Chronological response of prostacyclin changes to moderately low doses of radiation in rat cervical spinal cord

Background: Study of vascular and its secretory profile changes is an important issue in pathogenesis of radiation myelopathy. This paper reports the prostacyclin concentration changes after low-moderate doses of X-irradiation within a short period of time. Materials and Methods: Cervical cords of Wistar rats were irradiated to doses of 0.5, 1, 2, 4 and 6 Gy X-rays. After 24 hours, 2 and 13 weeks post-irradiation, prostacyclin contents were quantified and cords specimens were also stained routinely for histological studies. Results: Twenty four hours post-irradiation, showed a decrease in the content of prostacyclin after doses of 0.5 and 1 Gy 91.67±1.47 96.80±2.17 of respectively age-matched control group. After 2 weeks the concentration of prostacyclin showed significant decreases after 6 Gy. After 13 weeks irradiation shows marked differences even after a small dose of 2 Gy (p<0.001), and after doses of the low dose group. The differences between concentration values at doses of 4 Gy and 6 Gy were significant in comparison with the control (p<0.001 and p<0.002, respectively). Conclusion: Results suggested that the response of the vascular tissues to low and moderate doses of radiation occurs prior to that of the nervous tissue of the spinal cord. It means that the asymptomatic interval after radiation is characterized by sequential physiological changes which are imperfectly reflected in routine histological study and that even in the histologically unaffected spinal cord; severe impairment is present in substructures and biochemistry of irradiated spinal

Long-term changes of prostacyclin secretion in radiation-induced myelopathy

Background: We have previously reported the short-term changes in prostacyclin profile after irradiation of rat cervical cord. Aim: Present research investigated the long-term changes of prostacyclin content. Materials/Methods: Wistar rats in groups of five were irradiated with doses of 2, 4, 6, 15, 25, 30Gy and a single group of 25 with 35Gy X-rays. After 26 and 39 weeks, prostacyclin content was quantified by 6-keto-prostaglandin-F1α (prostacyclin stabilized metabolite) . Specimens were stained routinely for histological studies. Results: The 50 latent period and effective dose were 14.86±1.16 weeks and 25.66±0.54Gy (p<0.0001), respectively. Average ratios of 6-keto-PG-F1α for doses of 2-30Gy were between 78.33-12.93 and 79.48-99.96 for 26 and 39 weeks, respectively. Prostacyclin level after 35Gy shows approximately a 7:1 ratio in comparison to the control group (p<0.002). Histopathological changes in glial and vascular tissues were diagnosed and scored. Prostacyclin bimodal profile was observed. Conclusions: Radiation can cause complex fluctuations of prostacyclin in association with marked histopathological changes

Antileishmanial and antibacterial activities of the hydroalcoholic extract of Rhus coriaria L

Leishmaniosis is one of the most serious public health concern with a worldwide distribution. Since the current treatments of leishmaniosis are toxic and expensive, frequent studies have been conducted to investigate the benefits of new resources such as medicinal plants for treatment of this infectious disease. Recent studies revealed the antiparasitic potential of Rhus coriaria. Here we investigated the potential antileishmanial and antibacterial activities of the hydroalcoholic extract of R. coriaria fruits. The fruits were extracted using 80 methanol by maceration method. The concentrations of 312, 156, 78, and 37 μg/ml of the extract were added separately to the wells containing Leishmania major (L. major) promastigotes and amastigotes. Amphotericin B was considered as positive control. Finally, the death rate was determined for the extract-treated parasites as compared to the non-treated parasite. The antibacterial activity was evaluated by measurement of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract against a set of Gram-positive and Gram-negative bacteria. The extract significantly inhibited the growth of both promastigotes (60,7) and amastigotes (59) at the concentration of 312 μg/ml with the IC50 values of 147 μg/ml and 233 μg/ml, respectively. The extract showed bactericidal effects against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, and Acinetobacter baumannii. Totally, Grampositive bacteria were more susceptible to the extract. Our findings show that the hydroalcoholic extract of R. coriaria fruits are rich in tannins and can be considered for further in vivo studies on the antileishmanial and antibacterial activities especially on dermal lesions caused by L. major