Jamun has a rich history of use in India and it is known to have been cultivated in ngland by the herbalist Miller during the 1700s. Almost all the parts of the tree are used in olk medicine. The plant is associated with the Lord Krishna and the elephant-headed Ganesh in Hindu mythology and it is sacred to Buddhists also. The ripe fruits are eaten throughout India and a wine is made from the fruits in Goa.
It is indigenous to India and Indonesia, but is naturalised in Thailand, the Philippines and Madagascar and cultivated widely throughout Africa, the Caribbean and tropical America. It grows commonly along streams and in damp places and in evergreen forests. The tree is planted as an ornamental in gardens and at roadsides.
A moderate-sized evergreen tree with a dense canopy attaining a height of up to 50 m (Plate 59). The bark is brown to greyish, smooth and exfoliating in hard woody scales. The leaves are lanceolate, oblong or broadly ovate and elliptic, smooth, shiny and coriaceous with visible glands dotted over the surface and an aromatic scent. The flowers are greenish white and the fruits black and plum?like, with a juicy pink pulp, containing a single oblong seed.
Bark, fruit, seed and leaves.
Almost all the parts of the tree are used in folk medicine. The fruits are used as an astringent and to treat diarrhoea and are eaten to relieve the symptoms of diabetes. The bark and seeds are also popular antidiabetic agents in many parts of India. Extracts of the bark are given as an astringent for chronic diarrhoea in adults and in children are mixed with goats' milk. The bark is also used for mouth freshening and to treat disorders of the gums and teeth.
The bark is used to staunch bleeding in ruminants.
Betulinic acid, friedelin, friedelanol, ?-Sitosterol, daucosterol and a ?-Sitosterol glucoside have been found in the bark.
Quercetin has been isolated from the pulp and kaempferol, myricetin, quercetin and astragalin from the bark.
Lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, malvalic acid, sterculic acid and vernolic acid in the seeds.
Gallic, ellagic, caffeic and ferulic acids and derivatives, guaicol, resorcinol dimethyl ether and corilaginin are found in the seeds and gallic acid in the bark.
?-Pinene, y-terpinene, terpinolene, borbeneol, ?-phellanderene, a-terpineol and eugenol are present in the seeds.
Glucose, galactose, mannose and fructose are the principal sugars in the ripe fruit pulp and 3,6,hexahydroxy diphenoyl glucose, 4,6,hexahydroxy-diphenoyl glucose, 1?galloyl glucose, 3-galloyl-glucose and 6-galloyl-glucose occur in the seeds.
Calcium, iron, potassium, vitamin A, thiamin, riboflavin, nicotinic acid and ascorbic acid are present in the fruit pulp.
Hypoglycaemic activity: A number of scientific studies in animals have substantiated the role ofjambul in the management of diabetes. Antihyperglycaemic effects of the aqueous and alcoholic extracts and the lyophilised seed powder were evaluated in diabetic animals. Although all produced a reduction in blood glucose levels, the lyophilised powder was the most potent. In combination with Momordia charantia (qv), the effect of different doses of aqueous and alcoholic extracts was studied on metabolic parameters including body weight, serum glucose, insulin and triglyceride levels. Fructose feeding for 15 days increased serum glucose and insulin levels markedly, and triglyceride levels marginally, but treatment with 400 mg per day of the aqueous extracts prevented hyperglycaemia and hyperinsulinaemia.'The seeds have also been found to be active in rats at doses of 170-510 mg/animal/dayfor 15 days.1O In rabbits, a hot water extract equivalent to 50 g of dried fruit pulp, when administered by gastric intubation, was active in reducing blood glucose levels.
In human volunteers, the ethanol (95%) and hot water extracts of dried seeds at variable doses levels were found to have potent hypoglycaemic activity when given both orally and intravenously. The seeds themselves, at a dose of 4-24 g/person, were found to have a hypoglycaemic effect in a trial of 28 diabetic patients. A decoction of the aerial parts, also in human adults, was reported to have hypoglycaemic effects; however, this was associated with oliguria and pain, which resolved within one week.
Diuretic activity: The leaf extract when administered by gastric intubation at a concentration of 2.5% was found to have a diuretic effect in experimental rats. Animals were divided into two categories and the first category was given water while the second category was given 2.5% extract. The results showed urinary excretion of 59% for controls and 68 % for the extract group. No changes in sodium and potassium levels were found.
Antiinflammatory activity: The antiinflammatory activity of orally administered hexane, dichloromethane, ethylacetate and methanol extracts was investigated in rats. All inhibited both the acute and chronic phases of experimental inflammation in a dose-dependent manner. The ethyl acetate and methanol extracts were the most active and were comparable to phenylbutazone; however, in a chronic model, the methanolic extract was found to be more potent. The chloroform extract of the seeds, when administered intraperitoneally to rats at a dose of 100 mg/kg, was found to have potent effects in reducing carageenan-induced paw oedema.'s In a separate study, the hydro alcoholic extract of the aerial parts, given at a dose of 0.375 mg/kg orally, had no effect.
Antidiarrhoeal activity: The ethanol extract was evaluated for activity against different experimental models of diarrhoea in rats. It produced significant inhibition of castor oil? induced diarrhoea and PGE2-induced entero-pooling and a significant reduction in gastrointestinal motility in charcoal meal tests.
Antiplaque activity: Aqueous, methanolic and methanol-water (1:1) extracts of the bark were able to suppress plaque formation in vitro. All were active against Streptococcus mutans at 260,120 and 380 /lg per ml respectively.
The use of the leaves, fruit, seeds and bark is prevalent throughout the Indian subcontinent and no harmful effects have been reported.