Effect of Horse-chestnut seed extract on matrix metalloproteinase-1 and -9 during diabetic wound healing.

The effects of aqueous-ethanol extract of Horse chestnut (HCE) on MMP-1 and MMP-9 expressions during cutaneous wound healing in diabetic rats were investigated in this study. The expressions of MMP-1 and MMP-9, wound closure, myeloperoxidase (MPO) activity, hydroxyproline, and malondialdehyde (MDA) levels in wound tissue were measured. Quercetin glucuronide in HCE was identified as main compound using a LC-MS/MS. The hydroxyproline level was significantly increased in the treated group versus control after the 3rd and 7th days (p < 0.05). The MDA level and MPO activity were significantly lower in the treatment group (p < 0.05). MMP-1 gene expression level in treated rats was increased in the 7th day while it was reduced in 14th day. MMP-9 gene expression level in treated rats was decreased in 7th, and 14th days compared to control (p < 0.05). These results show that HCE accelerated the cutaneous wound-healing process in diabetic rats via MMP-1 and MMP-9 regulation. PRACTICAL APPLICATIONS: The main function of MMPs is to degrade and deposite the various components of the extracellular matrix. Also, they participate physiological processes such as inflammation, angiogenesis, and tissue remodeling. Horse chestnut seeds (HC) are known to be rich in saponins and flavonoids. HC are used for the treatment of abdominal pain, stomach ache, cold, hemorrhoids, arterial stiffness, rheumatism, oedema, diarrhea, chronic venous insufficiency and also as an antihemorrhagic and antipyretic in traditional medicine. It has been shown that HC has anti-inflammatory, antioedema, vessel protective, and free radical scavenging properties. This study indicates that HCE could be an effective agent for wound healing in diabetic wound model via its ability to suppress the MMP-9 gene expression and regulates MMP-1 gene expression besides its antioxidative, anti-inflammatory effects.

Dracorhodin perchlorate regulates fibroblast proliferation to promote rat's wound healing.

In recent years, plant-derived extracts are increasing interest from researchers worldwide due to good efficacy and lower side effects. Among the different plant extracts, Dracorhodin perchlorate (DP) is originated from Dragon's blood which has long been used as a natural medicine with various pharmacological activities. In the present study, we have explored the potential regulation of DP on fibroblast proliferation which promotes wound healing both in vitro and in vivo. DP at treatment of 12-24 h significantly induced fibroblast proliferation which is associated with increasing level of phosphorylated-extracellular signal-regulated kinase (ERK). Moreover, if ERK is halted with siRNA, DP cannot induce fibroblast proliferation. In vivo, DP ointment treatment at low- (2.5 µg/mL), medium- (5 µg/mL) and high-(10 µg/mL) doses, rat wounds healed more rapidly compared with the control group. After DP treatment for 7 days, Serpin family H member 1 (SERPINH1) staining confirmed enhanced fibroblast proliferation in the wound tissue. Finally, phosphorylated-ERK in the wound tissue remarkably increased with DP ointment treatment. Therefore, DP may be developed into a potential lead compounds for the treatment of wounds in clinical trials in the near future.

The antioxidant property of chitosan green tea polyphenols complex induces transglutaminase activation in wound healing.

The present study examined, for the first time, the in vitro wound healing potential of chitosan green tea polyphenols (CGP) complex based on the activation of transglutaminase (TGM) genes in epidermal morphogenesis. Response surface methodology was applied to determine the optimal processing condition that gave maximum extraction of green tea polyphenols. The antioxidant activity, scavenging ability, and chelating ability were studied and expressed as average EC50 values of CGP and other treatments. In silico analysis and gene coexpression network was subjected to the TGM sequences analysis. The temporal expressions of TGMs were profiled by semi-quantitative reverse transcription (RT)-PCR technology within 10 days after wounding and 2 days postwounding. CGP showed the effectiveness of antioxidant properties, and the observations of histopathological photography showed advanced tissue granulation and epithelialization formation by CGP treatment. In silico and coexpression analysis confirmed the regulation via TGM gene family in dermatological tissues. RT-PCR demonstrated increased levels of TGM1-3 expression induced by CGP treatment. The efficacy of CGP in wound healing based on these results may be ascribed to its antioxidant properties and activation of the expression of TGMs, and is, thus, essential for the facilitated repair of skin injury.

Incision wound healing activity of pine bark extract containing topical formulations: a study with histopathological and biochemical analyses in albino rats.

The present study was designed to identify and compare the in vivo wound healing capacity of a bark extract from Pinus brutia and Pycnogenol in an incision wound model in rats. O/W cream formulations were prepared incorporating 2% Pycnogenol and P. brutia bark extract. The rats were divided into three groups (n = 8). Subsequently placebo and test formulations were applied to animals once a day from day "0" until the 9th day. Malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) were studied in addition to histopathological examinations. Treatment with F. brutia extract containing cream inhibited lipid peroxidation by a 35% decrease in MDA and 46.8% increase in SOD activity, whereas 19.3% decrease in MDA and 34.7% increase in SOD activity were attained with Pynogenol compared to control. The histological data revealed a better performance of P. brutia extract enriched formulation in terms of degeneration of hair roots, increased vascularization and a decrease in necrotic area. Consequently, a high wound healing activity was observed in animals treated with P. brutia extract significantly accelerating the wound healing process.

Supplemental L-arginine enhances wound healing in diabetic rats.

L-arginine has been shown to enhance wound strength and collagen deposition in rodents and humans. Diabetes mellitus, which impairs wound healing, is accompanied by a reduction in nitric oxide at the wound site. The amino acid L-arginine is the only substrate for nitric oxide synthesis. We sought to determine whether supplemental L-arginine can restore the impaired wound healing of diabetic rats. Fifty-six male Lewis rats were used in this study, of which twenty-nine rats were rendered diabetic 7 days prior to surgery with intraperitoneal streptozotocin. Twenty-seven untreated rats served as controls. Animals underwent a dorsal skin incision with implantation of polyvinyl-alcohol sponges. Sixteen diabetic and 14 normal rats received 1 g/kg/day of L-arginine by injection, while the remainder received saline injections only. Animals were euthanized 10 days postwounding, and their wounds were analyzed for breaking strength. The wound sponges were assayed for total hydroxyproline and nitrite/nitrate content. Plasma and wound fluid concentrations of L-arginine, ornithine, and citrulline were determined. Wound sponge RNA was extracted and subjected to Northern blot analysis for procollagen I and III. Diabetic wounds had greatly decreased breaking strengths compared with controls. L-arginine significantly enhanced wound breaking strengths in both control (+23%) and diabetic animals (+44%), and also increased wound hydroxyproline levels in both diabetic (+40%) and control animals (+24%) as compared to their saline-treated counterparts. mRNA for procollagen I and III were elevated by L-arginine treatment in both diabetic rats and controls. Treatment with L-arginine significantly increased wound fluid nitrite/nitrate levels in diabetic animals. The data show that the impaired healing of diabetic wounds can be partially corrected by L-arginine supplementation, and that this effect is accompanied by enhanced wound nitric oxide synthesis.

L-Arginine supplementation enhances diabetic wound healing: involvement of the nitric oxide synthase and arginase pathways.

Diabetes impairs wound healing and there are few therapeutic options to reverse it. Previous work has demonstrated the importance of nitric oxide for successful wound healing. In diabetes, NO synthesis is reduced in the wound milieu. The amino acid L-arginine is the only substrate for NO synthesis. We hypothesized that L-arginine supplementation would enhance wound healing by restoring NO synthesis. Thirty-six male Sprague-Dawley rats (body weight, 225 to 250 g) were separated in 4 groups: 20 rats were rendered diabetic 7 days prior to wounding by intraperitoneal streptozotocin (STZ) injection (70 mg/kg). Sixteen rats served as controls. Half of the animals of each group received 1 g/kg supplemental L-arginine administered by gavage twice daily. Control rats were gavaged with water. Treatment was started 3 days before wounding. All rats underwent a dorsal skin incision and subcutaneous implantation of polyvinyl alcohol (PVA) sponges. The rats were killed 10 days post wounding and wound breaking strength, hydroxyproline content of the sponges, nitrite/nitrate (NO(x)) concentration, arginase activity, and amino acid composition of the wound fluid and plasma were analyzed. Wound fluid NO(x) concentrations and wound breaking strength were significantly reduced in the diabetic group compared to the controls. L-Arginine treatment restored diabetic NO(x) levels toward normal values and significantly enhanced wound breaking strength. Wound fluid arginase activity and ornithine concentrations were significantly lower in the diabetic animals but unaffected by treatment. The data demonstrate that the impaired NO synthesis in the diabetic wound milieu can at least partially be reversed by arginine supplementation. In view of previous results on the importance of NO for wound healing, the data suggest that arginine supplementation restores impaired healing in this acute wound model by normalizing the NO pathway but without affecting arginase activity.

Induction of inducible nitric oxide synthase and its corresponding tetrahydrobiopterin-cofactor-synthesizing enzyme GTP-cyclohydrolase I during cutaneous wound repair.

Recent work has suggested a possible role of nitric oxide, a free radical gas, during the wound healing process. In this study we investigated the regulation of inducible nitric oxide synthase (iNOS) and GTP-cyclohydrolase I (GTP-CH I), the rate-limiting enzyme in the biosynthesis of the iNOS cofactor (6R) 5,6,7,8-tetrahydrobiopterin (6-BH4), during the repair process. We found a similar time course of induction of iNOS and GTP-CH I expression, whereas absolute expression levels were different for both genes. Immunohistochemical analysis revealed colocalization of iNOS and GTP-CH I proteins in the wound. Systemic treatment with glucocorticoids significantly altered the expression levels of iNOS and GTP-CH I. Expression of iNOS and GTP-CH I was suppressed by glucocorticoids in normal, and to a much greater extent in wounded skin. Furthermore, a role of nitric oxide as a novel mediator of gene regulation during healing is suggested by the demonstration of nitric oxide-mediated induction of vascular endothelial growth factor expression in keratinocytes. These findings may provide an explanation for the beneficial effects of orally supplemented L-arginine on wound healing, and suggest that a disturbed induction of iNOS and GTP-CH I expression may at least partially underlie the wound healing defect seen in glucocorticoid-treated animals.

Characterization of the constitutive and wound-inducible monoterpene cyclases of grand fir (Abies grandis).

Monoterpene cyclase activity is greatly increased in grand fir (Abies grandis) sapling stems in response to wounding and the composition of the cyclic olefin mixture generated differs from that produced constitutively as determined by radio gas-liquid chromatography. Cell-free extracts from wounded stems and from non-wounded controls were systematically compared for monoterpene cyclase activities following partial purification and separation of these enzymes by anion-exchange chromatography (Mono Q FPLC) and native PAGE. The increase in monoterpene cyclase activity following wounding represents both the apparent enhancement of constitutive cyclase activities and the appearance of novel cyclization enzymes that are absent in nonwounded controls. A pinene cyclase was shown to be the major wound-inducible enzyme directly responsible for oleoresin monoterpene formation and was tentatively identified as a 62-kDa protein by SDS-PAGE.