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Gastrointestinal activity of Ficus sur
Fitoterapia 70 Ž1999. 542]547
Gastrointestinal activity of Ficus sur O.O. Kunle a,U , A. Shittu a , R.N. Nasipuri a , O.F. Kunle a , C. Wambebe a , P.A. Akahb a
National Institute for Pharmaceutical Research and De¨ elopment (NIPRD) P.M.B. 21, Abuja, Nigeria b Department of Pharmacology and Toxicology, Uni¨ ersity of Nigeria, Nsukka, Nigeria Received 1 September 1998; accepted in revised form 9 April 1999
Abstract The gastroprotective effects of some extracts of the dried leaves of Ficus sur in animals were investigated in order to validate the use of the plant in traditional medicine. The water and methanol extracts showed antiulcer activity, the hot water extract being the most effective. These extracts had also spasmolytic effects on the rabbit jejunum. LD50 values ranged from 900 to 1200 mgrkg in mice. These results show that F. sur has potential in the treatment of ulcers. Q 1999 Elsevier Science B.V. All rights reserved. Keywords: Ficus sur; Antiulcer activity
1. Introduction Ficus sur Forsk. ŽMoraceae. is widely distributed in Africa, especially the eastern, western and southern parts. The plant is used in traditional medicine for different purposes depending on the region. Zulu people drink a decoction of the root and bark for pulmonary tuberculosis, while they use an infusion of the leaf and bark to improve milk production in cattle w1x. In Tanganyika a decoction of the bark is used as a galactogogue in women and cows and to prevent vomiting while in West Africa the plant is used by traditional eye doctors. The latex is used in Zaire for the treatment of burns w2x. In the northern part of Nigeria, the fresh young U
Corresponding author. Tel.: q234-9-5231-602; fax: q234-9-5231-043.
0367-326Xr99r$ - see front matter Q 1999 Elsevier Science B.V. All rights reserved. PII: S 0 3 6 7 - 3 2 6 X Ž 9 9 . 0 0 0 7 9 - 9
O.O. Kunle et al. r Fitoterapia 70 (1999) 542]547
543
aerial root along with the inner bark is chewed with kolanut to alleviate thirst and to treat sore throat, while the leaves Žchewed and swallowed three times per day for approx. 6 weeks. are claimed to act as a remedy for peptic ulcer by people in the middle-belt region of the country Žpersonal communication.. A search of the literature did not reveal any report on the antiulcer activity of this plant. This study was therefore carried out to evaluate the antiulcer properties of F. sur leaves on acetylsalicylic acid ŽASA.-induced gastric ulcer in rats.
2. Experimental 2.1. Plant material Ficus sur leaves, collected between January and March 1996 Ždry season. from their natural habitat in Suleja, Niger State, Nigeria, and identified by Prof. Z. Gbile ŽPlant Taxonomist. of the Department of Botany, Ogun State University, AgoIwoye, Nigeria. A voucher specimen is deposited at NIPRD herbarium. 2.2. Preparation of the extracts Freshly harvested leaves were washed with water, air-dried and milled to a coarse powder. Soxhlet extraction of different samples afforded hot water, methanol and hexane extracts ŽHWE, ME and HE, respectively.. Maceration in water for 48 h gave the cold water extract ŽCWE.. Yields and results of phytochemical tests w3x are reported in Table 1. 2.3. Animals New Zealand rabbits Ž1.8]2.5 kg., Wistar rats Ž150]200 g. and Swiss albino mice Ž20]25 g. of either sex, maintained under standard conditions at the Animal Facility Centre ŽAFC. of NIPRD, Abuja, and fed with standard diet with water ad libitum were used for the experiments. 2.4. Acute toxicity The intraperitoneal Ži.p.. acute toxicity ŽLD50 . of the four extracts was evaluated in mice according to the method of Lorke w4x. Varying doses ranging from 50 to 2000 mgrkg were given to the animals as a single dose. The animals were observed over a 24-h period for signs of toxicity and mortality. 2.5. Effect on ASA-induced ulcer in rats Thirty rats were fasted for 48 h with water allowed. The animals were then randomly divided into six groups of five each. One group serving as control
O.O. Kunle et al. r Fitoterapia 70 (1999) 542]547
544
Table 1 Phytochemical data and acute toxicity Žmgrkg, i.p.. in mice of Ficus sur leaf extracts a Parameter
Cold water extract
Hot water extract
Methanol extract
Hexane extract
Yield Ž%.
10.0
12.0
13.4
2.3
y y y y q y q q y q y
q q q y q y q q y q y
y y q y q y q q y q y
y y y y y y y y y y y
1204
1162
1053
902
Ž1012.5]1395.5.
Ž991.7]1332.3.
Ž789.4]1316.6.
Phytochemical screening Alkaloids Anthraquinones Digitalis glycosides Flavonoids Glycosides Žgeneral. Hydrosable tannins Saponins Žgeneral. Saponin glycosides Steroidsrterpenoids Tannins Žgeneral. Volatile oils LD50 ŽConfidence limits, P - 0.05. a
Ž699.3]1104.66.
q , positive test; y, negative test.
received distilled water, orally. The extracts were administered p.o. to the other groups at a dose of 250 mgrkg Ža dose based on the herbal practitioner’s prescribed dose, which was found to be well below the determined LD50 values.. Thirty minutes later, an aqueous suspension of ASA Ž250 mgrkg, p.o.. was administered to each rat. After 6 h, the animals were killed, the stomachs removed and opened along the greater curvature. The stomach was rinsed under a stream of water and pinned flat on a cork board. The various specimens were coded and evaluated by an examiner unaware of the study protocol with a hand lens Ž10 = .. Erosions formed on the glandular portion of the stomach were counted and the ulcer index calculated as previously described w5x. Cimetidine Ž75 mgrkg, p.o.. and aluminium hydroxide Ž15 mgrkg p.o.. were used as reference drugs. 2.6. Studies on isolated rabbit jejunum Segments of rabbit jejunum Ž2 cm long. removed from freshly killed animals were suspended in a 20-ml organ bath containing aerated Tyrode solution maintained at 378C. The Tyrode solution had the following composition Žmmolrl.: NaCl 137, KCl 2.7, CaCl 2 1.0, NaHCO3 12.0, NaH 2 ? PO4 0.2, glucose 5.6. The tension on the tissues was 1.0 g. After 60 min equilibration, the effect of the extracts on the pendular movements of the preparation was investigated at concentrations ranging from 50 to 800 mgrml. The responses were recorded on Ugo Basile Microdynamometer 7050, through isometric transducer 7004. The effect of 25 mgrml noradrenaline was also recorded for comparison.
O.O. Kunle et al. r Fitoterapia 70 (1999) 542]547 Fig. 1. Effect of Ficus sur leaf extracts Ž250 mgrkg, p.o.. on ASA-induced gastric ulcer in rats compared to cimetidine Ž75 mgrkg, p.o.. and aluminium U hydroxide Ž15 mgrkg, p.o... Values are mean " SEM, n s 5; P - 0.05 vs. control, student’s t-test. CWE, HWE, ME and HE s cold water, hot water, methanol and hexane extracts, respectively. 545
546
O.O. Kunle et al. r Fitoterapia 70 (1999) 542]547
3. Results 3.1. Acute toxicity LD50 values ŽTable 1. were for all tested extracts approximately fourfold higher than the experimental dose Ž250 mgrkg, p.o.. used for the evaluation of the antiulcer. 3.2. Effect on ASA-induced ulcer As shown in Fig. 1, ASA Ž250 mgrkg, p.o.. induced ulcer in 100% of the control rats with a mean ulcer index of 1.6 " 0.13. The HWE significantly Ž P - 0.05. protected the animals from ASA-induced ulcers and was as active as cimetidine. The hexane extract was devoid of antiulcer effect while the other extracts showed varying degrees of antiulcer activity. 3.3. Effect on pendular mo¨ ement of rabbit jejunum All the extracts tested produced dose-dependent relaxation with a threshold dose of 50, 100 and 50 mgrml for HWE, CWE and ME, respectively. There was complete inhibition of intestinal motility at 500 and 200 mgrml for HWE and CWE, respectively, while the maximal effect of ME was obtained at 200 mgrml. The effect of ME seemed to be very transient, since intestinal motility recovered very quickly when compared to the two water extracts that produced sustained relaxation. The HE was not tested because of its poor miscibility with the Tyrode solution.
4. Discussion All the Ficus sur leaf extracts tested were found to possess antiulcer and spasmolytic activity. The cold water ŽCWE., hot water ŽHWE. and methanol ŽME. extracts produced dose-dependent spasmolytic effect on the rabbit intestine. While the effect of ME was transient, both water extracts produced sustained effects, HWE being more active. All the extracts except the hexane extract ŽHE. exhibited gastroprotective activity. HWE, which showed again the best activity, was found to have gastroprotective activity comparable to that of the H 2-receptor antagonist cimetidine but to be less effective than aluminum hydroxide, an antacid. Further studies are needed to confirm the observed gastroprotective effect and establish the mechanism by which the F. sur extracts produce their antiulcer effect.
Acknowledgements The assistance of Messrs D. Akumka and Muazam is appreciated. This work was
O.O. Kunle et al. r Fitoterapia 70 (1999) 542]547
547
conducted through a study grant by NIPRD to OOK.
References w1x Watt JM., Breyer-Brandwijk GM. Medicinal and poisonous plants of southern and eastern Africa, 2nd ed. Edinburgh: E.S. Livingstone Ltd., 1962:773. w2x Burkill HM. The useful plants of West Tropical Africa. Kew, Richmond Surrey: Royal Botanical Gardens, 1985:226. w3x Evans WC. Trease and Evans pharmacognosy, 13th ed. London: Bailliere Tindall, 1989:28, 54,55,282]396,420]480,509]543. w4x Lorke T. Arch. Toxicol. 1983;54:275. w5x Akah PA, Gamaniel KS, Wambebe CN, Shittu A, Kapu SD, Kunle OO. Fitoterapia 1997;68:17.
Gastrointestinal activity of Ficus sur O.O. Kunle a,U , A. Shittu a , R.N. Nasipuri a , O.F. Kunle a , C. Wambebe a , P.A. Akahb a
National Institute for Pharmaceutical Research and De¨ elopment (NIPRD) P.M.B. 21, Abuja, Nigeria b Department of Pharmacology and Toxicology, Uni¨ ersity of Nigeria, Nsukka, Nigeria Received 1 September 1998; accepted in revised form 9 April 1999
Abstract The gastroprotective effects of some extracts of the dried leaves of Ficus sur in animals were investigated in order to validate the use of the plant in traditional medicine. The water and methanol extracts showed antiulcer activity, the hot water extract being the most effective. These extracts had also spasmolytic effects on the rabbit jejunum. LD50 values ranged from 900 to 1200 mgrkg in mice. These results show that F. sur has potential in the treatment of ulcers. Q 1999 Elsevier Science B.V. All rights reserved. Keywords: Ficus sur; Antiulcer activity
1. Introduction Ficus sur Forsk. ŽMoraceae. is widely distributed in Africa, especially the eastern, western and southern parts. The plant is used in traditional medicine for different purposes depending on the region. Zulu people drink a decoction of the root and bark for pulmonary tuberculosis, while they use an infusion of the leaf and bark to improve milk production in cattle w1x. In Tanganyika a decoction of the bark is used as a galactogogue in women and cows and to prevent vomiting while in West Africa the plant is used by traditional eye doctors. The latex is used in Zaire for the treatment of burns w2x. In the northern part of Nigeria, the fresh young U
Corresponding author. Tel.: q234-9-5231-602; fax: q234-9-5231-043.
0367-326Xr99r$ - see front matter Q 1999 Elsevier Science B.V. All rights reserved. PII: S 0 3 6 7 - 3 2 6 X Ž 9 9 . 0 0 0 7 9 - 9
O.O. Kunle et al. r Fitoterapia 70 (1999) 542]547
543
aerial root along with the inner bark is chewed with kolanut to alleviate thirst and to treat sore throat, while the leaves Žchewed and swallowed three times per day for approx. 6 weeks. are claimed to act as a remedy for peptic ulcer by people in the middle-belt region of the country Žpersonal communication.. A search of the literature did not reveal any report on the antiulcer activity of this plant. This study was therefore carried out to evaluate the antiulcer properties of F. sur leaves on acetylsalicylic acid ŽASA.-induced gastric ulcer in rats.
2. Experimental 2.1. Plant material Ficus sur leaves, collected between January and March 1996 Ždry season. from their natural habitat in Suleja, Niger State, Nigeria, and identified by Prof. Z. Gbile ŽPlant Taxonomist. of the Department of Botany, Ogun State University, AgoIwoye, Nigeria. A voucher specimen is deposited at NIPRD herbarium. 2.2. Preparation of the extracts Freshly harvested leaves were washed with water, air-dried and milled to a coarse powder. Soxhlet extraction of different samples afforded hot water, methanol and hexane extracts ŽHWE, ME and HE, respectively.. Maceration in water for 48 h gave the cold water extract ŽCWE.. Yields and results of phytochemical tests w3x are reported in Table 1. 2.3. Animals New Zealand rabbits Ž1.8]2.5 kg., Wistar rats Ž150]200 g. and Swiss albino mice Ž20]25 g. of either sex, maintained under standard conditions at the Animal Facility Centre ŽAFC. of NIPRD, Abuja, and fed with standard diet with water ad libitum were used for the experiments. 2.4. Acute toxicity The intraperitoneal Ži.p.. acute toxicity ŽLD50 . of the four extracts was evaluated in mice according to the method of Lorke w4x. Varying doses ranging from 50 to 2000 mgrkg were given to the animals as a single dose. The animals were observed over a 24-h period for signs of toxicity and mortality. 2.5. Effect on ASA-induced ulcer in rats Thirty rats were fasted for 48 h with water allowed. The animals were then randomly divided into six groups of five each. One group serving as control
O.O. Kunle et al. r Fitoterapia 70 (1999) 542]547
544
Table 1 Phytochemical data and acute toxicity Žmgrkg, i.p.. in mice of Ficus sur leaf extracts a Parameter
Cold water extract
Hot water extract
Methanol extract
Hexane extract
Yield Ž%.
10.0
12.0
13.4
2.3
y y y y q y q q y q y
q q q y q y q q y q y
y y q y q y q q y q y
y y y y y y y y y y y
1204
1162
1053
902
Ž1012.5]1395.5.
Ž991.7]1332.3.
Ž789.4]1316.6.
Phytochemical screening Alkaloids Anthraquinones Digitalis glycosides Flavonoids Glycosides Žgeneral. Hydrosable tannins Saponins Žgeneral. Saponin glycosides Steroidsrterpenoids Tannins Žgeneral. Volatile oils LD50 ŽConfidence limits, P - 0.05. a
Ž699.3]1104.66.
q , positive test; y, negative test.
received distilled water, orally. The extracts were administered p.o. to the other groups at a dose of 250 mgrkg Ža dose based on the herbal practitioner’s prescribed dose, which was found to be well below the determined LD50 values.. Thirty minutes later, an aqueous suspension of ASA Ž250 mgrkg, p.o.. was administered to each rat. After 6 h, the animals were killed, the stomachs removed and opened along the greater curvature. The stomach was rinsed under a stream of water and pinned flat on a cork board. The various specimens were coded and evaluated by an examiner unaware of the study protocol with a hand lens Ž10 = .. Erosions formed on the glandular portion of the stomach were counted and the ulcer index calculated as previously described w5x. Cimetidine Ž75 mgrkg, p.o.. and aluminium hydroxide Ž15 mgrkg p.o.. were used as reference drugs. 2.6. Studies on isolated rabbit jejunum Segments of rabbit jejunum Ž2 cm long. removed from freshly killed animals were suspended in a 20-ml organ bath containing aerated Tyrode solution maintained at 378C. The Tyrode solution had the following composition Žmmolrl.: NaCl 137, KCl 2.7, CaCl 2 1.0, NaHCO3 12.0, NaH 2 ? PO4 0.2, glucose 5.6. The tension on the tissues was 1.0 g. After 60 min equilibration, the effect of the extracts on the pendular movements of the preparation was investigated at concentrations ranging from 50 to 800 mgrml. The responses were recorded on Ugo Basile Microdynamometer 7050, through isometric transducer 7004. The effect of 25 mgrml noradrenaline was also recorded for comparison.
O.O. Kunle et al. r Fitoterapia 70 (1999) 542]547 Fig. 1. Effect of Ficus sur leaf extracts Ž250 mgrkg, p.o.. on ASA-induced gastric ulcer in rats compared to cimetidine Ž75 mgrkg, p.o.. and aluminium U hydroxide Ž15 mgrkg, p.o... Values are mean " SEM, n s 5; P - 0.05 vs. control, student’s t-test. CWE, HWE, ME and HE s cold water, hot water, methanol and hexane extracts, respectively. 545
546
O.O. Kunle et al. r Fitoterapia 70 (1999) 542]547
3. Results 3.1. Acute toxicity LD50 values ŽTable 1. were for all tested extracts approximately fourfold higher than the experimental dose Ž250 mgrkg, p.o.. used for the evaluation of the antiulcer. 3.2. Effect on ASA-induced ulcer As shown in Fig. 1, ASA Ž250 mgrkg, p.o.. induced ulcer in 100% of the control rats with a mean ulcer index of 1.6 " 0.13. The HWE significantly Ž P - 0.05. protected the animals from ASA-induced ulcers and was as active as cimetidine. The hexane extract was devoid of antiulcer effect while the other extracts showed varying degrees of antiulcer activity. 3.3. Effect on pendular mo¨ ement of rabbit jejunum All the extracts tested produced dose-dependent relaxation with a threshold dose of 50, 100 and 50 mgrml for HWE, CWE and ME, respectively. There was complete inhibition of intestinal motility at 500 and 200 mgrml for HWE and CWE, respectively, while the maximal effect of ME was obtained at 200 mgrml. The effect of ME seemed to be very transient, since intestinal motility recovered very quickly when compared to the two water extracts that produced sustained relaxation. The HE was not tested because of its poor miscibility with the Tyrode solution.
4. Discussion All the Ficus sur leaf extracts tested were found to possess antiulcer and spasmolytic activity. The cold water ŽCWE., hot water ŽHWE. and methanol ŽME. extracts produced dose-dependent spasmolytic effect on the rabbit intestine. While the effect of ME was transient, both water extracts produced sustained effects, HWE being more active. All the extracts except the hexane extract ŽHE. exhibited gastroprotective activity. HWE, which showed again the best activity, was found to have gastroprotective activity comparable to that of the H 2-receptor antagonist cimetidine but to be less effective than aluminum hydroxide, an antacid. Further studies are needed to confirm the observed gastroprotective effect and establish the mechanism by which the F. sur extracts produce their antiulcer effect.
Acknowledgements The assistance of Messrs D. Akumka and Muazam is appreciated. This work was
O.O. Kunle et al. r Fitoterapia 70 (1999) 542]547
547
conducted through a study grant by NIPRD to OOK.
References w1x Watt JM., Breyer-Brandwijk GM. Medicinal and poisonous plants of southern and eastern Africa, 2nd ed. Edinburgh: E.S. Livingstone Ltd., 1962:773. w2x Burkill HM. The useful plants of West Tropical Africa. Kew, Richmond Surrey: Royal Botanical Gardens, 1985:226. w3x Evans WC. Trease and Evans pharmacognosy, 13th ed. London: Bailliere Tindall, 1989:28, 54,55,282]396,420]480,509]543. w4x Lorke T. Arch. Toxicol. 1983;54:275. w5x Akah PA, Gamaniel KS, Wambebe CN, Shittu A, Kapu SD, Kunle OO. Fitoterapia 1997;68:17.