Anti-inflammatory evaluation of methanol extract and aqueous fraction of the leaves of Anthocleista djalonensis A. Chev (Gentianaceae).
L Okunrobo, C Usifoh, P Ching, M Bariweni
anthocleista djalonensis, anti-inflammatory activity, carragenaan-induced oedema, dextran-induced oedema, leaf extracts
L Okunrobo, C Usifoh, P Ching, M Bariweni. Anti-inflammatory evaluation of methanol extract and aqueous fraction of the leaves of Anthocleista djalonensis A. Chev (Gentianaceae).. The Internet Journal of Pharmacology. 2008 Volume 7 Number 1.
The effects of the methanol extract (crude) and aqueous fraction of
The use of plants to treat ailments is as old as antiquity. Records of humans using plants to treat diseases have been recorded as far back as 6000 to 4000 years ago when Ayurvedic physicians started treating tumors with extracts from
Traditionally, the leaves are reputed to be used for the treatment of malaria and jaundice . The bark is used as a purgative in small doses as large doses are considered toxic. According to the Mendi ethnomedicine, when the tree is used as firewood, the people sitting around the fire become sick .
The decoction of the leaves is drunk in Sierra Leone as treatment for jaundice, in Ivory Coast the root is used as a diuretic, vigorous purgative, poison antidote, treatment for leprosy, as an emmenagogue and in the treatment of edemas and elephantiasis of the scrotum. The root decoction is taken against chest pain, constipation and stomach pain . The study was therefore aimed at investigating the anti-inflammatory activity of the leaf extracts with a view to justifying the use of the plant in the treatment of oedemas and elephantiasis of the scrotum.
Materials and Methods
Plant collection and identification
The fresh leaves of
Extraction and fractionation of plant
The fine powder (600 g) was marcerated in 2.5 litres methanol for 48 hours, filtered, concentrated in a rotary evaporator, weighed (84 g) and stored. Forty grams of the concentrate was dissolved in methanol and successively and exhaustively partitioned into various fractions using n-hexane, chloroform and water. The various fractions were evaporated to dryness, weighed and stored in the fridge.
Qualitative assay, for the presence of plant secondary metabolites such as carbohydrate, alkaloids, glycosides, flavonoids, tannins and saponins were carried out on the powdered leaves following standard procedure .
Drugs and chemicals
Indomethacin (BDH chemical), n-hexane (sigma-Aldrich), chloroform (Sigma-Aldrich), methanol (Sigma-Aldrich), ethylacetate (BDH-chemicals), and normal saline (Unique pharmaceuticals).
Albino rats (170 – 200 g) of both sexes were kept at the laboratory animal house of the Department of Pharmacology and Toxicology, University of Benin, Benin City. Nigeria. The animals were maintained under standard environmental conditions and were allowed free access to feed (Bendel Feeds and Floor mill, Ewu, Edo State, Nigeria) and water
Determination of Anti-inflammatory Activity
The albino rats were divided into groups of 5 each. Acute inflammation was induced by intra-plantar administration of 0.1ml 1% freshly prepared Lambda-carrageenan or dextran solution into the right hind paw of each rat .The rats were treated with either normal saline, crude extract (250 mg/kg or 500 mg /kg P.O) or aqueous fraction (250 mg/kg or 500 mg/kg P.O) 1 hour before administration of phlogistic agents. Paw volume of rats were measured prior to administration of phlogistic agents and then at predetermined intervals. For carrageenan the interval was 1 hour for 6 hours while dextran was 30 minutes for 4 hours, change in paw volume was measured using Vernier calipers and anti-inflammatory activity calculated.
Results were expressed as mean ± standard error of mean. Statistical analysis of the data was done using one-way analysis of variance (ANOVA) followed by Dunnett’s test and significance determined using P-values < 0.05.
Inflammation is the response of living tissues to injury. It involves a complex array of enzyme activation, mediator release fluid extravasation, cell migration, tissue breakdown and repair . It is also known that anti-inflammatory effects can be elicited by a variety of chemical agents and that there is little correlation between their pharmacological activity and chemical structure .This associated with the complexity of the inflammatory process makes the use of different experimental models essential when conducting pharmacological trials.
The present study establishes the anti-inflammatory activity of the methanol extract (crude) of
Dextran induced edema is a well known experimental model in which the edema is a consequence of liberation of histamine and serotonin from mast cells . At 500 mg/kg the methanol extract significantly inhibited dextran induced rat paw edema (P<0.01) after 60 minutes (table 3). The aqueous fraction also inhibited dextran induced edema significantly (P< 0.05) both at 250 mg/kg and 500 mg/kg after 60 minutes (table 4).
The methanol extract showed a dose dependent activity but was less than that produced by Indomethacin (table 2), the aqueous fraction showed an improved activity as compared to the methanol extract with a maximal effect at 500 mg/kg which was greater than the effect produced by Indomethacin after 60 minutes (table 4).
Preliminary phytochemical screening shows that the extract contains alkaloids, glycosides, saponins and tannins, it has been reported to contain phthalides, xanthones, glucosides and steroids .
It can be concluded that both the methanol extract and aqueous fractions of the methanol extract of
The aqueous fraction of the methanol extract showed better activity profile compared to the methanol extract hence it can be said to possess majority of the activity.
This study demonstrates the efficacy of
The authors are grateful to Dr. B.A Ayinde for his technical assistance and Mrs B.D Okunrobo for reading through the manuscript for it syntactic errors