Alismatis rhizome is the rhizome of the perennial marsh plant Alisma orientale (Sam.) Juzepcz., of the Alismataceae family. It is grown in ditches, damp ground and shallow pond margins in water up to 15 cm deep. Native to Europe, it is naturalized in the Middle East, Egypt and China. In China, alismatis is mainly produced in the provinces Fujian, Sichuan, Jiangxi, etc.
The plant grows to about 1 m tall. It is in flower from June to August, and the seeds ripen from July to September. The flowers are hermaphrodite (have both male and female organs) and are pollinated by flies. The plant cannot grow in the shade. It requires wet soil and can grow in water. This plant is also called Water Plantain, Common Water Plantain, or European Water Plantain. It is sweet and bland in flavor, cold in nature, and related to the kidney and urinary bladder channels. Alismatis rhizome also have functions to induces diuresis, removes dampness and purges heat.
Alismatis rhizome contains triterpenoids, alisol A, B, C and its acetate, epialisol A, alismol, alismoxide, lecithin, choline, furfural, volatile oil, alkaloids, asparagine, resin and potassium, calcium, magnesium, etc. The leaf contains vitamin C, manganese, calcium, etc. and the fruit contains starch.
For self protection, the outer skin (bark) of many plants contains essential oil, which in turn has elements that serve as an immediate chemical defense against herbivores and pathogens. How? There is an element called hydroxynitrile glucoside in essential oil. This element will release toxic hydrogen cyanide by endogenous plant glucosidase upon tissue disruption. Glucosidase is a catalyzing enzyme that improves healthy functions of our body. It is a lipase that decomposes fat; it can also check inflammation and improve memory.
Alismatis rhizome has an obvious diuretic effect, being able to increase the excretion of urine, urea and chlorides. Its diuretic action on nephritis patients, with acute or chronic inflammation of the kidney, is more notable. It also has hypotensive, blood-sugar-reducing and lipotrophic effects. Alismatis rhizome can inhibit Staphylococcus aureus, Diplococcus pneumoniae and Mycobacterium tuberculosis.
The leaves are antibacterial, anticholesterolemic, diaphoretic, diuretic, hypoglycaemic and hypotensive. They are used in the treatment of cystitis (inflammation of the urinary bladder), dysentery, renal calculus, gravel etc. The fresh leaf is rubefacient. It is used in the treatment of leprosy and is also applied locally to bruises and swellings. Dried stem bases eaten, or grated and taken with water in treating digestive disorders such as heartburn, cramps and stomach flu. The powdered seed is an astringent, used in cases of bleeding. The seed is also said to promote sterility. The root is antibacterial, anticholesterolemic, diuretic and hypotensive. It is said to lower blood pressure, cholesterol and blood sugar levels whilst it also has an antibacterial action on Staphococci, Pneumococci and Mycobacteria. The root is used in the treatment of oliguria, oedema, nephritis, acute diarrhoea, cholesterolemia and fatty liver. It has been thought of as a cure for rabies, though this has not been substantiated.
The whole plant is believed to promote conception.