Simvastatin improves the healing of infected skin wounds of rats

Comprehensive developmental investigation on simvastatin enriched bioactive film forming spray using the quality by design paradigm: a prospective strategy for improved wound healing

The use of topical antimicrobials in wound healing presents challenges like risk of drug resistance and toxicity to local tissue. Simvastatin (SIM), a lipid-lowering agent which reduces the risk of cardiovascular events, is repurposed for its pleiotropic effect in wound healing. A bioactive bioadhesive polymer-based film forming spray (FFS) formulation of SIM was designed using chitosan, collagen, hyaluronic acid and optimised by employing the DoE approach. Optimised formulation demonstrated moderate viscosity (12.5 ± 0.3 cP), rapid film formation (231 ± 5.6 s), flexibility, tensile strength and sustained drug release (T80 - time for 80% drug release - 9.05 ± 0.7 h). Scanning electron microscopy (SEM) verified uniformly dispersed drug within the composite polymer matrix. SIM FFS demonstrated antimicrobial activity against gram positive and gram negative bacteria. In vivo excision wound model studies in mice affirmed the beneficent role of bioactive polymers and the efficacy of SIM FFS in wound contraction and closure, tissue remodelling and re-epithelization in comparison to standard antimicrobial preparation. Cytokines TNF- alpha, IL-6 were downregulated and IL-10 was upregulated. Biochemical markers; hydroxyproline, hexosamine and histopathology were consistent with wound contraction observed. This is an exploratory effort in repurposing SIM for wound healing in a novel dosage form, underscoring its potential as an alternative to conventional topical antimicrobials.

Topical application of simvastatin acid sodium salt and atorvastatin calcium salt in vitiligo patients. Results of the randomized, double-blind EVRAAS pilot study

Contemporary treatment of vitiligo remains a great challenge to practitioners. The vast majority of currently conducted clinical trials of modern therapeutic methods are focused on systemic medications, while there is only a very limited number of reports on new topical treatment in vitiligo. With their pleiotropic activities statins turned out to be efficient in the treatment of various autoimmune/autoinflammatory disorders. The randomized, double-blind placebo-controlled study of topical administration of the active forms of simvastatin and atorvastatin has been designed to evaluate their efficacy in patients with vitiligo. The study was registered in clinicaltrials.gov (registration number NCT03247400, date of registration: 11th August 2017). A total of 24 patients with the active form of non-segmental vitiligo were enrolled in the study. The change of absolute area of skin lesions, body surface area and vitiligo area scoring index were evaluated throughout the 12 week application of ointments containing simvastatin and atorvastatin. Measurements were performed with planimetry and processed using digital software. Use of active forms of simvastatin and atorvastatin did not result in a significant repigmentation of the skin lesions throughout the study period. Within the limbs treated with topical simvastatin, inhibition of disease progression was significantly more frequent than in the case of placebo (p = 0.004), while the difference was not statistically significant for atorvastatin (p = 0.082). Further studies of topical simvastatin in vitiligo patients should be considered.

Therapeutic Effects of Statins: Promising Drug for Topical and Transdermal Administration

Statins are HMG-CoA reductase inhibitors and decrease plasma low-density lipoprotein cholesterol (LDL-C) levels. They are well tolerated, and because of their LDL-C-lowering effect, they are utilized to decrease the risk of atherosclerosis and cardiovascular disease. However, statins have pleiotropic effects, including immunomodulatory, anti-inflammatory, antioxidant, and anticancer. Currently, oral administration is the only Food and Drug Administration (FDA)-approved route of administration for statins. However, other administration routes have demonstrated promising results in different pre-clinical and clinical studies. For instance, statins also seem beneficial in dermatitis, psoriasis, vitiligo, hirsutism, uremic pruritus, and graft-versus-host disease. Topically applied statins have been studied to treat seborrhea, acne, rhinophyma, and rosacea. They also have beneficial effects in contact dermatitis and wound healing in animal studies, (HIV) infection, osseointegration, porokeratosis, and some ophthalmologic diseases. Topical and transdermal application of statins is a non-invasive drug administration method that has shown significant results in bypassing the first-pass metabolism in the liver, thereby reducing possible adverse effects. This study reviews the multifaceted molecular and cellular impacts of statins, their topical and transdermal application, novel delivery systems, such as nanosystems for topical and transdermal administration and the challenges concerning this approach.

Simvastatin nanocrystals-based dissolving microneedles for wound healing

Currently, one of the main problems encountered in wound healing therapy is related to inefficient drug delivery. However, dissolving microneedles (DMNs) can be administered percutaneously to effectively deliver a drug to a deep wound area. Simvastatin (SIM) can promote wound healing, albeit its insolubility in water limits its application. Here, we designed a DMNs (SIM-NC@DMNs) drug delivery system loaded with SIM nanocrystals (SIM-NC) and evaluated its efficacy in wound healing. Based on our observations, the dissolution performance of insoluble SIM is significantly improved after the preparation of SIM-NC. For example, the saturation solubility of SIM-NC in deionized water and PBS increased by 150.57 times and 320.14 times, respectively. After the SIM-NC@DMNs are deeply inserted into the wound, the needle portion, which is composed of hyaluronic acid (HA), dissolves rapidly, and the SIM-NC loaded on the needle portion is efficiently released into the deep wound area for optimal therapeutic efficacy. The combination of NC and DMNs makes this system further effective for wound healing. Our cumulative work suggests that the newly developed SIM-NC@DMNs possess great potential in accelerating wound healing. By day 12 after treatment, the residual wound area in the Control group was 21.34 %, while the residual wound area in the SIM-NC@DMNs group was only 2.36 %. This result as well as provides certain evidence of its efficacy for wound healing therapy. The SIM-NC@DMNs drug delivery system may become an efficient treatment modality that promotes wound healing, with a promising potential in the field of wound healing research.

Formulation and evaluation of simvastatin cubosomal nanoparticles for assessing its wound healing effect

Wound healing is one of the most challenging medical circumstances for patients. Pathogens can infect wounds, resulting in tissue damage, inflammation, and disruption of the healing process. Simvastatin was investigated recently, as a wound healing agent that may supersede the present therapies for wounds. Our goal in this paper is to focus on formulation of simvastatin cubosomes for topical delivery, as a potential approach to improve simvastatin skin permeation. By this technique its wound healing effect could be improved. Cubosomes were prepared using the top-down method and the prepared cubosomes were characterized by several techniques. The most optimal simvastatin cubosomal formulation was then included in a cubogel dosage form using different gelling agents. The results showed that the average particle size of the prepared cubosomes was 113.90 ± 0.58 nm, the entrapment efficiency was 93.95 ± 0.49% and a sustained simvastatin release was achieved. The optimized formula of simvastatin cubogel displayed pseudoplastic rheological behavior. This same formula achieved enhancement in drug permeation through excised rat skin compared to free simvastatin hydrogel with flux values of 46.18 ± 2.12 mcg cm-2 h-1 and 25.92 ± 3.45 mcg cm-2 h-1 respectively. Based on the in-vivo rat studies results, this study proved a promising potential of simvastatin cubosomes as wound healing remedy.

Wound healing dynamics, morbidity, and complications of palatal soft-tissue harvesting

Palatal-tissue harvesting is a routinely performed procedure in periodontal and peri-implant plastic surgery. Over the years, several surgical approaches have been attempted with the aim of obtaining autogenous soft-tissue grafts while minimizing patient morbidity, which is considered the most common drawback of palatal harvesting. At the same time, treatment errors during the procedure may increase not only postoperative discomfort or pain but also the risk of developing other complications, such as injury to the greater palatine artery, prolonged bleeding, wound/flap sloughing, necrosis, infection, and inadequate graft size or quality. This chapter described treatment errors and complications of palatal harvesting techniques, together with approaches for reducing patient morbidity and accelerating donor site wound healing. The role of biologic agents, photobiomodulation therapy, local and systemic factors, and genes implicated in palatal wound healing are also discussed.

Comparing the wound healing effect of a controlled release wound dressing containing curcumin/ciprofloxacin and simvastatin/ciprofloxacin in a rat model: A preclinical study

Inflammation and infection are two main factors predisposing a wound to become a chronic one. Degradable wound dressings involving the controlled release of suitable drugs at the ulcer site are one of the solutions to make wounds healing progress smoothly and rapidly. In this research, biodegradable dressings made of polyglycerol sebacate/polycaprolactone (PGS/PCL) containing curcumin/ciprofloxacin (CUR/CIP) and simvastatin/ciprofloxacin (SIM/CIP) were prepared by using the coaxial electrospinning method. Transmission electron microscopy for uniform core/shell structure, swelling ratio, and drug release pattern of the wound dressings were evaluated. At the in vivo study, histometric, histopathologic, and collagen expression study was performed. The PGS/PCL samples containing SIM/CIP showed a burst release pattern of CIP with a delay in the release of SIM; meanwhile, in the samples containing CUR/CIP, both drugs showed a burst release behavior. No cytotoxicity response was observed in the study groups. The in vivo study showed that wound closure was almost completed only in the SIM/CIP group after 14 days. After 14 days, in the wound treated with SIM/CIP dressing, the amount of collagen deposition and angiogenesis was higher than that of the others. These results clearly showed the effect of SIM/CIP on the improvement of the wound healing efficiency in the long term (14 days) and the effect of CUR/CIP on wound contraction in the short term (4 day). It seems, therefore, that the use of SIM and CUR simultaneously in a wound dressing could cause a synergistic effect in the wound repair.

The protective effect of statins against pressure ulcers in stroke patients: A propensity-score matched study based on a real-world database

BACKGROUND AND AIMS

Limited information is available regarding the association between statins and pressure ulcers. The purpose of this study is to evaluate the beneficial effects of statins on pressure ulcers in stroke patients.

METHODS

Using the claims data of Taiwan's National Health Insurance, we conducted a retrospective cohort study and identified new-onset stroke patients in 2000-2004. The propensity-score matching procedure was used to select eligible stroke patients with (n = 49,919) and without (n = 49,919) the use of statins. These two groups were followed until the end of 2009 to track the occurrence of pressure ulcers. Multivariate Cox proportional hazard models were conducted to calculate adjusted hazard rations (HRs) and 95% confidence intervals (CIs) of pressure ulcer associated with the use of statins.

RESULTS

Stroke patients who used statins had a reduced risk of pressure ulcers during the follow-up period (HR 0.74, 95% CI 0.71-0.78). The association between statin use and a reduced risk of poststroke pressure ulcers was significant in men (HR 0.73, 95% CI 0.68-0.78), women (HR 0.75, 95% CI 0.71-0.80), and people aged more than 50 years. Use of lovastatin, pravastatin, rosuvastatin, atrovastatin, fluvastatin, and simvastatin was associated with reduced poststroke pressure ulcers. There was a dose-dependent decrease in the frequency of pressure ulcers with increasing quantities of statins used, from 1 prescription to ≥3 prescriptions.

CONCLUSION

We raised the possibility that use of statins was associated with reduced risk of pressure ulcers in stroke patients. However, the potential beneficial effect associated with statins requires further validation using randomized clinical trials.

Psychometric Evaluation of Stress in 17,414 Critical Care Unit Nurses: Effects of Age, Gender, and Working Conditions

Recent events regarding the COVID-19 pandemic have demonstrated the importance of healthcare workers around the world and the stressful working conditions that are often associated with their profession. The severity of stress can be influenced by a number of factors such as age, seniority gender, family status, and position in the wards. Thus, it is important to monitor signs of stress and other psychiatric symptoms in order to understand the mediating factors and guide appropriate interventions. Here, we describe a cross-sectional study of 17,414 nurses from 31 Iranian cities carried out from 2011 to 2015, using a 22-item tool of work stressors. The tool examined interactive, managerial, and situational domains and the main objective was to identify the main background variables associated with the stress of nurses in critical care settings.

Coconut Oil Nanoemulsion Loaded with a Statin Hypolipidemic Drug for Management of Burns: Formulation and In Vivo Evaluation

Burn wound healing is a complex process that involves the repair of injured tissues and the control of infection to diminish the scar formation, pain, and discomfort associated with such injuries. The aim of this research was to formulate and optimize a self-nanoemulsion drug delivery system based on the use of coconut oil and loaded with simvastatin. Coconut oil possesses antiinflammatory and antibacterial activity, and simvastatin has interesting properties for promoting the wound-healing process because it increases the production of the vascular endothelial growth factor at the site of injury. The Box–Behnken design was employed for the optimization of the coconut oil–simvastatin self-nanoemulsion drug delivery system. The prepared formulations were characterized according to globular size and their activity in the healing of burn wounds by assessing the mean wound diameter and level of interlukin-6 in experimental animals. Additionally, the antimicrobial activity of the prepared formulations was assessed. The nanoemulsion was considered adequately formed when it had droplets of between 65 and 195 nm. The statistical design proved the important synergistic effect of coconut oil and simvastatin for burn wound management in their synergistic potentiation of wound closure and their anti-inflammatory and antimicrobial effects. The optimum formulation achieved up to a 5.3-fold decrease in the mean burn wound diameter, a 4.25-fold decrease in interleukin-6 levels, and a 6-fold increase in the inhibition zone against Staphylococcus aureus when compared with different control formulations. Therefore, the designed nanoemulsions containing a combination of coconut oil and simvastatin could be considered promising platforms for the treatment of chronic and burn wounds.

Skin wound healing assisted by angiogenic targeted tissue engineering: A comprehensive review of bioengineered approaches

Skin injuries and in particular, chronic wounds, are one of the major prevalent medical problems, worldwide. Due to the pivotal role of angiogenesis in tissue regeneration, impaired angiogenesis can cause several complications during the wound healing process and skin regeneration. Therefore, induction or promotion of angiogenesis can be considered as a promising approach to accelerate wound healing. This article presents a comprehensive overview of current and emerging angiogenesis induction methods applied in several studies for skin regeneration, which are classified into the cell, growth factor, scaffold, and biological/chemical compound-based strategies. In addition, the advantages and disadvantages of these angiogenic strategies along with related research examples are discussed in order to demonstrate their potential in the treatment of wounds.

The effects of statins on dental and oral health: a review of preclinical and clinical studies

The statin family of drugs are safe and effective therapeutic agents for the treatment of arteriosclerotic cardiovascular disease (CVD). Due to a wide range of health benefits in addition to their cholesterol lowering properties, statins have recently attracted significant attention as a new treatment strategy for several conditions, which are not directly related to normalizing a lipid profile and preventing CVD. Statins exert a variety of beneficial effects on different aspects of oral health, which includes their positive effects on bone metabolism, their anti-inflammatory and antioxidant properties, and their potential effects on epithelization and wound healing. Additionally, they possess antimicrobial, antiviral, and fungicidal properties, which makes this class of drugs attractive to the field of periodontal diseases and oral and dental health. However, to the best of our knowledge, there has been no comprehensive study to date, which has investigated the effects of statin drugs on different aspects of dental and oral health. Therefore, the primary objective of this paper was to review the effect of statins on dental and oral health. Results of our extensive review have indicated that statins possess remarkable and promising effects on several aspects of dental and oral health including chronic periodontitis, alveolar bone loss due to either extraction or chronic periodontitis, osseointegration of implants, dental pulp cells, orthodontic tooth movement, and orthodontic relapse, tissue healing (wound/bone healing), salivary gland function, and finally, anti-cancer effects. Hence, statins can be considered as novel, safe, inexpensive, and widely-accessible therapeutic agents to improve different aspects of dental and oral health.

Comparison of the effects of pentoxifylline, simvastatin, tamoxifen, and losartan on cavernous bodies after penile fracture in rats: a stereological study

Penile fracture (PF) is described as a rupture and fibrosis of the cavernous bodies. This study aimed to collect quantitative data on the impacts of pentoxifylline, simvastatin, tamoxifen, and losartan on cavernous body structure after PF. The rats were divided into six groups. The control group received anesthesia and incision without actual PF. The other groups (second to sixth) underwent PF induction in addition to administration of distilled water, pentoxifylline (200 mg/kg/day), simvastatin (40 mg/kg/day), tamoxifen (10 mg/kg/day), and losartan (20 mg/kg/day) for 8 weeks. The volumes of cavernous bodies, collagen bundles, and vessels and number of fibroblasts were increased significantly in the PF group in comparison to the control rats (p < 0.01), indicating a fibrotic process. Moreover, the mean volume of the cavernous bodies decreased in the groups with PF that received pentoxifylline, simvastatin, tamoxifen, or losartan when compared with the PF group. However, the volumes of the collagen bundles and vessels as well as the population of fibroblasts remained at the control level or even lower in PF plus pentoxifylline, simvastatin, tamoxifen, and losartan groups. This indicated the anti-fibrotic effects of the four drugs. It can be concluded that pentoxifylline, simvastatin, tamoxifen, and losartan could reduce fibrosis activities by minimizing the formation of collagen bundles and vessels as well as decreasing the population of fibroblasts 8 weeks after PF. Yet, losartan brought about a better outcome compared with the other chemicals.

Formulation and evaluation of simvastatin polymeric nanoparticles loaded in hydrogel for optimum wound healing purpose

Purpose

The aim of this study was to formulate a hydrogel loaded with polymeric nanoparticles (PoNPs) of simvastatin (SIM) for topical wound healing application.

Materials and methods

The SIM PoNPs were prepared by using the nanoprecipitation method to improve the drug solubility and skin permeation. Furthermore, drug content, solubility, particle size, surface charge, and transmission electron microscopy of the prepared PoNPs were evaluated. Then, the PoNPs were loaded on hydrogel, and physical characteristics, in vitro release, and ex vivo permeation of the hydrogel were evaluated. Finally, the prepared gel was applied on rat wounds, and a histopathological study was performed.

Results

The results showed that the drug content in the PoNPs was 86.4%. The PoNPs were spherical in shape with a smooth surface and a uniform size distribution. The particle size was 268.4±2.6, polydispersity index was ≤0.302, and zeta potential was −33±1.67 mV. The hydrogel loaded with SIM PoNPs was homogenous, and the pH was accepted and compatible with the skin. Moreover, the viscosity and spreadability assured its ease of application. The drug content was 97.25±0.02%. Furthermore, about 81% of SIM was released within 24 hours, while in the ex vivo permeation study 69.19% of SIM passed through the skin after 24 hours. Finally, the histopathological studies confirmed the efficacy of the SIM PoNPs-loaded hydrogel in wound healing due to the formation of the normal epithelial layer on day 11 after wound creation.

Conclusion

The hydrogel loaded with SIM PoNPs showed a good efficacy in accelerating the healing of the rat wound with complete epithelialization and minimal inflammatory cell infiltration.

Topical simvastatin gel as a novel therapeutic modality for palatal donor site wound healing following free gingival graft procedure

OBJECTIVE

Autogenous soft-tissue grafting is a commonly used procedure nowadays in dentistry. However, the prolonged healing time needed for the donor site leads to increase the patient's pain and discomfort. Statin has been observed to be beneficial in reducing bacterial burden, improving epithelization and wound healing. The aim of this study was to evaluate intra-oral topical application of simvastatin/chitosan gel (10 mg/mL) over the palatal donor site following free gingival graft (FGG) procedure.

MATERIAL AND METHODS

Subjects indicated for FGG procedure were divided into four groups. Group I: Simvastatin suspension (S), group II: simvastatin/chitosan gel (SC), group III: chitosan gel (C), group IV: petroleum gel (P). Treatment was applied three times/day for the following 7 days. Wound healing was evaluated at day 3, 7 and 14 post-surgery. A visual analogue scale (VAS) was used to measure the experienced discomfort at 1, 3, 5, 7 and 14 days.

RESULTS

Statistical significant reduction in wound-healing scores was observed after 3 and 7 days for group II compared to other groups (p  = .015). A significant reduction was also observed in VAS score for group II compared to other groups at day 1, 3, 5 and 7.

CONCLUSION

Topical application of S/C gel could be used as a novel therapeutic modality that improved healing and reduced pain in the palatal donor site following FGG procedure.

Topical simvastatin promotes healing of Staphylococcus aureus-contaminated cutaneous wounds

Cutaneous wounds are prompt to be contaminated by bacteria, but the clinical benefits of applying antibiotics and antiseptics in wound management have not been proven. Statins are 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors commonly used to lower cholesterol levels. Studies indicated that statins, especially simvastatin, promote wound healing in experimental models. As Staphylococcus aureus is one of the most important microorganism responsible for wound infections, the aims of this study were to characterise the anti-staphylococcal activity of simvastatin and to evaluate the application of simvastatin as a topical therapy for S. aureus-contaminated wounds. In the present study, simvastatin was bacteriostatic against S. aureus at sub-inhibitory concentrations up to 8 hours after exposure. Further increased concentrations of simvastatin above the minimal inhibitory concentration (MIC) did not enhance the growth inhibitory effect. By contrast, the ability of simvastatin to inhibit S. aureus biofilm formation was concentration dependent. Topical application of simvastatin at its MIC against S. aureus accelerated the healing and bacterial clearance of S. aureus-contaminated wounds in an excisional mice wound model. This effective concentration is well below the safe concentration for topical use. Collectively, topical application of simvastatin has the potential as a novel modality for managing wound infections and promoting wound healing.

Effects of Topic Simvastatin for the Treatment of Chronic Vascular Cutaneous Ulcers: A Pilot Study

Recent research suggests that statins might be useful in the process of wound healing, playing a positive immune-modulatory role, improving microvascular function and reducing oxidative stress. The aim of this pilot study was to evaluate the efficacy of topic application of Simvastatin-based cream in the treatment of chronic vascular cutaneous ulcers, comparing this type of treatment to a collagen-based dressing, proven to be effective for ulcer treatment. A total of 20 ulcers were studied in 2 Groups of randomly-chosen patients for a period of one month. In the first Group a 0.5% Simvastatin-based cream was topically administered, while the second Group (control) was treated with an absorbable type I bovine collagen-based medication. Each week, wound healing progress was observed in both Groups, and the ulcers photographed. Wound healing rate was calculated by considering the absolute change in area and by the formula "healing ratio (%) = [(Area₀ - Area_t4)/Area₀] × 100," both sets of data being related to the days comprised in the study in order to calculate healing rate per day. Statistical analysis was performed by Student t test. Study endpoint equaling the time-course changes of ulcer areas. At the end of the study, when considering absolute change in area, the experimental Group appeared to heal better and faster than the control Group although differences between the Groups were not statistically significant. Conversely, rates of wound healing in the experimental and control Groups were 46.88% and 64% respectively, revealing statistically significant differences. (P < 0.05). In conclusion, topic application of a simvastatin-based cream proved to be well- tolerated but not effective in the management of vascular leg ulcers in a 4 week-period.

The Effects of Simvastatin on Ischemia Reperfusion Injury in an Experimental Colon Anastomosis Model

Anastomotic leakage is more frequently reported in colonic anastomoses. Ischemia reperfusion injury is one of the main reasons for anastomotic leakage. Simvastatin is known to prevent tissue damage induced by free oxygen radicals after ischemia reperfusion injury. The effect of simvastatin on colonic anastomosis impaired by ischemia reperfusion injury is investigated. Single layer, end-to-end colocolic anastomosis after 0.5-cm colon resection was performed in Wistar Albino rats. In Group 1 (control) (n = 10), colonic anastomosis without I-R was performed. In Group 2 (n = 10), the superior mesenteric artery was clamped for 10 min followed by 60 min of reperfusion after which resection anastomosis was performed. In Group 3 (n = 10), 10 mg/kg simvastatin was given by gavage for 7 days after I-R and resection anastomosis. In Group 4 (n = 10), the rats received 10 mg/kg simvastatin by gavage 7 days before and 7 days after ischemia reperfusion and surgery. All of the rats were sacrificed 8 days after surgery. Anastomotic bursting pressure and tissue hydroxyproline levels were measured. Postoperative administration of simvastatin restored the anastomotic bursting pressure and hydroxyproline levels to that of control group thus overcoming the effect of ischemia reperfusion injury. Simvastatin administered postoperatively in an experimental model of colonic resection anastomosis impaired by ischemia reperfusion injury increased anastomotic bursting pressures and tissue hydroxyproline levels. Further experimental and clinical studies will show whether administration of simvastatin will increase reliability of the anastomosis and decrease postoperative morbidity and mortality in colonic anastomosis after ischemia reperfusion injury.

Acceleration of hard and soft tissue healing in the oral cavity by a single transmucosal injection of fluvastatin-impregnated poly (lactic-co-glycolic acid) microspheres. An in vitro and rodent in vivo study

Antihyperlipidemic drug statins reportedly promote both bone formation and soft tissue healing. We examined the effect of sustained-release, fluvastatin-impregnated poly(lactic-co-glycolic acid) (PLGA) microspheres on the promotion of bone and gingival healing at an extraction socket in vivo, and the effect of fluvastatin on epithelial cells and fibroblasts in vitro. The maxillary right first molar was extracted in rats, then one of the following was immediately injected, as a single dose, into the gingivobuccal fold: control (no administration), PLGA microspheres without a statin (active control), or PLGA microspheres containing 20 or 40 μg kg(-1) of fluvastatin. At days 1, 3, 7, 14, and 28 after injection, bone and soft tissue healing were histologically evaluated. Cell proliferation was measured under the effect of fluvastatin at dosages of 0, 0.01, 0.1, 1.0, 10, and 50 μM. Cell migration and morphology were observed at dosages of 0 and 0.1 μM. Following tooth extraction, the statin significantly enhanced bone volume and density, connective tissue volume, and epithelial wound healing. In the in vitro study, it promoted significant proliferation and migration of epithelial cells and fibroblasts. A single dose of topically administered fluvastatin-impregnated PLGA microspheres promoted bone and soft tissue healing at the extraction site.

Using skin for drug delivery and diagnosis in the critically ill

Skin offers easy access, convenience and non-invasiveness for drug delivery and diagnosis. In principle, these advantages of skin appear to be attractive for critically ill patients given potential difficulties that may be associated with oral and parenteral access in these patients. However, the profound changes in skin physiology that can be seen in these patients provide a challenge to reliably deliver drugs or provide diagnostic information. Drug delivery through skin may be used to manage burn injury, wounds, infection, trauma and the multisystem complications that rise from these conditions. Local anaesthetics and analgesics can be delivered through skin and may have wide application in critically ill patients. To ensure accurate information, diagnostic tools require validation in the critically ill patient population as information from other patient populations may not be applicable.

Efficacy of topical atorvastatin for the treatment of pressure ulcers: a randomized clinical trial

STUDY OBJECTIVE

To evaluate the effects of topical atorvastatin on the healing process of pressure ulcers in critically ill patients.

DESIGN

Randomized, double-blind, placebo-controlled clinical trial.

SETTING

Medical-surgical intensive care unit of a university-affiliated teaching hospital in Tehran, Iran.

PATIENTS

One hundred four patients with stage I or II pressure ulcers, graded according to the 2-digit Stirling Pressure Sore Severity Scale.

INTERVENTION

Patients were randomized to receive topical atorvastatin 1% ointment (51 patients [atorvastatin group]) or placebo ointment (53 patients [control group]) applied once/day to pressure ulcers for 14 days in addition to standard care for pressure ulcers.

MEASUREMENTS AND MAIN RESULTS

The efficacy of each treatment was assessed on days 7 and 14. Efficacy was determined based on the degree of healing of the existing pressure ulcer by using the 2-digit Stirling scale. The baseline stage of the pressure ulcers did not differ significantly between the control and atorvastatin groups. However, the mean ± SD stage of pressure ulcers significantly decreased in the atorvastatin group compared with the control group on day 7 (0.97 ± 0.76 vs 1.74 ± 0.75, p<0.01) and day 14 (0.42 ± 0.67 vs 1.71 ± 0.78, p<0.01) of treatment. In addition, the mean ± SD surface areas of ulcers in the atorvastatin group were significantly declined compared with the control group after 7 days (5.55 ± 4.55 vs 9.41 ± 5.03 cm², p<0.01) and 14 days (3.72 ± 4.45 vs 10.41 ± 6.41 cm², p<0.01) of treatment.

CONCLUSION

Topical application of atorvastatin ointment 1% for 14 days in addition to standard care significantly accelerated the healing of stage I or II pressure ulcers in critically ill patients.

Statins induce biochemical changes in the Achilles tendon after chronic treatment

Statins have been widely prescribed as lipid-lowering drugs and are associated with tendon rupture. Therefore, this study aimed to evaluate the possible biochemical changes in the Achilles tendon of rats after chronic treatment with statins. Dosages of statins were calculated using allometric scaling with reference to the 80mg/day and 20mg/day, doses recommended for humans. The rats were divided into the following groups: treated with simvastatin (S-20 and S-80), treated with atorvastatin (A-20 and A-80), and the control group that received no treatment (C). Measurements of low-density lipoprotein (LDL) in the plasma were performed. The levels of non-collagenous proteins, glycosaminoglycans (GAGs) and hydroxyproline were quantified. Western blotting for collagen I was performed, and the presence of metalloproteinases (MMPs)-2 and -9 was investigated through zymography. The concentration of non-collagenous proteins in S-20 was less than the C group. There was a significant increase in pro-MMP-2 activity in A-80 group and in active MMP-2 in S-20 group compared to the C group. A significant increase in latent MMP-9 activity was observed in both the A-80 and S-20 groups when compared to C group. In the A-20 group, there was a lower amount of collagen I in relation to C group. In addition, a higher concentration of hydroxyproline was found in the S-20 group than the C group. The analysis of GAGs showed a significant increase in the A-20 group when compared to C group. The treatment induced remarkable alterations in the Achilles tendon and the response of the tissue seems to depend of the used statin dosage. The presence of MMP-2 and MMP-9 is evidence of the degradation and remodeling processes in the extracellular matrix of the tendons. Our results show that statins induce imbalance of extracellular matrix components and possibly induce microdamage in tendons.

Potential role of statins on wound healing: review of the literature

Wound healing is a dynamic and complex biological process, which requires coordinated events including haemostasis, inflammation, proliferation, revascularisation and remodelling. Impaired wound healing is a common problem that occurs in both community and hospital settings. Various experimental and clinical studies have evaluated different modalities for the treatment of topical wounds, such as sugar, antibiotics, honey and phytotherapies; also statins have diverse pleiotropic effects that have been suggested to be useful to improve wound healing. Data derived from both animal and human studies showed that statins especially atorvastatin, simvastatin and pravastatin can accelerate the wound-healing process. However, further high-quality and evidence-based studies are needed to address the best statin drug, appropriate dose, the best administration route, duration of treatment and to determine correlation between pleiotropic effects of statins and their probable clinical benefits.

Effect of sildenafil in renal ischemia/reperfusion injury in rats

PURPOSE

To evaluate the effect of sildenafil, administered prior to renal ischemia/reperfusion (I/R), by scintigraphy and histopathological evaluation in rats.

METHODS

Twenty-four rats were divided randomly into two groups. They received 0.1 ml of 99mTechnetium-etilenodicisteine intravenous, and a baseline (initial) renal scintigraphy was performed. The rats underwent 60 minutes of ischemia by left renal artery clamping. The right kidney was not manipulated. The sildenafil group (n=12) received orally 1 mg/kg of sildenafil suspension 60 minutes before ischemia. Treatment with saline 0.9% in the control group (n=12). Half of the rats was assessed after 24 hours and half after seven days I/R, with new renal scintigraphy to study differential function. After euthanasia, kidneys were removed and subjected to histopathological examination. For statistical evaluation, Student t and Mann-Whitney tests were used.

RESULTS

In the control group rats, the left kidneys had significant functional deficit, seven days after I/R, whose scintigraphic pattern was consistent with acute tubular necrosis, compared with the initial scintigraphy (p<0.05). Sildenafil treatment resulted in better differential function of the left kidneys 24h after reperfusion, compared with controls. Histopathologically, the left kidney of control rats (24 hours after I/R) showed a higher degree of cellular necrosis when compared with the sildenafil treated rats (p<0.05).

CONCLUSION

Sildenafil had a protective effect in rat kidneys subjected to normothermic I/R, demonstrated by scintigraphy and histomorphometry.

Statins in dermatology

Statins are competitive inhibitors of 3-hydroxy-3-methylyglutaryl-coenzyme A reductase and reduce low-density lipoprotein-C levels. Statins are well-tolerated drugs used for prevention of atherosclerosis and cardiovascular events. Statins possess anti-inflammatory, immunomodulatory, antioxidant, metabolic, and possible anticancer effects. Statins are reported to be effective against psoriasis, dermatitis, graft-versus-host disease, uremic pruritus, vitiligo, and hirsutism. Topical forms of statins are employed in the treatment of acne, seborrhea, rosacea, and rhinophyma. Animal studies show the beneficial effect of statins against contact dermatitis and wound healing. They have promising anti-HIV effects as well. This article succinctly reviews the various cellular and molecular effects of statins, their applications in cutaneous medicine and their side effects.

[Effect of the simvastatin in abdominal sepsis of diabetic rats]

OBJECTIVE

Infection and sepsis are major causes of morbidity and mortality after surgery of diabetic patients. Statins have been shown to exhibit anti-inflammatory and immunomodulatory (pleiotropic) effects, independent of lipid lowering. This study aimed to observe whether the pretreatment with simvastatin in a cecal ligation and perforation model of sepsis is beneficial in diabetic rats.

METHODS

Fifty six Wistar rats were randomly assigned to non-diabetic group (n=28), and streptozotocin-induced diabetic group (n=28). Abdominal sepsis was induced in 14 diabetic and in 14 non diabetic rats and the other 28 rats were allocated on sham group. Sepsis rats and sham rats (each with 7 animals) were treated with oral simvastatin (20 mg kg-1 day-1) or normal saline solution 0.9%. Peripheral blood TNFalpha, IL-1beta, IL-6, C-reactive protein, procalcitonin, leukocytes and neutrophils were tested in all the animals. Statistical analysis was done by ANOVA and Tukey test, with p<0.05.

RESULTS

Simvastatin reduced mortality in diabetic rats. Peripheral blood TNFalpha, IL-1beta, IL-6, C-reactive protein, procalcitonin, leukocytes and neutrophils were lower in diabetic and non diabetics septic rats treated with simvastatin, than after saline treatment.

CONCLUSION

Simvastatin showed anti-inflammatory effect, which could play some protection against the progress of sepsis in diabetic rats.

Statin use does not affect the outcome of acute infection: a prospective cohort study

Statins are used to prevent atherosclerosis because of their hypolipemic effects. In vitro testing and murine models suggest that statins may affect outcome in sepsis. Our meta-analysis of epidemiological studies in humans confirms that previous statin use appears to have a protective effect on infection rates and outcomes. The studies considered, however, were very different and heterogeneity was high, especially for mortality criteria.

OBJECTIVE

To compare outcome for current statin users and nonusers hospitalized with fever, under pragmatic circumstances.

DESIGN

Prospective cohort study.

SETTING

University Hospital of Brest (France).

PARTICIPANTS

Febrile (>38 degrees C) patients older than 40 years, admitted to the hospital on an emergency basis in 2005. Patients' outcome was compared according to their exposure to statins (current user or nonuser).

MAIN OUTCOME MEASURES

Mortality, length of hospitalization, admission to ICU and to convalescent homes

RESULTS

Of 40 343 patients referred for admission by the emergency department in 2005, 964 patients older than 40 years had a fever higher than 38 degrees C and were included in the study. Statin-user status, however, was available for only 921. The ICU admission rate (relative risk: 4.69; 95% CI: 2.42-9.08) was significantly higher (p=0.009) among statin users (n=139) than nonusers (n=782). The groups had similar lengths of hospitalization and similar rates of mortality and of convalescent home admissions.

CONCLUSION

Our study does not confirm that statin use affects infection outcome and suggests that previous findings may be associated instead with more cautious care or nonspecific cardiovascular prevention rather than with a specific infection-related effect. Thus, these data support the continuation of statin therapy during physiological aggression, including infection.

Protective effect of simvastatin in the cyclophosphamide-induced hemohrragic cystitis in rats

PURPOSE: Cyclophosphamide (CYP) is an antineoplastic agent used for the treatment of many neoplastic and inflammatory diseases. Hemorrhagic cystitis is a frequent side effect of CYP. Several studies show that simvastatin has important pleiotropic (anti-inflammatory and immunomodulatory) effects. The purpose of the study was to investigate the effect of simvastatin on bladder, ureter and kidney injury caused by CYP. METHODS: Adult male Wistar rats were randomly divided into three groups. The CYP/SIM group received simvastatin microemulsion by gavage during 7 days (10 mg/kg body wt) before the administration of CYP and the CYP/SAL group rats received saline 0.9%. The control rats were not treated. After that, all rats were treated with a single dose of CYP 200 mg/kg body wt intraperitoneally. The rats were killed 24 h after CYP administration. Plasma cytokines (TNF-α, IL-1β, IL-6) were measured by ELISA. Macro and light microscopic study was performed in the bladder, kidney and ureter. RESULTS: In the bladders of CYP/SIMV treated rats edema of lamina propria with epithelial and sub-epithelial hemorrhage were lower than in CYP/SAL treated rats. The scores for macroscopic and microscopic evaluation of bladder and ureter were significantly lower in CYP/SIMV rats than in CYP/SAL rats. The kidney was not affected. The expression of TNF-α, IL-1β and IL-6 was significatly lower in CF/SINV rats (164.8±22, 44.8±8 and 52.4±13) than in CF/SAL rats (378.5±66, 122.9±26 e 123.6±18), respectively. CONCLUSION: The results of the current study suggest that simvastatin pretreatment attenuated CYP-induced urotelium inflammation and decreased the activities of cytokines.

Farnesyl pyrophosphate inhibits epithelialization and wound healing through the glucocorticoid receptor

Farnesyl pyrophosphate (FPP), a key intermediate in the mevalonate pathway and protein farnesylation, can act as an agonist for several nuclear hormone receptors. Here we show a novel mechanism by which FPP inhibits wound healing acting as an agonist for glucocorticoid receptor (GR). Elevation of endogenous FPP by the squalene synthetase inhibitor zaragozic acid A (ZGA) or addition of FPP to the cell culture medium results in activation and nuclear translocation of the GR, a known wound healing inhibitor. We used functional studies to evaluate the effects of FPP on wound healing. Both FPP and ZGA inhibited keratinocyte migration and epithelialization in vitro and ex vivo. These effects were independent of farnesylation and indicate that modulation of FPP levels in skin may be beneficial for wound healing. FPP inhibition of keratinocyte migration and wound healing proceeds, in part, by repression of the keratin 6 gene. Furthermore, we show that the 3-hydroxy-3-methylglutaryl-CoA-reductase inhibitor mevastatin, which blocks FPP formation, not only promotes epithelialization in acute wounds but also reverses the effect of ZGA on activation of the GR and inhibition of epithelialization. We conclude that FPP inhibits wound healing by acting as a GR agonist. Of special interest is that FPP is naturally present in cells prior to glucocorticoid synthesis and that FPP levels can be further altered by the statins. Therefore, our findings may provide a better understanding of the pleiotropic effects of statins as well as molecular mechanisms by which they may accelerate wound healing.

Antisense oligonucleotides and all-trans retinoic acid have a synergistic anti-tumor effect on oral squamous cell carcinoma

Background

Antisense oligonucleotides against hTR (As-ODN-hTR) have shown promising results as treatment strategies for various human malignancies. All-trans retinoic acid (ATRA) is a signalling molecule with important roles in differentiation and apoptosis. Biological responses to ATRA are currently used therapeutically in various human cancers. The aim of this study was to evaluate the anti-tumor effects of As-ODN-hTR combined with ATRA in vivo.

Methods

In situ human oral squamous cell carcinoma (OSCC) models were established by subcutaneous injection of Tca8113 cells. Mice were treated with sense oligonucleotides against hTR(S-ODN-hTR) alone, As-ODN-hTR alone, ATRA alone, As-ODN-hTR plus ATRA, or S-ODN-hTR plus ATRA. Tumor size and weight were assessed in the mice. Telomerase activity was detected by a TRAP assay, apoptotic cells were evaluated with a Tunel assay, the expression of apoptosis-related proteins (Bcl-2 and Bax) was evaluated by immunohistochemistry and ultrastructural morphological changes in the tumor specimen were examined.

Results

Both As-ODN-hTR and ATRA can significantly inhibit tumor growth in this OSCC xenograft solid-tumor model, and the combination of the two agents had a synergistic anti-tumorogenic effect. We also demonstrated that this anti-tumor effect correlated with inhibition of telomerase activity. Furthermore, significant increases in the number of apoptotic cells, typical apoptotic morphology and a downregulation of the anti-apoptotic protein, bcl-2 were observed in the treated tissues.

Conclusion

The combination of As-ODN-hTR and ATRA has a synergistic anti-tumor effect. This anti-tumor effect can be mainly attributed to apoptosis induced by a decrease in telomerase activity. Bcl-2 plays an important role in this process. Therefore, combining As-ODN-hTR and ATRA may be an approach for the treatment of human oral squamous cell carcinoma.