Phytochemistry Many different Alkaloids are found in the whole plant of Datura, which increased gradually with increase in age of the plant (Afsharypuor et al., 1995). Main constituents of the Datura plant are a huge number of tropane alkaloids (hyoscyamine, hyoscine, littorine, acetoxytropine, valtropine, fastusine, fastusinine), a number of withanolides and various trigloyl esters of tropine and pseudotropine. Calystegines, the nortropane alkaloids with glycosidase inhibitory activity, have also been found in various Datura species (Ghani, 2003). The root contains higher amount of atropine compared to the other parts. The aerial parts usually accumulated relatively higher amounts of scopolamine and relatively lower amounts of atropine as compared to the root of the plant (Afsharypuor et al., 1995).
Pharmacological action D. metel contains tropane alkaloids and are used as sedative, anti-spasmodic and mydriatic agents (Nuhu, 2002). The whole plant, but especially the leaves and seed, have anaesthetic, hallucinogenic, anti-asthmatic, anti-spasmodic, anti-tussive, narcotic, bronchodilator, anodyne, hypnotic and mydriatic effects. Leaves are used as a local application for rheumatic swellings of the joints, Lumbago, Sciatica, Neuralgia, painful Tumors, Scabies, Eczema, Allergy and glandular Inflammations, such as Mumps; used externally for earache and smoked to relieve spasmodic Asthma. Seeds are also used externally for piles (Yusuf et al., 2009). Seeds, leaves and roots are used in insanity, fever with catarrh, diarrhea, skin diseases and cerebral complications.
Arthritis Treatment Gout is a disease that results from an overload of uric acid in the body, leads to the formation of tiny crystals of monosodium urate monohydrate that deposit in tissues of the body, especially the joints (Virsaladze et al., 2007), also called gouty arthritis. The xanthine oxidase inhibitory activity was assayed for D. metel which is traditionally used for the treatment of gout (Umamaheswari, 2007). More than 50% xanthine oxidase inhibitory activity (in vitro) was seen in the methanolic extracts of D. metel which was comparable with the standard antigout drug, allopurinol which showed 93.21% inhibition at 100 µg/mL concentration with an IC50 value of 6.75µg/mL. The methanolic extract was also screened for in vivo hypouricaemic activity against potassium oxonate-induced hyperuricaemia in mice and the extract was found effective (Umamaheswari, 2007). Hyoscyamine and scopolamine are the two commercially important anesthetic, antispasmodiac and anticholinergic drugs, also the two most important alkaloids produced in roots and then translocated to the aerial parts of Datura plants.