Effects of Ethanol Extract of Sida acuta Leaves on Some Organ Function Parameters and Physiologically Important Electrolytes in Normal Wistar Albino Rats

MATERIALS AND METHODS

Collection and processing of plant specimen: Sida acuta was identified by P.O. Ugwuozor, a taxonomist in the Department of Botany, Nnamdi Azikiwe University, Awka, in the South East of Nigeria. A large quantity of fresh leaves of Sida acuta were harvested and dried under shade at room temperature within the laboratory of Department of Biochemistry, Madonna University, Elele, in Rivers State of Nigeria. The leaves were then pulverized using electric blender, Eurosonic (ES 6613).

Preparation of extract: Exactly 1 kg of the pulverized leaf sample was weighed and soaked in ethanol (80%) for 24 h. The mixture was carefully filtered using whatman filter paper and the filtrate was concentrated by evaporation in a rotary evaporator RE 52-2 (Searchtech Instruments). The concentrate (extract) was kept in the refrigerator and was used for administration to the experimental animals.

Experimental animals: Wistar albino rats were obtained from a Veterinary Stock in Ibadan, Nigeria. The animals were housed in cages kept in an adequate animal house environment at the Madonna University, Elele, Nigeria. The animals were allowed to acclimatize for seven days before the commencement of administration. They were adequately fed with normal rat chow purchased from Bendel Feeds and Flour Mills Limited, Ewu, Nigeria.

Administration of extract: A total of thirty-six male albino rats were divided into six groups of six animals per group. The groups were numbered A to F and animals in each group were marked for proper identification. Groups A-E, all experimental groups, were administered graded doses of the extract, 100, 200, 300, 400 and 500, mg kg^-1 b.wt., respectively. They were orally administered daily for two weeks. Members of group F were kept as control and were maintained on normal feeding and water.

Preparation of serum sample: About 24 h, after the last administration the animals were sacrificed, group by group, by cardiac puncture and the blood transferred into already labeled centrifuge tubes and allowed to stand for 30 min at room temperature. They were then centrifuged at 4000 rpm for five minutes in an 80-1 electric centrifuge (B-Bram Scientific and Instrument Co., England). The resulting sera were used for the analysis of creatinine, urea, bilirubin, sodium, potassium, chloride and bicarbonate concentrations.

Analysis of biochemical parameters: Creatinine and urea were assayed by methods involving protein precipitation. The measurement of creatinine was carried out by the Jaffe reaction method (Fabiny and Erthinghausen, 1971). The determination of urea was carried out by the diacetyl monoxime method as described by Vijayalakshmi et al (2000). Absorbances for both indices were read from a spectrumlab 22 spectrophotometer at 520 nm. Bilirubin was assayed by the method involving diazotized sulphanilic acid reaction (Srivastav et al., 1999) with absorbance read at 540 nm.

Sodium and potassium were determined by use of flame photometer (IL 943). Bicarbonate concentration was assayed by simple titration method (Scribner and Caillouette, 1954). Biorex reagent kits (UK), BXCO281A was used to analyze chloride concentration according to specifications of the manufacturer.

Statistical analyses: Data generated in the course of this study were statistically analyzed using student t-test (2-tailed) and analysis of variance (ANOVA) at 0.05 level of significance. The Statistical Package for Social Sciences (SPSS) for windows was used for the analysis.

RESULTS

Analysis of serum samples from wistar albino rats treated with varying doses of ethanol extract of Sida acuta leaves showed that urea levels of the test animals were nonsignificantly decreased, comparative to the control (Table 1). Creatinine levels were nonsignificantly reduced except for 300 and 400 mg kg^-1 b.wt. schedules which showed significant increases (p<0.05) (Table 1).

Table 1:	Serum concentrations (mg dL-1) of urea, creatinine and bilirubin (Data represented as Mean±SD)
*Significantly different from the control (p<0.05). NB: SD (standard deviation); mg kg-1 b.wt. (milligram per kilogram body weight); mg dL-1 (milligram per deciliter)

Table 2:	Serum concentrations (mmol L-1) of various electrolytes (data represented as Mean±SD)
*Significantly different from the control (p < 0.05). NB: SD (standard deviation), mg kg-1 b.wt. (milligram per kilogram body weight); mmol L-1 (millimol per liter)

Bilirubin levels were apparently unaffected by the extract, showing only slight fluctuations when compared with the control. Only at a dose of 500 mg kg^-1 b.wt. was a significant increase recorded comparative to the control (Table 1).

The effects of the extract on various electrolytes are shown on Table 2. Sodium decreased nonsignificantly (p>0.05) except with 300 and 400 mg doses which showed significant reductions (p<0.05). Comparative with the control, both potassium and chloride concentrations were significantly affected; potassium levels were significantly reduced (p<0.05) while chloride levels were significantly increased (p<0.05).

DISCUSSION

Sida acuta extract showed only slight reductions in blood urea concentrations. Creatinine levels were also slightly reduced except in a few cases that are insufficient to elicit any fears of toxicity. There are reports that confirm the capacity of some plant extracts to cause major fluctuations in both urea and creatinine levels (Lienou et al., 2007; Ghasi et al., 2011). An increase in blood creatinine level would indicate kidney dysfunction since creatinine is cleared rapidly from the blood and excreted. Any medication that interferes with the normal actions of the kidney can lead to elevations in blood creatinine levels. Thus the relatively non-significant influence of Sida acuta extracts on these markers of kidney function is a proof of its non-toxic effect on this organ. Several plant extracts also can remarkably affect serum status of bilirubin (Takate et al., 2010; Kolawole and Kolawole, 2010; Tsala et al., 2010). Thus, Sida acuta would have no adverse effects on the liver linked to alteration in bilirubin functions. Reduction in sodium ion levels is an indication of the antihypertensive potentials of Sida acuta. However, significant decreases in potassium levels may be a source of worry since hypokalaemia is believed to predispose to clinical conditions such as muscular weakness, cardiac arrhythmias and hypotonia. Bicarbonate is reduced nearly almost insignificantly. Reduction in bicarbonate may lead to a drop in blood pH. This situation occurs when losses through urine and/or gastrointestinal tract exceeds the rate at which it can be replenished by normal homeostatic mechanisms. This situation can arise with intake of certain drugs and thus may be aggravated by Sida acuta extracts if taken in very large concentrations. Components of Sida acuta may work synergistically to depress bicarbonate and elevate chloride which was significantly elevated. Chloride is known to function actively in keeping a normal balance of fluids in the body. Administration of certain drugs may lead to elevated blood chloride (hyperchloraemia), associated with hypokalaemia. Sida acuta extract may be so implicated, from the outcome of balance of these electrolytes following its administration.

The use of crude plant extracts for treatment of diseases dates back in history. This is because plants constitute important sources of biologically active compounds. Certainly, several modern drugs in use today were developed from plants. Obviously, too, certain health challenges have presently defied orthodox medications and interestingly a good number are responsive to traditional herbal preparations, sources of which are in most cases concealed as patents. The dependence on herbal medication has continued to increase. What is more disturbing is that emphases are often placed on efficacy of the herbal extract or products with little and in numerous cases no attention directed to any possible harmful effects. Most traditional practitioners of herbal medicine lack any formal education and identify their herbal plants based only on evidence of their efficacy over certain health challenges, in most cases as inherited from some predecessors. Herbal substances and products are often administered as water extracts and tinctures (using local gins) and in many cases as blends of mixture of different plants believed to work in synergy. Unfortunately, many of these herbal blends are not scientifically resolved. We continue to process identifiable species of commonly used medicinal plants and assessing their margin of safety by monitoring the effects of administration of such extracts on essential biochemical markers.

Sida acuta has been shown extensively to possess rich medicinal properties. It is as important to exploit the rich pharmacological potentials of these natural resources that have decorated our environment which also bears numerous inundations of diseases, some of which have no defined remedies. Nevertheless, caution is necessary in the use and applications of crude plant extracts since many are also sources of certain toxic compounds. Consequently, despite the ability of Sida acuta, as for many other plants’ crude extracts to effectively cure ailments, the best approach consists in extracting the active principles and incorporating them into formulations of refined medications.