INFLUENCE OF CRUDE EXTRACT OF ROOT OF TELFAIRIA OCCIDENTALIS ( FLUTED PUMPKIN ) ON THE CYTOARCHITECTURE OF THE RAT KIDNEY AND BODY WEIGHT

The effect of crude extract of root of Telfairia occidentalis (fluted pumpkin) was investigated on the kidney of adult wistar rats. The crude extract of pumpkin root were given both intraperitoneally and orally to rats respectively. The control group received distilled water throughout the duration of experiment. The administration lasted for seven days and on the eight day, the animals were sacrificed. Morphologically, there was decrease in the body weight, loss of appetite, weakness and death of some animals in the experimental groups. Histologically, the architecture of the kidneys in the experimental animals treated with pumpkin root extract orally and intraperitoneally showed enlarged tubules, distorted glomeruli and Bowman’s capsule, shrinking of proximal and distal convoluted tubules compared with the control. These results suggest that the root of Telfairia occidentalis may be nephrotoxic in wistar rats.


INTRODUCTION
Telfairia occidentalis is a plant named after an Irish botanist-Charles Telfairia .It belongs to the family-Cucurbitaceae that consist mostly of herbs or rarely under shrubs with watery juice.It is popularly known as fluted pumpkin (English), ikong ubong (Efik), ugwu (Igbo) and egusi iroko (Yoruba) (Gbile, 1984).The leaves are common vegetables used for preparation of soup in Efik, Ibibio and Igboland.It contains proteins, vitamins and minerals such as calcium, phosphorus and iron (Sofowora, 1986).Oil from the seed is suitable for manufacturing soap, vegetable oil (Irvine, 1969), paints, varnishes and emulsions (Asiegbu, 1987;Odemena and Onyeneke, 1988).
Telfairia occidentalis is popular among the herbal practitioners and its leaves are said to be useful in maintenance of high degree of blood alkalinity, provision of roughage which stimulates peristalsis and proper elimination of waste matter from the colon thus assisting in preventing constipation with all its associated problems like colitis, appendicitis, haemorrhoid and fissure (Iwu, 1983).It is useful in the remedy of all cases of anaemia (Ajayi et al, 2000).The leaves have been documented to stimulate bone marrow to produce blood cells and maintain body resistance to infection (Kafaruk, 1998).Phytochemical study carried out on the root of Telfairia occidentalis showed that it contains alkaloids, saponins, flavinoid, phlobatanin, tannins, anthraquinone, glycosides and terpene.Ekanem et al (2005) reported that the crude extract of the root of Telfairia occidentalis is hepatotoxic and should be used with great caution.The root of the fluted pumpkin could be used as an antibacterial agent.It contains poisonous compound, which makes it useful as rodenticide and ordeal poison (Odemena and Essien, 1988).Though the root however has been documented to be poisonous, there is hardly any information in literature regarding the effect of root Telfairia occidentalis on any organ system.This study was therefore undertaken to investigate the effect of crude extract of Telfairia occidentalis on the kidney using wistar rats as models.This study will create more awareness about the poisonous nature of the root of Telfairia occidentalis so that it should not be ignorantly used for treatment of various ailment by herbalist especially the untrained ones.

Preparation of aqueous crude extract
Fresh roots of Telfairia occidentalis were obtained from a farm in Ibiono L.G.A. in Akwa Ibom State.The roots were washed free of soil and debris.10g of the roots were pounded into paste using a pestle and mortar.40ml of water was then added to the paste and filtered with Whatman filter paper No. 1.The filtrate obtained was then administered to the rats.The crude extract was prepared on daily basis.

Procedures
Twenty-five adult wistar rats weighing about 180-200g were used in this study.They were divided into four groups labeled A, B, C, D and E, with each group consisting of five rats.The filtrate obtained was administered to the rats both orally with the aid of orogastric tube and intraperitoneally with the aid of a syringe and needle.
The rats in groups A and B were given 0.38mg/Kg body weight (1.5ml) of the crude extract intraperitoneally and orally respectively.The rats in groups C and D were given 0.75mg/Kg body weight (3.0ml) of the extract intraperitoneally and orally respectively.The group E rats (control) were given equal volumes of distilled water daily.The administration lasted for seven days.The rats were then sacrificed on the 8 th day using chloroform inhalation method.The body weight of rats in each group was taken before and during the experimental period.

Histological analysis
The kidneys were removed, fixed in 10% buffered formalin for 48 hours, then processed, sectioned at 5µm and stained using haematoxylin and eosin staining method (Drury and Wallington, 1978).

Data analysis
The data obtained from body weight measurements was subjected to the statistical analysis using student t-test.The values were expressed as mean± standard error of mean.Values of p>0.05 was taken as significant.Percentage decrease or increase in body weight was calculated.

Morphological changes
There was decrease in weight of the animals in the experimental groups as shown in The percentage decrease in weight was significantly (p>0.05)greater in the oral groups than in the intraperitoneal groups (Table 1).There was reduction in food and water intake and the rats were dull throughout the experimental period of seven days.Some rats died during the experiment.In group A animals that received 0.38mg/kg body weight of the crude extract intraperitoneally, one animal died, and group B animals that received 0.38mg/kg of the extract orally, all the animals survived till the last day of administration.In group C animals that received 0.75mg/kg body weight of the extract intraperitoneally, four animals died out of five, one was sacrificed on the fifth day of administration because it was very weak.In group D that received 0.75mg/kg orally, one animal died while all the animals in group E (control) survived till the last day because they were given distilled water.

Histological study
Histological study of the kidney of the control group, E, using haematoxylin and eosin staining method showed the renal corpuscles made up of glomeruli and Bowman's capsules.Also seen were the proximal convulated tubules, loops of Henle and distal convulated tubules (plate 1).
In the group A animals administered 0.38mk/kg body weight of the crude extract intraperitoneally, the glomeruli were slightly enlarged with reduced Bowman's spaces and the tubules are dilated (plate 2).
In the group B animals administered 0.33mgkg body weight of the crude extract orally, the histological features of the kidney showed distorted glomerulus compared to the control.The Bowman's spaces were smaller and discontinuous.The tubules were dilated compared to the control (plate 3).
In group C animals that administered 0.75mg/kg body weight of crude extract intraperitoneally, there was degeneration of the glomeruli and dilation of the tubules (plate 4).
In group D animals administered 0.75mg/kg body weight of the crude extract orally, there was total distortion of the renal cytoarchitecture (plate 5).

DISCUSSION
The observation of significant reduction in weight of the animals, loss of appetite and death of some rats may be associated with the lethal effect of the alkaloids, saponin and glycoside content of the crude extract of the root of Telfairia occidentalis.Saponins when taken orally are relatively harmless as they are only slightly absorbed by the digestive tract (Tyler et al, 1981).Saponins hemolytic properties and when injected into the blood stream are largely toxic especially to cold blooded animals and many saponins are used as fish poisons (Tyler et al, 1981) and many glucosides have formerly been used for poisoning arrows (Tyler et al, 1981).
Histologically, renal corpuscles, proximal and distal convoluted tubules were adversely affected by the oral and intraperitoneal administration of the crude extract of root of Telfairia occidentalis to rats in a manner similar to the report of Samter and Parker (1972), that the morphological sites for the adverse effect of drugs include, the tubules, interstitium, glomeruli and blood vessels.In the present study, dilation of the tubules and enlarged glomeruli seen in animals that received the crude extract of the root of Telfairia occidentalis orally and intraperitoneally may be due to increased tubular secretion, a mechanism employed to clear harmful toxins and drugs from the blood (Guyton and Hall, 1996).
Distortion and degeneration of glomeruli and total distortion of the kidney cytoarchitecture observed in the study may have been due to the effect of some components of the root of Telfairia occidentalis like the anthraquinone.Anthraquinone is not excreted by the kidney, on resorption stimulates calcium-binding proteins in the kidney to bind calcium.This therefore deposits calcium in the renal interstitium causing lithiasis.Lithiasis destroyed the interstitium, blood vessels and nephrons (Robbins et al, 2005).
The death of rats observed may have been due to renal failure.It has been reported that toxins and drugs may cause subtle but cumulative injury to the tubules, this might take years to become manifest resulting in chronic renal insufficiency.Renal failure is therefore a manifestation of cumulative effect of injury to the morphological sites of the kidney and may eventually lead to death (Guyton and Hall, 1996).
From this work, it can be concluded that the crude extract of the root of Telfairia occidentalis is nephrotoxic, effect being more pronounced in the animals, which were administered intraperitoneally.
Photomicrograph of the kidney section of group C that received 0.75g/kg body weight of crude extract of Telfairia occidentalis intraperitoneally showing degeneration of glomeruli (DG) and dilated tubules (DT) .Mag x 100 (H&E).

table 1 Table 1 :
Effect of crude extract of the root of Telfairia occidentalis on body weight (BW) of rats.