Radioprotective effect of Date syrup on radiation- induced damage in Rats

Abstract

Ionizing radiation has cytotoxic and genotoxic effects caused mainly by the oxidative damage induced by free radical release. The need for radioprotectives is increasing to protect normal tissues during radiotherapy. In the present study, we investigated the radioprotective effect of Date syrup in rats subjected to whole body radiation at 6 Gy through biochemical, molecular and histopathological analysis. Significant elevations were recorded in the activities of serum ALT, AST, ALP and LDH and in the levels of all lipid profiles parameters, while the level of HDL-C was reduced. The concentration of liver MDA was elevated with depletion of hepatic glutathione (GSH) and catalase. DNA damage was evidenced by increased DNA strand breakage and DNA-protein crosslinks. Significant elevations were observed in the expression of liver TNF-α and serum activity of matrix metalloproteinase (MMP-9). Pretreatment of rats with Date syrup ameliorated the tissue damage induced by radiation as evidenced by the improvement of liver function, antioxidant status and reduction of DNA damage. Besides, liver TNF-α expression and serum MMP-9 activity were reduced. In conclusion, Date syrup could alleviate the toxic effects of ionizing radiation and thus is useful as a radioprotective in radiotherapy regimen.

Figure 1

Comet assay in hepatic tissue of different groups. (a) Group 1 (control) showing circular intact DNA; (b) Group 2 (irradiated animals) showed comet shape and tailed DNA; (c) Group 3 (Date syrup) showing circular intact DNA similar to control group; (d) Group 4 (Irradiation + Date syrup) showing moderately intact circular DNA.

Figure 2

Activity of MMP-9 and gelatin zymography of enzyme activity in control and treated groups (a) A cropped zymogram gel for identification the activity of MMP-9. Lanes 2–3 = control; lanes 4–5 = Irradiated; lanes 6–7 = Date syrup; lanes 8–9 = Irradiated + Date syrup. Positive control shown in lane 1 is from baby hamster kidney cells transfected with active MMP-9 (86 kDa) and MMP-2 (66 KDa) that are indicated by arrows. (b) Quantification of enzyme activity shown as % of bands intensity, the zymogram was quantified by MyImage Analysis Software; Thermoscientific^TM. Values are presented as mean ± SE. Means above column of histogram with different letter (a–b) are significantly different at (P < 0.05).

Figure 3

Relative quantitative expression (RQ) of TNF-α gene in liver of different groups. (a) Cropped gels identify the electrophoretic mobility of quantitative RT-PCR products of TNF-α and GAPDH (internal control) genes on two separate 2% agarose gels. Lane: 1= control; lane 2= Irradiated animal; lane 3= Date syrup animal; lane 4= Irradiated + Date syrup animal. (b) Evaluation of TNF-α gene expression in different groups. Real-Time PCR analysis was used to determine mRNA levels of TNF-α gene. The data were normalized to an endogenous reference, GAPDH and expressed as relative to control. Values are presented as mean ± SE. Means above column of histogram with different letter (a–b) are significantly different at (P < 0.05).

Figure 4

Histopathological findings. (a) Liver of control rat. (b) Liver of irradiated rat showing focal areas of degeneration, congested and dilated sinusoids. (c) Liver of a rat received dates syrup. (d) Liver of a rat pretreated with date syrup and exposed to radiation revealing slight congestion of sinusoids.