ALOE ARBORESCENS GENERAL DESCRIPTION

Transcription

ALOE ARBORESCENS GENERAL DESCRIPTION
ALOE ARBORESCENS
GENERAL DESCRIPTION
Scientific name
with author
Aloe arborescens Mill.
Plant photo – live
plant
Synonyms
A. arborescens Mill. var. frutescens (Salm Dyck) Link
Family
Asphodelaceae
Vernacular/
traditional/
regional names
Kransaalwyn (Afrikaans); krantz aloe (English); ikalene (Xhosa); inhlaba encane, inkalane encane,
unhlabana (Zulu)
Botanical
description
Aloe arborescens is a succulent leaved, perennial shrub of up to 2m high. Branched stems bear rosettes
of narrow down-curved leaves that have soft marginal teeth. Flowers are bright red to orange and occur
in conical, unbranched clusters.
Reference
Reynolds, G.W. (1950). The Aloes of South Africa. The Trustees of the Aloes of South Africa Book Fund,
Johannesburg.
Geographical
distribution
A. arborescens is distributed mainly over the eastern, summer rainfall areas of the country, occurring
from the Cape Peninsula along the eastern coast, through KwaZulu-Natal, Mpumalanga and Limpopo
province and further north into Mozambique, Zimbabwe and Malawi.
References
Reynolds, G.W. (1950). The Aloes of South Africa. The Trustees of the Aloes of South Africa Book Fund,
Johannesburg.
South African National Biodiversity Institute. (2004). Aloe arborescens Mill.
http://www.plantzafrica.com/plantab/aloearbor.htm
Distribution map
ETHNOBOTANICAL INFORMATION
Medicinal uses
Leaf sap is mainly used to treat burns, wounds and a variety of skin ailments such as eczema, bruises
and abrasions.
The Zulu people use the leaves of this plant, dried and pounded into a powder, as a protection against
storms. Decoctions of the leaves are also used in childbirth and in treating sick calves. In the Transkei
cold water leaf infusions are used for stomach ache and given to chickens to prevent them from getting
sick. Leaves have purgative properties.
References
Grace, O.M., Simmonds, M.S.J., Smith, G.F. and van Wyk, A.E. (2008). Therapeutic uses of Aloe L.
(Asphodelaceae) in southern Africa. Journal of Ethnopharmacology, 119(3): 604-614.
South African National Biodiversity Institute. (2004). Aloe arborescens Mill.
http://www.plantzafrica.com/plantab/aloearbor.htm
Van Wyk, B.-E. and Gericke, N. (2007). People’s plants: a guide to useful plants of southern Africa. Briza,
Pretoria.
Watt, J.M. and Breyer-Brandwijk, M.G. (1962). The medicinal and poisonous plants of southern and
eastern Africa. 2nd ed. Livingstone, London.
QUALITY STANDARDS
Macroscopial
A multiheaded shrub up to 2m high with striking grey green leaves arranged in attractive rosettes. The
leaf margins are armed with conspicuous pale teeth. The large colourful flower spikes are borne in
profusion during the cold winter months (May-July). Deep orange is the most common colour. The
inflorescence is usually unbranched, with two to several arising from a single rosette.
Reference
South African National Biodiversity Institute. (2004). Aloe arborescens Mill.
http://www.plantzafrica.com/plantab/aloearbor.htm
Microscopial
CHEMICAL CONSTITUENTS
Chemical
constituents –
compounds diagrams
Chemical
constituents –
compounds description
A.arborescens gel contains glycoproteins and lectins, such as aloctin A and aloctin B. Compounds isolated
from the leaves contain aloenin, aloein, Mg lactate and aloe emodin. Also present are β-polysaccharides,
the well known anthraquinone and chromones such as aloesin, aloesone and aloe resins A and C. Aloin
content increases with age and is highest in summer, lowest in winter. Anthraquinone content is highest
before blooming and lowest at full bloom.
Reference
Reynolds, T. and Dweck, A.C. (1999). Aloe vera leaf gel: a review update. Journal of Ethnopharmacology,
68 (1-3): 3-37.
Chemical
constituents –
organoleptic
properties
Chemical
constituents –
TLC / HPLC / GC
Chemical
constituents –
NIR Spectroscopy
image
Large, colourful, bright red or deep orange flower spikes are borne in profusion during the winter months.
Striking grey green leaves are arranged in attractive rosettes. The leaf margins are armed with
conspicuous soft, pale teeth.
Chemical
constituents –
NIR
Purity tests /
Requirements
TLC, HPLC and GC are used.
A national standard for South African aloe raw materials provides methods to determine the quality of
aloe gel.
Assay
Not yet available.
Plant part used
Fresh leaves and fresh leaf juice are used. Processed leaf juice and gel are also used.
Plant part used
photograph
Dosage forms
Traditionally decoctions of the leaves and cold water leaf infusions are used.
Pharmacology/
bioactivity
Leaf extracts have shown significant wound healing, anti-bacterial, anti-ulcer, anti-inflammatory, anticarcinogenic, hypoglycaemic and also alopoeic activity. Wound healing effects are mainly ascribed to the
anti-inflammatory activity of glycoproteins and Aloesin in fresh or processed leaf gel. Aloesin also inhibits
melanin formation in the skin, resulting in skin-lightening effects.
Immunomodulatory properties have been ascribed to leaf gel polysaccharides, especially the acetylated
mannans.
The purgative properties of Aloesin are well known.
References
Jia, Y., Zhao, G. and Jia, J. (2008). Preliminary evaluation: The effects of Aloe ferox Miller and Aloe
arborescens Miller on wound healing. Journal of Ethnopharmacology, 120(2): 181-189.
Viljoen, A.M. (2000). A chemotaxonomic study of phenolic leaf compounds in the genus Aloe. Ph.D.
thesis, University of Johannesburg, South Africa.
Contraindications
Adverse
reactions
Arabinose is a potential toxin. Snuff made from Aloes has been associated with a high rate of cancer of
the nasal sinuses. Laxative preparations containing Aloe species may cause nephritis, diarrhoea and
gastritis and should be avoided by pregnant women. Cases of abortion have been reported following
medicinal usage.
Reference
Watt, J.M. and Breyer-Brandwijk, M.G. (1962). The medicinal and poisonous plants of southern and
eastern Africa. 2nd ed. Livingstone, London.
Precautions
Laxative preparations containing Aloe species should be avoided by pregnant women.
Dosage and
preparation
Leaf decoctions are used in childbirth. Cold water leaf infusions are used for stomach ailments. Fresh leaf
juice or gel is applied topically or used as tonic drinks. Leaf juice or gel powder is obtained by freezedrying or spray-drying the leaves. Pounded leaf infusions are used as sprinkling charms against storms.
Reference
Watt, J.M. and Breyer-Brandwijk, M.G. (1962). The medicinal and poisonous plants of southern and
eastern Africa. 2nd ed. Livingstone, London.
Source References
Hutchings, A., Scott, A.H., Lewis, G. and Cunningham, A.B. (1996). Zulu Medicinal Plants: an inventory. Natal University Press,
Pietermaritzburg.
Van Wyk, B.-E., van Oudtshoorn, B. and Gericke, N. (2009). Medicinal plants of South Africa. 2nd ed. Briza, Pretoria.