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Ethnobotanical Leaflets
13: 77-82. 2009. Pharmacognostical Study of Dioscorea oppositifolia L. *R. Felix, N. Nirmal Kumar and T.
Leon Stephan Raj P. G. and Research Department of Plant Biology and
Biotechnology, St. Xavier’s College (Autonomous), Palayamkottai-
627 002. Tamilnadu, India. *felicon@rediffmail.com Issued 04 January 2009 ABSTRACT Extraction of bioactive
compounds from medicinal plants permits demonstration of their physiological activity.
It also facilitates pharmacology studies leading to discovery of synthesis of
more potent drugs. The plant selected in the present study is Dioscorea
oppositifolia L. (Dioscoreaceae) which is used traditionally for
antiseptics, ulcers and abscesses. The root is chewed to cure toothache and
aphthae. The whole plant extract is used for secondary syphilis and Psorasis.
The present investigation was intended to evaluate the preliminary
phytochemical characters and fluorescence analysis of this species. Keywords: Dioscorea
oppositifolia, Preliminary Phytochemical Screening, Fluorescence
analysis. INTRODUCTION Nature
has provided a complete storehouse of remedies to cure ailments of mankind.
The knowledge of drugs has accumulated over thousands of years as a result of
man's inquisitive nature so that we possess many effective means of ensuring
health-care. Today, a vast store of knowledge concerning therapeutic
properties of different plants has been accumulated. All classes of plants viz. Thallophyta, Bryophyta,
Pteridophyta and Spermatophyta contain species that yield primary and
secondary products of medicinal importance. Herbal medicine has been
practiced worldwide and is now recognized by WHO as an essential building
block for primary healthcare (Onayade et al., 1990). Different people
in different areas named their systems of medicine according to their
experience, wisdom and knowledge. In In the nineteenth
century, the term "Materia Medica" was used for the subject now
called as "Pharmacognosy". It was Seydler, a German who coined the
term "Pharmacognosy" in 1815 used in the title of his work
"Analecta Pharmacognostica". Pharmacognosy is derived from two
Greek words viz. pharmakon
means a drug and Gignosco means to acquire the knowledge. The leaves,
flowers, tender shoots and tubers of Dioscorea oppositifolia L.
are used for cooling and demulcent; they are used in the form of decoction
for leprosy and cancerous lesions. The leaves are antiseptic; the paste is
applied on ulcers and abscesses. The root is chewed to cure toothache and
aphthae. The whole plant is used in application for oedematous tumours and
the ash extract of flowering twigs along with tender leaves cure cancer and
leprosy. The whole plant extract is used for secondary syphilis and Psorasis.
Pharamacognosy study deals with the drug plants, their history, selection,
collection, identification and preservation. Anatomical characters of
powdered drugs proved to be of great significance especially at a period when
adulteration of both in drugs and food articles is common. Quality control of
a crude drug and its pharmaceuticals can be attempted by different methods of
evaluation depending upon the morphological and microscopical studies of the
crude drugs and their physical, chemical and biological behaviour. The
systematic identification of crude drugs and their quality assurance form an
integral part of drug-description. MATERIALS Dioscorea
oppositifolia L. (Dioscoreaceae) was collected from Karaiyar hills
in Tirunelveli district. Taxonomic features collected from the species have
been checked with the Flora of Presidency of Madras (Gamble, 1915-1921) and
the Flora of TamilNadu Carnatic (Matthew, 1983-88). Later it was confirmed
with the voucher specimens of Arinathan (2006), Nirmal Kumar
(2008). MACROSCOPIC
STUDIES The
observation was made using a student dissection microscope and the
morphological and taxonomical characters were described in technical terms PHYTOCHEMICAL STUDIES The collected plants
were dried and powdered. About 10gms of the powdered sample of the species
was separately extracted with benzene, methanol, chloroform, petroleum ether and
distilled water. These extracts were concentrated and used for preliminary
phytochemical screening following the methods of Brindha et al., (1990). RESULTS Taxonomic Studies Morphological
characters were studied in Dioscorea oppositifolia and their
variations were presented. It is a
small climber. Stem woody, clothed with minute gland tipped hairs.
Branchlets viscid. Leaves sub-opposite, 4 cm; leaflets 7-9 pairs, opposite,
oblong-elliptic, 1 - 15 x 0.4- 0.6 cm, pubescent, base and apex obtuse,
margin entire, petiole 1.5 cm; stipules setaceous, 4 mm; stipples minute.
Inflorescence racemes or panicles, axillary to 7 cm; peduncle to 7 cm; bracts
linear, 4 mm; pedicel 1mm. Flowers 4mm, across, base narrow, claw O; wings
oblong 3.5 mm; keels obovate, 4.5 mm; spur to 0.5 mm. Staminal sheath 3 mm,
ovary 3 mm, hispid, style l mm. Pod spreading, straight, 2.5 cm, hirsute,
torulose. Seeds 10 - 12, cuboids, pitted, rotted and round tubers. It is
usually distributed in hilly regions. Flowering
period is November to February. Preliminary Phytochemical Analysis Preliminary phytochemical
screening of the Dioscorea oppositifolia L. plant powder was done as per standard methods
and results are presented in the Table 1. Petroleum ether extract shows the
presence of steroids, triterpene, sugar, tannin and amino acid. Methanol
extracts shows the presence of sugar, alkaloid, phenolic group, flavone,
catachin, tannin and amino acid. Benzene and chloroform extracts show the
presence of steroid, sugar and steroid, triterpene, sugar respectively. In
distilled water extract shows the presence of steroid, triterpene, sugar and
tannin. In all the extract saponin is absent. The medicinal properties
exhibited by this species are due to the presence of alkaloids, triterpenes
and flavones. Fluorescence Analysis Dioscorea oppositifolia L leaf
powder treated with 1 N aqueous NaOH, 50% HNO3 and 1 N HCL for the
fluorescent analysis using UV and visible light. Leaf powder treated with 1 Solvent extracts of the leaf
powder have also been analyzed in the fluorescent chamber. The petroleum
ether extract of leaf powder is dark yellow in visible and yellowish green in
UV light. The benzene extract of the leaf powder is brown and greenish brown
in visible and UV light. The chloroform extract of Dioscorea oppositifolia L is dark brown in visible and brown in UV light. The methanol
extract shows yellow and pale green in visible and UV light. The water
extract of the
leaf powder shows brown
in visible and green in UV light. The result of fluorescence analysis is
shown in the Table 2. QUANTITATIVE DETERMINATION Ash
Analysis The
percentage of loss of weight on drying, total ash, acid insoluble ash, water
soluble ash and sulphate ash are obtained by employing standard method of
analysis and described in Table 3 and 4. The loss of weight on drying is
40.2% and it is found to be maximum. The total ash content is 7.7%, the acid
insoluble ash content is 1.9 and it is found to be minimum. The water
insoluble ash content is (23.2%). The sulphate ash content is 24 %. This
method is used to check the adulterants present in the species. CONCLUSION The
comparative and multidisciplinary approach to the study of Dioscorea
oppositifolia L does
help in understanding their identification taxonomical determination, and medicinal
importance in depth. The adulterants in drugs obtain from Dioscorea
oppositifolia L can be identified by this investigation. Adulterants
if any can be easily identified using these parameters. REFERENCES Arinathan
S.
(2006). Pharmacology in yam plants. Indian Jourmal of forestry (52) (2). Brindha P., Saraswathy A., Sasikala A. and
Purushothaman KK. (1990) Anatomical
and Phytochemical methods in the identification of an Indian drugs pendant
pattai Plectranthus urticifolius, Journal of Research and Education in
Indian Medicine (4) : pp 11-16. Gamble JS. (1921). Fabaceae In:
Flora of the Presidency of Madras. Publ. Adlard & Son. Ltd. London, pp
301 – 305. Johansen. (1940).
Plant microtechnique stains McGRAW- HILL publications. pp. 40 - 50. Matthew
KM. (1984). Fabaceae the flora of the Tamilnadu Karnatic Vol (I-IV):
pp479-489. Nirmal
kumar N.
(2008) Genetic variability in Dioscorea
species. Indian Journal of current science. 35 (2). 15-18. Onayade OA, Scheffer JJC and Svendsen AB, The importance of phytotherapy and screening of
plants used medicinally in Africa, Planta Med, 1990, 56, 503-504. Table 1. Phytochemical analysis of various extracts
of Dioscorea oppositifolia. L.
(+ present, - absent) Table 2. Fluorescence characters of leaf powder and their extract in different
solvents of Dioscorea
oppositifolia. L
Table 3. Physiochemical characteristics of leaf in Dioscorea oppositifolia. L.
Table 4.
Ash for mineral constituents.
(+ present, - absent) |
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