Protective Effect of Bauhinia purpurea on Gentamicin-induced Nephrotoxicity in Rats

Indian Journal of Pharmaceutical Sciences 551 September October 2009 Accepted 10 September 2009 Revised 11 June 2009 Received 05 September 2008 Indian J. Pharm. Sci., 2009, 71 (5): 547-551 min, respectively and decrease in 2% organic phase, the retention time for butenaÞ ne hydrochloride and betamethasone were observed to be 5.8 and 8.2 min, respectively. The solution stability study revealed that butenaÞ ne hydrochloride and betamethasone solutions were stable for 24 h without detectable degradation and the percentage recovery of both the drugs were found to be more than 98.02%.

Bauhinia purpurea is a flowering plant (Family: Fabaceae).Several species of this plant are known to possess pharmacological activities.Aqueous extract of leaves have antinociceptive, antiinflammatory and antipyretic [1] , hypoglycemic [2] , antimalarial, antimycobacterial, antifungal and cytotoxic activities [3] .Antioxidant and hepatoprotective activities of Bauhinia species have also been reported [4] .Methanol extract obtained from Bauhinia purpurea led to the isolation and identification of 6-butyl-3-hydroxy ß avone [5] .However, systematic and scientiÞ c reports on the investigation of ethanol extract of leaves and unripe pods of B. purpurea for its effects on renal function are scarce.In the present study, an effort has been made to evaluate the effects of the ethanol extract of leaves and unripe pods of this plant on gentamicin-induced nephrotoxicity in rats.
Bauhinia purpurea leaves and unripe pods were collected from Dhulapally, Rangareddy district, Hyderabad.The plant was authenticated at the department of Botany, Osmania University.A voucher specimen is deposited there for further reference.Leaves and unripe pods were air dried, powdered to 40 mesh and subjected to Soxhlet extraction at 60 o with ethanol.The extract was concentrated under reduced pressure.Leaf extract due to its sticky constituency was suspended in 1% Tween-80 and unripe pod extract with 1% gum acacia for oral administration.Chemical tests for carbohydrates, proteins, alkaloids, ß avonoids, triterpenes, glycosides and steroids were carried out on the Bauhinia purpurea extracts using the standard procedures available in text books [6] .
Healthy, male Wistar rats each weighing 150-200 g were used for this study.The rats were housed in    Twenty-four male Wistar rats were assigned to four groups, group I was the control group, group II was the gentamicin-treated group, group III was the gentamicin-as well as ethanol extract of leaves-treated group (BPLE) and group IV was the gentamicin-as well as ethanol extract of unripe pods of B. purpureatreated group (BPPE).Each group consisted of six rats.The gentamicin-treated group received 100 mg/ kg/day gentamicin (Hi Media Laboratories, Mumbai, India) by the intraperitoneal (i.p.) route [7] .Group III received 100 mg/kg/d gentamicin i.p. and 300 mg/ kg/d of the BPLE p.o. for eight days and group IV received 100 mg/kg/d gentamicin i.p. and 300 mg/ kg/day of the BPPE p.o. for eight days.Rats in the control group were given sterile saline solution i.p. for the same number of days.After dosing on the 8 th day, blood samples were collected via cardiac puncture method at the end of these 24 h.The serum was rapidly separated and processed for determination of serum creatinine, serum uric acid, blood urea nitrogen (BUN) and serum urea using commercially available kits of Span Diagnostics Ltd, Hyderabad, India [8] .Changes in kidney weight were recorded.Three rats per group were sacrificed and both kidneys were isolated from each rat [9] .The kidneys were weighed and processed for histopathological examination [10] .
The kidneys were sectioned longitudinally in two halves and were kept in 10% neutral formalin solution [11] .Both kidneys were processed and embedded in paraffin wax and sections were taken using a microtome.The sections were stained with hematoxylin and eosin and were observed under a computerized light microscope.The data obtained was analyzed using one-way ANOVA followed by Dunnet's multiple comparison test.P < 0.01 was considered signiÞ cant.
Serum creatinine, serum uric acid, blood urea nitrogen, serum urea and the weights of the kidneys were found to be signiÞ cantly increased in rats treated with only gentamicin; whereas treatment with the BPLE and BPPE was found to protect the rats from such effects of gentamicin.As shown in Table 1.
Control rats showed normal glomerular and tubular histology (fig.1A) Group II animals exhibited glomerular, peritubular and blood vessel congestion and result in the presence of inflammatory cells in kidney sections (Þ g. 1B).Concurrent treatment with the ethanolic extract of leaves (fig.1C) and unripe pods (Þ g. 1D) were found to reduce such changes in kidney histology induced by gentamicin (Table 2).
Our study results showed that the ethanol extract of leaves and unripe pods of B. purpurea possessed potent nephroprotective activity.Many Phytochemical reports revealed the presence of flavonoids, carbohydrates, glycosides, tannins, volatile oils, anthocyanidins, lactones and terpenoids [12] .The qualitative phytochemical investigations on the ethanolic extracts also showed positive for ß avonoids by ferric chloride, alkaline reagent and Shinoda tests.Further it has been reported that flavonoid constituents of the plant possess antioxidant and hepatoprotective properties [13] .The results of our study suggest that Bauhinia purpurea contains constituents having nephroprotective activity.Of the two extracts ethanol extract of unripe pods has signiÞ cant activity as compared to leaves extract which may be due to the phytoconstituents present in the extract.Further investigations using speciÞ c fractions of the extracts can help to isolate and identify potential nephroprotective constituents.
Peptic ulcer is worldwide problem and its prevalence is quite high in India.Several field studies from different parts of our country suggest its occurrence in 4 to 10 per thousand populations.Three states of India viz.Tamil Nadu, Andhra Pradesh, and Jammu and Kashmir are considered to be very high risk areas.The exact cause of peptic ulcer is not known, the disease results in chronic suffering, loss of working hours and occasional fatality.Smoking, alcoholism, and spices add to the severity of the disease that often precipitate serious complication of ulcer [1] .
Over the past few decades, there has been surge in research activity aimed towards the development of effective and safe antiulcer drugs both synthetically and from natural resources.Reports on clinical evaluation of synthetic drugs show that there are incidences of relapses and danger of drug interactions during ulcer therapy.Hence, the search for new and ideal antiulcer drug continues and has also been extended to herbal in search for new and novel molecules, which afford better protection and decrease the incidence of relapse.Further, herbal drugs mostly augment the defensive factors such as mucin secretion, cellular mucus, bicarbonate secretion, mucosal blood ß ow and cell turnover [2] .
Ginger (Zingiber officinale Roscoe) is one of the most commonly used herbal supplements and its substantial use in folk remedies for different medical

Fig. 1 :
Fig. 1: Photomicrographs of rat kidneys from different groups (A): Kidney tissue of control animal with normal glomeruli with an intact bowman's capsule and proximal convoluted capsule and stained with Haematoxylin and Eosin at magniÞ cation 40X.(B): Kidney tissue of animal treated with gentamicin with glomerular congestion, inß ammatory cells, necrosis and tubular casts and stained with Haematoxylin and Eosin, at magniÞ cation 200X.(C): Kidney tissue of leaves extract-treated animals with blood vessel congestion, interstitial edema and tubular casts and stained with Haematoxylin and Eosin, at magniÞ cation 800X.(D): Kidney tissue of unripe pods extract-treated animals with normal arrangement of cells and stained with Haematoxylin and Eosin, magniÞ cation 100X.

TABLE 1 : PARAMETERS STUDIED FOR THE NEPHROPROTECTIVE ACTIVITY OF ETHANOL EXTRACTS OF BAUHINIA PURPUREA Groups Serum creatinine (mg/ml) Serum uric acid (mg/ml) Blood urea nitrogen (mg/ml) Serum urea (mg/ml) Weight of kidney (g)
Values are expressed as mean±SEM.n=6 rats in each group.*P<0.01 compared to control group.

TABLE 2 : HISTOPATHOLOGICAL FEATURES OF THE KIDNEYS OF RATS OF DIFFERENT TREATMENT GROUPS
polypropylene cages and maintained under standard conditions (12 h light and dark cycles, at 25±3º and 35-60% humidity).Standard pelletized feed and tap water were provided ad libitum.The Institutional Animal Ethical Committee of Malla Reddy College of Pharmacy, Hyderabad, with college Reg.No. 1217/a/08/CPCSEA, approved the study.