are busy translating Japan's oldest medical records dating from the Heian Period (794-1185) into modern Japanese with plans to complete the mammoth project next autumn.

A series of documents known as the “Daido Ruijuho” collection were commissioned by Emperor Kanmu (737-806) to provide a record of hundreds of traditional medicines in common use in those days.

Among the remedies is one developed by renowned poet Otomo no Yakamochi (c. 717-785) of "Manyoshu" (Collection of Ten Thousand Leaves) fame.

The researchers said the aim of the translation project was to make centuries-old medical prescriptions available to the modern world.

The original “Daido Ruijuho” has been lost to history, but copies of the series exist, although some are believed to be forgeries.

However, one highly regarded work known as “Ryobon” was adopted for translation under the project initiated by the Yokohama University of Pharmacy’s Japanese and Chinese medicine research center.

Researchers noted that Sato Hojo, a doctor active in the waning years of the Edo Period (1603-1867), held the work in high regard.

In 1985, traditional medicine researcher Sachiko Maki released a translation based on another copy that provided detailed compositions of herbs used in olden times.

According to the researchers, “Ryobon” covers the combination rates and other details of all 808 known agents from “Daido Ruijuho.” It will mark the first time the tome has been made available in modern Japanese.

“Even natural drugs using the same ingredients could have different effects and outcomes if their rates are different,” said Noriyasu Hada, a professor of pharmacognosy at the Tokyo University of Science. “Combination rates are extremely important, so translating ‘Ryobon’ into modern language has grave significance.”

“Daido Ruijuho” was commissioned after a Japanese mission to Tang Dynasty China returned home laden with hugely expensive herbs for medical use.

Emperor Kanmu decided that Japan needed cheaper medications if they were to be made widely available.

The series, which mainly features Japanese ingredients, is thought to have been completed after the emperor’s death about 1,200 years ago.

Among other prescriptions, Yakamochi cited six ingredients to alleviate fever and settle the stomach. He wrote that the mix should contain 20 percent of dodder, a plant in the morning glory family, for use as a tonic and 50 percent of orchid to produce bodily fluid. Preparations involved crushing and mixing the ingredients in a pot and storing them underground for more than 100 days.

After Japanese yam extract is added, the finished substance should be “dried on a board and ground into powder for use as medicine,” according to the document.

Yukio Nemoto, 72, head of the research center, said “Daido Ruijuho” states that Yakamochi’s prescription can be used to treat depression and fevers characterized by a hacking cough and bloody phlegm.

As the whereabouts of six of the 100 known volumes of “Ryobon” remain unknown, Nemoto called on temple and shrine operators, as well as old-established families, to contact the center, if they have any information on the lost installments.