Changes

*''Ludwigia adscendens'' (L.) H. Hara, *''L. hyssopifolia'' (G. Don) Exell, *''L. octovalvis'' (Jacq.) P.H. Raven.

The aerial parts of ''Ludwigia'' are mucilaginous and considered antiseptic and emollient. They are widely used in Asia, including Indonesia and Malaysia, for poulticing headache, wounds, burns, boils, ulcers, impetigo, pimples and other skin complaints. In Indo-China, crushed young shoots of ''L. adscendens'' are mixed with castor oil ( ''Ricinus communis'' L.), and used to treat ringworm. Because of its antiseptic properties, ''Ludwigia'' is also used in ophthalmia, fever, sore throat, and bites of snakes and dogs. In Peninsular Malaysia, a cold infusion of the roots of ''L. hyssopifolia'' is also drunk for syphilis, while in China, a decoction of the aerial parts of ''L. adscendens'' is used. In decoction, ''Ludwigia'' is considered astringent and diuretic and commonly used in the region for diarrhoea and dysentery, as a carminative and as a laxative. In China and Indo-China, a decoction of the aerial parts of ''L. adscendens'' or ''L. octovalvis'' is prescribed for rheumatic pains. In Peninsular Malaysia, India and Nigeria, ''L. octovalvis'' is also used for nervous diseases and also as a vermifuge.

 In several broad screening experiments, crude extracts of ''L. octovalvis'' were active, including a more than 50% inhibition against cytotoxicity, induced by carbon tetrachloride and D-galactosamine in rodents, and antibacterial activity against the carcinogenic bacteria, ''Streptococcus mutans'' . For the latter, the extract showed significant growth-inhibiting activity of serotypes c and d at a concentration equal to or lower than 7.8 mg/ml. In the presence of 5% sucrose, the antibacterial activity did not change for type c, but decreased for type d. The extract also showed antibacterial activity against ''Streptococcus aureus'' ATCC 25933 and ''Yersinia enterocolitica'' 03, and some non-pathogenic bacteria. A crude methanol extract was screened for its effect in immunoglobulin A nephropathy, by testing its effect on human mesangial cell proliferation. The extract inhibited human cell proliferation activated by interleukin-1β(IL-1β) and IL-6 at 50μg50 μg/ml, and decreased IL-1βand 1β and tumour necrosis factor-α(TNF-α) production. The antidiarrhoeal potential of a methanol extract of the aerial parts was studied with several experimental models of diarrhoea in rats at doses of 100, 200 and 300 mg/kg. Rats treated with the extract showed significant inhibitory activity against castor oil induced diarrhoea and prostaglandin E2 (PGE2) induced enteropooling. It also significantly reduced gastro-intestinal motility following a charcoal meal. The same extract was also evaluated for its antipyretic potential on normal body temperature and yeast-induced pyrexia in albino rats. Following subcutaneous injection, a yeast suspension (10 ml/kg body weight) increased the rectal temperature after 19 hours. The extract, at doses of 100, 200 and 300 mg/kg, showed significant reduction in normal body temperature and yeast-provoked elevated temperature in a dose-dependent manner, and the effect extended up to 5 hours after drug administration. The anti-pyretic effect of the extract was comparable to that of paracetamol (150 mg/kg). In addition, the dried methanol extract was evaluated for its central nervous system activity in rats and mice. General behaviour, exploratory behaviour, muscle relaxant activity and phenobarbitone-induced sleeping time were evaluated, and the extract was found to cause a reduction in spontaneous activity, a decrease in exploratory behavioural pattern in the Y-maze and Head dip tests and a reduction in muscle relaxant activity in rotarod, 30°inclined 30° inclined screen and traction tests. The extract also significantly potentiated the phenobarbitone-induced sleeping time. These preliminary tests indicate that the extract in doses of 200-400 mg/kg, has significant psychopharmacological activity.

*Erect to creeping herbs, rooting at the nodes, or large shrubs; underwater parts often swollen and spongy, or with white spongy aerophores. *Leaves alternate or opposite, simple, entire; petiole present; stipules absent or reduced, deltoid. *Flowers mostly 4-merous, solitary, axillary, sometimes terminal and racemose; bracteoles absent or conspicuous, near base of ovary. Sepals 3-–77, persistent; petals as many as the sepals or absent, caducous, yellow or white, contorted at aestivation; stamens as many as the sepals or twice as many, and then epipetalous ones smaller, anthers usually versatile, sometimes basifixed, pollen shed in tetrads or singly; disk flat to conical, normally with depressed, hairy nectaries, surrounding the base of each epipetalous stamen; ovary inferior, 4-5-celled, ovules numerous, style simple, stigma hemispherical or capitate, often lobed, upper part receptive. *Fruit a capsule, irregularly dehiscent, or by a terminal pore, or by flaps separating from the apex; seeds numerous. *Seed rounded or elongate, raphe usually visible, sometimes as long as the seed; endosperm absent; embryo straight. *Seedling with epigeal germination.

The former genera ''Jussiaea'' (stamens twice the number of sepals) and ''Ludwigia'' (stamens as many as the sepals) have been merged into 1 genus, ''Ludwigia'' , because they show a reticulate pattern of relationships.

Several insects are currently being screened for their potential as biological control agents for weedy ''Ludwigia'' throughout the world. In Thailand and India, the chrysomelids ''Altica foveicollis'' and ''A. cyanea'' are promising for the control of ''L. adscendens'' , while in Bangladesh, ''A. foveicollis'' is active on ''L. octovalvis'' . In India, a fruit-infesting weevil ( ''Nanophyes nigritulus'' ) is also being screened. Several snails, which are vectors of serious diseases, feed on ''Ludwigia'' .

In Vietnam ''Ludwigia'' is harvested from June–June-September.

''Ludwigia'' is widespread and common as a weed throughout South-East Asia, and therefore certainly not endangered. There are no known breeding programmes for ''Ludwigia'' .

General pharmacological screening reveals a multitude of interesting pharmacological effects of the methanol extract of ''L. octovalvis'' . These merit further research, to evaluate their potential, and this should focus on the phytochemistry to define (bio-)markers related to the pharmacology shown. The toxicological aspects should be investigated thoroughly as well.

*Isa Ipor