Anthraquinone glycosides are used as laxatives and purgatives. They are absorbed in the small intestine and excreted in the large intestine where they increase motility and produce laxation. Aglycons can cause griping so an antispasmodic is often prescribed. Five common sources are: Aloe, whose active ingredient is barbaloin; Cascara containing cascarosides; Rhubarb with rhein anthrone; Senna with sennosides; and Cochineal, a dye made from dried female insects containing carminic acid.

1. Anthraquinone Glycosides Most of agents are used as laxatives and purgatives. Cochineal is a dye. Mechanism: The glycosides are absorbed from the small intestine and re-excreted in the large intestine where they increase the motility so produce laxation. Aglycons produce griping effect so it is recommended to prescribe antispasmodic with them.

2. Chemistry: Chemically these are related to anthracene.

3. a) Aloe Botanical origin: Aloe barbadensis Aloe ferox Aloe perryi Aloe vera Family: Asphodelaceae Part used: Dried juice of leaves

4. Collection: Leaves are cut from 9-12 years old plant and placed in v-shaped trough which in turn is placed on incline so that juice can be collected in receiver. It is allowed to evaporate, finally thickened juice is placed in metal box for drying. Chemistry: Barbaloin is active ingredient. Upon hydrolysis, it yields; Aloe emodin Uses: Laxatives and purgatives Emollient Ingredient of benzoin tincture

5. b) Cascara Botanical Origin: Cascara sagrada Rhamnus purshiana Family: Rhamnaceae Part used: Dried bark Collection: Bark is collected from April to August when it can be readily separated from wood. It is dried in shade.

6. Chemistry: Cascarosides Cascarosides A and B (related to Barbaloin) Cascarosides C and D (related to chrysaloin)

8. c) Rhubarb Botanical Origin: Rheum officinale Rheum emodi Family: Polygonaceae Part used: Dried rhizome and root Collection: Rhizome and roots are collected from 6-10 years old plant in spring or autumn. These are dried either in sunlight or by artificial heat.

9. Chemistry: Active constituent is Rhein anthrone .

10. d) Senna Botanical Origin: Cassia angustifolia Cassia acutifolia Family: Febaceae Part used: Dried leaflets

11. Chemistry: It contains; Sennoside A and B Sennoside C and D

12. e) Cochineal Zoological Origin: Dactylopius coccus Family: Dactylopidus Part used: Dried female insects containing eggs and larvae Collection: Insects are collected and killed by steam or hot water. These are dried in oven.

13. Chemistry: Active constituent is Carminic acid . In addition it also contains; 10% wax 2% wax Uses: As a dye in; Fabrics Cosmetics Food Paints Colouring agent for pills etc.