Topical combined Phyllanthus emblica Linn. and simvastatin improves wound healing in diabetic mice by enhancing angiogenesis and reducing neutrophil infiltration.

The present study aimed to investigate the effects of combined Phyllanthus emblica Linn. (PE) and simvastatin (SIM) on diabetic wounds in male BALB/C mice. Bilateral full thickness wound excisions were performed in the control and diabetic groups (45 mg/kg streptozotocin, intraperitoneally injected daily for 5 days). The diabetic mice received daily treatment with four different types of cream: Vehicle [diabetes mellitus (DM) + Vehicle group], 100% PE (DM + PE group), 5% SIM (DM + SIM group) and combined 100% PE + 5% SIM (DM + Combination group) for 4, 7 and 14 days. The tissue malondialdehyde (MDA) and IL-6 protein levels, the number of infiltrated neutrophils, and the percentages of wound closure (%WC), capillary vascularity (%CV) and re-epithelialization (%RE) were subsequently measured. The results indicated that in the DM + Combination group, %CV and %WC were significantly increased when compared with the DM + Vehicle group on days 7 and 14. The tissue MDA content on day 14, and the number of infiltrated neutrophils on days 4 and 7 were significantly reduced in the DM + Combination group compared with those in the DM + Vehicle group. Furthermore, a strong positive correlation was revealed between %CV and %WC in the five groups on day 7 (r=0.736; P=0.0003). These findings indicated that topical application of combined PE and SIM could enhance wound healing by upregulating angiogenesis and reducing neutrophil infiltration in mice with diabetic wounds.

The effects of oral Aloe vera on the efficacy of transplanted human endothelial cells and the expression of matrix metalloproteinases in diabetic wound healing.

BACKGROUND: Diabetic wounds are characterized by delayed healing and impaired angiogenesis. Aloe vera and human umbilical vein endothelial cells (HUVECs) are reported to facilitate wound healing, and the former also has hypoglycemic property. Matrix metalloproteinases are enzymes that play a role in diabetic wound pathogenesis. OBJECTIVE: To investigate whether oral Aloe vera can enhance the efficacy of HUVEC transplantation and inhibit the expression of matrix metalloproteinases in wound healing of diabetic mice. MATERIALS AND METHODS: BALB/c nude mice were randomly assigned into five groups: normal control group, diabetic group (DM), DM transplanted with HUVECs, DM treated with oral Aloe vera, and DM treated with combined HUVECs and oral Aloe vera. Diabetes was induced by streptozotocin. Bilateral full-thickness excision cutaneous wounds were created. At days 7 and 14 post-wounding, the following parameters were determined: blood glucose, wound area, wound perfusion, capillary vascularity, re-epithelialization rate and tissue VEGF levels. Tissue expressions of MMP-2 and MMP-9 were compared between the DM mice and those treated with oral Aloe vera. RESULTS: Over days 7 and 14, Aloe vera exerted glucose-lowering effect in diabetic mice. Higher wound closure rate, blood flow and capillary vascularity, and lower MMP-2 and MMP-9 expressions were observed at both time points in DM treated with Aloe vera group compared with DM group (P < 0.05). Moreover, combined therapy of HUVECs and oral Aloe vera was more effective than Aloe vera or HUVECs alone in increasing VEGF levels, capillary vascularity and wound perfusion. Blood glucose levels were negatively correlated with angiogenesis (P = 0.000. CONCLUSION: It is suggested that oral Aloe vera enhances the efficacy of HUVEC transplantation on diabetic wound angiogenesis, partly through improving glycemic control. Oral Aloe vera also promotes diabetic wound healing via inhibition of MMP-2 and MMP-9 expressions.

High dose oral vitamin C and mesenchymal stem cells aid wound healing in a diabetic mouse model.

OBJECTIVE: This study sought to determine the effects of oral vitamin C (VitC) and mesenchymal stem cells (MSCs) on wound healing in diabetic nude mice. METHOD: Bilateral, full-skin thickness wounds were created as an in vivo wound model in BALB/C diabetic nude mice. The mice were separated into five groups: control (CON); diabetes mellitus (DM, from a streptozotocin injection); DM treated with MSCs (DM+MSCs); DM treated with VitC (DM+VitC), and DM treated with MSCs and VitC (DM+MSCs+VitC). After wounding, daily oral-feeding of high dose VitC (1.5g/l) was administered, and a single dose of MSCs (1x106 cells) was given topically using matrix gel application to the wounded area. RESULTS: At day seven, the lowest rate of wound healing, in terms of percentage of wound closure, appeared in the DM group, as compared with the CON and all other treatment groups (mean percentage of wound closure and standard deviation), CON=75.94±7.09%; DM=55.65±9.59%; DM+MSCs=78.57±6.46%; DM+VitC=77.52±3.31%; and DM+MSCs+VitC=84.61±2.87%, p≤0.05. At day 14 post-wounding, the combination of oral high dose VitC and MSCs accelerated wound healing (91.44±3.19%, p≤0.05). In addition, the highest capillary density in DM+MSCs+VitC was obtained at 14 days post-wounding (29.49±7.30%, p≤0.05). CONCLUSION: The findings of this study highlight the possibility of using oral high dose VitC in adjunct to MSCs to increase angiogenesis and accelerate diabetic wound healing in an animal model. This novel therapeutic approach should be studied further to test if it could be a useful adjunct of existing therapies to prevent infection and amputation in patients with diabetes.

Pleiotropic Effects of Simvastatin on Wound Healing in Diabetic Mice.

OBJECTIVE: To evaluate the effects of pre-treatment with low-dose simvastatin on angiogenesis and wound healing in a diabetic mouse model. MATERIAL AND METHODS: Balb/c nude mice were divided into three groups, including control (CON), diabetic (DM, and diabetic pre-treated with low-dose simvastatin (DM+ SIM). Seven days prior to wounding, the DM + SIM group was started on oral simvastatin (0.25 mg/kg/day). Eleven weeks after diabetes was induced, all mice were subjected to a bilateral full-thickness excisional skin wound on the back (0.6 x 0.6 cm²). On day 14 after wounding, percentage of wound closure (%WC), percentage of capillary vascularity (%CV), and neutrophil infiltration were determined using Image Pro-Plus, confocal fluorescence microscopy, and hematoxylin and eosin (H&E) staining, respectively. Tissue vascular endothelial growth factor (VEGF) was detected by ELISA at days 7 and 14, post-wounding. RESULTS: On day 14, %WC and %CV in CON and DM + SIM groups were significantly increased, with no significant change observed in the DM group. Neutrophil infiltration in the CON and DM + SIM groups was signficantly lower than that of the DM group. VEGF levels in the CON and DM + SIM groups were significantly higher than levels in the DM group on day 7, but not different among groups on day 14. CONCLUSION: The present study demonstrated that pre-treatment with low-dose simvastatin could increase angiogenesis, reduce inflammation, and improve wound healing in diabetic mice.

Vasculoprotective effects of combined endothelial progenitor cells and mesenchymal stem cells in diabetic wound care: their potential role in decreasing wound-oxidative stress.

To investigate whether the combined endothelial progenitor cells (EPCs) and mesenchymal stem cells (MSCs) could enhance angiogenesis and wound healing in diabetic mice. Balb/c nude mice were divided into five groups, including a control group, diabetic group (DM), DM injected with 1 × 10(6) cells MSCs, DM injected with 1 × 10(6) cells EPCs, and DM injected with combined 0.5 × 10(6) cells MSCs and 0.5 × 10(6) cells EPCs. After seven weeks, the mice were anesthetized, and bilateral full-thickness excision skin wounds were made on the dorsorostral back. The percentage of wound closure in DM group decreased significantly than in control and all other treated groups on day 7 and day 14 (P < 0.005). On day 14, the percentage of capillary vascularity in combine-treated group was significantly higher than in DM (P < 0.005). In the present study, we have demonstrated that the combined EPCs and MSCs can increase vascular endothelial growth factor (VEGF) level and angiogenesis which resulted in reduced neutrophil infiltration, decreased malondialdehyde (MDA) levels, and enhanced wound healing in diabetic mice model.