Protective effect of quercetin on histomorphometric changes in kidney of retinoid acid-treated rat fetuses / Efecto protector de la quercetina sobre los cambios histomorfométricos en el riñón de fetos de rata tratados con ácido retinoico

SUMMARY: Retinoic acid, an active metabolite of vitamin A, plays essential signaling roles in mammalian embryogenesis. Prenatal rat fetuse exposure to retinoid induces some malformations in various organs, the most active and teratogenic metablolite is all-transretinoic acid (atRA). The teratogenic effects of some drugs can be prevented by the application of antioxidant drugs and stimulation of the maternal immune system. Also, quercetin, a naturally occurring flavonoid has excellent antioxidant properties. Therefore, the aim of this study was assess the protective effects of quercetin against atRA in fetuses of rat's kidney tissue. This study was performed on 40 pregnant rats that were divided into seven groups. Control group received normal saline and test groups received DMSO, quercetin (75 mg/kg), quercetin (200 mg/kg), atRA (25 mg/kg), atRA (25 mg/kg) plus quercetin (75 mg/kg) and atRA (25 mg/kg) plus quercetin (200 mg/kg), intraperitoneally at 8-10th days of gestation. Fetuses were collected at 20th day of gestation. Kidneys were collected and placed in 10 % buffered formalin solution. Then, kidneys were sectioned by routine method and stained by H&E and examined histologically. On histomorphomertrical examination, it was observed the priglomerular space and diameter of renal corpuscle in group which received only atRA were significantly (p≤0.05) greater than those received normal saline, dimethyl sulfoxide and quercetin, while these two indexes in group which received atRA plus quercetin significantly (p≤0.05) decreased by quercetin as dose dependent manner. Number of renal corpuscles were significantly (p≤0.05) decreased by atRA, but the quercetin could not affect the glomerular numbers. It is concluded that quercetin can protect fetuses against atRA damages and prevent their incidence probably via its antioxidant effect.

RESUMEN: El ácido retinoico, un metabolito activo de la vitamina A, desempeña un papel esencial de señalización en la embriogénesis de mamíferos. La exposición al ácido retinoico en fetos de ratas prenatales induce malformaciones en varios órganos, siendo el metabolito más activo y teratogénico el ácido transretinoico (ATRA). Los efectos teratogénicos de algunos medicamentos se pueden prevenir mediante la aplicación de medicamentos antioxidantes y la estimulación del sistema inmune materno. Además, la quercetina, un flavonoide de origen natural, tiene excelentes propiedades antioxidantes. Por lo tanto, el objetivo de este estudio fue evaluar los efectos protectores de quercetina contra ATRA en fetos de tejido de riñón de rata. Este estudio se realizó en 40 ratas preñadas que se dividieron en siete grupos. El grupo control recibió solución salina normal y los grupos de prueba recibieron DMSO, quercetina (75 mg / kg), quercetina (200 mg / kg), ATRA (25 mg / kg), ATRA (25 mg / kg) más quercetina (75 mg / kg) y ATRA (25 mg / kg) más quercetina (200 mg / kg), por vía intraperitoneal a los 8-10 días de gestación. Los fetos se recolectaron a los 20 días de gestación. Los riñones se recogieron y se colocaron en solución de formalina tamponada al 10 %. Luego, los riñones se seccionaron por método de rutina y se tiñeron con H & E y se examinaron histológicamente. En el examen histomorfométrico, se observó que el espacio periglomerular y el diámetro del corpúsculo renal en el grupo que recibió solo ATRA fueron significativamente (p≤0.05) mayores que los que recibieron solución salina normal, dimetilsulfóxido y quercetina, mientras que estos dos índices, en el grupo que recibió ATRA más quercetina, disminuyó significativamente (p≤0.05) en forma dependiente de la dosis. El número de corpúsculos renales disminuyó significativamente (p≤0.05) por el ATRA, pero la quercetina no pudo afectar el número de glomérulos. Se concluye que la quercetina puede proteger a los fetos contra daños de ATRA y prevenir su incidencia, probablemente, a través de su efecto antioxidante.

The effects of photobiomodulation therapy on Staphylococcus aureus infected surgical wounds in diabetic rats. A microbiological, histopathological, and biomechanical study

ABSTRACT PURPOSE: To evaluate the effects of photobiomodulation therapy (PBMT) at 685 nm on diabetic wound healing in rats suffering from bacterial infection induced by Staphylococcus aureus (S. aureus). METHODS: Thirty streptozotocin-induced diabetic rats were allocated into two groups: control and PBMT. A 4-cm full-thickness linear-incision was made on the dorsal midline and was contaminated with S. aureus. The wounds in the PBMT group were irradiated daily for 5 consecutive days, starting 3 days after the induction and always in the mornings. RESULTS: The result revealed that PBMT resulted in a significant decrease in S. aureus CFU in the PBMT group in comparison to the control group (P<0.05). The length of wounds, in the 2nd and 3rd weeks, in the PBMT group were significantly shorter compared to the control group (P<0.05). PBMT caused a significant increase in the histological parameters in comparison to the control group (P<0.05). Moreover, PBMT significantly increased the breaking strength of the surgical scars produced in the skin of the PBMT group when compared to the control group (P<0.05). CONCLUSION: Photobiomodulation therapy may be useful in the management of wound infection through a significant bacterial growth inhibition and an acceleration of wound healing process.

The effects of low level laser therapy on Staphylococcus aureus infected third-degree burns in diabetic rats

PURPOSE: To characterize the effects of low-level laser (LLL) on third-degree burn wounds which were infected with Staphylococcus aureus (S. aureus) in diabetic rats. METHODS: Thirty streptozotocin-induced diabetic rats were divided into two groups: the control and the LLL groups. Third-degree burns were induced using a heated metal rod, and then, were contaminated with S. aureus. The wounds in the LLL group were irradiated with a LLL (685nm) daily for five consecutive days, starting three days after the induction. The wound area was measured at 3, 5, 8, 14 and 21 days after burning. At the end of trial, the skin samples were harvested. RESULTS: Reduction in wound areas in the LLL and control groups were significantly different only on the 21st day (p<0.05). The mean bacterial numbers in the LLL group were significantly lower (p<0.05) than those in the control group. The number of macrophages, new blood vessels, fibroblast, and elevated collagen deposition in the LLL group significantly increased compared to the control group (p<0.05). The mean breaking strength of scars in the control group was significantly lower (p<0.05) than that of the LLL group. CONCLUSION: The low-level laser improved the healing of S. aureus third-degree burn infections in diabetic rats.

Increased isolation and characterization of Shigella sonnei obtained from hospitalized children in Tehran, Iran.

Shigella flexneri has been the most frequent cause of shigellosis in children in Iran. To evaluate the changes in frequency of serogroups, 302 Shigella species were isolated in 2003 from hospitalized children, aged less than 12 years, with acute diarrhoea in Tehran, Iran. The number of collected S. sonnei, S. flexneri, S. boydii, and S. dysenteriae isolates was 178 (58.9%), 110 (37.4%), 10 (3.3%), and 4 (1.3%) respectively. Most (94%) S. sonnei isolates were resistant to co-trimoxazole. They were, however, relatively or completely sensitive to 15 commonly-used antibiotics. The extracted plasmids showed 12 different profiles with two closely-related patterns constituting 70% of the total isolates. Ribotyping, using PvuII, HindIII or SalI restriction enzymes, generated a single pattern for all S. sonnei isolates. Data suggest that S. sonnei has become the predominant serogroup in children in the hospitals of Tehran.