Agrimonia eupatoria L. Aqueous Extract Improves Skin Wound Healing: An In Vitro Study in Fibroblasts and Keratinocytes and In Vivo Study in Rats.

BACKGROUND/AIM: We have previously shown that the water extract of Agrimonia eupatoria L. (AE) is a valuable source of polyphenols with excellent antioxidant properties and has clinical potential for the prevention and/or adjuvant therapy of cardiovascular complications associated with diabetes. Inspired by our previously published data, in the present study we examined whether AE improves skin wound healing in a series of in vitro and in vivo experiments. MATERIALS AND METHODS: In detail, we investigated the ability of the AE extract to induce fibroblast to myofibroblast conversion, extracellular matrix (ECM) deposition, and keratinocyte proliferation/differentiation, in vitro. In parallel, in an animal model, we measured wound tensile strength (TS) and assessed the progression of open wounds using basic histology and immunofluorescence. RESULTS: The AE extract induced the myofibroblast-like phenotype and enhanced ECM deposition, both in vitro and in vivo. Furthermore, the wound TS of skin incisions and the contraction rates of open excisions were significantly increased in the AE-treated group. CONCLUSION: The present data show that AE water extract significantly improves the healing of open and sutured skin wounds. Therefore, our data warrant further testing in animal models that are physiologically and evolutionarily closer to humans.

Pharmacological activation of estrogen receptors-α and -ß differentially modulates keratinocyte differentiation with functional impact on wound healing.

Estrogen deprivation is considered responsible for many age-related processes, including poor wound healing. Guided by previous observations that estradiol accelerates re­epithelialization through estrogen receptor (ER)­ß, in the present study, we examined whether selective ER agonists [4,4',4''-(4-propyl [1H] pyrazole-1,3,5-triyl)­trisphenol (PPT), ER­α agonist; 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN), ER­ß agonist] affect the expression of basic proliferation and differentiation markers (Ki­67, keratin­10, ­14 and ­19, galectin­1 and Sox­2) of keratinocytes using HaCaT cells. In parallel, ovariectomized rats were treated daily with an ER modulator, and wound tissue was removed 21 days after wounding and routinely processed for basic histological analysis. Our results revealed that the HaCaT keratinocytes expressed both ER­α and ­ß, and thus are well-suited for studying the effects of ER agonists on epidermal regeneration. The activation of ER­α produced a protein expression pattern similar to that observed in the control culture, with a moderate expression of Ki­67 being observed. However, the activation of ER­ß led to an increase in cell proliferation and keratin­19 expression, as well as a decrease in galectin­1 expression. Fittingly, in rat wounds treated with the ER­ß agonist (DPN), epidermal regeneration was accelerated. In the present study, we provide information on the mechanisms through which estrogens affect the expression patterns of selected markers, thus modulating keratinocyte proliferation and differentiation; in addition, we demonstrate that the pharmacological activation of ER-α and -ß has a direct impact on wound healing.

Pre- and/or postsurgical administration of estradiol benzoate increases skin flap viability in female rats.

BACKGROUND: It has been shown that estrogens have a protective effect with regard to tissue ischemia. Therefore, in this macroscopic and histological investigation, the effect of estradiol benzoate on skin flap viability was studied in sham-operated and ovariectomized Sprague-Dawley rats. METHODS: Three months prior to flap surgery a group of rats underwent ovariectomy, while the remaining animals underwent a sham operation. Subsequently, all rats had a 2 × 8-cm skin flap created on the dorsum. Rats were randomly divided into estradiol- or saline-treated groups. Treatment started either on the day of flap excision or 3 days prior to the surgery. RESULTS: Our results showed that administration of estradiol benzoate prior to and after flap surgery significantly decreases skin flap necrosis in both sham-operated and ovariectomized rats, with the highest survival rate in animals where treatment started 3 days prior to flap surgery. CONCLUSION: In conclusion, the observed protective effect of estradiol on skin flap viability could potentially be applied to plastic and reconstructive surgery in postmenopausal women. Nevertheless, further research is needed to explain the exact underlying mechanism and to find the optimal treatment protocol for human clinical practice.

[The role of estrogens in regulations of biological processes involved into wound healing--a review]. / Uloha estrogénov v regulácii biologických procesov zapojených do hojenia rán--literárny prehl'ad.

Since the average age of female population in developed countries has increased, women live up to one-third of their life in the post-menopausal period during which altered wound healing frequently occurs. It has been shown that estrogens and estrogen receptors play a key role in the regulation of processes involved in tissue repair and regeneration. Hence, for better orientation in this area of biomedical research and clinical practice the role of estrogens and their receptors in wound healing was described in this review.

Effects of equal daily doses delivered by different power densities of low-level laser therapy at 670 nm on open skin wound healing in normal and corticosteroid-treated rats: a brief report.

The optimal parameters for low-level laser therapy (LLLT) for wound healing are still open to discussion. Hence, our study was aimed at comparing the effects of different power densities of LLLT at 670 nm in rats. Four round full-thickness skin wounds were placed on the backs of 16 rats which were divided into two groups (non-steroid and steroid-treated). Three wounds were stimulated daily with a diode laser (daily dose 5 J/cm(2)) at different power densities (5, 15 and 40 mW/cm(2), respectively), and the fourth wound served as a control. Six days after surgery all animals were killed and samples removed for histological evaluation. Significant acceleration of fibroblast proliferation and new vessel formation was observed in wounds treated at the selected power densities. No significant differences were found in corticosteroid-treated rats. In conclusion, LLLT with the methodology used improved wound healing in non-steroid rats, but was not effective after corticosteroid-treatment.

The effect of equal daily dose achieved by different power densities of low-level laser therapy at 635 and 670 nm on wound tensile strength in rats: a short report.

OBJECTIVE: The aim of our study was to compare the effects of different power densities of LLLT at 635 and 670 nm achieving a daily dose of 5 J/cm(2) on wound tensile strength (TS) in rats. BACKGROUND DATA: Optimal parameters of low-level laser therapy (LLLT) are still unknown. MATERIALS AND METHODS: Under general anesthesia, one full-thickness skin incision was performed on the back of each rat (n = 40) and immediately closed using an intradermal running suture. Rats were separated into five groups depending on treatment parameters: (1) sham irradiated control group (SIC); (2) 635 nm laser-treated group at 4 mW/cm(2) (L-635/4); (3) 635 nm laser-treated group at 15 mW/cm(2) (L-635/15); (4) 670 nm laser-treated group at 4 mW/cm(2) (L-670/4); and (5) 670 nm laser-treated group at 15 mW/cm(2) (L-670/15). The total daily dose was 5 J/cm(2). Seven days after surgery each wound was removed for wound TS measurement. RESULTS: The lowest wound TS results were measured in the SIC rats (10.5 +/- 2.8 g/mm(2)). Higher wound TS results were measured in group L-670/15 (11.5 +/- 2.5 g/mm(2)) and group L-635/4 (11.7 +/- 4.3 g/mm(2)) rats, while significantly higher results were found in group L-670/4 (15.8 +/- 4.4 g/mm(2)) and group L-635/15 (15.9 +/- 4.8 g/mm(2)). The differences were significant between certain groups (p < 0.01: SIC vs. L-635/15, SIC vs. L-670/4; p < 0.05: L-635/4 vs. L-635/15, L-635/4 vs. L-670/4, L-635/15 vs. L-670/15, L-670/4 vs. L-670/15). CONCLUSION: Both red lasers significantly increased wound TS at selected parameters. Whereas the 635 nm laser significantly improved wound healing by using the higher power density, the 670 nm laser improved healing using a lower power density.