This document summarizes information about aloes, including its biological source from various aloe species, cultivation practices, microscopic and chemical characteristics. Aloes are indigenous to parts of Africa and cultivated elsewhere. Upon collection, the leaves are cut at the base to exude the latex. Microscopically, aloe leaves contain mucilaginous parenchyma and aloetic cells that house aloe gel. Chemically, aloes contain anthraquinone glycosides like aloins. Tests can distinguish between varieties. Aloes are used as a strong purgative and in cosmetics as a protective gel.

1. Aloes

2.  Synonym:
Aloe, Hindi-musabbar , kumari . Marathi-korphad.
 Biological Source:
Aloe is the dried latex of leaves of various species of Aloes,
namely:
Aloe barbadensis Miller (or Curacao Aloe);
Aloe ferox Miller (or Cape Aloe);
Aloe perryi Baker (or Socotrine Aloe);
Aloe africana Miller and Aloe spicata Baker (or Cape Aloe).
Family: Liliaceae.
Geographical Source:
Aloe is indigenous to eastern and south Africa and grown in Cape
colony, Zanzibar and island of Socotra. It is also cultivated in
Caribbean islands, Europe and many parts of India , including
North West Himalaya region.

3. Cultivation and Collection:
Its propagation occurs through root suckers.
Young offsets are planted in rows about 50 cm apart just after the
rainy season.
Plant grow in dry climate.
It is grown in all kind of soils but well drained soil with high organic
matter is most suitable.
Roots do not penetrate much in soil.
Manure is provided.
First cutting of the leaves is done in the second year.
The plant yields aloes continuously for about twelve years.
During collection cut is given at base of leaves so juice located in
parenchymatous cells of pericycle exudes out.

4.  Preparations of Aloes:

5.  Macroscopic Characteristics of various aloes:

6. Microscopic characteristics:
Leaves grow in a rosette shape.
Outermost cuticle followed by epidermis, palisade tissue,
mucilaginous
parenchyma mesophyll.
Mesophyll contains vascular bundle covered with pericycle
fibers layer.
Inside pericycle ,aloetic cells are located which contains aloe
gel( viscous yellow).
Calcium oxalate crystals present in parenchyma. leaves are
sessile.

7. Microscopic characters of aloe powder:
It is useful for identification of powdered aloes. It is studied in lacto
phenol because in this reagent the particles are gradually
solubilized so that crystals are clearly and quickly observed.
1.Curacaoaloes:
Fragments consist of large number of very small needle or slender
prisms
2.Cape aloes :
Transparent, brown, angular or irregular fragments.
3.Socotrinealoes:
Fragments consist of large prisms in group or dispersed form.
4.Zanzibar aloes:
Irregular lumps in with modular masses are embedded.

8. Chemical Constituents :
Category: Anthraquinone glycosides.
The most important constituents of Aloes are the Aloins.
Aloin contains not less than 70% anhydrous barbaloin.
Barbaloin is C-glyscoside.
Other constituents: isobarbaloin , β-barbaloin , aloe-emodin , resins ,aloetic
acid, homonataloin , aloesone , saponins, mucopolysccharides , glucosamines,
hexuronicacid , aloe resin contains aloesin (purgative action)

9. Chemical Tests :
The chemical test for aloes are performed either for general detection or
detection of specific variety of aloe.
a) General Test: Prepare a 0.1%(w/v) aqueous solution of aloes by gentle heating,
add to it 0.5g of kiesulgur and preserve the filtrate for following tests:
1. Bromine test:-filtrate+ freshly prepared bromine solution= pale yellow ppt. of
tetrabromalin.
2.Schoentetentest:-filtrate +borax shake well until borax dissolves. Few drop of this
solution added in test tube filled with water = green fluorescence appears.
3.Modified Borntrager’s Test:-
0.1 gm drug + 2ml dil HCl + 2 ml ferric chloride( 5%w/v)
Boil on water bath for 10 min, cool , filter
Filtrate then extracted with CCl4
add equal volume of ammonia solution
Pink or red colour forms due to anthraquinone

10. Special Test:
These test are to distinguish between varieties of aloe.
1. Nitrous acid test:
Aqueous solution of aloe + sodium nitrate crystals + acetic acid
Curacao aloes-sharp pink to carmine colour
Cape aloes-faint pink colour
Socotrine and Zanzibar aloes-very less change in colour.
2.Nitric acid test:
Nitric acid applied to drug or its aqueous solution
Curacao aloes-deep brownish red colour
Cape aloe-brownish colour changes to green
Socotrine aloes-pale brownish to yellow colour
Zanzibar aloes-yellowish brown colour
3. Kupraloin test( kluge's isobarbaloin test):
Dil. aqueous solution of aloe+ drop of copper sulphate + sodium chloride + excess
90%alcohol
 Curacao aloes-wine red colour persist for 4hours
 Cape aloes-faint colour rapidly changes to yellow
 Socotrine aloes-no colour
 Zanzibar aloes-no colour

11. Use:
Strong purgative.
To counter effect the gripping action it is given with
carminatives.
It is ingredient of compound tincture of benzoin (friar's
balsam).
Aloe gel is used for topical application and in many cosmetics
as a protective.
 In the treatment of sunburn,
itching, irritation
 In creams, lotions, moisturizers.
 Shampoos, hair conditioners.

12. Aloe Gel:It is obtained from inner parenchyma cells of leaf.
Slightly viscous and clear liquid. It should not be contaminated
with aloe juice.
Adulterants and substitutes :
Natal aloes-It contains natalion , homonatalion , resin, it is
weak purgative.
Mocha aloes-brittle, black and glossy with strong odour
Aloe can be adulterated with blackcatechu.

13. Preparations

14. Thank You