Article Type : Research Article
Authors : Shargi AH, Magbool FF, Ibrahim ME, Aboied M4, Alsdig M and Ahmed ASA
Keywords : Kigelia africana; Antidiarrheal; Metronidazole; Anticancer; Antimicrobial; Phytochemical screening
Kigelia Africana is a locally growing tree
used in alternative medicine. Studies have shown that the tree is used in blood
and circulatory system disorders, and has a wide activity ranging from
anticancer, antimicrobial, anti-malarial, anti-inflammatory and antidiarrheal.
The present study was carried out to detect the presence of some phytochemical
groups and metronidazole in the fruit. The Phytochemical screening of the fruit
revealed the presence of tannins, steroids, terpenoids and alkaloids. The HPLC analysis
of the alkaloid extract of the fruit showed the presence of metronidazole by
comparison with a standard reference. The antidiarrheal property associated
with the plant could be due to the presence of metronidazole. The presence of
metronidazole in the fruit of Kigelia Africana has not been reported before in
literature and /or iridoids which have been reported to be present in the
fruit. This plant has great potential to be developed as drug by pharmaceutical
industries but before recommending its use in modern system of medicine,
clinical trials are to be done.
The term medicinal plants include various types of
plants used in herbalism (herbology or herbal medicine).The word herb has been
derived from the Latin word “herba” and old French word “herbe”. Nowadays, herb
refers to any part of the plant like fruit, seed, stem, bark, flower, leaf,
stigma or root, as well as non-woody plant. Earlier, the term “herb” was only
applied to non-woody plant, including those that come from trees and shrubs.
Medicinal plants are used as medicine, food, flavour, or perfume and also in
certain spiritual activities. Treatment with medicinal plants is considered
very safe as there is no or minimal side effects [1]. The golden fact is that,
use of herbal treatment is independent of any age groups and the sexes. In
Sudan, we have broad selection of medicinal plants with great potential of
medicinal substances to the good of mankind [2]. Plant-based antimicrobials
have enormous therapeutic potential as they can serve the purpose with lesser
side effects that are often associated with synthetic antibacterial [3].
Natural products, either as pure compounds or as standardized plant extract,
provide unlimited opportunities for new drug leads because of the unmatched
availability of chemical diversity. The increasing failure of chemotherapeutics
and antibiotic resistance exhibited by pathogenic microbial infectious agents
has led to the screening of several medicinal plants. Kigelia Africana is an
important medicinal plant [4]. The many uses of K. Africana in therapy of
physical and magi co-religious or spiritual complaints indicate that this tree
is a valuable and popular source of traditional medicine. K. Africana is used
in treatment of primary and secondary infections, and as a disinfectant the
unripe fruit is used as vermifuge and as treatment for hemorrhoids and
rheumatism. It can be used orally as enema in treating children stomach
ailments usually worms and for dressing wounds. The present work is aimed at
studying the Phytochemical and antimicrobial properties of Kigelia Africana.
Materials
Plant material
The plant material (fresh K. Africana fruits) was
brought from Medani (Jazera state).
Chemicals and solvents
Ethanol, Methanol, Acetone, Glacial acetic acid,
Potassium iodide, Bismuths nitrate, Acetic acid, Toluene, Distilled water,
Chloroform, Ethyl acetate, Petroleum ether and Ammonia.
Reagents
Dragendoroff`s reagent, Mayer`s reagent, Fehling`s
reagent, Wagner`s reagent and Ferric chloride.
Equipment’s
Glassware, Capillary tubes, Conical flask, Funnels,
Graduated measuring cylinder, Separator funnel, Beakers, Mortar and pestle,
Rack and holder, Peppite and Petri dish.
Apparatus and
instruments
Oven –Baird and Tat lock, Water bath, Melting point
apparatus, HPLC instrument, IR –Shimadzu.
Preparation of plant
material
The plant material of Kigelia Africana was cleaned,
freed from dust and foreign material, and then dried under shade and finally
powdered using an electrical house-hold spice grinder.
Phytochemical screening
of Kigelia Africana fruit
In order to study chemical composition of kigelia
Africana fruit four extractions were prepared namely, chloroform, ethanol,
methanol, and acetone [5-17].
The powdered plant material (30g) was weighed into a beaker. It was moistened with concentrated ammonia solution and allowed to stand for 20 minutes. 150 ml of chloroform were added; the mixture was stirred for 10 minutes and filtered through a plug of cotton wool. The meal was washed twice with 15 ml chloroform and the washings were added to the filtrate. The combined filtrate was evaporated to dryness on a water bath. The residue was cooled and dissolved in 20 ml chloroform. The chloroform extract was transferred to a separating funnel and shaken with 75 ml of 5% sulphuric acid. The two layers were allowed to separate. The chloroform (lower) layer was drained off and discarded. 10 ml of chloroform was further added, shaken, drained off and discarded until the acid layer was colourless the acid layer was made alkaline with concentrated ammonia solution and extracted with 20 ml of chloroform. The extract was retained and evaporated to dryness. The residue was dissolved in 10 ml of ethanol and the following tests were carried out (Evans, 1989). To 1 ml of the methanol extract in separate test tubes, 2-3 drops of the following reagents were added
Frothing test
The powdered material (0.5 g) was shaken with 5 ml of
water in the test tube for 30 seconds. A persisted froth suggests the presence
of the saponin (Brain and turner, 1975).
Salkowski` test
The powdered drug (0.5g) was extracted with 5 ml of
chloroform and filtered into a clean and dry test tube. 2ml of concentrated
sulphuric acid were carefully added down the side of test tube to form a lower
layer .a reddish brown colour at the interface indicates the presence of
steroidal ring (Sofowora, 1993).
Ferric chloride test
The powdered fruit (2.0 g) was extracted with 10 ml of
water and filtered. To 2 ml of the filtrate in a test tube two drops of ferric
chloride solution were added. A green or greenish black precipitate indicates
the precipitate shows the presence of hydrolysable tannins (Evans, 1989).
Extraction of
metronidazole
20 tablets of Metronidazole of 500mg were grounded by
mortar and pestle and added acetone and set in water bath. Then filtered and
left to evaporate, pale yellow crystals were formed.
Metronidazole
identification from extraction
Melting point test was done on a melting point
apparatus and infra-red spectroscopy was done on a Shimadzu IR instrument.
Strengths and
limitations
The limited references, and few local studies that
have been done on the Kigelia Africana, the present study will provide
significant information on the strains of this plant growing in Sudan.
Dissemination of results
This study results will be disseminated through
presentation to Nile College staff and students and publication via biomedical
journals. Results and discussion.
The Phytochemical screening of the fruits gave the results shown in below (Table 1).
Table 1: Phytochemical screening of Kigelia africana fruit.
Test |
Result |
color |
Alkaloids(Wagner`s reagent ) |
+ve |
Brown |
Alkaloids
(Mayer reagent) |
+ve |
Yellow |
Alkaloids (Dragendoroff’s reagent) |
+ve |
Orange |
Anthraquinone |
-ve |
- |
Saponin |
-ve |
- |
Tannins |
+ve |
Greenish black |
Key: +ve- present, -ve-not present |
The identity of Metronidazole extracted from tablets (Figure 2) was confirmed by the melting point (159-163o C) and its infra-red spectrum as shown in Figures 3 and 4 and retention time of the sample and standard on HPLC chromatograms (Figures 1-4).
Figure 1: HLPC Chromatogram of Metronidazole sample A and standard B.
Figure 2: Metronidazole extracted from Nilozol tablets.
Figure 3: IR-spectrum of metronidazole STD.
Figure 4: IR-spectrum of metronidazole STD.
HPLC
of metronidazole compared to sample of kigelia africana: Metro std 400ppm.
This study revealed the presence of steroids, anthraquinone,
terpenoids and alkaloids. These results are in agreement with those reported.
HPLC of the alkaloid extract of the plant showed the presence of Metronidazole
which is significant in the treatment of diarrhea. The presence of
Metronidazole in Kigelia pinnata (synonym of K. Africana) has been reported in
literature. The antidiarrheal property associated with Kigelia Africana could
be due to presence of Metronidazole.
The Kigelia Africana fruits were found to contain
alkaloids, steroids, tannins, terpenoids and anthraquinone. The alkaloid
extract was found to contain Metronidazole. The presence of Metronidazole in
Kigelia Africana fruit has not been reported before in literature.