Kava

解説コショウ科（APG分類：コショウ科）のつる性低木。太平洋諸島原産で、栽培もされる。カバはトンガ語で「苦い」の意味で、島によりアバ、カワカワ、シャカオなどともよばれる。高さ2.5～3メートル、葉は心臓形。根は塊状で苦味があり、メシスチシン、カワインのほか、麻酔作用のあるカバ樹脂を含む。根から同名の飲料カバをつくる。宴会や儀式などの際、根の粉末と水を大きな木鉢に入れ、樹皮の繊維の束でかき回して抽出し、ヤシの実の殻のコップに取り分けて食前に飲む。その調整と飲用は厳粛に儀式化されている。泡立っていてすこし苦味があり、ややビールに似た風味がある。アルコール分はないが、飲めば酩酊(めいてい)し、眠気を催す。飲みすぎると中毒症状をおこす。小学館 日本大百科全書(ニッポニカ) ）

説明Kava or Piper methysticum is a shrub of the pepper family, native to Micronesia, Melanesia, and Polynesia. There are approximately 150 different cultivars with different content and composition of active ingredients, consequently resulting in different intoxicating effects after ingestion. On average, the kava lactones account for 3–20% of dry weight of the kava root and have relatively low solubility in water. The active components of kava are mostly contained in the lipid-soluble resin where the lactones account for approximately 96%. lactones varies according to the plant parts and the kava species used for extraction. The aerial parts of the shrub contain a relatively higher amount of alkaloids and are generally avoided in traditional preparations. Traditionally, extractions are made with cold water or coconut milk from macerated dry or fresh root. Due to the low water solubility of the lactones, commercial kava products such as herbal supplements are made from organic solvents (i.e., acetone and ethanol). During the 1990s, kava became very popular in Western countries resulting in increased import and demand. Following this popularity boom, a number of suspected kava-induced hepatotoxic events were reported. Kava preparations were banned in a number of European countries and the US Food and Drug Administration (FDA) issued warnings.

使用Aqueous extracts from the root of kava has been used for centuries in the South Pacific. The extract is used as a ceremonial and intoxicating drink, but has also been used as a medicine for various illnesses, including migraines and bladder disorders. The pharmacologically active compounds are the kava lactones, which allegedly possess analgesic, anticonvulsive, spasmolytic, and antimycotic effects. In Western countries, organic kava extracts have gained popularity in the twentieth century as herbal supplements for treating anxiety and insomnia.