Effects of Aloe Vera on healing of colonic anastomoses: experimental rat study / Efeitos da Aloe Vera na cicatrização de anastomoses colônicas: estudo experimental em ratos

ABSTRACT Background: Although herbal medicinal products are being used widely throughout the World, beneficial and harmful effects have not been well documented. Our aim was to evaluate the effects of Aloe Vera (AV) on colonic anastomosis healing. Material and methods: 112 albino Wistar rats were randomly assigned into five main groups: preoperative Aloe Vera Group (P), pre- and postoperative Aloe Vera Group (PP), Control Group (C), sham Aloe Vera Group (SA) and Sham Control Group (SC). Groups P, PP, and SA received 1.6 mL/kg per day Aloe Vera by orogastric feeding catheter for 1 month prior to the experiment. Groups P, PP, and C underwent anastomosis of the distal colon, and subgroups (n = 4) of each were sacrificed on postoperative day 3, 7, 14 and 21. Anastomotic bursting pressure, perianastomotic collagen content and histopathological changes were studied. Results: The SC Group had significantly higher ABP when compared with the SA Group (p = 0.0002), although hydroxyproline content showed no difference. When ABP was compared between anastomosis groups, it was found significantly lower in Aloe Vera groups on Day 3 (P3 vs. C3, p = 0.003 and PP3 vs. C3, p = 0.007). Hydroxyproline content was significantly lower in Group PP than Group C, also on Day 3 (p = 0.05). Significant difference was not detected after Day 3 in any of the study parameters. Conclusion: Aloe Vera decreased tissue collagen content in the early postoperative period. It is advisable to call into question the concomitant usage of conventional medicine and the herbal supplements for the surgeons in their clinical practice.

RESUMO Fundamentação: Embora os medicamentos à base de plantas sejam amplamente utilizados no mundo inteiro, seus efeitos (benéficos e prejudiciais) não estão bem documentados. Este estudo teve como objetivo avaliar os efeitos da Aloe vera (AV) na cicatrização de anastomoses colônicas. Material e métodos: 112 ratos Wistar albinos foram distribuídos aleatoriamente em cinco grupos principais: AV pré-operatório (P), AV pré e pós-operatório (PP), controle (C), sham AV (SA) e sham controle (SC). Os grupos P, PP e SA receberam AV em uma dose de 1,6 mL/kg por dia por sonda de alimentação orogástrica por 1 mês antes do experimento. Os grupos P, PP e C foram submetidos a anastomose do cólon distal. Subgrupos (n = 4) de cada grupo foram sacrificados no terceiro, sétimo, 14° e 21° dias pós-operatórios. Os seguintes parâmetros foram avaliados: pressão de ruptura anastomótica (PRA), conteúdo de colágeno perianastomótico e alterações histopatológicas. Resultados: O grupo SC apresentou PRA significativamente maior quando comparado ao grupo SA (p = 0,0002), embora o conteúdo de hidroxiprolina não tenha apresentado diferença. Ao comparar a PRA entre os grupos de anastomose, ela foi significativamente menor no terceiro dia nos grupos que usaram AV (P3 vs. C3, p = 0,003 e PP3 vs. C3, p = 0,007). No terceiro dia, o teor de hidroxiprolina foi significativamente menor no grupo PP do que no grupo C (p = 0,05). Após o terceiro dia, não se observou diferença significativa em nenhum dos parâmetros do estudo. Conclusão: O uso de AV diminuiu o conteúdo de colágeno tecidual no período pós-operatório imediato. É aconselhável questionar o uso concomitante da medicina convencional e suplementos fitoterápicos na prática clínica.

Role of new biomarkers for predicting renal scarring in vesicoureteral reflux: NGAL, KIM-1, and L-FABP.

BACKGROUND: Reflux nephropathy is the most serious complication of vesicoureteral reflux (VUR). The aim of this study was to assess the role of urinary levels of neutrophil-gelatinase-associated lipocalin (NGAL),kidney injury molecule-1 (KIM-1), and liver-type fatty-acid-binding protein (L-FABP) in the early diagnosis of reflux nephropathy in patients with VUR. METHODS: This study assessed 123 patients with primary VUR and 30 healthy children as a control group. The children were divided into five groups: Group A, patients with VUR and renal parenchymal scarring (RPS); Group B, patients with VUR and without RPS; Group C, patients with RPS and resolved VUR; Group D, patients with resolved VUR and without RPS; Group E, healthy reference group. RESULTS: Median urinary NGAL (uNGAL)/Creatinine (Cr) was significantly higher in patients with than those without RPS and the control group (p = 0.0001). Median uKIM-1/Cr was similar in all groups (p = 0.417). Median uL-FABP/Cr was significantly higher in patients with RPS than in the reference group (p < 0.05). CONCLUSIONS: Urinary NGAL levels may be used as a noninvasive diagnostic marker for predicting renal scarring in reflux nephropathy.

Urinary NGAL, KIM-1 and L-FABP concentrations in antenatal hydronephrosis.

INTRODUCTION: The clinical tests currently in use for obstructive nephropathy (such as renal ultrasonography, differential radionuclide renal scans and urinary creatinine concentration data) are not efficient predictors of the subsequent clinical course. Novel and simple biomarkers are required which, if proven, could be clinically beneficial in determining if a patient is eligible for surgery or reno-protective therapy. More recently, the interest of clinicians has focused on the potential of urinary neutrophil gelatinase-associated lipocalin (uNGAL), urinary kidney injury molecule-1 (uKIM-1) and urinary liver-type fatty acid-binding proteins (uL-FABP) as biomarkers for renal function in children with hydronephrosis (HN). OBJECTIVE: The purpose of this study was to investigate possible clinical applications of uNGAL, uKIM-1 and uL-FABP as beneficial non-invasive biomarkers to determine whether or not surgical intervention is required in children with HN. STUDY DESIGN: Renal ultrasonography and radionuclide renal scans were used as diagnostic tools to detect HN. Patients were divided into two groups based on the antero-posterior diameter of their renal pelvis and the presence of dysfunction. Group 1 included 26 children with severe HN (with dysfunction), and group 2 consisted of 36 children with mild HN (without dysfunction). Urine samples were collected from 62 children with HN and 20 healthy children. RESULTS: Hydronephrosis was more common in males than in females, with a male to female ratio of 9:1 in the study sample. The incidence of left kidney involvement (32 patients) was slightly higher than right kidney involvement (28 patients). Compared with controls and group 2, the ratio of uNGAL to creatinine was significantly higher in group 1 (p < 0.05). The biomarker uNGAL/Cr exhibited fairly good diagnostic accuracy, with an area under the curve of 0.68 [95% confidence interval 0.6-0.7] and an optimal cut-off value of 0.16 ng/mg Cr (sensitivity 58%, specificity 75%) (p < 0.05). There was a positive correlation between the uNGAL/Cr ratio and the uKIM-1/Cr ratio (r = 0.582, p < 0.05) and uL-FABP/Cr ratio (r = 0675, p < 0.05) in group 1. DISCUSSION: The results clearly demonstrated that children with hydronephrosis and dysfunction had significantly increased uNGAL, and uNGAL/Cr concentrations. However, uKIM-1, uKIM-1/Cr, uL-FABP and uL-FABP/Cr concentrations were not significantly different when compared with controls. These results support the use of uNGAL concentrations as an early marker for renal dysfunction in HN. CONCLUSIONS: The study clearly demonstrated that pediatric patients with hydronephrosis and dysfunction had significantly higher uNGAL to creatinine concentrations as compared with controls.

Effects of a static magnetic field on wound healing: results in experimental rat colon anastomoses.

BACKGROUND: Research has shown that pulsed electromagnetic fields (EMFs) promote wound healing in experimental colonic anastomosis; however, the effects of static EMFs in this setting have not been investigated to date. METHODS: Fifty male Wistar rats were used. Ten served as controls for mechanical strength testing, and the other 40 underwent descending colon resection and anastomosis. Twenty of these 40 animals (M group) had NeFeB magnets placed in contact with the anastomosis site (magnetic field strength at the site 390 to 420 G). The other 20 animals (sham [S] group) had non-magnetized NeFeB bars of the same dimensions and weight implanted. Half of the animals in each group were killed and assessed for healing parameters on postoperative day 3 (M3 and S3 groups) and the other half on postoperative day 7 (M7 and S7 groups). Four types of assessment were done: gross healing, mechanical strength, hydroxyproline deposition, and histopathology. RESULTS: There were no differences between the M and S animals with respect to gross healing parameters. The mechanical strength was also not different between groups (23.8 +/- 12.7 and 24.7 +/- 9.6 mm Hg for M3 and S3, respectively; P = .863 and 91.3 +/- 65.4 and 94.8 +/- 55.9 mm Hg for M7 and S7, respectively; P = .902). Similarly, hydroxyproline deposition was not different between groups on postoperative day 3 or day 7. On postoperative day 3, the M group had significantly higher scores than the S group for fibroblast infiltration (2.4 +/- 0.7 vs 1.4 +/- 0.7, respectively; P = .008) and capillary formation (2.5 +/- 0.7 vs 0.9 +/- 0.4, respectively; P <.001). However, these effects were reversed and did not endure by day 7. CONCLUSIONS: The study results suggest that static EMF has no effect on experimental colonic wound healing in the rat.

The effect of tissue adhesive, octyl-cyanoacrylate, on the healing of experimental high-risk and normal colonic anastomoses.

BACKGROUND: Tissue adhesives may be advantageous over sutures in colonic anastomoses because they do not result in potentially dangerous tight tissue approximation. METHODS: Ninety male Wistar-albino rats were used in the study. Excluding the 10 animals that constituted the control, the rest of the animals were divided in two groups: normal (N) and high-risk (HR). Only resection and anastomosis were done on half of the animals in each group. Octyl-cyanoacrylate was applied on the anastomosis of the other half of the groups. Anastomotic assessment was done at the third and seventh postoperative days. Gross anastomotic healing, mechanical strength, hydroxyproline deposition, and histopathological healing indices were used for the assessment. RESULTS: There was no difference in the third day and the seventh day groups regarding the gross healing parameters and hydroxyproline concentration. Similarly there was no difference between the third day groups in terms of mechanical healing (P = 0.669). However, the mechanical strength of the anastomosis assessed the seventh postoperative day was lower in groups in which octyl-cyanoacrylate was applied (P <0.001). Furthermore, inflammatory reaction, presence of necrosis, peritonitis, and exudate was pronounced in groups in which octyl-cyanoacrylate was applied. CONCLUSIONS: Application of octyl-cyanoacrylate to both normal and high-risk colonic anastomosis does not provide any benefit over conventional suturing at the early phase of the healing. However, octyl-cyanoacrylate seems to be detrimental at the late phase of the healing probably due to the ongoing intense inflammatory reaction.