Local application reduces number of needed EPC for beneficial effects on wound healing compared to systemic treatment in mice

Role of hydrogen sulfide in dermatological diseases

Hydrogen sulfide (H2S), together with carbon monoxide (CO) and nitric oxide (NO), is recognized as a vital gasotransmitter. H2S is biosynthesized by enzymatic pathways in the skin and exerts significant physiological effects on a variety of biological processes, such as apoptosis, modulation of inflammation, cellular proliferation, and regulation of vasodilation. As a major health problem, dermatological diseases affect a large proportion of the population every day. It is urgent to design and develop effective drugs to deal with dermatological diseases. Dermatological diseases can arise from a multitude of etiologies, including neoplastic growth, infectious agents, and inflammatory processes. The abnormal metabolism of H2S is associated with many dermatological diseases, such as melanoma, fibrotic diseases, and psoriasis, suggesting its therapeutic potential in the treatment of these diseases. In addition, therapies based on H2S donors are being developed to treat some of these conditions. In the review, we discuss recent advances in the function of H2S in normal skin, the role of altering H2S metabolism in dermatological diseases, and the therapeutic potential of diverse H2S donors for the treatment of dermatological diseases.

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.