Talinum triangulare is a succulent herb from the family Portulacaceae.
It is popularly known as water leaf, mainly because of its high moisture content
(Herrara, 1999). The plant is widely cultivated in West
Africa, Asia and South America. The plant contains cardioglycosides, flavonoids
and polyphenols. The moisture content of the plant is 90.8%. It contains 2.4,
0.4, 4.4 g kg-1 of proteins, total fats and total carbohydrate, respectively
T. triangulare is edible and has nutritive value (Folarin
et al., 2001). There are claims that the plant also possesses medicinal
value. It has been credited with curing of internal heat, measles and some sexually
transmited diseases. It has prooxidant activity (Iwalewa
et al., 2005) and antiinflamatory effect (Oluwole,
2003). It can also be used as a tonic (Udo et al.,
This work was undertaken to evaluate the effect of the consumption of T. triangulare on some enzymes and biomolecules and to assess the safety or otherwise of the plant for its nutritive and medicinal use.
MATERIALS AND METHODS
Fresh plant of T. triangulare were collected from the University
of Uyo (Nigeria) medicinal gardens in March 2005. T he plant was identified
in Pharmacognosy Department of the same University. The leaves were cut into
small bits and soaked in 96% ethanol for 72 h. The extract was filtered and
concentrated in vacuo. The residue obtained was kept in a dessicator
until when used.
Twenty five wistar albino rats of both sexes weighing 144-179 g were used.
The rats were purchased from and kept in the animal house of the University
of Uyo under the care of experienced animal technicians. The rats had free access
to water and standard palletized animal feed.
Administration of Extract
The twenty five rats were divided equally into 5 groups: A, B, C, D and
E. The plant extract was administered orally to the rats once daily for 28 days.
Group A which served as control received water only. While groups B-E received
100, 250, 500 and 1000 mg kg-1 of the extract, respectively. The
weight of the rats were taken on days 1, 8, 15 and 28 (i.e., week 1, 2, 3 and
Collection of Blood
On the 29th day, the overnight fasted rats were anaesthesized with chloroform,
dissected and blood was collected directly from the heart.
Processing of Blood
The blood samples obtained were allowed to clot and were centrifuged at
7000 rpm for 10 min to obtain the blood serum. The serum was stored in a refrigerator
at 4°C until when needed for analysis.
Estimation of Enzymes and Biomolecules
Appropriate commercial kits (Randox Laboratories, United Kingdom) were used
to evaluate the serum level of the following molecules: Aspartate and alanine
transaminases, alkaline phosphatase, total cholesterol, triglycerides, high
density lipoproteins, total bilirubin, conjugated bilirubin, creatinine and
This was evaluated using the glucose oxidase method (Trinder,
Alanine Transaminase (ALAT)
The method involves the monitoring of the concentration of pyruvate hydrazone
formed with 2,4-dinitrophenyl hydrazine (Rietman and Frankel,
Aspartate Aminotransferase (ASAT)
The principle of the method used involved monitoring the concentration of
oxaloacetate hydrazone formed with 2,4,-dinitrophenyl hydrazine (Rietman
and Frankel, 1957).
Alkaline Phosphatase (Phenolphthalein Monophoshate Method)
This method is based on the principle that serum alkaline phosphatase hydrolyzes
a colourless substrate of phenolphthalein that results in phosphoric acid and
phenolphthalein at alkaline pH values. The pinkly coloured product is measured
colorimetrically at 550 nm.
This involves the enzymatic colorimetric test of glycerol phosphate oxidase
method (Zoppi and Fellini, 1976).
This was carried out by the enzymatic colorimetric chod-PAP method Zoppi
and Fellini, 1976).
High Density Lipoprotein (HDL) separated from chylomicrons. Very Low Density
Lipoproteins (VLDL) and Low Density Lipoproteins (LDL) by the addition of a
phosphotungstic and magnesium chloride (precipitating reagent) to the serum.
After centrifugation, the cholesterol content was determined by the enzymatic
colorimetric method (Zoppi and Fellini, 1976).
This was done using the Biuret method.
Modified Jaffes method (1886) was used. Creatinine
which is a hydride of creatine reacts with alkaline sodium picrate to form a
red complex which can be determined photometrically.
Total and Conjugated Bilirubin
This was based on colorimetric method (Jendrassik and
Data were expressed as Mean + SEM and were analysed by one way ANOVA and
Scheffes post test. p<0.05 was taken as significant.
RESULTS AND DISCUSSION
The results of the effects of the extract of T. triangulare on the various biomolecules are shown on Table 1. From the table, of all the parameters evaluated, only the levels of creatinine, total bilirubin and glucose were significantly affected by the extract compared to control. The extract increased serum glucose concentration at all dose levels (81.0, 76.8, 82.0, 72.8 mg dL-1 at 100, 250, 500, 1000 mg kg-1, respectively) as compared to that of control rats (47.00). The increase is not dose dependent. The reason for the hyperglycemic activity of this extract is not known. But it is possible that the extract decreased the release of insulin, stimulated release of glucagons or made the animals less sensitive to insulin.
The extract of T. triangulare also significantly reduced the serum
levels of creatinine. While control rats had creatinine concentration of 134.44;
doses of 100, 250, 500 and 1000 mg kg-1 of the extract reduced creatinine
level to 105.00, 94.20, 100.20 and 82.00 mmol L-1, respectively.
|| Effect of T. triangulare on the concentration of some
enzymes and biomolecules in rat
|Mean±SEM n = 5 *p<0.05
Increased level of creatinine is indicative of kidney disease (Annino
and Giese, 1976). The results therefore indicated that the extract did not
exert a harmful effect on the kidney.
The lower doses of the extract (100 and 250 mg kg-1) significantly
increased the serum level of total bilirubin. Hyperbilirubinemia may be due
to overproduction of bilirubin or to failure of its excretion and is seen in
numerous diseases, ranging from hemolytic anaemias to viral hepatitis and to
cancer of the pancreas (Robbert, 2000). It therefore seem
that the extract of T. triangulare might have one way or the other caused
hemolysis in the animal. Why higher dose of the extract did not exert this effect
is not known. As stated in the introduction, T. triangulare contains
cardioglycosides, flavonoids, polyphenols and other bioactive components. The
observed effect of this plant may therefore be attributable to one or more of
these constituents. However, further work needs to be done to unravel this.
The results of this study show that the extract of T. triangulare possesses hemolytic and hyperglycemic effects, suggesting that it may not be safe for a diabetic patient to consume the plant without medical supervision.