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Effect of Artocarpus heterophyllus and Asteracanthus longifolia on glucose tolerance in normal human subjects and in maturity-onset diabetic patients
277
Journal of Etknophurmacology, 31 (1991) 277-282 Elsevier Scientific Publishers Ireland Ltd.
EFFECT OF ARTOCARPUS ASTERACANTHUS
HETERO~HYLL~S AND LOIVGIFOLIA ON GLUCOSE TOLERANCE IN
NORMAL HUMAN DIABETIC PATIENTS
M.R.
FERNANDO=,
ARIYANANDAband
SUBJECTS
AND
IN
S.M.D. NALINIE WICKRAMASINGHEa, E.H.KARUNANAYAKE’
MATURITY-ONSET
M.I.
THABREW”,
P.L.
“Department of Biochemistry and bDepartment of Medicine, Faculty of Medicine, University of Ruhuna, Galle and aDepartment of Biochemistry, Faculty of Medicine, University of Colombo, K&se y Road, Colombo 8 6%-i Lanka)
(Accepted September l&1990)
Summary Investigations were carried out to evaluate the effects of hot-water extracts of Artocarpus heterophytlus leaves and Asteracanthus longifoliu whole plant material on the glucose tolerance of normal human subjects and maturity-onset diabetic patients. The extracts of both Artocarpus heterophyllus and Asteracanthus longifolia significantly improved glucose tolerance in the normal subjects and the diabetic patients when investigated at oral doses equivalent to 20 gfkg of starting material.
Introduction ATtoca~s hete~oph~~~us Lam. (family ~oraeeae) and Asteraeanth~s iongif0li.a Linn. (family Acanthaceael are two medicinal plants recommended by
some traditional and Ayurvedic medical practitioners in Sri Lanka for the control of blood sugar levels in diabetic patients (Jayaweera, 1982). Previous investigations (Fernando, 1989; Fernando et al., 1989) using Sprague-Dawley rats have shown that aqueous extracts of Artocarpus heteroph~llus leaves and Aste~cant~~s longhorn whole plants possess significant oral hypoglycaemic activity. However, no scientific reports are available on their activity in humans. Since there can be considerable species variations in the activities of drugs (Hucker, 1970) it was decided to carry out studies to evaluate the hypoglycaemic activities of the above plant extracts in humans. In Correspondence to: Prof. M.I. Thabrew, Department versity of Ruhuna, P.O. Box 70, Galle, Sri Lanka.
of Biochemistry,
0378-87411803.50 0 1991 Elsevier Scientific Publishers Ireland Ltd. Published and Printed in Ireland
Faculty
of Medicine, Uni-
278
the present paper, the hypoglycaemic activities of Artocarpus heterophyllus and Asteracanthus longifolia in normal human subjects and non-insulindependent maturity-onset diabetic patients are reported. Materials and Methods Experimental
subjects
Twenty healthy male volunteers (average age 35.5 years) from the Faculty of Medicine, University of Ruhuna, Sri Lanka and 20 non-insulin-dependent diabetic patients (average age 51.4 years) attending the Karapitiya Teaching Bospital, Sri Lanka were used in this investigation. The diabetic patients chosen were free from ketoacidosis, cerebrovascular disease, acute myocardial infarction and renal complications and were not on oral or parenteral anti-diabetic drugs. Preparation
of plant extracts
The plant extracts were prepared according to the methods normally used by Ayurvedic medical practitioners for administration to diabetic patients. The botanical identity of the plants was determined by using the descriptions of Jayaweera (1982) and confirmed by comparing with authentic samples from the herbarium of the Royal Botanical Gardens in Peradeniya, Sri Lanka. Fresh mature leaves (200 g) of Artocarpus heterophyllus were boiled with distilled water (1000 ml) for 3 h and the final volume reduced to 200 ml (1 ml equivalent to 1 g of starting material). Fresh whole plant material (100 g) of Asterucanthus long~ol~ was boiled with distilled water (1000 ml) for 3 h and the final volume reduced to 200 ml, Oral glucose
tolerance
test
Following an overnight fast, a standard glucose tolerance test (50 g glucose) was performed with all experimental subjects receiving 10 ml/kg distilled water instead of the plant extracts 1 h before the glucose load. The oral glucose tolerance test was repeated on subsequent days with 10 persons in each group receiving the extract of Artocarpus heterophyllus 110 ml/kg) and the other 10 persons receiving the Asteracanthus longifolia extract (10 ml/kg) 1 h before the oral glucose load. Blood samples were then collected at 30-min intervals for 2 or 2.5 h and the blood-glucose content estimated. Blood-glucose
estimation
Blood samples (0.05 ml) were obtained by finger tip puncture using microcaps (Drummond Scientific Company, U.S.A.) and the blood glucose levels estimated by the glucose oxidase method of Hugget and Nixon (19573. Results and Discussion
The results
of the effect of the aqueous extract
of Artocarpus
heterophyl-
279
longifolia on oral glucose tolerance in healthy human subjects are illustrated in Fig. 1. In the control group receiving only distilled water (10 ml/kg) followed 1 h later by an oral load of glucose (50 gl, the peak increase in blood glucose concentration (102% or 87 mgldll was observed 30 min after glucose administration. In this group, the blood glucose concentration returned to the normal fasting range by + 2 h. In groups receiving the Artocarpus heterophyllus or Asteracanthus longifolia extracts there was a significant improvement in their ability to utilize the external glucose load. Statistical analyses by the Student’s t-test revealed significant differences between the control curve and the Artocarpus heterophyllus curve at all time intervals. The same was true for the Asteracanthus longifolia curve. The glucose tolerance curves of all 20 diabetic patients, along with a normal glucose tolerance curve of a healthy adult for comparison, are illustrated in Fig. 2. It is apparent that all 20 patients were clearly diabetic. lus or Asteracanthus
Fig. 1. Effect of the aqueous extracts of Artocarpus heterophyks (A, 10 ml/kg) and Asteracanthus longifolia (A, 10 ml/kg) on oral glucose tolerance in healthy human volunteers relative to controls (0, 10 mg/kg of distilled water). Blood samples were taken at 30-min intervals for 2.5 h and results are expressed as the percent increase in blood glucose level. Each point is the mean of 10 determinations + S.E.M. T’ < 0.001.
280
! oL_______ , ‘2
"TIME(h) Fig. 2. Glucose tolerance curves of all the diabetic patients compared to that of a representative normal healthy adult. All individuals were given distilled water (10 ml/kg) 1 h before the glucose load. . - ., glucose tolerance curves of diabetics; l - 0, glucose tolerance curve of a normal human adult.
A comparative analysis of the percentage increase in blood sugar level of each of these curves with the corresponding ones obtained with the administration of Artocarpus heterophyllus or Asteracanthus longifolia extract 1 h prior to glucose loading revealed that the patients treated with either of the plant extracts exhibited a significant improvement in glucose tolerance. In Fig. 3, the mean glucose tolerance curve of diabetic patients awaiting treatment with Artocarpus heterophyllus is compared with that obtained in patients with prior administration of the plant extract. Statistical analysis by the Student’s t-test revealed significant differences between the two curves at the 1.5 h and 2 h times, respectively. Figure 4 illustrates the mean glucose tolerance of the patients awaiting treatment with Asteracanthus 1ongifoli.a in comparison with that obtained in patients with prior administration of the plant extract. As before, statistical analysis by the Student’s ttest revealed a significant difference between the two curves from the 1.5 h time point onwards. With both plant extracts, the dosages used here correspond to those reputed to produce the maximum hypoglycaemic effects (Fernando, 1989; Fernando et al., 1989). Although both extracts had fairly comparable effects
281
on the glucose tolerance of normal individuals, Artocarpus heterophyllus appeared to be slightly more effective than Asterucanthus longifolia in diabetic patients. Thus, with diabetic patients, 2 h after the glucose load, the ATtocu~~s hetero~h~ll~-treated group showed a blood glucose level that was 36% less than the corresponding value in the control group (Fig. 31, while the Asteracanthus longifolia-treated group showed a blood glucose level only 25% less than the corresponding value in the control group (Fig. 41. In previous studies (Fernando, 1989; Fernando et al., 19891, it has been shown that both of the plant extracts under investigation here can decrease fasting blood glucose levels and improve peripheral glucose uptake and utilization in rats. Although the effects of the plant extracts on insulin release by the 6-cells of the islets of Langerhans has not been specifically investigated, the studies on rats together with the ability of the plant extracts to improve the glucose tolerance in non-insulin-dependent diabetic patients seems to suggest that Artocarpus heterophyllus and Asteracanthus longifolia may mediate their hypoglycaemic effects through an increased secretion of insulin from the pancreas. Whatever the mechanism of action, the results of the present study document the oral hypoglycaemic activity of ATtocu~~ heteToph~llus and Asterucanthus l~g~fol~ in healthy human individuals and maturity-onset diabetic
+l
‘lb
‘2
TIME(h) Fig. 3. Effect of the aqueous extract of Artocarpus heterophyllus (Cl, 10 ml/kg) on oral glucose tolerance in maturity-onset diabetic patients relative to diabetic controls (0, 10 ml/kg of distilled water). Blood samples were taken at 30-min intervals for 2 h and results are expressed as the percent increase in blood glucose level. Each point is the mean of 10 determinations + S.E.M. *P < 0.001.
TIME (h) Fig. 4. Effect of the aqueous extract of Asterucu~thus ZmgifoZiu 111, 10 ml/kg) on oral glucose tolerance in maturity-onset diabetic patients relative to diabetic controls (0, 10 ml&g of distilled water). Blood samples were taken at 30-min intervals for 2 h. Results are expressed as the percent increase in the blood glucose level. Each point is the mean of 10 determinations + S.E.M. fP < 0.001.
patients and give scientific validity for the use of these two plants as oral hypoglycaemic agents by traditional medical practitioners in Sri Lanka. Acknowledgements Part of this work was supported by Grant No. TWAS RG 68 - Sri 4 from the Third World Academy of Sciences (Italy). The authors wish to thank Miss Rohini Alahapperuma for her technical assistance. References Fernando, M.R. (1989)An Investigation of the Oral Hypoglycaemic Activity of Medici7aalPlants used in A~7vedic Medicine for the Control of ~~etes ~e~~tus. Doctoral dissertation, Faeulty of Medicine, University of Ruhuna, Sri Lanka. Fernando, M.R., Wickramasinghe, S.M.D. Nalini, Thabrew, M.I, and Karunanayake, E-H, (1989)A preliminary investigation of the possible hypog~yeaemieactivity of Aste~acu~thus ~~g~foZ~. Journal of Ethnopharmacology 2?,714. Hucker, H.B. (1970) Species differences in drug metabolism. Annual Review of Phamacology 10, 99- 118. Hugget, A. St. G. and Nixon, D.A. (1957) Use of glucose peroxidase and dianisidine in the determination of blood and urinary glucose. Lancet 2, 368-370. Jayaweera, D.M.A. (1982) Medicind Plm.ts used i% Ceykm, Parts I and IV. Nationaf Science Council of Sri-Lanka Publications, Colombo, pp. 9- 10, 89-90.
Journal of Etknophurmacology, 31 (1991) 277-282 Elsevier Scientific Publishers Ireland Ltd.
EFFECT OF ARTOCARPUS ASTERACANTHUS
HETERO~HYLL~S AND LOIVGIFOLIA ON GLUCOSE TOLERANCE IN
NORMAL HUMAN DIABETIC PATIENTS
M.R.
FERNANDO=,
ARIYANANDAband
SUBJECTS
AND
IN
S.M.D. NALINIE WICKRAMASINGHEa, E.H.KARUNANAYAKE’
MATURITY-ONSET
M.I.
THABREW”,
P.L.
“Department of Biochemistry and bDepartment of Medicine, Faculty of Medicine, University of Ruhuna, Galle and aDepartment of Biochemistry, Faculty of Medicine, University of Colombo, K&se y Road, Colombo 8 6%-i Lanka)
(Accepted September l&1990)
Summary Investigations were carried out to evaluate the effects of hot-water extracts of Artocarpus heterophytlus leaves and Asteracanthus longifoliu whole plant material on the glucose tolerance of normal human subjects and maturity-onset diabetic patients. The extracts of both Artocarpus heterophyllus and Asteracanthus longifolia significantly improved glucose tolerance in the normal subjects and the diabetic patients when investigated at oral doses equivalent to 20 gfkg of starting material.
Introduction ATtoca~s hete~oph~~~us Lam. (family ~oraeeae) and Asteraeanth~s iongif0li.a Linn. (family Acanthaceael are two medicinal plants recommended by
some traditional and Ayurvedic medical practitioners in Sri Lanka for the control of blood sugar levels in diabetic patients (Jayaweera, 1982). Previous investigations (Fernando, 1989; Fernando et al., 1989) using Sprague-Dawley rats have shown that aqueous extracts of Artocarpus heteroph~llus leaves and Aste~cant~~s longhorn whole plants possess significant oral hypoglycaemic activity. However, no scientific reports are available on their activity in humans. Since there can be considerable species variations in the activities of drugs (Hucker, 1970) it was decided to carry out studies to evaluate the hypoglycaemic activities of the above plant extracts in humans. In Correspondence to: Prof. M.I. Thabrew, Department versity of Ruhuna, P.O. Box 70, Galle, Sri Lanka.
of Biochemistry,
0378-87411803.50 0 1991 Elsevier Scientific Publishers Ireland Ltd. Published and Printed in Ireland
Faculty
of Medicine, Uni-
278
the present paper, the hypoglycaemic activities of Artocarpus heterophyllus and Asteracanthus longifolia in normal human subjects and non-insulindependent maturity-onset diabetic patients are reported. Materials and Methods Experimental
subjects
Twenty healthy male volunteers (average age 35.5 years) from the Faculty of Medicine, University of Ruhuna, Sri Lanka and 20 non-insulin-dependent diabetic patients (average age 51.4 years) attending the Karapitiya Teaching Bospital, Sri Lanka were used in this investigation. The diabetic patients chosen were free from ketoacidosis, cerebrovascular disease, acute myocardial infarction and renal complications and were not on oral or parenteral anti-diabetic drugs. Preparation
of plant extracts
The plant extracts were prepared according to the methods normally used by Ayurvedic medical practitioners for administration to diabetic patients. The botanical identity of the plants was determined by using the descriptions of Jayaweera (1982) and confirmed by comparing with authentic samples from the herbarium of the Royal Botanical Gardens in Peradeniya, Sri Lanka. Fresh mature leaves (200 g) of Artocarpus heterophyllus were boiled with distilled water (1000 ml) for 3 h and the final volume reduced to 200 ml (1 ml equivalent to 1 g of starting material). Fresh whole plant material (100 g) of Asterucanthus long~ol~ was boiled with distilled water (1000 ml) for 3 h and the final volume reduced to 200 ml, Oral glucose
tolerance
test
Following an overnight fast, a standard glucose tolerance test (50 g glucose) was performed with all experimental subjects receiving 10 ml/kg distilled water instead of the plant extracts 1 h before the glucose load. The oral glucose tolerance test was repeated on subsequent days with 10 persons in each group receiving the extract of Artocarpus heterophyllus 110 ml/kg) and the other 10 persons receiving the Asteracanthus longifolia extract (10 ml/kg) 1 h before the oral glucose load. Blood samples were then collected at 30-min intervals for 2 or 2.5 h and the blood-glucose content estimated. Blood-glucose
estimation
Blood samples (0.05 ml) were obtained by finger tip puncture using microcaps (Drummond Scientific Company, U.S.A.) and the blood glucose levels estimated by the glucose oxidase method of Hugget and Nixon (19573. Results and Discussion
The results
of the effect of the aqueous extract
of Artocarpus
heterophyl-
279
longifolia on oral glucose tolerance in healthy human subjects are illustrated in Fig. 1. In the control group receiving only distilled water (10 ml/kg) followed 1 h later by an oral load of glucose (50 gl, the peak increase in blood glucose concentration (102% or 87 mgldll was observed 30 min after glucose administration. In this group, the blood glucose concentration returned to the normal fasting range by + 2 h. In groups receiving the Artocarpus heterophyllus or Asteracanthus longifolia extracts there was a significant improvement in their ability to utilize the external glucose load. Statistical analyses by the Student’s t-test revealed significant differences between the control curve and the Artocarpus heterophyllus curve at all time intervals. The same was true for the Asteracanthus longifolia curve. The glucose tolerance curves of all 20 diabetic patients, along with a normal glucose tolerance curve of a healthy adult for comparison, are illustrated in Fig. 2. It is apparent that all 20 patients were clearly diabetic. lus or Asteracanthus
Fig. 1. Effect of the aqueous extracts of Artocarpus heterophyks (A, 10 ml/kg) and Asteracanthus longifolia (A, 10 ml/kg) on oral glucose tolerance in healthy human volunteers relative to controls (0, 10 mg/kg of distilled water). Blood samples were taken at 30-min intervals for 2.5 h and results are expressed as the percent increase in blood glucose level. Each point is the mean of 10 determinations + S.E.M. T’ < 0.001.
280
! oL_______ , ‘2
"TIME(h) Fig. 2. Glucose tolerance curves of all the diabetic patients compared to that of a representative normal healthy adult. All individuals were given distilled water (10 ml/kg) 1 h before the glucose load. . - ., glucose tolerance curves of diabetics; l - 0, glucose tolerance curve of a normal human adult.
A comparative analysis of the percentage increase in blood sugar level of each of these curves with the corresponding ones obtained with the administration of Artocarpus heterophyllus or Asteracanthus longifolia extract 1 h prior to glucose loading revealed that the patients treated with either of the plant extracts exhibited a significant improvement in glucose tolerance. In Fig. 3, the mean glucose tolerance curve of diabetic patients awaiting treatment with Artocarpus heterophyllus is compared with that obtained in patients with prior administration of the plant extract. Statistical analysis by the Student’s t-test revealed significant differences between the two curves at the 1.5 h and 2 h times, respectively. Figure 4 illustrates the mean glucose tolerance of the patients awaiting treatment with Asteracanthus 1ongifoli.a in comparison with that obtained in patients with prior administration of the plant extract. As before, statistical analysis by the Student’s ttest revealed a significant difference between the two curves from the 1.5 h time point onwards. With both plant extracts, the dosages used here correspond to those reputed to produce the maximum hypoglycaemic effects (Fernando, 1989; Fernando et al., 1989). Although both extracts had fairly comparable effects
281
on the glucose tolerance of normal individuals, Artocarpus heterophyllus appeared to be slightly more effective than Asterucanthus longifolia in diabetic patients. Thus, with diabetic patients, 2 h after the glucose load, the ATtocu~~s hetero~h~ll~-treated group showed a blood glucose level that was 36% less than the corresponding value in the control group (Fig. 31, while the Asteracanthus longifolia-treated group showed a blood glucose level only 25% less than the corresponding value in the control group (Fig. 41. In previous studies (Fernando, 1989; Fernando et al., 19891, it has been shown that both of the plant extracts under investigation here can decrease fasting blood glucose levels and improve peripheral glucose uptake and utilization in rats. Although the effects of the plant extracts on insulin release by the 6-cells of the islets of Langerhans has not been specifically investigated, the studies on rats together with the ability of the plant extracts to improve the glucose tolerance in non-insulin-dependent diabetic patients seems to suggest that Artocarpus heterophyllus and Asteracanthus longifolia may mediate their hypoglycaemic effects through an increased secretion of insulin from the pancreas. Whatever the mechanism of action, the results of the present study document the oral hypoglycaemic activity of ATtocu~~ heteToph~llus and Asterucanthus l~g~fol~ in healthy human individuals and maturity-onset diabetic
+l
‘lb
‘2
TIME(h) Fig. 3. Effect of the aqueous extract of Artocarpus heterophyllus (Cl, 10 ml/kg) on oral glucose tolerance in maturity-onset diabetic patients relative to diabetic controls (0, 10 ml/kg of distilled water). Blood samples were taken at 30-min intervals for 2 h and results are expressed as the percent increase in blood glucose level. Each point is the mean of 10 determinations + S.E.M. *P < 0.001.
TIME (h) Fig. 4. Effect of the aqueous extract of Asterucu~thus ZmgifoZiu 111, 10 ml/kg) on oral glucose tolerance in maturity-onset diabetic patients relative to diabetic controls (0, 10 ml&g of distilled water). Blood samples were taken at 30-min intervals for 2 h. Results are expressed as the percent increase in the blood glucose level. Each point is the mean of 10 determinations + S.E.M. fP < 0.001.
patients and give scientific validity for the use of these two plants as oral hypoglycaemic agents by traditional medical practitioners in Sri Lanka. Acknowledgements Part of this work was supported by Grant No. TWAS RG 68 - Sri 4 from the Third World Academy of Sciences (Italy). The authors wish to thank Miss Rohini Alahapperuma for her technical assistance. References Fernando, M.R. (1989)An Investigation of the Oral Hypoglycaemic Activity of Medici7aalPlants used in A~7vedic Medicine for the Control of ~~etes ~e~~tus. Doctoral dissertation, Faeulty of Medicine, University of Ruhuna, Sri Lanka. Fernando, M.R., Wickramasinghe, S.M.D. Nalini, Thabrew, M.I, and Karunanayake, E-H, (1989)A preliminary investigation of the possible hypog~yeaemieactivity of Aste~acu~thus ~~g~foZ~. Journal of Ethnopharmacology 2?,714. Hucker, H.B. (1970) Species differences in drug metabolism. Annual Review of Phamacology 10, 99- 118. Hugget, A. St. G. and Nixon, D.A. (1957) Use of glucose peroxidase and dianisidine in the determination of blood and urinary glucose. Lancet 2, 368-370. Jayaweera, D.M.A. (1982) Medicind Plm.ts used i% Ceykm, Parts I and IV. Nationaf Science Council of Sri-Lanka Publications, Colombo, pp. 9- 10, 89-90.