Steroidal alkaloids

lec. ( 5 )
1- steroidal alkaloids :

the steroidal alkaloids are derived biosynthetically from six isoprene units and could be classified as triterpenoids or steroids however they also contain nitrogen which giving them basic properties. steroidal alkaloids have been found in the plant families (apocynaceae, buxaceae , liliaceae , and solanaceae)
the important drugs of this group are ( veratrum viride and veratrum album ) .
veratrum viride :
veratrum viride, american or green hellebore, consists of the dried rhizome and roots of veratrum viride aiton ( fam. liliaceae ) . veratrum viride contains a large number of alkaloids classified in three groups :
1- consisting of esters of the steroidal bases ( alkamines ) with organic acids, includes ( cevadine, germidine, germitrine, neogermitrine, neoprotoveratrine, protoveratrine, and veratridine.
2- includes pseudojervine and veratrosine, which are glucosides of the alkamines.
3- the ester alkaloids, germidine,and germitrine,are probably the most important therapeutically.
veratrum viride possesses hypotensive, cardiac-depressant, and sedative properties. it has been used in the treatment of hypertention.
the drug has its most uniform effects in small doses.
veratrum album ( white hellebore ) : contains a complex mixture of ester alkaloids, glycoalkaloids, and alkamines similar, two ester alkaloids, protoveratrine a and protoveratrine b, are the most active.
white hellebore possesses hypotensive properties, but the crude drug is not used therapeutically . both white and green hellebores are also employed as insecticides.

2- lupinane alkaloids : ( quinolizidine alkaloid )

includes plant-origin alkaloids causing nervous dysfunction (e.g. sparteine, lupinine, lupanine, hydroxylupanine, spathulatine, thermopsine), and those causing congenital defects (e.g. anagyrine).

quinolizidine and isoquinoline alkaloids are a widely distributed, heterogeneous group of alkaloids with members of each group having known toxicity to humans and domestic animals.
plants containing quinolizidine alkaloids with known toxicity include the following:
• baptisia species (false indigo)
• cytisus species (scotch broom)
• laburnum species (goldenchain, laburnum)
• professor lupinus species (lupine, bluebonnet)
• sophora species (mescal bean, frijolito)
cytisine, a tricyclic quinolizidine alkaloid found in baptisia, cytisus, laburnum, and sophora species, has nicotinelike effects on the gastrointestinal (gi) tract and the central nervous system (cns).
these plants may be smoked recreationally for their stimulant effects and mild hallucinogenic properties. mescal bean may have been used by native american peoples for ceremonial and medicinal purposes. sophora root is used in traditional chinese medicine where it is known as "ku shen" and is used to treat dysentery, scabies, itchy rashes including eczema, skin lesions, jaundice, edema, urinary dysfunction, and vaginal discharge.
lupinus species contain sparteine, a tetracyclic quinolizidine alkaloid, and lupinine, a bicyclic quinolizidine alkaloid. lupinus species are broadly divided into bitter lupins that contain high levels of alkaloids in their seeds, and sweet lupins that contain lower levels of alkaloids and are cultivated for human consumption. sweet lupins do contain sparteine and lupinine and must be soaked in water to prevent toxicity following ingestion. these two alkaloids are also found in other genera.
the toxic isoquinoline alkaloids include papaverine, sanguinarine, dihydrosanguinarine, protoverine, berberine, coptisine, protopine, and chelidonine.
they act as gi tract irritants, cns stimulants, and have varying degrees of neurologic effects, ranging from relaxation and euphoria to seizures. they are also vasodilatory. prickly poppy is smoked as a euphoriant.
papaverine, found in prickly poppy and bloodroot, has been used medically as a smooth muscle relaxant. prickly poppy extracts act as capillary dilators and have been implicated in epidemic glaucoma in india.
sanguinaria species (bloodroot) extract was food and drug administration (fda) approved and used commercially as a dental plaque inhibitor however, it is no longer added to commercially available toothpaste and mouthwash due to concerns that chronic use may cause oral leukoplakia.
sanguinaria extract may still be purchased over the internet, where it is marketed as a mouthwash for dental decay, as an escharotic for skin lesions including cancer, and as a tea for a variety of indications. it is not fda approved for these uses.
celandine extracts are used in the herbal treatment of gastrointestinal disorders, including dyspepsia, gallstone disease, and irritable bowel syndrome.
celandine extracts have been shown to increase the flow of bile acids and decrease right upper quadrant pain due to biliary dyskinesia.
celandine extract also has stimulatory effects on smooth muscle contraction in the stomach and spasmolytic effects in the small intestine, which may explain its beneficial effects in dyspepsia and irritable bowel syndrome.
argemone oil poisoning is relatively common in india, where it is known as epidemic dropingsy and is a result of argemone oil being added as an adulterant to mustard oil. in 1998, an epidemic of argemone oil poisoning in new delhi led to 3000 victims and 60 deaths. argemone oil poisoning has also been reported after transcutaneous absorption from adulteration of mustard oil used in massages.

dr. saad ali ihsan
professor of medicinal & aromatic plants

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