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Pharmacological screening of the aqueous extract of Musanga cecropiodes
Fitoterapia 71 Ž2000. 143]146
Pharmacological screening of the aqueous extract of Musanga cecropiodes Peter I. Azibaa,U , Zacchaeus O. Gbile b a
Department of Pharmacology, Obafemi Awolowo College of Health Sciences, Ogun State Uni¨ ersity, Ago-Iwoye, Nigeria b Department of Botany, Faculty of Biological Sciences, Ogun State Uni¨ ersity, Ago-Iwoye, Nigeria
Received 5 July 1999; accepted in revised form 9 October 1999
Abstract The aqueous extract of the leaves of Musanga cecropioides did not affect ache-induced contractile response, but produced significant inhibition of the twitch and pendular movement of the rat and rabbit smooth muscles, respectively, and reduced writhing induced by acetic acid in mice. Q 2000 Elsevier Science B.V. All rights reserved. Keywords: Musanga cecropiodes; Contractile activity; Analgesic and spasmogenic effects
1. Introduction In Nigerian ethnomedicine, Musanga cecropiodes Br. ŽMoraceae., locally known as ‘umbrella tree’ is reported to have a blood pressure lowering effect, and it is also used to procure painless child birth w1,2x. It is also claimed to be effective against cough and asthma w2x. In the present study the effects of the aqueous extract of the leaves on the smooth and skeletal muscle of rat, and on writhing induced by acetic acid in mice were studied. U
Corresponding author. E-mail address: [email protected] ŽP.I. Aziba.
0367-326Xr00r$ - see front matter Q 2000 Elsevier Science B.V. All rights reserved. PII: S 0 3 6 7 - 3 2 6 X Ž 9 9 . 0 0 1 3 0 - 6
144
P.I. Aziba, Z.O. Gbile r Fitoterapia 71 (2000) 143]146
2. Experimental 2.1. Plant M. cecropioides leaves collected along Ago-Iwoye road, south-western Nigeria, in April 1995. Voucher specimen authenticated by Prof. Z.O. Gbile, Botany Department, Ogun State University is deposited at the Herbarium of Forestry Research Institute of Nigeria. 2.2. Preparation of extract Air-dried, powdered leaves were extracted by maceration in water Žyield: 10.5%.. Phytochemical screening w3x gave positive tests for alkaloids, glycosides and tannins. 2.3. Animals Male Wistar rats, weighing 200]210 g, Swiss mice Ž20]25 g. and New Zealand rabbits Ž2.5]3.5 kg., kept under standardized environmental conditions with free access to water and commercial feed, were used. 2.4. In-¨ itro studies 2.4.1. Effect on rat stomach strip Animals were killed by exsanguination. The stomach was dissected out and cut into strips ŽRSS. according to Vane w4x. The preparations were placed in Krebs solution ŽKS. administered with 95% O 2r5% CO 2 and maintained at 378C. The stomach strip was connected via a transducer model FT 03 to a polygraph recorder model 7PD for isometric measurements. Tension was maintained at 500 mg and all preparation were allowed 1 h for equilibration before the testing of the extract at concentrations up to 10 mgrml. 2.4.2. Effect on diaphragm-phrenic preparation The whole preparation, prepared and mounted according to Bulbring w5x was placed in KS aerated with 95% O 2r5% CO 2 and stimulated with rectangular pulses having 20]40-V pulse width, 0.5]2.0 ms frequency of Hz. 2.4.3. Rabbit ileum preparation Rabbits of either sex were starved for 24 h, killed by cervical dislocation and exsanguinated. Segments of the ileum, approximately 1.5 cm long, were mounted according to the method of Finkelman w6x in a 10-ml organ bath containing Krebs Henseleit solution maintained at 378C, administered with 95% O 2r5% CO 2 , and mounted as previously described for RSS. The extract was tested at concentrations from 1 to 10 mgrml.
P.I. Aziba, Z.O. Gbile r Fitoterapia 71 (2000) 143]146
145
Table 1 Effect of M. cecropiodes leaf aqueous extract on the pendular movement of the rabbit ileuma Concentration Žmgrml.
Contractile response Žcm.
Inhibition Ž%.
0 ŽControl. 5 10 20
3.5 " 0.24 3.2 " 0.15U 2.5 " 0.25U 0.8 " 0.43UU
] 8.5 28.5 77.1
a
Values are mean " S.D., n s 8; U P - 0.05; UU P - 0.01 vs. control; Student’s t-test.
2.5. In ¨ i¨ o study 2.5.1. Effect on acetic acid-induced writhing in mice Analgesic activity was evaluated on the acetic acid induced-writhing according to Whittle w7x. Each mouse was given 0.4 ml of a 1% Žvrv. solution of acetic acid intraperitoneally. Groups of 10 mice each received either the plant extract Ž5, 10, 20 mgrkg, i.p.. or paracetamol Ž10 mgrkg, i.p.. as reference 30 min before acetic acid injection. Controls received an equal volume of saline Ž0.2 ml, i.p.. The number of writhings was recorded for 20 min after acetic acid injection.
3. Results and discussion Musanga cecropiodes leaf aqueous extract did not induce any effect on isolated rat stomach strip ŽRSS. up to 10 mgrml. Moreover, it did not modify the contractile response of RSS to acetylcholine tested at concentrations up to 16 mgrml Ždata not shown.. On phrenic nerve diaphragm preparation, the extract showed a weak inhibitory effect on twitch response. At concentrations of 5, 10 and 20 mgrml, the extract dose-dependently inhibited the pendular movement of the rabbit ileum ŽTables 1 and 2.. The dose-related effect was reversed after washing out the extract. Table 2 Effect of M. cecropiodes leaf aqueous extract on the acetic acid-induced writhing in mice a Treatment
Dose Žmgrkg, i.p.
Writhings Ž n..
Inhibition Ž%.
Control Žsaline, 10 mlrkg. M. cecropiodes
]
50.5 " 0.5
]
5 10 20 10
32.2 " 1.6U 27.4 " 1.2U 13.2 " 0.5UU 9.5 " 0.3UUU
30 46 74 94.5
Paracetamol a
Values are mean " S.E.M., n s 10; t-test.
U
P - 0.05;
UU
P - 0.01;
UUU
P - 0.001 vs. control; Student’s
146
P.I. Aziba, Z.O. Gbile r Fitoterapia 71 (2000) 143]146
A significant and dose-dependent reduction in writhing induced by acetic acid in mice was observed following intraperitoneal administration of the extract, the effect of 20 mgrkg being comparable to that of 10 mgrkg of paracetamol. Taken together, these results seem to exclude a cholinergic activity of the extract while the relaxant effect on rabbit ileum is indicative of adrenergic properties. Moreover, the dose-dependent inhibition of writhing in mice suggests that the aqueous extract of M. cecropiodes leaves possesses analgesic activity. Further studies are needed to better characterize the importance of these adrenergic and analgesic effects in view of the popular use of this plant.
Acknowledgements The author is grateful to Mr Segun Oyenuga for phytochemical work and technical assistance. Part of this study was funded by Osu Senate research grant.
References w1x Adjanohoun EJ, Alji AM, Ake Assi et al. In medicine traditionelle et pharmacopea. Paris: ACCT, ´ 1989:148]149. w2x Bouquet A. Feticheurs et medicines traditionelles du Congo Brazaville. Paris: ORSTOM, ´ ´ 1979:48]53. w3x Trease GE, Evans MC. Textbook of pharmacognosy. 12th ed. London: Balliere-Tindal, 1983:343]383. w4x Vane JR. Br J Pharmacol Chemother 1957;12:344. w5x Bulbring E. Br J Pharmacol 1934;1:38. w6x Finkelman BJ. Physiol London 1930;70:145. w7x Whittle BA. Br J Pharmacol Chemother 1964;22:246.
Pharmacological screening of the aqueous extract of Musanga cecropiodes Peter I. Azibaa,U , Zacchaeus O. Gbile b a
Department of Pharmacology, Obafemi Awolowo College of Health Sciences, Ogun State Uni¨ ersity, Ago-Iwoye, Nigeria b Department of Botany, Faculty of Biological Sciences, Ogun State Uni¨ ersity, Ago-Iwoye, Nigeria
Received 5 July 1999; accepted in revised form 9 October 1999
Abstract The aqueous extract of the leaves of Musanga cecropioides did not affect ache-induced contractile response, but produced significant inhibition of the twitch and pendular movement of the rat and rabbit smooth muscles, respectively, and reduced writhing induced by acetic acid in mice. Q 2000 Elsevier Science B.V. All rights reserved. Keywords: Musanga cecropiodes; Contractile activity; Analgesic and spasmogenic effects
1. Introduction In Nigerian ethnomedicine, Musanga cecropiodes Br. ŽMoraceae., locally known as ‘umbrella tree’ is reported to have a blood pressure lowering effect, and it is also used to procure painless child birth w1,2x. It is also claimed to be effective against cough and asthma w2x. In the present study the effects of the aqueous extract of the leaves on the smooth and skeletal muscle of rat, and on writhing induced by acetic acid in mice were studied. U
Corresponding author. E-mail address: [email protected] ŽP.I. Aziba.
0367-326Xr00r$ - see front matter Q 2000 Elsevier Science B.V. All rights reserved. PII: S 0 3 6 7 - 3 2 6 X Ž 9 9 . 0 0 1 3 0 - 6
144
P.I. Aziba, Z.O. Gbile r Fitoterapia 71 (2000) 143]146
2. Experimental 2.1. Plant M. cecropioides leaves collected along Ago-Iwoye road, south-western Nigeria, in April 1995. Voucher specimen authenticated by Prof. Z.O. Gbile, Botany Department, Ogun State University is deposited at the Herbarium of Forestry Research Institute of Nigeria. 2.2. Preparation of extract Air-dried, powdered leaves were extracted by maceration in water Žyield: 10.5%.. Phytochemical screening w3x gave positive tests for alkaloids, glycosides and tannins. 2.3. Animals Male Wistar rats, weighing 200]210 g, Swiss mice Ž20]25 g. and New Zealand rabbits Ž2.5]3.5 kg., kept under standardized environmental conditions with free access to water and commercial feed, were used. 2.4. In-¨ itro studies 2.4.1. Effect on rat stomach strip Animals were killed by exsanguination. The stomach was dissected out and cut into strips ŽRSS. according to Vane w4x. The preparations were placed in Krebs solution ŽKS. administered with 95% O 2r5% CO 2 and maintained at 378C. The stomach strip was connected via a transducer model FT 03 to a polygraph recorder model 7PD for isometric measurements. Tension was maintained at 500 mg and all preparation were allowed 1 h for equilibration before the testing of the extract at concentrations up to 10 mgrml. 2.4.2. Effect on diaphragm-phrenic preparation The whole preparation, prepared and mounted according to Bulbring w5x was placed in KS aerated with 95% O 2r5% CO 2 and stimulated with rectangular pulses having 20]40-V pulse width, 0.5]2.0 ms frequency of Hz. 2.4.3. Rabbit ileum preparation Rabbits of either sex were starved for 24 h, killed by cervical dislocation and exsanguinated. Segments of the ileum, approximately 1.5 cm long, were mounted according to the method of Finkelman w6x in a 10-ml organ bath containing Krebs Henseleit solution maintained at 378C, administered with 95% O 2r5% CO 2 , and mounted as previously described for RSS. The extract was tested at concentrations from 1 to 10 mgrml.
P.I. Aziba, Z.O. Gbile r Fitoterapia 71 (2000) 143]146
145
Table 1 Effect of M. cecropiodes leaf aqueous extract on the pendular movement of the rabbit ileuma Concentration Žmgrml.
Contractile response Žcm.
Inhibition Ž%.
0 ŽControl. 5 10 20
3.5 " 0.24 3.2 " 0.15U 2.5 " 0.25U 0.8 " 0.43UU
] 8.5 28.5 77.1
a
Values are mean " S.D., n s 8; U P - 0.05; UU P - 0.01 vs. control; Student’s t-test.
2.5. In ¨ i¨ o study 2.5.1. Effect on acetic acid-induced writhing in mice Analgesic activity was evaluated on the acetic acid induced-writhing according to Whittle w7x. Each mouse was given 0.4 ml of a 1% Žvrv. solution of acetic acid intraperitoneally. Groups of 10 mice each received either the plant extract Ž5, 10, 20 mgrkg, i.p.. or paracetamol Ž10 mgrkg, i.p.. as reference 30 min before acetic acid injection. Controls received an equal volume of saline Ž0.2 ml, i.p.. The number of writhings was recorded for 20 min after acetic acid injection.
3. Results and discussion Musanga cecropiodes leaf aqueous extract did not induce any effect on isolated rat stomach strip ŽRSS. up to 10 mgrml. Moreover, it did not modify the contractile response of RSS to acetylcholine tested at concentrations up to 16 mgrml Ždata not shown.. On phrenic nerve diaphragm preparation, the extract showed a weak inhibitory effect on twitch response. At concentrations of 5, 10 and 20 mgrml, the extract dose-dependently inhibited the pendular movement of the rabbit ileum ŽTables 1 and 2.. The dose-related effect was reversed after washing out the extract. Table 2 Effect of M. cecropiodes leaf aqueous extract on the acetic acid-induced writhing in mice a Treatment
Dose Žmgrkg, i.p.
Writhings Ž n..
Inhibition Ž%.
Control Žsaline, 10 mlrkg. M. cecropiodes
]
50.5 " 0.5
]
5 10 20 10
32.2 " 1.6U 27.4 " 1.2U 13.2 " 0.5UU 9.5 " 0.3UUU
30 46 74 94.5
Paracetamol a
Values are mean " S.E.M., n s 10; t-test.
U
P - 0.05;
UU
P - 0.01;
UUU
P - 0.001 vs. control; Student’s
146
P.I. Aziba, Z.O. Gbile r Fitoterapia 71 (2000) 143]146
A significant and dose-dependent reduction in writhing induced by acetic acid in mice was observed following intraperitoneal administration of the extract, the effect of 20 mgrkg being comparable to that of 10 mgrkg of paracetamol. Taken together, these results seem to exclude a cholinergic activity of the extract while the relaxant effect on rabbit ileum is indicative of adrenergic properties. Moreover, the dose-dependent inhibition of writhing in mice suggests that the aqueous extract of M. cecropiodes leaves possesses analgesic activity. Further studies are needed to better characterize the importance of these adrenergic and analgesic effects in view of the popular use of this plant.
Acknowledgements The author is grateful to Mr Segun Oyenuga for phytochemical work and technical assistance. Part of this study was funded by Osu Senate research grant.
References w1x Adjanohoun EJ, Alji AM, Ake Assi et al. In medicine traditionelle et pharmacopea. Paris: ACCT, ´ 1989:148]149. w2x Bouquet A. Feticheurs et medicines traditionelles du Congo Brazaville. Paris: ORSTOM, ´ ´ 1979:48]53. w3x Trease GE, Evans MC. Textbook of pharmacognosy. 12th ed. London: Balliere-Tindal, 1983:343]383. w4x Vane JR. Br J Pharmacol Chemother 1957;12:344. w5x Bulbring E. Br J Pharmacol 1934;1:38. w6x Finkelman BJ. Physiol London 1930;70:145. w7x Whittle BA. Br J Pharmacol Chemother 1964;22:246.