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Antidiabetic activities of aqueous leaves extract of Leonotis leonurus in streptozotocin induced diabetic rats

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The present study was carried out to investigate the antidiabetic properties of aqueous leaves extract of Leonotis leonurus in streptozotocin (45 mg/kg intraperitoneal) induced diabetic rats for 15 days. The induced diabetic rats exhibited high blood glucose level, cholesterol, high density lipoprotein (HDL) and triglycerides accompanied with weight loss while the level of low density lipoprotein (LDL) was very low. In addition, the water intake was remarkably high while feed intake was decreased as compared with normal control group. The continuous oral administration of the extract at the dose of 125, 250 and 500 mg/kg for 15 days was able to lower the blood glucose level, HDL, feed and water intake while that of LDL was increased. Also, the weight loss of diabetic rats (31 g) after extract treatment was near that of glibenclamide treated groups. The extract yielded high phenolics content (48 mg/g tannic acid equivalent) and flavonoids (4.8 mg/g quercetin equivalent). These compounds have been reported to potentiate insulin secretion. The present study revealed that aqueous extract of L. leonurus possesses antihyperglycemia and antilipidemic potential and thus could support ethnotherapeutic usage of this plant.
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Journal of Medicinal Plants Research Vol. 5(1), pp. 119-125, 4 January, 2011
Available online at http://www.academicjournals.org/JMPR
ISSN 1996-0875 ©2011 Academic Journals
Full Length Research Paper
Antidiabetic activities of aqueous leaves extract of
Leonotis leonurus in streptozotocin induced diabetic
rats
S. O. Oyedemi*, M. T. Yakubu and A. J. Afolayan
School of Biological Sciences, University of Fort Hare, Alice 5700, South Africa.
Accepted 3 November, 2010
The present study was carried out to investigate the antidiabetic properties of aqueous leaves extract of
Leonotis leonurus in streptozotocin (45 mg/kg intraperitoneal) induced diabetic rats for 15 days. The
induced diabetic rats exhibited high blood glucose level, cholesterol, high density lipoprotein (HDL) and
triglycerides accompanied with weight loss while the level of low density lipoprotein (LDL) was very low.
In addition, the water intake was remarkably high while feed intake was decreased as compared with
normal control group. The continuous oral administration of the extract at the dose of 125, 250 and 500
mg/kg for 15 days was able to lower the blood glucose level, HDL, feed and water intake while that of LDL
was increased. Also, the weight loss of diabetic rats (31 g) after extract treatment was near that of
glibenclamide treated groups. The extract yielded high phenolics content (48 mg/g tannic acid equivalent)
and flavonoids (4.8 mg/g quercetin equivalent). These compounds have been reported to potentiate
insulin secretion. The present study revealed that aqueous extract of L. leonurus possesses
antihyperglycemia and antilipidemic potential and thus could support ethnotherapeutic usage of this
plant.
Key words: Leonotis leonurus, lipids, blood glucose, phenolics, flavonoids.
INTRODUCTION
Diabetes mellitus is a complex chronic disorder that
affects the metabolism of carbohydrates, fats, proteins
and electrolytes due to deficiency of insulin or
insensitivity of target organs to insulin. This disorder is
characterized by chronic hyperglycemia and abnormality
of lipid profile such as cholesterol, low and high density
lipoprotein and triglyceride leading to series of secondary
complications (Rang et al., 1991; Ravi et al., 2005).
These complications include polyuria, polyphagia,
polydypsia, ketosis, retinopathy as well as cardiovascular
disorders (Kumar and Clark, 2002). Presently, the
frequency of diabetes is increasing with a major impact
on the population of developing countries due to the
absence of effective and affordable interventions of
diabetes (Marx, 2002). According to Wild et al. (2004),
*Corresponding author. E-mail: silvanusdemi@gmail.com. Fax:
+27866282295.
about 366 million peoples were projected to be diabetic
by the year 2030. Several hypoglycemic agents have
been used for the treatment of diabetes mellitus but are
reported to produce serious adverse side effect such as
liver problems, lactic acidosis and diarrhea (Rajalakshmi
et al., 2009). In addition, they are not suitable for use
during pregnancy. Therefore, the search for more
effective agents with low cost and low side effect from
plant source has continued to be an important area of
research because of their ready availability, affordability
and low adverse side effect.
In South Africa, L. leonurus (Lamiaceae) is a shrub
indigenous plant found along forest margins, on rocky
hillsides and riverbanks as well as grasslands of the
Eastern and Western Cape, Kwazulu-Natal and
Mpumalanga Provinces of South Africa (Van Wyk et al.,
2000).
The leaves of the plant have a characteristic aromatic-
pungent odour, bright yellow- green colour and rough
texture. It has long been used traditionally for the
120 J. Med. Plant. Res.
treatment of cough, cold, influenza, chest infections,
diabetes mellitus, eczema, epilepsy, delayed
menstruation; intestinal worms, constipation, scorpion
stings, spider and snake bite (Van Wyk et al. 2000;
Ososki et al., 2002; Jager et al., 1996). Our previous
work reported the toxicological effect of sub-chronic
administration of L. leonurus in male Wistar rats
(Oyedemi et al., 2010b). Similarly, we also assessed in
vitro and in vivo antioxidant activities of this plant
(unpublished). Evidences from traditional healers have
shown that L. leonurus may have antidiabetic activity but
have not been proved scientifically (Oyedemi et al.,
2009).
Before the commencement of this study, there was
scanty information on the antidiabetic effect of this plant
in male Wistar rats induced with streptozotocin.
Therefore, the objective of this study was aimed to
investigate the antidiabetic and antilipidemic potential of
aqueous leaves extract of L. leonurus in streptozotocin
induced diabetic rats.
MATERIALS AND METHODS
Plant material
The leaves of L. leonurus were collected from rockhill field near
Ntselamanzi location in Nkokonbe Municipality (Eastern Cape,
South Africa) between May and June, 2008. It was authenticated by
Prof. DS. Grierson of the Department of Botany, University of Fort
Hare. Voucher specimen (Sun MED 2) was deposited at the Giffen
herbarium of the University.
Animals used
Male Wistar rats (Rattus novergicus) with average weight of 250.00
± 7.22 g were obtained from the animal house of the Agricultural
and Rural Development Research Institute, University of Fort Hare.
The animals were maintained at a controlled temperature of 28°C
with a 12 h light-dark cycle at room temperature and humidity of 45
to 50%. The animals were allowed free access to food (Balanced
Trusty Chunks (Pioneer Foods (Pty) Ltd, Huguenot, South Africa)
and water for 15 days. The experiment was approved by the Animal
Ethics Committee of the University of Fort Hare.
Assay kits and reagents
The assay kits for triglycerides, cholesterol and high and low
density lipoproteins were obtained from Roche Diagnostic GmbH,
Mannheim, Germany. All other reagents used were of analytical
grade and were supplied by Merck Chemicals (Pty) Ltd., Bellville,
South Africa.
Induction of experimental diabetes in animals
Streptozotocin was freshly prepared in 10 mmol/citrate buffers, pH
4.5, and injected to experimental animals (25 rats) intraperitoneally
at the dosages of 125, 250 and 500 mg/kg body weight (Siddique et
al., 1987). After 48 h of STZ administration, rats with moderate
diabetes having glycosuria and hyperglycemia (blood glucose > 8.1
mmol/L) were taken for the experiment.
Animal grouping and extract administration
Thirty-six male rats were randomized into six groups of six animals
each (30 diabetic surviving rats, 6 normal rats) were used in this
study. The extract was administered orally into the rats using
gavages throughout the experimental period. Group 1: Diabetic rats
received distilled water only (0.5 ml) on daily basis repeatedly for 15
days. Groups 2: Diabetic animals treated daily with 0.5 ml of
glibenclamide (0.6 g/kg body weight). Group 3 to 5 animals were
treated daily with 0.5 ml doses of 125, 250 and 500 mg/kg body
weight of aqueous leaves extract of L. leonurus respectively. The
blood samples were collected every fifth day from the tail vein of the
animals to determine the blood glucose level using glucometer
(Bayer Health Care, Japan). On day 16, the rats were sacrificed by
ether anesthesia.
Preparation of extract
The leaves of the plant were air dried at room temperature for 7
days. The dried leaves were thereafter pulverized using an electric
blender (Waring Products Division, Torrington, USA). The
powdered plant material (200 g) was extracted in distilled water on
a mechanical shaker (Stuart Scientific Orbital Shaker, UK) for 48 h.
The extract was filtered using a Buchner funnel and Whatman No.1
filter paper. The filtrate was freeze-dried using Savant Refrigerated
Vapor Trap (RV T41404, USA) to give a yield of 30 g. The resulting
extract was reconstituted with distilled water to give the required
doses (125, 250 and 500 mg/kg body weight) used in this study.
Preliminary phytochemical screening
The aqueous extract of Strychnos henningsii was tested by
subjecting the extract to phytochemical analysis to determine the
presence of phenols, flavonoids, alkaloids, saponin, glycoside and
tannins using the general chemical test of Zafar and Mujeeb (2002).
Total phenolics
The total phenolics content in the aqueous leaf extract of L.
leonurus was determined spectrophotometrically with Folin
Ciocalteau reagent using the modified method of Wolfe et al.
(2003). An aliquot of the extract (0.5 ml) was mixed with 2.5 ml of
10% Folin-Ciocalteu reagent and 2 ml of Na
2
CO
3
(75% w/v). The
resulting mixture was vortexed for 15 s and incubated at 40°C for
30 min for colour development. The absorbance of the samples
was measured at 765 nm using Hewlett Packard, UV
spectrophotometer. Total phenolics content was expressed as mg/g
tannic acid equivalent from the calibration curve using the equation:
Y = 0.1216x, R
2
= 0.936512, where x was the absorbance and Y
was the tannic acid equivalent (mg/g). The experiment was
conducted in triplicate and the results are reported as mean ± SD
values.
Total flavonoids
The method of Ordonez et al. (2006) was used to estimate total
flavonoids contents of the extract solution based on the formation of
a complex flavonoids - aluminums. A volume of 0.5 ml of 2% AlCl
3
ethanol solution was added to 0.5 ml of extract solution. After one
hour of incubation at the room temperature, the absorbance was
measured at 420 nm using UV-VIS spectrophotometer. A yellow
colour indicated the presence of flavonoids at the final
concentration of 0.5 mg/ml. All determinations were done in
triplicate and values were calculated from calibration curve obtained
from quercetin using the equations: Y= 0.0255x, R
2
= 0.9812, where
x was the absorbance and Y the quercetin equivalent (mg/g). The
experiment was conducted in triplicate and the results are reported
as mean ± SD values.
Total proanthocyanidins
Total proanthocyanidins was determined based on the procedure of
Sun et al. (1998). To 0.5 ml of 1 mg/ml extract solution was added 3
ml of vanillin-methanol (4% v/v), and 1.5 ml of hydrochloric acid and
then vortexed. The absorbance of resulting mixture was measured
at 500 nm after 15 min at room temperature. Total proanthocyanidin
content was expressed as catechin equivalents (mg/g) using the
following equation from the calibration curve: Y = 0.5825x, R
2
=
0.9277, where x was the absorbance and Y is the catechin
equivalent (mg/g).
Preparation of serum
The preparation of serum was carried out using the method
described by Yakubu et al. (2005). The blood samples were
collected into clean dry centrifuge tubes. An aliquot (5 ml) of the
blood was collected into sample bottles containing EDTA (BD
Diagnostics, Pre-analytical Systems, Midrand, USA) and was
allowed to clot at room temperature for 10 min. This was
centrifuged at 1282 g × 5 min using Hermle Bench Top Centrifuge
(Model Hermle, Z300, Hamburg, Germany). The sera were later
aspirated with Pasteur pipettes into sample bottles and used within
12 h of preparation for the assay of lipid profiles.
Serum lipids analysis
The levels of low density lipoprotein, high density lipoproteins,
triacylglycerol and cholesterol in the serum of the animals were
determined using the method of Tietz et al. (1994). They were
determined spectrophotometrically using assay kits from Randox
Laboratories Limited, Ardmore, Co Antrim, UK.
Effect of extract on the weight, feed and water intake of the
animals
Feed and water intake were measured everyday at the same hour
during the experimental periods while the body weight of the
animals were measured before the start and every fifth day
throughout the experimental period (15 days).
Statistical analysis
Data were expressed as mean ± SD (standard deviation) of six
replicates and were statistically analyzed using one way analysis of
variance (ANOVA). Means were separated by the Duncan multiple
test using SAS (SAS, 2002). Values were considered significant at
p < 0.05.
RESULTS AND DISCUSSION
The phytochemical screening showed the presence of
flavonoids, tannins, phenolics and saponins (Table 1).
These compounds especially flavonoids and phenolics
have been reported to enhance insulin secretion and
Oyedemi et al. 121
scavenge free radicals that are generated during diabetic
state (Marles and Farnsworth, 1995). The results of
quantitative analysis of polyphenolics compounds
investigated in this study revealed the high phenolics and
flavonoids in the aqueous leaves extract of L. leonurus
phenolics contents (48 mg/g tannic acid equivalent) and
flavonoids (4.8 mg/g quercetin equivalent) as shown in
Table 1. Flavonoids are well known to regenerate the
damaged beta cells in the diabetic rats while phenolics
are found to be effective antihyperglycemic agents
(Chakravarthy et al., 1980; Manickam et al., 1997).
The intraperitoneal injection of streptozotocin at the
dose of 45 mg/kg into rats was characterized by
polydipsia, polyuria, weight loss and hyperglycemia.
These symptoms agree with the previous findings of
Shenoy and Ramesh (2002). The elevated level of blood
glucose observed after 48 h of streptozotocin induction
confirmed the diabetic state in rats which may be
attributed to the selective cytotoxicity effect of
streptozotocin on the beta cells (Bedoya et al., 1996).
The continued treatment of diabetic rats for 15 days with
the plant extract caused a significant reduction of blood
glucose level (10.5 to 14 mmol/L) comparable to
glibenclamide which is used for the treatment of type II
diabetes (Table 2). Glibenclamide is a standard
hypoglycemic drug that stimulates insulin secretion from
beta cells of islet of Langerhans. The result obtained from
this study was in accordance with that of Ojewole et al.
(2005) who observed antihyperglycemic effect of this
plant in mice. The glucose lowering activity of plant
extract was compared with that of glibenclamide. The
possible mechanism though not investigated in this study
may be attributed to the ability of the extract to potentiate
insulin secretion from pancreatic beta cells or sensitizing
insulin receptors (Ratnasooriya et al., 2004). The
presence of flavonoids and phenolics compounds in the
extract may be responsible for this observation.
The serum cholesterol level in diabetic untreated rats
increased significantly (p< 0.05) above the normal rats
throughout the experimental period (Table 3). The
abnormal high concentration of serum lipids in the
diabetic rats induced by STZ was in agreement with the
findings of Nikkila and Kekki (1973). Similar observation
was made by Bopanna et al. (1997) who linked the rise in
serum lipid to increase mobilization of free fatty acids
from the peripheral fat depots, where free fatty acid
esterification is balanced in lipolysis cycle. In addition,
deficiency of insulin had been reported to be associated
with hypercholesterolemia and hypertriglyceridemia due
to inactivation of lipases to hydrolyze these lipids. In the
present study, the continuous administration of aqueous
leaves extract of L. leonurus and glibenclamide for 15
days reduced the level of cholesterol, triglyceride, HDL
and rise in LDL at certain doses. This observation
corroborates with several studies reported on
antilipidemic effect of plant extract used traditionally in
experimental diabetic animals (Daisy et al., 2009; Marles
122 J. Med. Plant. Res.
Table 1. Phytochemical analysis of aqueous extract of L. leonurus.
Phytochemical compounds Plant extract Total content
Alkaloids + ND
Tannins + ND
Saponin + ND
Flavonoids + 34.16 mg/g
A
Cardiac glycosides + ND
Proanthocyanidins + 25 mg/g
B
Phenolics + 220 mg/g
C
+ = Presence.
A
Tannic acid equivalent.
B
Quercetin equivalent.
C
Catechin equivalent
Table 2. Effect of oral administration of L. leonurus extract on plasma blood glucose levels of STZ induced diabetic rats.
Plasma blood glucose
Treatment
0 (day) 5 (day) 10 (day) 15 (day)
Normal 5.60 ± 0.01 5.60 ± 0.01 5.42 ± 0.02 5.40 ± 0.00
Diabetic control 25.60 ± 0.24 26.30 ± 0.21 31.30 ± 0.16 33.30 ± 0.16
Diabetic + LL (125 mg/kg) 27.47 ± 0.02 20.43 ± 0.05 17.40 ± 0.06 16.97 ± 0. 06
Diabetic + LL (250 mg/kg) 28.50 ± 0.06 18.30 ± 0.04 15.30 ± 0.12 15.23 ± 0.00
Diabetic + LL (500 mg/kg) 27.83 ± 0.05 20.50 ± 0.07 16.30 ± 0.16 13.60 ± 0.04
Diabetic + glibenclamide 27.40 ± 0.02 25.95 ± 0.04 22.30 ± 0.11 18.03 ± 0.02
Values are expressed as means ± SD (n = 6 rats).
Table 3. Effect of aqueous extract of L. leonurus extract at doses investigated on serum lipid profiles in streptozotocin induced
diabetic rats.
Serum lipids parameter
Normal
control
Diabetes
control
Do D1 D2 D3
Cholesterol (mmol/L) 1.57 ± 0.12 2.33 ± 0.05 1.50 ± 0.16 1.55 ± 0.05 1.60 ± 0.0 1.67 ± 0.12
Triacylglycerol (mmol/L) 2.17 ± 0.34 3.53 ± 0.33 1.10 ± 0.57 1.60 ± 0.30 1.00 ± 0.00 1.60 ±0.22
HDL-C (mmol/L) 1.10 ± 0.08 0.47 ± 0.05 1.30 ± 0.22 1.35 ±0.05 1.30 ±0.00 1.37 ±0.05
LDL-C (mmol/L) 0.92 ± 0.05 3.24 ± 0.02 1.27 ± 0.20 1.30 ± 0.03 1.28 ± 0.01 1.32 ± 0.03
Atherogenic index (LDL-
C/HDL-C)
0.84 6.90 0.97 0.96 0.98 0.96
Values are expressed as means ± SD (n= 6 rats). Do = diabetes+125 mg/kg extract; D1 = diabetes + 250 mg/kg extract; D2 = diabetes +
500 mg/kg extract; D3 = diabetes + glibenclamide (0.6 mg/kg). HDL-C High density lipoprotein-cholesterol. LDL-C =Low density
lipoprotein-cholesterol.
and Farnsworth, 1995; Grover et al., 2002) (Figure 1).
The induction of diabetes into the rats resulted into loss
of body weight between 20 to 31 g in comparison with the
control rats. The feed and water intake of the diseased
animals was significantly increased throughout the study
period. These symptoms are well known marker of
diabetes mellitus in both human and animal models
which is a direct consequence of insulin deficiency
(Shenoy and Ramesh, 2002). Oral administration of plant
extract at the three doses investigated was able to
improve the body weight of the animals. The extract at
the dose of 500 mg/kg significantly decreased the level of
feed and water intake comparable to glibenclamide
treated group while the dose at 250 mg/kg did not have
any significant effect. The result obtained in this study
support the report of Kim et al. (2006) who reported the
effect of Morus alba in controlling the desire for food and
water intake under diabetic condition. The significant
body weight gain observed in diabetic rats was nearly
similar to the control group after oral administration of
plant extract in a dose dependent manner. This result
agrees with other investigators who noticed increase in
body weight gain upon improvement of diabetes status
(Schwechter et al., 2003; Craft and Failla, 1983). The
Oyedemi et al. 123
-50
-40
-30
-20
-10
0
10
20
30
40
50
60
Normal Diabetes Do D1 D2 D3
Animal groups
Body weight gain (g)
Figure 1. The effect of plant extract on body weight gain after 15 days of
experimental periods. Values are expressed as means ± SD (n= 6 rats). Do =
diabetes + 125 mg/kg extract; D1 = diabetes + 250 mg/kg extract; D2 = diabetes
+ 500 mg/kg extract; D3 = diabetes + glibenclamide (0.6 mg/kg).
0
50
100
150
200
250
300
350
Normal Diabetes Do D1 D2 D3
Animal groups
Water intake (ml)
Figure 2. Effect of plant extract on water intake. Values are expressed as means ± SD (n = 6
rats). Do = diabetes+125 mg/kg extract; D1 = diabetes + 250 mg/kg extract; D2 = diabetes + 500
mg/kg extract; D3 = diabetes + glibenclamide (0.6 mg/kg).
mechanisms of action is unknown but suggest a
protective effect of L. leonurus in controlling muscle
wasting (Swanston-Flatt et al., 1990).
In conclusion, the present findings reveal that oral
administration of aqueous extract of L. leonurus leaf has
a beneficial effect in reducing the blood glucose levels as
well as lipids. This study also showed that the plant
extract improves the polydipsia, polyuria and body weight
loss of diabetic rats. Further studies on the
pharmacological and biochemical investigation to
elucidate the mechanism of antidiabetic effect of this
plant will be needed to justify its usage (Figures 2 and 3).
124 J. Med. Plant. Res.
0
10
20
30
40
50
60
70
80
90
Normal Diabetes Do D1 D2 D3
Animal groups
Feed intake (ml)
Figure 3. Effect of aqueous extract of L. leonurus on feed intake in STZ induced diabetic rats.
Values are expressed as means ± SD (n = 6 rats). Do = diabetes + 125 mg/kg extract; D1 =
diabetes + 250 mg/kg extract; D2 = diabetes+500 mg/kg extract; D3 = diabetes + glibenclamide
(0.6 mg/kg)
ACKNOWLEDGEMENT
The authors are grateful to the Govan Mbeki Research
and Development Center, University of Fort Hare, Alice,
South Africa for financial support.
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... A decrease in the body weight in the D group rats in this study agrees with the findings of Oyedemi et al. [37], where body weight loss was reported in diabetic animals induced with streptozotocin. This decrease in the body weight has been linked to deterioration of structural proteins and muscle wastage, which are commonly observed as symptoms of T2DM [25]. ...
... This decrease in the body weight has been linked to deterioration of structural proteins and muscle wastage, which are commonly observed as symptoms of T2DM [25]. Increased water intake in the D group and the subsequent polydipsia in the D and TzD groups are well known markers of T2DM in animal models, which are a direct consequence of insulin deficiency [37][38][39][40]. ...
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Diabetes mellitus is a chronic metabolic disease induced by the inability to control high blood glucose level. Helminth-induced immunomodulation has been reported to prevent or delay the onset of type 2 diabetes mellitus (T2DM), which, in turn, ameliorates insulin sensitivity. Therefore, there is a need to understand the underlying mechanisms utilized by helminths in metabolism and the induction of immuno-inflammatory responses during helminthic infection and T2DM comorbidity. This study aimed at using a laboratory animal model to determine the cytokines, chemokines and haematological indices in diabetic (T2DM) male Sprague Dawley (SD) rats infected with Trichinella zimbabwensis. One hundred and two male SD rats (160–180 g) were randomly selected into three experimental groups (i. T2DM-induced group (D) ii. T. zimbabwensis infected + T2DM group (TzD) and iii. T. zimbabwensis-infected group (Tz)). Rats selected for the D group and TzD group were injected with 40 mg/kg live weight of streptozotocin (STZ) intraperitoneally to induce T2DM, while animals in the Tz and TzD group were infected with T. zimbabwensis. Results showed that adult T. zimbabwensis worm loads and mean T. zimbabwensis larvae per gram (lpg) of rat muscle were significantly higher (p < 0.001) in the Tz group when compared to the TzD group. Blood glucose levels in the D group were significantly higher (p < 0.001) compared to the TzD group. An increase in insulin concentration was observed among the TzD group when compared to the D group. Liver and muscle glycogen decreased in the D when compared to the TzD group. A significant increase (p < 0.05) in red blood cells (RBCs) was observed in the D group when compared to the TzD and Tz groups. An increase in haematocrit, haemoglobin, white blood cells (WBCs), platelet, neutrophils and monocyte were observed in the D group when compared to the TzD group. TNF-α, IFN-γ, IL-4, IL-10 and IL-13 concentrations were elevated in the TzD group when compared to the D and Tz groups, while IL-6 concentration showed a significant reduction in the Tz when compared to the D and the TzD groups. A significant increase in CCL5 in the D and TzD groups was observed in comparison to the Tz group. CXCL10 and CCL11 concentration also showed an increase in the TzD group in comparison to the Tz and the D groups. Overall, our results confirm that T. zimbabwensis, a parasite which produces tissue-dwelling larvae in the host, regulates T2DM driven inflammation to mediate a positive protective effect against T2DM outcomes.
... The assessment of hematological parameters to determine possible alterations in the levels of biomolecules such as enzymes, metabolic products, hematology and normal function (Magalhaes et al., 2008). The occurrence of anemia in diabetes mellitus has been reported to be due to the increased nonenzymatic glycosylation of RBC membrane proteins (Oyedemi et al., 2011). Oxidation of these proteins and hyperglycemia in diabetes mellitus causes an increase in the production of lipid peroxides that leads to hemolysis of RBCs (Arun and Ramesh, 2002). ...
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This study investigated the inhibitory effect of alpha-amylase, LD50 and antidiabetic properties of the methanolic seed extract of Hunteria umbellata and its effect on biochemical parameters in streptozotocin-induced diabetic rats. Twelve albino rats were used for the acute toxicity test, while thirty-five were divided randomly into seven groups of five in each group. Group 1served as the normal control, Group 2 served as the diabetic control, Group 3 was treated with glycinorm at 50 mg/kg body weight, Group 4 was treated with extract at 200 mg/kg body weight, Group 5 was treated with 400 mg/kg body weight, Group 6was treated with 600 mg/kg body weight and Group 7 was treated with 800 mg/kg body weight by oral administration. Diabetes was induced in albino rats by intraperitoneal injection of streptozotocin at a single dose of 120 mg/kg body weight into groups 3 to 7 and was fed with methanolic seed extract of Hunteria umbellata for a period of 28 days.. The oral acute (LD 50 ) toxicity study showed that extract did not cause mortality in any experimental animals even at the highest dose of 5000 mg/kg. Body weight and glucose levels were measured on days 0, 7, 14,21 and 28. The animal was sacrificed on day 28. Serum biochemical parameters were analysed. Additionally, renal function tests, including potassium, sodium, and chloride levels and protein and albumin levels, were performed. The study also evaluated hematological parameters in the animals that were fed the methanolic seed extract of Hunteria umbellata . The animals that received different methanolic seed extracts of Hunteria umbellata showed significant (P < 0.05) reductions in blood glucose, serum liver enzymes, renal function biomarkers, packed cell volume and platelet counts and improved body weight. Conclusively,from this study, it has been demonstrated that the methanolic seed extract of Hunteria umbellata may possess weight enhancing, antihyperglycemic, hepatoprotective, improved hematological values, and cell and organ protective activities.
... The occurrence of anemia in diabetes mellitus has been reported to be due to the increased nonenzymatic glycosylation of RBC membrane proteins [38]. Oxidation of these proteins and hyperglycemia in diabetes mellitus causes an increase in the production of lipid peroxides that leads to hemolysis of RBCs [39]. Diabetes mellitus causes the development of hypochromic anemia due to a decrease in the iron content of the body resulting from oxidative stress associated with the condition [40][41][42]. ...
Article
This study investigated the inhibitory effect of alpha-amylase, LD50 and antidiabetic properties of the methanolic seed extract of Hunteria umbellata and its effect on biochemical parameters in streptozotocin-induced diabetic rats. Twelve albino rats were used for the acute toxicity test, while thirty-five were divided randomly into seven groups of five in each group. Group 1 served as the normal control, Group 2 served as the diabetic control, Group 3 was treated with glycinorm at 50 mg/kg body weight, Group 4 was treated with extract at 200 mg/kg body weight, Group 5 was treated with 400 mg/kg body weight, Group 6 was treated with 600 mg/kg body weight and Group 7 was treated with 800 mg/kg body weight by oral administration. Diabetes was induced in albino rats by intraperitoneal injection of streptozotocin at a single dose of 120 mg/kg body weight into groups 3 to 7 and was fed with methanolic seed extract of Hunteria umbellata for a period of 28 days. The oral acute (LD50) toxicity study showed that extract did not cause mortality in any experimental animals even at the highest dose of 5000 mg/kg. Body weight and glucose levels were measured on days 0, 7, 14,21 and 28. The animal were sacrificed on day 28. Serum biochemical parameters were analysed. Additionally, renal function tests, including potassium, sodium, and chloride levels and protein and albumin levels, were performed. The study also evaluated hematological parameters in the animals that were fed the methanolic seed extract of Hunteria umbellata. The animals that received different methanolic seed extracts of Hunteria umbellata showed significant (p<0.05) reductions in blood glucose, inhibitory effect of alpha-amylase, serum liver enzymes, renal function biomarkers, packed cell volume and platelet counts and improved body weight. Conclusively, from this study, it has been demonstrated that the methanolic seed extract of Hunteria umbellata may possess weight enhancing, inhibitory effect of alpha-amylase, antihyperglycemic, hepatoprotective, improved hematological values, and cell and organ protective activities. Therefore, it can be concluded that H. umbellata protects against streptozotocin-induced diabetes via regulation of blood glucose, inhibition of alpha amylase and reverse some biochemical parameters.
... However, administration of AEAMP and metformin led to a significant decline in the VLDL-c, TG, LDL-c, and TC levels, with a resultant increase in the HDL-c levels. This is indicative of the potential of the extract to improve dyslipidemia due to the lipase activation required for lipid hydrolysis [68]. Our results agree with those of Ojo et al. [47] who documented that the extract of Blighia sapida bark improved the lipid parameters in alloxaninduced diabetic rats. ...
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Background and objective Annona muricata L. peel has been recognized for many ethnobotanical uses, including diabetes management. However, limited detailed scientific information about its mechanism of antidiabetic activity exists. The objective of this study was to evaluate the anti-diabetic properties of an aqueous extract of A. muricata peel (AEAMP) and its mechanism of action on alloxan-induced diabetic rats. Methods In vitro antidiabetic assays, such as α-amylase and α-glucosidase were analyzed on AEAMP. Alloxan monohydrate (150 mg/kg b.w) was used to induce diabetes in the rats. 150 mg/kg b.w positive control group doses of 6.67, 13.53, and 27.06 mg/kg were administered to 3 groups for twenty-one days. The positive control group was administered 30 mg/kg of metformin. The negative and normal control groups were administered distilled water. The fasting blood glucose, serum insulin, lipid profile, inflammatory cytokines, antioxidant markers, carbohydrate metabolizing enzymes, and liver glycogen were analyzed as well as PI3K/AKT and apoptotic markers PCNA and Bcl2 by RT-PCR. Results AEAMP inhibited α-amylase and α-glucosidase enzymes more effectively than acarbose. AEAMP reduced FBG levels, HOMA-IR, G6P, F-1,6-BP, MDA, TG, TC, AI, CRI, IL-6, TNF-α, and NF-κB in diabetic rats. Furthermore, in diabetic rats, AEAMP improved serum insulin levels, HOMA-β, hexokinase, CAT, GST, and HDL-c. Liver PI3K, liver PCNA and pancreas PCNA were not significantly different in untreated diabetic rats when compared to normal rats suggesting alloxan induction of diabetes did not downregulate the mRNA expression of these genes. AEAMP significantly up-regulated expression of AKT and Bcl2 in the liver and pancreatic tissue. It is interesting that luteolin and resorcinol were among the constituents of AEAMP. Conclusions AEAMP can improve β-cell dysfunction by upregulating liver AKT and pancreatic PI3K and AKT genes, inhibiting carbohydrate metabolizing enzymes and preventing apoptosis by upregulating liver and pancreatic Bcl2. However, the potential limitation of this study is the unavailability of equipment and techniques for collecting more data for the study.
... Oyedemi et al., 2011) with slight modification was used to estimate total flavonoids content of the Alum and Sphatika Bhasma. The method is based on formation of a complex flavonoids-aluminums. ...
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Microbial biofilms may form on wide variety of surfaces and are problematic in medical, industrial and environmental settings. Natural antibiofilm agents are promising candidates for treatment of biofilm-associated infections. One such natural products used for therapeutic purposes is Alum (Sphatika). Besides, Ayurvedic Bhasmas are used for treatment of various ailments in India. In the present in vitro study, anti-Biofilm potential of Alum as well as its Bhasma- Sphatika Bhasma was evaluated against total 8 bacteria, viz., 4 gram negative and 4 gram positive using crystal violet staining method. Antibiofilm activity of Sphatika Bhasma was noted in the order of P. aeruginosa > S. lutea > E. coli > K. pneumoniae > S. typhi > MRSA > B. subtilis > E. faecalis, whereas, Antibiofilm effect of Alum was found to be in the order of S. lutea > P. aeruginosa > E. coli > MRSA > S. typhi > B. subtilis > K. pneumoniae > E. faecalis. In general, Sphatika Bhasma exhibited better Anti-Biofilm activity than Alum. Furthermore, four different combinations prepared from Alum (AL), Sphatika Bhasma (SB) and Ciprofloxacin (CP)- standard antibiotic were evaluated for their combinatorial effect against 8 bacterial biofilms. In general, the combination (AL + SB) displayed the highest Anti-biofilm activity against all the 8 bacterial biofilms. Antibiofilm effects of Alum and Sphatika Bhasma could be attributed to their Flavonoid content. Moreover, to best of our knowledge, this is the first study revealing the anti-biofilm potential of Sphatika Bhasma.
... Very little has been done to establish the in vitro antidiabetic properties of this plant. The aqueous extract of L. leonurus has been reported to exhibit hypoglycaemic effects in streptozotocin-induced diabetic rats, thereby decreasing blood glucose levels as well as lowdensity lipoprotein [60]. Another study conducted by Odei-Addo et al. [61] revealed that the extract Nanostructured lipid carriers (NLCs) formulation improved glucose uptake in liver cells. ...
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Oral antidiabetic drugs are usually costly and are associated with several adverse side effects. This has led to the use of medicinal plants that are considered to have multiple therapeutic targets and are readily accessible. In the Eastern Cape province of South Africa, the number of people using medicinal plants for the management of diabetes has been climbing steadily over the past two decades due to their cultural acceptability, accessibility, affordability, efficacy, and safety claims. In this study, a review of antidiabetic medicinal plants used in the Eastern Cape province of South Africa was conducted. A comprehensive literature survey was thoroughly reviewed using several scientific databases, ethnobotanical books, theses and dissertations. About forty-eight (48) plant species were identified as being used to treat diabetes by the people of Eastern Cape province. Among the plant species, only eight (8) species have not been scientifically evaluated for their antidiabetic activities and twenty antidiabetic compounds were isolated from these medicinal plants. This review has confirmed the use and potential of the antidiabetic medicinal plants in the Eastern Cape province and identified several promising species for further scientific investigation.
... In streptozotocin-induced diabetic mice, hypercholesterolemia was observed with an increased level of triglycerides, total cholesterol, and LDL-cholesterol due to an increase in cholesterol biosynthesis and intestinal absorption [33]. Treatment with nanoparticles decreases triglycerides, total cholesterol, and LDL-cholesterol to a significant level (p < 0.05); in addition, it produced a significant increase in HDL levels compared with nondiabetic mice. ...
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The absence of a treatment efficient in the control of type 2 diabetes mellitus requires more functional products to assist treatment. Luteolin (LU) and diosmin (DIO) have been known as bioactive molecules with potential for the treatment of diabetes. This work aimed to establish the role that a combination of LU and DIO in selenium nanoparticles (SeNPs) played in streptozotocin (STZ)- induced diabetes mice. Green synthesis of Se NPs was performed by mixing luteolin and diosmin with the solution of Na2SeO3 under continuous stirring conditions resulting in the flavonoids conjugated with SeNPs. The existence of flavonoids on the surface of SeNPs was confirmed by UV-Vis spectra, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) images, and DLS graphs via Zetasizer. The average diameter of GA/LU/DIO-SeNPs was 47.84 nm with a PDI of −0.208, a zeta potential value of −17.6, a Se content of 21.5% with an encapsulation efficiency of flavonoids of 86.1%, and can be stabilized by gum Arabic for approximately 175 days without any aggregation and precipitation observed at this time. Furthermore, The C57BL/6 mice were treated with STZ induced-diabetes and were exposed to LU/DIO, SeNPs, and GA/LU/DIO-SeNPs for six weeks. The treatment by nanospheres (GA/LU/DIO-SeNPs) in the mice with diabetes for a period of 6 weeks restored their blood glucose, lipid profile, glycogen, glycosylated hemoglobin, and insulin levels. At the same time, there were significant changes in body weight, food intake, and water intake compared with the STZ- untreated induced diabetic mice. Moreover, the GA/LU/DIO-SeNPs showed good antioxidant activity examined by catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) in liver and kidney and can prevent the damage in the liver evaluated by aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) activities. The nanospheres exhibited a significant anti-diabetic activity with a synergistic effect between the selenium and flavonoids. This investigation provides novel SeNPs nanospheres prepared by a high-efficiency strategy for incorporating luteolin and diosmin to improve the efficiency in type 2 diabetes.
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A study aims to determine comparative pathology of induced anchylostomiasis was conducted in murine model. L3 larvae of Ancylostoma caninum were given at the rate of 200 larvae per rat orally and 1000 per rat through per cutaneous route in both healthy and diabetic groups as per the design of the experiment. Blood samples were collected on day 15, 30 and 45 for haemato-biochemical investigations. Decrease in Hb, PCV, TEC was observed in all groups as compared to healthy control. Leukocytosis with neutrophilia and eiosinophilia was also recorded. An increase in glucose, cholesterol, ALT and AST was recorded in diabetic groups as compared to their counterparts. BUN and creatinine was elevated in all infected group. Similarly total protein and albumin gradually declines (after initial increase) in all the groups. Most of the parameters remain unaffected in group V as compared to control. It was concluded that the pathology of induced anchylostomiasis in murine model is more sever in diabetic group as evident by the significantly altered haemato-biochemical parameters when compare to their counterparts. This may be due to damage caused by non treated diabetes to different body system in addition to the anchylostomiasis.
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In this chapter, the composition and biofunctional characteristics of clove (Syzygium aromaticum) extracts were reviewed. Extraction is a key process for gaining valuable ingredients from plants and plant-derived products. There are several extraction techniques, including conventional and novel methods in the literature. Solvent and Soxhlet extraction, maceration, hydro- or steam-distillation, squeezing, and cold processing are the most known and used techniques. In contrast, microwave, pulsed electric field, ultrasound-assisted extraction, pressurized liquid extraction, and supercritical fluid extraction methods are novel techniques that have been intensively used in the plant extraction process. Syzygium aromaticum (syn. Eugenia caryophyllata Thunb., Eugenia aromaticum), commonly known as clove, is a tree from the Myrtaceae family and the second most important spice in the world trade. The plant has been used as medicine traditionally and flavoring agent in different parts of the world. The leaves, buds, and stems of the cloves can be used to prepare extracts and are generally used as whole plants. The clove extracts comprise the major compounds such as eugenol, eugenyl acetate, and caryophyllene. Among these, eugenol is the active ingredient of clove and is a phenolic and aromatic compound. The antibacterial, antifungal, antioxidant, anticancer, anti-inflammatory, antidiabetic, and antistress potentials of eugenol were reported in several studies. As well as eugenol, clove extracts have also been studied for their health-promoting effects. Clove extracts could also be utilized in the food industry as a natural antioxidant for better oxidative stability of food substances and as an anticarcinogenic agent in dentistry. In this chapter, extraction techniques used for the clove, the compositional and functional properties of clove extracts, and also using the potential for different industries are discussed.
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The selected plant extract produced concentration dependent percentage inhibition of antioxidant activity. The ethanolic extract of Leonotis nepetifolia showed low activity on hydroxyl and DPPH radical and moderate effect on nitric oxide radical. The results of the present study suggest that the tested ethanolic extract have antioxidant activity and/or free radical scavenging activity.
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The anti-diabetic and antioxidative effect of amaranth grain (AG) and its oil fraction (AO) was studied in streptozotocin-induced diabetic rats. Male Sprague-Dawley rats were divided into four groups after induction of STZ-diabetes: normal control; diabetic control; diabetic-AG supplement (500 g kg(-1) diet); diabetic-AO supplement (100 g kg(-1) diet) and fed experimental diets for 3 weeks. Serum glucose, insulin, activities of serum marker enzymes of liver function and liver cytosolic antioxidant enzymes were measured. The AG and AO supplement significantly decreased the serum glucose and increased serum insulin level in diabetic rats. Serum concentration of liver function marker enzymes, GOT and GPT, were also normalized by AG and AO treatment in diabetic rats. Liver cytosolic SOD and GSH-reductase activities were significantly increased, and catalase, peroxidase and GSH-Px activities were decreased in diabetic rats. AG and AO supplement reverted the antioxidant enzyme activities to near normal values. Hepatic lipid peroxide product was significantly higher, and GSH content was decreased in diabetic rats. However, AG and AO supplement normalized these values. Our data suggest that AG and AO supplement, as an antioxidant therapy, may be beneficial for correcting hyperglycaemia and preventing diabetic complications. Copyright (c) 2005 John Wiley & Sons, Ltd.
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Altered tissue levels of trace metals have been reported in streptozotocin-diabetic (STZ) rats. To determine whether increased hepatic and renal levels of Cu and Zn were associated with enhanced intestinal absorption, trace metal absorption was studied in control (C) and STZ rats using dietary balance and in situ ligated-loop techniques. The apparent daily absorption of dietary Zn and Cu per 100 g body wt was threefold higher in STZ than C rats. In comparison, dietary Fe absorption per day was not altered. Increased Zn absorption was closely correlated with diabetes-associated polyphagia. The initial rate of injected 65Zn excretion was more rapid in STZ rats, although the rate of excretion beyond day 7 was similar for C and STZ animals. The quantity of Zn, Fe, and Cu absorbed per 20 cm duodenal loop was similar for C and STZ rats. Zn, Fe, and Cu absorption per gram dry mucosa were reduced 45-53% in STZ rats due to the 50% increase in mucosal mass. Moreover, the quantity of radioisotopes accumulated per gram dry mucosa and the concentration of metallothionein per gram mucosal cytosol protein were similar in C and STZ animals. Together, these data demonstrate that increased absorption of dietary Zn and Cu is in part responsible for accumulation of these elements in STZ tissues and suggest altered metal transport at the luminal (brush border) surface of the intestinal epithelium.
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The root, stem and leaf calli of Tephrosia purpurea L. pers were successfully developed and main-tained on Murashige and Skoog's medium supplemented with various plant growth regulators. The content of rotenoids and rutin in the callus cultures were estimated by spectrophotometric method.
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Objective: To study the effects of perindopril on insulin sensitivity and cardiovascular complications in Wistar and spontaneously hypertensive (SH) rats made diabetic with sterptozotocin (STZ). Methods: Streptozotocin (STZ, 45 mg/kg) was given as a single dose tail-vein injection and perindopril in the dose of 1 mg/kg, p.o. daily for six weeks. The serum samples were analyzed for glucose, insulin, cholesterol and triglycerides. Oral Glucose Tolerance Test (OGTT) was done using 1.5 g/kg glucose and area under the curve for glucose (AUCglucose) and area under the curve for insulin (AUCinsulin) were determined. Cardiac functions were recorded as per the method of Neely's working heart preparation. Results: SH rats showed hyperinsulinemia along with hypertension. Injection of STZ produced a decrease in insulin levels and hyperglycemia in both Wistar as well SH rats. Treatment with perindopril prevented STZ-induced hyperglycemia and decreased the elevated blood pressure in both Wistar diabetic and SH diabetic rats. The AUCglucose was found to be significantly higher in Wistar as well as SH diabetic rats whereas, the AUCinsulin was significantly decreased. Treatment with perindopril caused a significant decrease in AUCglucose without any alteration in AUCinsulin. Injection of STZ also produced hypercholesterolemia; hypertriglyceridemia and decrease in left ventricular developed pressure (LVDP). These changes were prevented by perindopril in both Wistar and SH rats. Conclusion: Perindopril produces an improvement in insulin sensitivity, prevents dyslipidaemia and cardiac dysfunctions associated with STZ-diabetes in Wistar and SH rats.
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A flavonoid fraction (XE) extracted from the bark of pterocarpus marsupium Roxb. (Leguminoceae) was studied for the hypoglycaemic activity normal and alloxanised albino rats. The drug XE did not show a consistent effect on normal blood sugar levels but it effectively reversed the alloxan-induced changes in the blood sugar level and the beta-cell population in the pancreas. It also showed a protective effect when it was given prior to alloxan administration. The novel action of drug on the pancreatic beta-cells and absence of acute toxicity may offer a new hope to the diabetics in future.