Volume 2, No.5, July to September' 2013 - amam-ayurveda.org

BRIEF REVIEW ON ASHWAGANDHA (Withania somnifera L. Dunal)
With special reference to its quality, efficacy and safety
Satyajyoti Kanjilal, Arun Gupta, Sanjay Sharma and JLN Sastry
Dabur Research & Development Center,
Sahibabad, Ghaziabad, U.P.
1. INTRODUCTION ON ASHWAGANDHA - PLANT
DESCRIPTION, DISTRIBUTION & CULTIVATION 1
2. QUALITY SPECIFICATIONS OF
ASHWAGANDHA
Withania somnifera commonly known as Ashwagandha, is a dicotyledonous
plant belonging to the family Solanaceae. The plant of Ashwagandha
is usually erect, branched, unarmed, shrubby, upto 1.25 m in height,
minutely stellate tomentose especially on the stem, leaf veins and the
calyx. Leaves are simple, petiolate and upto 10 cm long. Flowers shortly
pedicullate, 4-6 mm in diameter. Berry globose, enclosed in the green
persistent calyx, 5 mm in diameter, green when unripe, orange-red when
mature, containing numerous small, smooth, discoid seeds. The roots of
the commercial varieties of Ashwagandha cultivated in Madhya Pradesh
are soft textured, tuberous starchy, unbranched or slightly branching in
lower half with slightly fusiform crown, very light, pale brown colour and
smooth thin pale brown Bark. 1
It is a shrubby bush which grows in dry arid soils of subtropical regions.
In India, the plant grows well throughout the drier parts and in the sub
tropical and semi temperate regions, including the states of Maharashtra,
Madhya Pradesh, Gujarat, Rajasthan, Uttar Pradesh, Haryana and Punjab
extending to Himachal Pradesh and Jammu and Kashmir from plains to
the height of 1700 meters. Plant seldom occurs in the north eastern part
covering Orissa, Bengal, Sikkim and Assam. 1
The estimated annual production of Ashwagandha roots in India is
about few thousand tonnes. The plant is cultivated mainly in the northwestern
region of Madhya Pradesh and adjoining villages of Kota district
of Rajasthan. Ashwagandha is planted late in the rainy season around
August-September and harvested in the next May. The semi-tropical areas
receiving 500-700 mm rainfall are suitable for cultivation of this rainfed
crop. It requires dry season during its growing period; 1-2 late winter
rains are conducive for the proper development of roots. It grows well
in sandy loam or light red soil, having pH 7.5-8.0, with good drainage.
Seed germination normally takes 6-7 days after sowing. The plant starts
flowering and bearing fruits from February-March onwards. The crop
is ready to harvest in April-May i.e. 240-250 days after sowing. The
maturity of crop is judged by drying out of leaves and red berries. The
entire plant is uprooted for roots which are separated from the aerial part
by cutting the stem 1-2 cm above the crown. The roots are then either cut
transversely into small pieces (7-10 cm) or dried as a whole in the sun.
Berries are hand plucked separately, dried, beaten and seeds are taken
out. 1 Ashwagandha has been reported to be infected by fungi, viruses,
phytoplasmas, nematodes and pests. Roots collected in winter, washed
and cut into short pieces. 2
Quality specification of Ashwagandha has been published in various
Pharmacopeias, two of them are referred below -
i. Ayurvedic Pharmacopoeia of India 3
According to Ayurvedic Pharmacopoeia of India the following different
parameters are measured for the standardization of Ashwagandha like
Foreign matter (Not more than 2 per cent), Total Ash (Not more than 7 per
cent), Acid-insoluble ash (Not more than 1 per cent), Alcohol (25 per cent)
soluble extractive (Not less than 15 per cent) etc
ii. Indian Pharmacopoeia 4
According to the Indian Pharmacopoeia of India 2007, Ashwagandha
contains not less than 0.02 per cent of total withanolide A and withaferin
A, calculated on the dried basis.
Description: Buff to grayish – yellow roots. Taste, slightly mucilaginous,
bitter and acrid.
Identification:
a. Macroscopic – Primary roots are slight, conical or finger like in
shape, variable in thickness with the age. Secondary roots are thin
and fibrous. Surface buff to grayish – yellow with longitudinal
wrinkles.
b. Microscopic – Vessels with bordered pits and horizontal perforations.
Fibres aseptate with pointed ends. Wood elements lignified. Starch
grains abundant, simple, mostly spherical, reniform – oval with
central hilum. Microcrystal in parenchyma cells.
c. Thin Layer Chromatography –
Mobile phase: A mixture of 9 volumes of chloroform and 1 volume
of methanol.
Test solution: Reflux 3 g of coarsely powdered substance under
examination with 50 ml methanol for 15 minutes, cool and filter.
Reference Solution: Reflux 0.6 g of coarsely powdered ashwagandha RS
with 10 ml methanol for 15 minutes, cool and filter. Apply to the plate 10
µl of each solution as bands 10 mm by 2 mm. Allow the mobile phase to
rise 8 cm above the line of application. Dry the plate in air, spray with
solution of anisaldehyde reagent. Heat at 100 o for 5-10 minutes and
examine the plate in day light. The chromatographic profile of the test
solution is similar to that of the reference solution.
info Ayurveda, Volume 2, No.5, July - Sept’ 2013
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