Dietary supplementation of N-acetylcysteine enhances early inflammatory responses during cutaneous wound healing in protein malnourished mice

Impact of Thermo-Responsive N-Acetylcysteine Hydrogel on Dermal Wound Healing and Oral Ulcer Regeneration

This study investigates the efficacy of a thermo-responsive N-acetylcysteine (NAC) hydrogel on wound healing and oral ulcer recovery. Formulated by combining NAC with methylcellulose, the hydrogel's properties were assessed for temperature-induced gelation and cell viability using human fibroblast cells. In vivo experiments on Sprague Dawley rats compared the hydrogel's effects against saline, NAC solution, and a commercial NAC product. Results show that a 5% NAC and 1% methylcellulose solution exhibited optimal outcomes. While modest improvements in wound healing were observed, significant enhancements were noted in oral ulcer recovery, with histological analyses indicating fully regenerated mucosal tissue. The study concludes that modifying viscosity enhances NAC retention, facilitating tissue regeneration. These findings support previous research on the beneficial effects of antioxidant application on damaged tissues, suggesting the potential of NAC hydrogels in improving wound care and oral ulcer treatment.

Copaifera langsdorffii Oleoresin-Loaded Nanostructured Lipid Carrier Emulgel Improves Cutaneous Healing by Anti-Inflammatory and Re-Epithelialization Mechanisms

The skin is essential to the integrity of the organism. The disruption of this organ promotes a wound, and the organism starts the healing to reconstruct the skin. Copaifera langsdorffii is a tree used in folk medicine to treat skin affections, with antioxidant and anti-inflammatory properties. In our study, the oleoresin of the plant was associated with nanostructured lipid carriers, aiming to evaluate the healing potential of this formulation and compare the treatment with reference drugs used in wound healing. Male Wistar rats were used to perform the excision wound model, with the macroscopic analysis of wound retraction. Skin samples were used in histological, immunohistochemical, and biochemical analyses. The results showed the wound retraction in the oleoresin-treated group, mediated by α-smooth muscle actin (α-SMA). Biochemical assays revealed the anti-inflammatory mechanism of the oleoresin-treated group, increasing interleukin-10 (IL-10) concentration and decreasing pro-inflammatory cytokines. Histopathological and immunohistochemical results showed the improvement of re-epithelialization and tissue remodeling in the Copaifera langsdorffii group, with an increase in laminin-γ2, a decrease in desmoglein-3 and an increase in collagen remodeling. These findings indicate the wound healing potential of nanostructured lipid carriers associated with Copaifera langsdorffii oleoresin in skin wounds, which can be helpful as a future alternative treatment for skin wounds.

Beta-caryophyllene as an antioxidant, anti-inflammatory and re-epithelialization activities in a rat skin wound excision model

The skin is a critical organ for the maintenance of the integrity and protection of the organism. When a wound occurs, a sequence of healing mechanisms is triggered to reconstruct the wounded area. β-caryophyllene is a sesquiterpene in Copaifera langsdorffii oleoresin with antioxidant and anti-inflammatory potential. On the basis of previous studies with C. langsdorffii, β-caryophyllene was selected to evaluate its wound healing potential and pharmacological mechanisms. The excision wound model was used with male Wistar rats and macroscopic, histological, immunohistochemical and biochemical analyses were performed with skin samples, comparing the β-caryophyllene-treated group with reference drugs. The results showed macroscopic retraction of the wounds treated with β-caryophyllene. Biochemical assays revealed the antioxidant and anti-inflammatory mechanisms of the β-caryophyllene-treated group with increasing levels of IL-10 and GPx and decreasing levels of pro-inflammatory molecules, including TNF-α, IFN-γ, IL-1β and IL-6. After β-caryophyllene treatment, immunohistochemical assays showed enhanced re-epithelialization, through the increase in laminin-γ2 and desmoglein-3 immunolabeling. β-caryophyllene also act in the remodeling mechanism, increasing the collagen content in the Masson’s trichrome staining. These findings indicated the wound-healing potential of β-caryophyllene topical formulation in rat skin wounds, mediated by antioxidant, anti-inflammatory and re-epithelialization mechanisms.

Stereological and molecular studies on the effects of Ferula persica extract on wound healing in rats

Background

Ferula persica is one of the most important traditional medicinal plants that is used to treat various diseases such as diabetes, backache and rheumatism. The aim of the present study was to evaluate the anti‐inflammatory and wound healing potential of F. persica using stereological and molecular methods in experimental models.

Methods

In the present study, two wound models (circular excision and linear incision) were used. Male Wistar rats were divided into four groups (n = 16), including control, vehicle treated, treated with F. persica extract ointment (5% w/w) and treated with the reference drug (Madecassol). All the animals were treated topically once a day. The circular and linear wounds were treated for 9 and 17 days, respectively. At the end of the study, samples from wounds area were harvested for histology, stereology, immunohistochemistry and molecular assessments to determine the in vivo healing potential and anti‐inflammatory activity.

Results

We observed significant recovery in macroscopic evaluation of wound healing in the F. persica extract treated group compared with the control and vehicle treated groups (p < 0.05). Histological and stereological assessments showed complete repair of the epidermal layer, increasing fibroblast cells and collagen density, decreasing inflammatory cells and a remarkable degree of neovascularization by determining length density of blood vessels in the extract group, which were significant as compared to the control and vehicle treated groups (p < 0.05). Expressions of TNF‐α and TGF‐β were found to be decreased and increased (p > 0.05, p < 0.05, respectively), in the extract treated group as compared to the control and vehicle treated groups. Also, greater COX‐2 expression could be detected in the control and vehicle treated groups, which was significantly attenuated in the extract group.

Conclusion

Our results confirm that the F. persica extract is a valuable source of antioxidant and anti‐inflammatory activity and can allow damaged tissue in wounds to recover markedly.

Changes of Mineralogical Properties and Biological Activities of Gypsum and Its Calcined Products with Different Phase Structures

Raw gypsum (RG) and calcined gypsum (CG) are widely used in traditional Chinese medicine (TCM). RG is usually taken orally to resolve heat and diminish inflammation, while CG is only used externally to treat ulcerations and empyrosis. Calcination at different temperatures, three phase CG structures, namely, bassanite, anhydrite III, and anhydrite II, may be generated. We herein investigated the relationship between the phase structure and the efficacy of CG and the optimum phase structure for CG. RG has a compact structure, small pore size, weak anti-inflammatory effect, but no antibacterial effect, and has almost no effect on the repair of scalds. CG150 (bassanite) has a loose texture, large pore size and specific surface area, and certain antibacterial and anti-inflammatory effects, but it has a poor repair effect on scalds. CG750 (anhydrite II) has a compact structure, small pore size and specific surface area, and low antibacterial and anti-inflammatory effects, but it has a certain repair effect on scalds. Only CG350 (anhydrite III) has good performance in texture, pore size, specific surface area, antibacterial, anti-inflammatory, and scald repair. Our research has proved that the mineral properties and biological activities of CG are different due to different phase structures. CG350, namely, anhydrite III, is considered by our research to be the optimal phase structure as CG.

Cysteine/cystine-rich undenatured whey protein supplement in patients' pressure ulcers outcomes: an open label study

OBJECTIVE

The prevalence and costs associated with treating pressure ulcers (PU) are at high levels. Frequently, PUs heal slowly or not at all, which may be due to the patient's catabolic state which may include protein energy malnutrition. The objective of this open label clinical trial was to improve healing rates by providing patients with a patented, high-quality protein containing all essential amino acids to ensure positive nitrogen balance. An additional benefit of this protein is the delivery of bioavailable cysteine (cystine) to promote glutathione (GSH) synthesis which supports immune function and heightens antioxidant defences.

METHODS

Patients with category II, III and IV PUs were fed 20g BID whey protein dietary supplement for 16-120 days, without change in ongoing 'best practice' PU management and their progress recorded.

RESULTS

A total of 10 patients were recruited, with an average age of 77 years. Most had shown no improvement in healing for ≥2 months before treatment and usually had other complications including chronic obstructive pulmonary disease (COPD), diabetes and various cardiovascular diseases. There were a total of 23 PUs, with some patients having more than one. Of these, 44% (n=10) showed complete resolution 83% (n=19) had better than 75% resolution over the observation period. Healing rates ranged from 16.9-0.2cm²/month (healed PUs) and 60.0-1.6cm²/month for resolving PUs.

CONCLUSION

By providing the necessary amino acids to rebuild tissues and bioactive cysteine (cystine) to promote synthesis of intracellular GSH and positive nitrogen balance, improvement in PUs healing was achieved.

Nutrition in wound healing: investigation of the molecular mechanisms, a narrative review

Nutrition can be outlined in terms of epigenetic signals influencing each of the wound healing steps (haemostasis, inflammatory, proliferative and remodelling phase). Specific nutrients, such as amino acids, minerals, vitamins, natural compounds and herbal extracts, target DNA-regulating transcription factors, cytokines, extracellular matrix proteins and glycosaminoglycan, and are specifically involved in the wound healing process. This review focuses on experimental in vivo and clinical evidence of dietary supplements administration in pressure ulcers. A good nutritional status is, for example, fundamental to the haemostasis phase of skin wounds. In the inflammatory phase, vitamin A enhances cytokine release, bromelain and amino acids prevent prolonged inflammatory events, while vitamin C enhances neutrophil migration and lymphocyte activation. In the proliferative phase, vitamin C and Centella asiatica are required for collagen synthesis. Glucosamine enhances hyaluronic acid production, vitamin A promotes epithelial cell differentiation, zinc is required for DNA and protein synthesis and cell division, and Aloe vera supports granulation tissue generation. Finally, in the remodelling phase, amino acids and proteins play a key role in wound scar stabilisation.

Sustained release of N-acetylcysteine by sandwich structured polycaprolactone/collagen scaffolds for wound healing

PCL (poly-caprolactone) nanofibers have good biocompatibility and high porosity, which are usually utilized for application in wound dressings. However, wound healing could be hindered by the overproduction of reactive oxygen species (ROS) and different factors. Pure nanofibers cannot satisfy these requirements of wound healing. N-acetylcysteine (NAC), as an antioxidant, meets the requirements for wound healing by resisting the overproduction of ROS and by promoting angiogenesis and maturation of the epidermis. In this study, we prepared a sandwich structured PCL-Col/NAC scaffold using the molding method, which consisted of PCL nanofibers at the core and NAC-loaded collagen on both sides. The hydroscopicity and tensile modulus of PCL-Col/NAC scaffolds showed best performance of these properties among groups. Meanwhile, the drug release profiles of PCL-Col/NAC scaffolds were investigated using the HPLC method and the results suggested a sustained drug release of NAC for PCL-Col/NAC scaffolds. In addition, PCL-Col/NAC scaffolds presented better properties than the control groups in cell migration and proliferation. The in vivo wound healing therapy effect was studied using an oval (2 × 1 cm) full-thickness skin defect wound model for SD rats. After 21 days, gross view and histological analysis showed a favorable beneficial therapeutic effect as well as better epidermal maturation compared with the control groups. CD31 immunohistology results revealed relatively more new vessels in the PCL-Col/NAC group than the control groups. This study developed novel PCL-Col/NAC scaffolds with an excellent hydroscopicity, tensile modulus and the ability to promote epidermal maturation and angiogenesis, demonstrating its promising potential in wound healing treatment. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.

Skin Wound Healing Potential and Mechanisms of the Hydroalcoholic Extract of Leaves and Oleoresin of Copaifera langsdorffii Desf. Kuntze in Rats

The wound healing is a complex process which, sometimes, can be a problem in public health because of the possibility of physical disability or even death. Due to the lack of a gold standard drug in skin wound treatment and aiming at the discovery of new treatments in skin repair and the mechanisms involved in the process, we used oleoresin (OR) from Copaifera langsdorffii and hydroalcoholic extract of the leaves (EH) to treat rat skin wounds. For that, male Wistar rats were divided into groups (n = 8): Lanette, Collagenase, 10% EH, or 10% OR and, after anesthesia, one wound of 2 cm was made in the back of animals. The wounds were treated once a day for 3, 7, or 14 days and the wound areas were measured. The rats were euthanized and skin samples destined to biochemical, molecular, and immunohistochemical analysis. The results showed a macroscopic retraction of the wounds of 10% EH and 10% OR creams and both treatments showed anti-inflammatory activity. Molecular and immunohistochemical results demonstrated the activity of Copaifera langsdorffii creams in angiogenesis, reepithelialization, wound retraction, and remodeling mechanisms.

Early application of negative pressure wound therapy to acute wounds contaminated with Staphylococcus aureus: An effective approach to preventing biofilm formation

Negative pressure wound therapy (NPWT) has been demonstrated to be effective at preventing biofilm-associated infections; however, its role in biofilm prevention is unknown. The present study evaluated the effect of NPWT on biofilm prevention when rapidly initiated following wound contamination. Full-thickness dermal wounds (8 mm) were created in rabbit ears and inoculated with green fluorescent protein-labeled Staphylococcus aureus (S. aureus). At 6 h following inoculation, continuous NPWT at -125 mmHg was initiated, with the wounds on the contralateral ear left untreated in order to serve as self-controls. S. aureus rapidly formed mature biofilms in the wound beds post-inoculation, with a persistent bacterial burden of ~10⁵-10⁷ colony-forming units (CFUs)/wound and impaired wound healing. Compared with the untreated group, NPWT resulted in a significant reduction in biofilm matrix, which was verified by scanning electron microscopy and epifluorescence. A reduction in bacterial counts followed (P<0.05) with ~10³ CFUs/wound on postoperative day 13 and improvement in all healing parameters (P<0.05) relative to control wounds. The results of the present investigation suggest that NPWT is an effective strategy to impeding the formation of S. aureus wound biofilms when initiated rapidly following bacterial contamination. The early application of NPWT, aimed at biofilm prevention, may improve wound care.

N-acetyl-L-cysteine increases MnSOD activity and enhances the recruitment of quiescent human fibroblasts to the proliferation cycle during wound healing

The rebuilding of the connective tissue during wound healing requires the recruitment of fibroblasts to the wound area as well as reentry of quiescent fibroblasts to the proliferative cycle. Whether this process can be modulated by a small molecular weight thiol antioxidant N-acetyl-L-cysteine (NAC) was tested in normal human skin fibroblasts (NHFs) using a uni-directional wound healing assay. NAC treated cells demonstrated a decreased migration rate but increased number of proliferating cells recruited into the wound area post wounding. Fifteen day quiescent control and NAC treated NHFs were re-plated at a lower density and cell numbers counted at different days post-plating. Interestingly, NAC treated cells exhibited increased cellular proliferation indicated by both decreased cell population doubling time and increased S phase cells. NAC treated cells demonstrated decreased steady state levels of reactive oxygen species as well as increased protein and activity levels of manganese superoxide dismutase (MnSOD). NAC treatment failed to induce proliferation in quiescent cells lacking MnSOD expression. These results demonstrate that NAC enhanced the recruitment of quiescent NHFs into proliferation cycle during wound healing. Our results also suggest that the wound healing properties of NAC might be due to its ability to induce and enhance MnSOD expression and activity. Altogether, these findings suggest NAC might be potentially developed as a dietary intervention to improve tissue injury in animals and humans.

Topical N-acetylcysteine improves wound healing comparable to dexpanthenol: an experimental study

In this study, we aimed to compare the effects of dexpanthenol and N-acetylcysteine on wound healing. The wound healing process is a multifaceted sequence of activities associated with tissue restoration process. A number of investigations and clinical studies have been performed to determine new approaches for the improvement of wound healing. A total of 30 rats were divided into 3 equal groups. A linear 2-cm incision was made in the rats' skin. No treatment was administered in the first (control) group. Dexpanthenol cream was administered to the rats in the second group and 3% N-acetylcysteine cream was administered to the rats in the third group. The wound areas of all of the rats were measured on certain days. On the 21st day, all wounds were excised and histologically evaluated. The epithelialization and granulation rates between the groups were revealed to be similar in microscopic evaluations. Although the fibrosis was remarkable in the control group as compared with the other groups, it was similar in N-acetylcysteine and dexpanthenol groups. Angiogenesis rate was remarkable in the N-acetylcysteine group compared with the others. In multiple-comparison analysis, Dexpanthenol and N-acetylcysteine groups had similar results in terms of wound healing rates (P < 0.05), which were both higher than in the control group (P > 0.05). The efficacy of N-acetylcysteine in wound healing is comparable to dexpanthenol, and both substances can be used to improve wound healing.

The effect of 17β-estradiol on cutaneous wound healing in protein-malnourished ovariectomized female mouse model

Cutaneous wound healing is delayed by protein malnutrition (PM). On the other hand, estrogen promotes cutaneous wound healing by its anti-inflammatory and cell proliferation effects. Therefore, we hypothesized that estrogen administration in protein-malnourished ovariectomized (OVX) female mice might improve the inflammatory response and promote cutaneous wound healing as well as normal nutrition. To test this hypothesis, we used full-thickness excisional wounds in Control SHAM, PM SHAM, PM OVX and PM OVX+17β-estradiol mice. The Control diet included 200 g/kg protein and the PM diet included 30 g/kg protein. The ratio of wound area in the Control SHAM group was significantly smaller than those in the three PM groups. In addition, microscopic findings also showed that the ratio of collagen fibers, the ratio of myofibroblasts and the number of new blood vessels in the Control SHAM group were significantly greater than those in the three PM groups. However, the number of Ym1-positive cells as an anti-inflammatory M2-like macrophage marker in the PM OVX+17β-estradiol group was significantly higher than those in the other three groups. These results indicate that the appearance of anti-inflammatory M2-like macrophages was promoted by estrogen administration; however, it could not promote cutaneous wound healing upon a low-protein diet. Therefore, it may be confirmed that nutrition is more important for promoting cutaneous wound healing than estrogen administration.

Thiol-based antioxidant supplementation alters human skeletal muscle signaling and attenuates its inflammatory response and recovery after intense eccentric exercise

BACKGROUND

The major thiol-disulfide couple of reduced glutathione (GSH) and oxidized glutathione is a key regulator of major transcriptional pathways regulating aseptic inflammation and recovery of skeletal muscle after aseptic injury. Antioxidant supplementation may hamper exercise-induced cellular adaptations.

OBJECTIVE

The objective was to examine how thiol-based antioxidant supplementation affects skeletal muscle's performance and redox-sensitive signaling during the inflammatory and repair phases associated with exercise-induced microtrauma.

DESIGN

In a double-blind, crossover design, 10 men received placebo or N-acetylcysteine (NAC; 20 mg · kg(-1) · d(-1)) after muscle-damaging exercise (300 eccentric contractions). In each trial, muscle performance was measured at baseline, after exercise, 2 h after exercise, and daily for 8 consecutive days. Muscle biopsy samples from vastus lateralis and blood samples were collected before exercise and 2 h, 2 d, and 8 d after exercise.

RESULTS

NAC attenuated the elevation of inflammatory markers of muscle damage (creatine kinase activity, C-reactive protein, proinflammatory cytokines), nuclear factor κB phosphorylation, and the decrease in strength during the first 2 d of recovery. NAC also blunted the increase in phosphorylation of protein kinase B, mammalian target of rapamycin, p70 ribosomal S6 kinase, ribosomal protein S6, and mitogen activated protein kinase p38 at 2 and 8 d after exercise. NAC also abolished the increase in myogenic determination factor and reduced tumor necrosis factor-α 8 d after exercise. Performance was completely recovered only in the placebo group.

CONCLUSION

Although thiol-based antioxidant supplementation enhances GSH availability in skeletal muscle, it disrupts the skeletal muscle inflammatory response and repair capability, potentially because of a blunted activation of redox-sensitive signaling pathways. This trial was registered at clinicaltrials.gov as NCT01778309.

Effect of calorie restriction and refeeding on skin wound healing in the rat

Calorie restriction (CR) is a reliable anti-aging intervention that attenuates the onset of a number of age-related diseases, reduces oxidative damage, and maintains function during aging. In the current study, we assessed the effects of CR and other feeding regimens on wound healing in 7-month-old Fischer-344 rats from a larger cohort of rats that had been fed either ad libitum (AL) or 40% calorie restricted based on AL consumption. Rats were assigned to one of three diet groups that received three skin punch wounds along the dorsal interscapular region (12-mm diameter near the front limbs) of the back as follows: (1) CR (n = 8) were wounded and maintained on CR until they healed, (2) AL (n = 5) were wounded and maintained on AL until wound closure was completed, and (3) CR rats were refed (RF, n = 9) AL for 48 h prior to wounding and maintained on AL until they healed. We observed that young rats on CR healed more slowly while CR rats refed for 48 h prior to wounding healed as fast as AL fed rats, similar to a study reported in aged CR and RF mice (Reed et al. 1996). Our data suggest that CR subjects, regardless of age, fail to heal well and that provision of increased nutrition to CR subjects prior to wounding enhances the healing process.

Topical application of Acalypha indica accelerates rat cutaneous wound healing by up-regulating the expression of Type I and III collagen

ETHNOPHARMACOLOGICAL RELEVANCE

Acalypha indica Linn. (Acalypha indica) vernacularly called Kuppaimeni in Tamil, has been used as a folklore medicine since ages for the treatment of wounds by tribal people of Tamil Nadu, Southern India. The present study investigates the biochemical and molecular rationale behind the healing potential of Acalypha indica on dermal wounds in rats.

MATERIAL AND METHODS

Acalypha indica extract (40 mg/kg body weight) was applied topically once a day on full-thickness excision wounds created on rats. The wound tissue was removed and used for estimation of various biochemical and biophysical analyses and to observe histopathological changes with and with-out extract treatment. The serum levels of pro-inflammatory cytokine tumor necrosis factor (TNF-α) was measured at 12 h, 24 h, 48 h and 72 h post-wounding using ELISA. Reverse transcription-polymerase chain reaction (RT-PCR) analysis was performed to study the expression pattern of transforming growth factor [TGF-β1], collagen 1 α (I) [Col 1 α (I)] and collagen 3 α (I) [Col 3 α (I)]. Likewise, linear incision wounds were created and treated with the extract and used for tensile strength measurements.

RESULTS

Wound healing in control rats was characterized by less inflammatory cell infiltration, lack of granulation tissue formation, deficit of collagen and significant decrease in biomechanical strength of wounds. Acalypha indica treatment mitigated the oxidative stress and decreased lipid peroxidation with concomitant increase in ascorbic acid levels. It also improved cellular proliferation, increased TNF-α levels during early stages of wound healing, up-regulated TGF-β1 and elevated collagen synthesis by markedly increasing the expression of Col 1 α (I) and Col 3 α (I). Increased rates of wound contraction, epithelialization, enhanced shrinkage temperature and high tensile strength were observed in the extract treated rats.

CONCLUSION

Acalypha indica extract was shown to augment the process of dermal wound healing by its ability to increase collagen synthesis through up-regulation of key players in different phases of wound healing and by its antioxidative potential.

Whey protein enhances normal inflammatory responses during cutaneous wound healing in diabetic rats

Background

Prolonged wound healing is a complication of diabetes that contributes to mortality. Impaired wound healing occurs as a consequence of excessive reactive oxygen species (ROS) production. Whey protein (WP) is able to reduce the oxygen radicals and increase the levels of the antioxidant glutathione. Thus, the aim of this study was to determine whether dietary supplementation with WP could enhance normal inflammatory responses during wound healing in diabetic rats. Animals were assigned into a wounded control group (WN), a wounded diabetic group (WD) and a wounded diabetic group orally supplemented with whey protein (WDWP) at a dose of 100 mg/kg body weight.

Results

Whey protein was found to significantly decrease the levels of malondialdehyde (MDA), nitric oxide (NO) and ROS. A significant restoration of the glutathione level was observed in WDWP rats. During the early wound healing stage, IL-1β, TNF-α, IL-6, IL-4 and neutrophil infiltration were significantly decreased in WD mice. WP supplementation was found to restore the levels of these inflammatory markers to the levels observed in control animals. In addition, the time required for wound healing was significantly prolonged in diabetic rats. WP was found to significantly decrease the time required for wound healing in WDWP rats.

Conclusion

In conclusion, dietary supplementation with WP enhances the normal inflammatory responses during wound healing in diabetic mice by restoring the levels of oxidative stress and inflammatory cytokines.

Effect of low-protein diet on anthracycline pharmacokinetics and cardiotoxicity

OBJECTIVES

Anthracyclines are broad spectrum anticancer drugs with dose-dependent cardiotoxicity. Protein malnutrition commonly occurs in cancer patients and is considered a risk factor for development of cardiotoxicity. This study was designed to assess the modulatory effect of protein malnutrition on the pharmacokinetics and drug disposition properties of a single dose of doxorubicin and epirubicin and how these possible changes will affect the degree of cardiotoxicity of these drugs.

METHODS

A single interperitoneal dose of 15 mg/kg of either doxorubicin or epirubicin was injected into rats fed with either normal protein diet or low-protein diet. The plasma concentration-time profiles of doxorubicin and epirubicin and their concentrations in different tissues were determined. Serum creatine kinase level was determined at different time intervals and histopathological examination of heart tissue was carried out.

KEY FINDINGS

Protein malnutrition significantly altered the pharmacokinetics of doxorubicin and epirubicin, with a significant decrease in their elimination, and prolonged the exposure of the heart to these drugs. Histopathological examination and serum creatine kinase measurements supported the role of protein malnutrition in enhancement of anthracycline cardiotoxicity.

CONCLUSIONS

If similar alteration in anthracyclines' pharmacokinetics occurs in malnourished cancer patients, protein malnutrition will be a risk factor for development of anthracycline cardiotoxicity and dose adjustment will be required in nutritionally deprived patients.

Serum albumin level is a limited nutritional marker for predicting wound healing in patients with pressure ulcer: two multicenter prospective cohort studies

BACKGROUND & AIMS

We aimed to investigate the predictive validity of serum albumin for pressure ulcer healing, according to patient condition and wound characteristics.

METHODS

This study was a secondary analysis of pooled data from two multicentre cohort studies undertaken in 2005 and 2007. All adult patients with pressure ulcer were included and were tracked until wound healing or discharge from care. Baseline serum albumin data were obtained from medical charts.

RESULTS

A total of 2530 patients were analyzed. By multivariate Cox proportional hazards analysis, higher serum albumin level was associated with wound healing of only superficial pressure ulcers for patients in acute/postoperative conditions (hazard ratio 1.29, 95% confidence interval 1.13-1.46) and the cutoff point was 24/25 g/L. However, the addition of serum albumin level to other factors resulted in little increase in the ability to predict wound healing as measured by the overall C-statistics. For patients in chronic/palliative conditions, serum albumin level as the continuous variable was not significantly associated with ulcer healing.

CONCLUSIONS

The addition of serum albumin marker may not have much advantage to predict pressure ulcer healing although its level can be associated with ulcer healing, depending on patient condition and wound depth.

Effect of dietary conjugated linoleic acid supplementation on early inflammatory responses during cutaneous wound healing

Inflammatory response is considered the most important period that regulates the entire healing process. Conjugated linoleic acid (CLA), a class of linoleic acid positional and geometric isomers, is well known for its antioxidant and anti-inflammatory properties. We hypothesized that dietary CLA supplementation accelerates cutaneous wound healing by regulating antioxidant and anti-inflammatory functions. To investigate wound closure rates and inflammatory responses, we used a full-thickness excisional wound model after 2-week treatments with control, 0.5%, or 1% CLA-supplemented diet. Mice fed dietary CLA supplementation had reduced levels of oxidative stress and inflammatory markers. Moreover, the wound closure rate was improved significantly in mice fed a 1% CLA-supplemented diet during early stage of wound healing (inflammatory stage). We conclude that dietary CLA supplementation enhances the early stage of cutaneous wound healing as a result of modulating oxidative stress and inflammatory responses.

Effects of N-acetylcysteine on the detoxification and biological metabolism of C3A immortalized cell line

AIM: To investigate the effects of N-acetylcys-teine (NAC) on hepatocyte (using C3A immortalized cell line) detoxification and biological metabolism, and to compare the therapeutic effect between NAC and GSH (reduced glutathione).

METHODS: C3A cells were cultured with chronic severe hepatitis plasma (CSHP), while NAC and GSH were added to the medium with a dosage of 25 mmol/L, 5 mmol/L or 1 mmol/L, respectively. Meanwhile, C3A cells cultured with normal human plasma (NHP) or 100 mL/L FBS-MEM were as controls. The contents of GSH and MDA in C3A cells and the metabolic rate of diazepam were detected 24, 48 and 72 h after administration, respectively.

RESULTS: Comparison between groups showed that the content of intra-cellular GSH and the metabolic rate of diazepam in C3A cells were significantly higher at 24, 48 and 72 h in the FBS-MEM group, the NHP group and the groups added NAC or GSH in CSHP than those in the CSHP group (GSH: F = 246.116, 235.489, 201.536, all P < 0.01; diazepam: F = 306.812, 476.722, 502.061, all P < 0.01), but the content of intra-celluar MDA in the CSHP group was markedly higer than those in the other groups (F = 332.48, 662.349, 492.983, all P < 0.01). The content of intra-celluar GSH and the metabolic rate of diazepam in C3A cells in the CSHP + NAC groups were higher than those in the CSHP + GSH groups (comparison between the same dosage: P < 0.01), but the content of intra-celluar MDA was in the opposite situation (P < 0.01).

CONCLUSION: NAC can obviously improve the detoxification and biological metabolism of C3A cells cultured in CSHP. NAC is superior to GSH at the same dosage.