Acacia Senegal gum exudate offers protection against cyclophosphamide-induced urinary bladder cytotoxicity

Abstract

Cylophosphamide (CYCL) is a strong anticancer and immunosuppressive agent but its urotoxicity presents one of the major toxic effects that limit its wide usage particularly in high dose regimens. Therefore, this study aimed to investigate Acacia Senegal gum exudate ,Gum Arabic (GA), for its possible role as a natural, nontoxic agent against CYCL-induced urotoxicity. Male Swiss albino rats were exposed to CYCL (150 mg/kg BW, once i.p) with or without GA oral supplementation (7.5 g/kg/day for 6 days) through drinking water. Glutathione (GSH), Malondialdehyde (MDA) and Nitric oxide (NO) bladder contents were assessed. Responsiveness of the bladder rings to acetylcholine (ACh) in vitro, microscopic and macroscopic features are also investigated. CYCL produced pronounced harmful effects on bladder urothelial lining with significant increases in (MDA) and NO levels in the tissue homogenates. Bladder-GSH content is dropped by over 60% following CYCL injection. Bladder contractility, as measured by its responsiveness to ACh, recorded a marked reduction. The isolated bladders exhibited such macroscopic changes as severe edema, inflammation and extravasation. The bladder weight increased as well. Histological changes were evident in the form of severe congestion, petechial hemorrhage and chronic inflammatory reaction in the lamina propria accompanied with desquamated epithelia. GA, a potential protective agent, produced an almost complete reversal of NO induction, lipid peroxidation or cellular GSH bladder contents in the GA+CYCL-treated group. Likewise, bladder inflammation and edema were reduced. Bladder rings showed a remarkable recovery in their responsiveness to ACh. Bladder histological examination showed a near normal configuration and structural integrity, with a significant reduction in inflammation and disappearance of focal erosions. These remarkable effects of GA may be attributed to its ability to neutralize acrolein, the reactive metabolite of CYCL and/or the resultant reactive oxygen metabolites, through a scavenging action. GA may limit the cascading events of CYCL -induced damage, initiating a cytoprotective effect leading to structural and functional recovery of the bladder tissues.

Figure 1

Effect of Gum Arabic on cyclophosphamide-induced changes in the urinary bladder contractile response to different concentrations of ACh. Data is presented as Mean ± SEM (g tension/g tissue weight). GA was given in a dose of 7.5 g/kg/day for 6 days in drinking water before and during the experimental period (24 h) of CYCL that was given in a dose of 150 mg/kg i.p. CYCL induced a marked reduction in the contractile response, in a dose-response fashion, of the urinary bladder strips to Ach while GA significantly reserved this effect. Statistical analysis was done using one-way ANOVA followed by Tukey-Kramer as post-ANOVA test. *Significant difference from control group was accepted at p < 0.05.

Figure 2

Effect of Gum Arabic on cyclophosphamide induced changes in urinary bladder relative weight. Data is presented as Mean ± SEM (g tension/g tissue weight). GA was given in a dose of 7.5 g/kg/day for 6 days in drinking water before and during the experimental period (24 h) of CYCL that was given in a dose of 150 mg/kg i.p. CYCL induced a marked increase in urinary bladder relative weight while GA significantly reserved this effect. Statistical analysis was done using one-way ANOVA followed by Tukey-Kramer as post-ANOVA test. *Significant difference from control group, # and from CYCL-treated group was accepted at p < 0.05.

Figure 3

Effect of Gum Arabic and/or cyclophosphamide on the lipid peroxide content in rat urinary bladder homogenates. Data is presented as Mean ± SEM (g tension/g tissue weight). GA was given in a dose of 7.5 g/kg/day for 6 days in drinking water before and during the experimental period (24 h) of CYCL that was given in a dose of 150 mg/kg i.p. CYCL induced a marked increase in urinary bladder MDA content while GA significantly prevented this effect. Statistical analysis was done using one-way ANOVA followed by Tukey-Kramer as post-ANOVA test. *Significant difference from control group, # and from CYCL-treated group was accepted at p < 0.05.

Figure 4

Effect of Gum Arabic and/or cyclophosphamide on the glutathione content in rat urinary bladder homogenates. Data is presented as Mean ± SEM (g tension/g tissue weight). GA was given in a dose of 7.5 g/kg/day for 6 days in drinking water before and during the experimental period (24 h) of CYCL that was given in a dose of 150 mg/kg i.p. CYCL induced a marked deplesion in urinary bladder GSH content while GA significantly restored GSH level. Statistical analysis was done using one-way ANOVA followed by Tukey-Kramer as post-ANOVA test. *Significant difference from control group, # and from CYCL-treated group was accepted at p < 0.05.

Figure 5

Effect of Gum Arabic and/or cyclophosphamide on the (NO) nitric oxide content in rat urinary bladder homogenates. Data is presented as Mean ± SEM (g tension/g tissue weight). GA was given in a dose of 7.5 g/kg/day for 6 days in drinking water before and during the experimental period (24 h) of CYCL that was given in a dose of 150 mg/kg i.p. CYCL induced a marked increase in urinary bladder NO content while GA significantly prevented its induction. Statistical analysis was done using one-way ANOVA followed by Tukey-Kramer as post-ANOVA test. *Significant difference from control group, # and from CYCL-treated group was accepted at p < 0.05.

Figure 6

(A) Urinary bladder section from control animal showing a normal mucosa (arrow 1) and muscular coat with fluid in the lumen (arrow 2) (H&E stain X100). (B) Urinary bladder section from CYCL-treated animal showing edema, congestion (arrow 1), petechial hemorrhage (arrow 2) and inflammation in the lamina propria (arrow 3) with protein aqueous material into the lumen as well as a desquamative epithelium (arrow 4) (H&E stain X200). (C) Urinary bladder section from CYCL-treated animal showing edema, congestion, polymorphonuclear leukocytes and occasional erythroctes (arrow 1), lymphocytes (arrow 2) and plasma cell (arrow 3) infiltration with acute and chronic inflammation (PSA stain X400). (D) Urinary bladder section from GA followed by CYCL-treated animal showing mild residual nonspecific inflammation with almost normal structure (H&E stain X200). GA was given in a dose of 7.5 g/kg/day for 6 days in drinking water before and during the experimental period (24 h) of CYCL that was given in a dose of 150 mg/kg i.p. CYCL induced marked histological changes in rat urinary bladder that were almost completely prevented by GA.