Antiinflammatory activity of a Ghanaian antiarthritic herbal preparation: I

Journul of Ethnophurmucology. 33 ( 199 I ) 263-267 Elsevier Scientific Publishers Ireland Ltd.

Antiinflammatory

263

activity of a Ghanaian herbal preparation: I

antiarthritic

G. Kweifio-Okai Department of Anatomy and Physiology, Phi/lip Institute of Technology, Bundoora, Victoria-3083 (Australia) (Accepted

January

25, 1991)

A boiling water extract from a powdered sample containing Alsfonia boonei root bark (90%) Rauvolfia vomitoria root bark (5%) and Elaeis guineensis nut without pericarp (5%) was tested intraperitoneally for its antiinflammatory activity by measuring rat hindpaw edema induced by the subplantar injection of carrageenin in the presence or absence of arachidonic acid. Arachidonic acid increased swelling during the early phase of carrageenin edema. The extract suppressed the late phase of carrageenin edema and both phases in the presence of arachidonic acid. These preliminary results are consistent with a herbal preparation known to be used in the management

of rheumatoid

Key words: arthritis;

arthritis.

antiinflammatory;

carrageenin:

Alsfonia boonei: Elaeis guineensis; Rauvolfia vomitoria.

Introduction

model. This combination of plants, of which A. boonei traditionalty constitutes 9&95% of the powdered material, is used for the management of rheumatoid arthritis in Ghana (personal communications: G.D. Koranteng, C.B. Nartey and G.K. Noamesi; government registered herbalists in Ghana). A. boonei is used for its antipyretic, antiinflammatory, antiparasitic, antimalarial and analgesic effects (Burkill, 1985). R. vomitoria has a distinctive sedative effect that is used traditionally to calm psychiatric patients or to make them more amenable to other treatments (Sofowora, 1982). The alkaloid reserpine, among the other alkaloids present in R. vomitoria, is now used as an antihypertensive agent in modern medicine, but the traditional herbalists of West Africa do not use the plant in this way (Sofowora, 1982). The boiled roots are used to treat swellings (Harley, 1941). The nut of E. guineensis is included primarily to reduce the toxicity of R. vomitoria roots which show a toxic potential (personal communication, G.L. Boye). Despite the modern pharmacologist’s inclination to test isolated chemical constituents for their pharmacological actions, it was believed that following such an approach might defeat the philosophy of a traditional Ghanaian herbal cure

The carrageenins (kappa, lambda and iota) are algal extracts of sulphated polysaccharides used to induce tissue edema in experimental animals. The edema induced in the rat hindpaw by subplantar injection of carrageenin (CR) is biphasic over 4 or more hours (Vinegar et al., 1969). The early phase involves the release of serotonin and histamine while the late phase is mediated by prostaglandins and the continuity between the two phases is provided by kinins, e.g. bradykinin (Vinegar et al., 1969; Holsapple et al., 1980; Flower et al., 1985). Since Winter et al. (1963) used the carrageenin model to develop indomethacin as an antiinflammatory drug, the procedure has enjoyed wide acceptability as a method for screening prospective antiinflammatory agents (Flower et al., 1985). In the present work, a crude extract prepared from three Ghanaian plants, Alstonia boonei (root bark), Rauvolfia vomitoria (root bark) and Elaeis guineensis (nut without pericarp), was tested for its antiinflammatory activity using the carrageenin Correspondence to: G. Kweifio-Okai, Department and Physiology, Phillip Institute of Technology, Victoria-3083, Australia.

0378-8741/$03.50 0 1991 Elsevier Published and Printed in Ireland

Scientific

of Anatomy Bundoora.

Publishers

Ireland

Ltd.

264

(personal communication, C.B. Nartey: government registered herbalist in Ghana). The present work aims to validate a native herbal preparation claimed to be useful in arthritic management. Materials and Methods Plants The local and botanical names of plant sources and the composition of the powdered drug mixture are given in Table 1. Extract preparation Ten grams of powdered drug mixture in 100 ml of warm water was boiled for 15 min, allowed to settle at room temperature, filtered and 83 ml of filtrate was diluted with 83 ml of water. Hence the drug extract represented 6% of starting material per volume of extract, prepared fresh just before testing. Limited and incomplete chemical analysis of the crude extract (unpublished observations) revealed the presence of palmitate, lupeol and amyrin acetate, amyrin palmitate and as yet unidentified alkaloids. Two indolic alkaloids, echitamine (a diuretic with a curare-like effect) and echitamidine (a hypotensive) have been reported in A. boonei (Goodson, 1932; Kucera et al., 1972; Burkill, 1985). In addition, A. boonei contains a lactone and triterpenes, amyrin and lupeol as well as steroids, sitosterol and sapogenin (Faparusi and Bassir, 1972; Faparusi et al., 1980). Animal stock Outbred male Wistar

TABLE

rats, 200-2.50

g (Monash

University Animal Centre, Clayton, Australia) were used. Animals were kept in groups of 6 at room temperature on a 12: 12 h light/dark cycle with free access to food (Clark King GR II Pellets, Packenham, Australia) and water prior to the experiments. Edema induction All phlogistons were obtained from the Sigma Chemical Company (St. Louis, MO): carrageenin (lambda type from Gigurtinu aciculaire and Gigartina pistilfata) and arachidonic acid (5,8,11,14eicosatetraenoic acid, sodium salt). Carrageenin, 1000 pg in 100 ~1 of 0.9’%1saline, was injected subplantarly in the midline, midmetatarsal region of the rat right hindfoot pad with or without arachidonic acid (CR = 500 pg + AA = 50 pg). Twenty minutes prior to the sterile injection of the phlogistic challenge, 1 ml of drug extract/kg was injected intraperitoneally (saline for controls). The pH of the drug extract was 5.20 f 0.05 and, therefore, the saline injected in controls was adjusted to a pH of 5.2. Despite the pH of the drug extract, there was no evidence of physical counterirritation at or around the sites of the intraperitoneal injections over the duration of the experiment nor did Faparusi et al. (1980) report any irritation after the intraperitoneal injection of an aqueous extract of A. boonei. Dorso-ventral measurements of rat hindfoot pads (hereinafter referred to as paw diameter) were measured before and after injection over 4 h using a sliding vernier caliper. Data were expressed as percent from preinjection paw diameter and were statistically analysed using unpaired Students t-test.

1

COMPOSITION

OF POWDERED

DRUG

MIXTURE”

Plant name

Family

Local name

Part used

Composition (‘%Iw/w)

Alstonia boonei de Wild Rauvolfia vomitoria Afz.

Apocynaceae Apocynaceae Palmae

Root bark Root bark Nuts without

90

Eiaeis guineensis

Onyame-dua Kakapenpen Bedwoa

Jacq.

“All plant materials

authenticated

by G.D.

Koranteng.

Government-registered

botanist

and herbalist

5

pericarp in Koforidua.

5 Ghana.

265 TABLE

2

EFFECT

OF EXTRACT

Carrageenin dose

ON CARRAGEENIN-INDUCED

N

Means

(pg) (a) CR (1000) (b) CR (500) (c) CR (1000)

17 24 17

+ extract (b - a) (c - a) Statistically

significant

f

S.E.M.

RAT HINDPAW

increase

in paw diameter

(‘%I)

+o.s

+I

+2

+3

+4 h

35.4 f 2.4 31.2 f 2.9 35.6 f 1.6

37.3 f 2.6 32.6 zt 3.2 34.5 f 1.9

42.5 f 2.0 40.0 f 4.3 33.3 zt 3.2

48.0 f 4.1 46.9 zt 4.0 37.3 f 4.3

44.0 l 3.1 48.5 zt 4.4 30.0 f 5.1

-4.2 +0.2

-4.6 -2.8

-2.6 -9.2*

- 1.1 -10.8

- 4.5 -14.0*

for the comparison

*P < 0.05. **P < 0.02; N = population

specified:

Results The profile of rat paw edema induced by 1000 pg of carrageenin (CR) is shown in Table 2. A rapid increase in paw diameter within 30 min of CR injection was sustained for a further 30 min. Thereafter, paw diameter slowly increased from +1 to +3 h and then sustained for a further hour. Therefore in these experiments the first hour represents the early phase whereas the period from +2 to +4 h represents the late phase of CR edema. The effect of the drug extract on CR edema is also shown in Table 2. The extract has no signiticant effect on the early phase of CR edema but significantly reduced the late phase at +2 and +4 h although the reduction at +3 h was not quite significant. In order to clarify the mechanism by which the

TABLE

EDEMA

drug extract reduced CR edema, it was decided to investigate the effect of CR edema induced in the presence of arachidonic acid (AA). The choice of AA is based on the knowledge that it potentiates swelling in the early phase of CR edema (Matsuda et al., 1987) and is associated with the rapid release (within minutes) of lipoxygenase products in mouse ear edema when applied topically (Arner et al., 1985; Chang et al., 1985). The use of this additional phlogiston necessitated the reduction of the amount of CR injected from 1000 pg to 500 pg. As shown in Table 2, the qualitative profiles of rat paw edema induced by both concentrations of CR are identical. Table 3 shows the effect of the drug extract on paw edema induced by carrageenin plus arachidonic acid. AA increased swelling caused by CR in the first hour. The greatest increase was observed in the first 30 min declining to no signifi-

3

EFFECT

OF EXTRACT N

(a) CR (b) CR + AA (c) CR + AA + extract (b - a) (c - b) Statistically

significant

ON RAT HINDPAW Mean

f

S.E.M.

EDEMA increase

INDUCED in paw diameter

+o.s

+I

24 I2

31.2 f 2.9 47.2 f 4.0

32.6 f 44.0 f

I2

42.7 zt 4.3

35.5 f

+16.0** - 4.5

+11.4** - 8.5*

for the comparison

specified:

WITH

CARRAGEENIN

AND ARACHIDONIC

ACID

(‘K) +2

+3

+4 h

3.2 2.3

40.0 l 4.3 50.6 f 4.2

46.9 f 4.0 54.4 zk 3.8

48.5 + 4.4 49.2 f 4.6

2.6

38.1 f

40.8 + 2.7

39.3 f

+7.5 -13.6;’

+0.7 -9.9*

+10.6 -12.5’

2.7

*P < 0.05; **P < 0.01; N = population.

1.4

266

cant effect by +2 h. The extract appeared to suppress edema induced by CR plus AA from +I to +4 h but had no effect on swelling at +30 min. Discussion The major finding in this work is the demonstration that a crude boiling water extract of three Ghanaian plants, Alstoniu hoonei, Ruuvolfiu vomitoriu and Eluies guineensis can suppress the late phase of rat hindpaw edema caused by carrageenin in the presence or absence of arachidonic acid. Di Rosa and Willoughby (1971) have shown that clinically effective antiinflammatory drugs are those that can suppress carrageenin-induced rat paw edema 3 h after pedal injection. In the present work, the profile of carrageenin edema is similar to that found by others in being biphasic over early and late periods (Van Arman et al., 1965; Vinegar et al., 1969; Zanin and Ferreird, 1978; Oyanagui, 1984). It was anticipated that measurement of the dorso-ventral thickness of rat paws would grossly underestimate the magnitude of carrageenin edema since this does not account for medio-lateral directions during swelling. However the magnitude of swelling recorded here is comparable to that measured by water displacement (Komoriya et al., 1978) and by mercury displacement (Holsapple et al., 1980). The similarity of time-edema profiles for the two doses of carrageenin used here (1000 and 500 pg) indicate similar operative factors for the two concentrations (Zanin and Ferreira, 1978). It has been shown here that arachidonic acid increased carrageenin foot edema in the early phase. Its effect was maximum at +30 min (+16X) but steadily subsided thereafter. This is consistent with data found on rat paw edema by Matsuda et al. (1987). Arachidonic acid can cause mouse ear edema with the maximum effect observed +I h after topical application, subsiding by +5 h (Chang et al., 1985). The edema has shown to be due to lipoxygenase as well as cycloxygenase products of arachidonic acid by the demonstration of the presence of LTB4, LTC4, PGE2 and 5-HETE as well as by the inhibition of edema by mixed lipoxygenase/cycloxygenase inhibitors, e.g. prednisolone (Arner et al., 1985; Chang et al., 1985). Results here show that the drug extract did not

affect swelling caused by arachidonic acid in the first 30 min of carrageenin edema. From +2 to +4 h, the magnitude of suppression of carrageenin edema by the extract was the same whether or not arachidonic acid was present. Over this period, it could reasonably be expected that the same mediators, e.g. prostaglandins, are involved. The suppression of carrageenin edema at +l h in the presence and not the absence of arachidonic acid may suggest an additional effect of the extract on the synthesis/release of other arachidonic acid products. The exact mechanism by which the extract exerts its antiinflammatory effect must be defined by more specific experiments. However, these preliminary results are consistent with the therapeutic ends to which the herbal preparation is put in Ghana. The acid pH of the drug extract (pH = 5.20 f 0.05) is also consistent with clinically effective drugs in antiinflammatory therapy as it would tend to concentrate in inflamed tissues (Brune, 1974). Acknowledgements This work was supported by a Phillip Institute of Technology Research and Development Grant. The author gratefully acknowledges the ready cooperation offered by the following persons while on professional leave to Ghana in December/ January 1989/90: professional herbalists and/or researchers, Dr. G.K. Noamesi (Hohoe), Mr. G.D. Koranteng (Koforidua), Mr. C.B. Nartey (Nsawarn) and Dr. G.L. Boye (Director, Centre for Scientific Research into Plant Medicine, Mampong, Akwapim). Special thanks to Dr. J.A. Appiah (Koforidua Clinic) for the above contacts. References Amer, E.C., Rule, B.L., Rudnick, M.S. and Galbraith, W (1985) Arachidonic acid-induced ear edema: Correlation of swelling with production of lipoxygenase (LO) products. Agents and Actions 16, 6O”l. Brune, K. (1974) How aspirin might work: A pharmacokinetic approach. Agents and Actions 4, 230-232 Burkill, H.M. (1985) The Useful Plants of West Tropical Africa. Royal Botanic Gardens, Kew, pp. 140---141. Chang, J., O‘Neill-Davis, L., Lamb, B., Carlson. R.P. and Lewis, A.J. (1985) The utility of arachidonic acid-treated mouse ear inflammatory model as a potential screen for lipoxygenase (LO) inhibitors. Agents and Actions 16, 600.

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Flower, F.J., Moncada, S. and Vane, J.R. (1985) Drug therapy of inflammation. In: A.G. Gilman. L.S. Goodman, T.W. Rail and R. Murad (Eds.), The Phormueological Basis of Therapeutics, 7th Edn. Macmillan. New York. p. 677. Goodson. J.A. (1932) Echitamine in Alstonia barks. Journul q/’ Chemieul Society 2. 262G-2630.

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