Wound Healing, Anti-Inflammatory and Anti-Oxidant Activities, and Chemical Composition of Korean Propolis from Different Sources

Propolis, such as is used as bio-cosmetics and in functional materials, is increasing because of its antioxidant medicinal benefits. However, its pharmacological and chemical composition is highly variable, relative to its geography and botanical origins. Comparative studies on three propolis samples collected from different regions in Korea have been essential for linking its provenance, chemical composition, and biological activity, thereby ensuring the efficient utilization of its beneficial properties. Here, we report the chemical composition and biological activities such as the antioxidant, wound healing, and anti-inflammatory effects of the ethanolic extract of Korean propolis collected from two regions. We compared the chemical constituents of three 70% ethanol-extracted (EE) samples, including the Andong, Gongju field (GF), and Gongju mountain (GM)-sourced propolis using Gas chromatography-mass spectrometry (GC-MS). The major and common components of these EE Korean propolis were flavonoids such as pinocembrin (12.0-17.7%), chrysin (5.2-6.8%), and apigenin (5.30-5.84%). The antioxidant property using a 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity assay of EEP showed substantial differences among samples with the highest from Andong. The sample 10% GM levigated in simple ointment was found to be the most active in wound healing activity based on the excision, incision, and dead space wound models. The potential of propolis for wound healing is mainly due to its evidenced properties, such as its antimicrobial, anti-inflammatory, analgesic, and angiogenesis promoter effects, which need further study. The anti-inflammatory activity and NO production inhibitory effect were highest in GM samples. However, GM and GF samples demonstrated similar inhibitory effects on the expression of inflammatory mediators such as iNOS, IL-1β, and IL-6. The presence of a higher concentration of flavonoids in Korean EE propolis might be responsible for their promising wound healing, anti-inflammatory, and antioxidant properties.

Dynamic optical coherence tomography for imaging acute wound healing

The aim of this study was to investigate acute wound healing with dynamic optical coherence tomography (D-OCT). From 22 patients with 23 split skin graft donor sites, vessels at four wound edges, the wound bed, and adjacent and unaffected skin of the contralateral leg were measured by D-OCT at six time points from surgery to 4 weeks of healing. Changes in vessel orientation, density, diameter, morphology and pattern in horizontal, vertical and 3D images were analysed for wound healing and re-epithelialization. At 300 μm depth, there were significant differences of blobs and serpiginous vessels between normal and wounded skin. The wound had significantly more vertically oriented vessels, a higher degree of branching, vessel density and diameter compared with healthy skin. 3D images showed increased angiogenesis from healthy skin towards the wound centre, significantly higher vessel density at the wound than at normal skin and the highest at the interface. During wound healing blobs, coils and serpiginous vessels occurred significantly more frequently in lesional than healthy skin. Vessel density was greatest at the beginning, decreased and then increased by 4 weeks post-surgery. D-OCT helps to evaluate acute wound healing by visualizing and quantifying blood vessel growth in addition to re-epithelialization.

Uterine Cesarean Scar Tissue-An Immunohistochemical Study

Background and Objectives: Wound healing encompasses a multitude of factors and entails the establishment of interactions among components of the basement membrane. The quantification of particle concentrations can serve as valuable biomarkers for assessing biomechanical muscle properties. The objective of this study was to examine the immunoexpression and immunoconcentration of myometrial collagen type VI, elastin, alpha-smooth muscle actin, and smooth muscle myosin heavy chain, as well as the expression of platelets and clusters of differentiation 31 in the uterine scar following a cesarean section (CS). Materials and Methods: A total of 177 biopsies were procured from a cohort of pregnant women who were healthy, specifically during the surgical procedure of CS. The participants were categorized into seven distinct groups. Group 1 consisted of primiparas, with a total of 52 individuals. The subsequent groups were organized based on the duration of time that had elapsed since their previous CS. The analysis focused on the immunoexpression and immunoconcentration of the particles listed. Results: No significant variations were observed in the myometrial immunoconcentration of collagen type VI, elastin, smooth muscle myosin, and endothelial cell cluster of differentiation 31 among the analyzed groups. The concentration of alpha-smooth muscle actin in the myometrium was found to be significantly higher in patients who underwent CS within a period of less than 2 years since their previous CS, compared to those with a longer interval between procedures. Conclusions: Our findings indicate that the immunoconcentration of uterine myometrial scar collagen type VI, elastin, smooth muscle myosin heavy chain, alpha-smooth muscle actin, and endothelial cell marker cluster of differentiation 31 remains consistent regardless of the duration elapsed since the previous CS. The findings indicate that there are no significant alterations in the biomechanical properties of the uterine muscle beyond a period of 13 months following a CS.

Sirolimus-coated Eustachian tube balloon dilatation for treating Eustachian tube dysfunction in a rat model

Eustachian tube balloon dilatation (ETBD) has shown promising results in the treatment of ET dysfunction (ETD); however, recurrent symptoms after ETBD frequently occur in patients with refractory ETD. The excessive pressure of balloon catheter during ETBD may induce the tissue hyperplasia and fibrotic changes around the injured mucosa. Sirolimus (SRL), an antiproliferative agent, inhibits tissue proliferation. An SRL-coated balloon catheter was fabricated using an ultrasonic spray coating technique with a coating solution composed of SRL, purified shellac, and vitamin E. This study aimed to investigate effectiveness of ETBD with a SRL-coated balloon catheter to prevent tissue proliferation in the rat ET after ETBD. In 21 Sprague-Dawley rats, the left ET was randomly divided into the control (drug-free ETBD; n = 9) and the SRL (n = 9) groups. All rats were sacrificed for histological examination immediately after and at 1 and 4 weeks after ETBD. Three rats were used to represent the normal ET. The SRL-coated ETBD significantly suppressed tissue proliferation caused by mechanical injuries compared with the control group. ETBD with SRL-coated balloon catheter was effective and safe to maintain ET luminal patency without tissue proliferation at the site of mechanical injuries for 4 weeks in a rat ET model.

Using Zhang's supertension-relieving suture technique with slowly-absorbable barbed sutures in the management of pathological scars: a multicenter retrospective study

Background

An ideal tension-relieving suture should be efficient for >3 months to retrieve normal tensile strength. Most preexisting suturing techniques provided tension elimination followed by relapse and scar proliferation due to absorption and cut-through of the sutures. This study introduces a simple but effective suture technique developed by a senior author (ZYX) to solve this problem.

Methods

A total of 120 patients with pathological scar (PS) had intervention treatment with the proposed suturing strategy at three centers from January 2018 to January 2021. A slowly absorbable 2-0 barbed suture was used for subcutaneous tension relieving with a set-back from the wound edge and a horizontal interval between proposed inserting points of 1 cm. The Patient and Observer Scar Assessment Scale (POSAS), scar width, perfusion and eversion of the wound edge were evaluated at 3-, 6- and 12-month follow-up. The time needed to place the tension-relieving suture was recorded and relapse was monitored for 18 months postoperatively.

Results

In total, 76 trunks, 32 extremities and 12 cervical PS were included, with an average subcutaneous tension-relieving suture time of 5 min. The Patient and Observer Scar Assessment Scale (POSAS) score decreased from 84.70 ± 7.06 preoperatively to 28.83 ± 3.09, 26.14 ± 1.92 and 24.71 ± 2.00 at 3, 6 and 12 months postoperatively, respectively (p < 0.0001). The scar widths were 0.17 ± 0.08, 0.25 ± 0.09 and 0.33 ± 0.10 cm, respectively, with perfusion significantly decreased from 213.64 ± 14.97 to 112.23 ± 8.18 at 6 months (p < 0.0001). The wound edge flattened out during the first 3 months in most cases with only two scar relapses.

Conclusions

Zhang's suture technique provides a rapid and long-lasting tension-relieving effect with ideal scar appearances and lower relapse rates in the surgical management of PS.

Structural and biological engineering of 3D hydrogels for wound healing

Chronic wounds have become one of the most important issues for healthcare systems and are a leading cause of death worldwide. Wound dressings are necessary to facilitate wound treatment. Engineering wound dressings may substantially reduce healing time, reduce the risk of recurrent infections, and reduce the disability and costs associated. In the path of engineering of an ideal wound dressing, hydrogels have played a leading role. Hydrogels are 3D hydrophilic polymeric structures that can provide a protective barrier, mimic the native extracellular matrix (ECM), and provide a humid environment. Due to their advantages, hydrogels (with different architectural, physical, mechanical, and biological properties) have been extensively explored as wound dressing platforms. Here we describe recent studies on hydrogels for wound healing applications with a strong focus on the interplay between the fabrication method used and the architectural, mechanical, and biological performance achieved. Moreover, we review different categories of additives which can enhance wound regeneration using 3D hydrogel dressings. Hydrogel engineering for wound healing applications promises the generation of smart solutions to solve this pressing problem, enabling key functionalities such as bacterial growth inhibition, enhanced re-epithelialization, vascularization, improved recovery of the tissue functionality, and overall, accelerated and effective wound healing.

The Wound Healing Potential of Lignosus rhinocerus and Other Ethno-myco Wound Healing Agents

Wound care has become increasingly important over the years. Various synthetic products for wound care treatment have been reported to cause toxic side effects and therefore natural products are in significant demand as they have minimal side effects. The presence of bioactive compounds in medicinal mushrooms contributes to various biological activities which assist in the early inflammatory phase, keratinocyte proliferation, and its migration enhancement which are pertinent to wound rehabilitation. Lignosus rhinocerus (tiger milk mushroom) can reduce the inflammation phase in wound healing by fighting off bacterial infection and modulating pro-inflammatory cytokines expression in the early stage to avoid prolonged inflammation and tissue damage. The antibacterial, immunomodulating, and anti-inflammatory activities exhibited by most macrofungi play a key role in enhancing wound healing. Several antibacterial and antifungal compounds sourced from traditional botanicals/products may prevent further complications and reoccurrence of injury to a wounded site. Scientific studies are actively underway to ascertain the potential use of macrofungi as a wound healing agent.

Effects of Dermatan Sulfate from Marine Invertebrate Styela plicata in the Wound Healing Pathway: A Natural Resource Applied to Regenerative Therapy

Acute and chronic dermatological injuries need rapid tissue repair due to the susceptibility to infections. To effectively promote cutaneous wound recovery, it is essential to develop safe, low-cost, and affordable regenerative tools. Therefore, we aimed to identify the biological mechanisms involved in the wound healing properties of the glycosaminoglycan dermatan sulfate (DS), obtained from ascidian Styela plicata, a marine invertebrate, which in preliminary work from our group showed no toxicity and promoted a remarkable fibroblast proliferation and migration. In this study, 2,4-DS (50 µg/mL)-treated and control groups had the relative gene expression of 84 genes participating in the healing pathway evaluated. The results showed that 57% of the genes were overexpressed during treatment, 16% were underexpressed, and 9.52% were not detected. In silico analysis of metabolic interactions exhibited overexpression of genes related to: extracellular matrix organization, hemostasis, secretion of inflammatory mediators, and regulation of insulin-like growth factor transport and uptake. Furthermore, in C57BL/6 mice subjected to experimental wounds treated with 0.25% 2,4-DS, the histological parameters demonstrated a great capacity for vascular recovery. Additionally, this study confirmed that DS is a potent inducer of wound-healing cellular pathways and a promoter of neovascularization, being a natural ally in the tissue regeneration strategy.

Copper and cobalt doped bioactive glass-fish dermal collagen electrospun mat triggers key events of diabetic wound healing in full-thickness skin defect model

The wounds arising out of underlying hyperglycemic conditions such as diabetic foot ulcers demand a multifunctional tissue regeneration approach owing to several deficiencies in the healing mechanisms. Herein, four different types of electrospun microfibers by combining Rohu fish skin-derived collagen (Fcol) with a bioactive glass (BAG)/ion-doped bioactive glass, namely, Fcol/BAG, Fcol/CuBAG, Fcol/CoBAG, and Fcol/CuCoBAG was developed to accelerate wound healing through stimulation of key events such as angiogenesis and ECM re-construction under diabetic conditions. SEM analysis shows the porous and microfibrous architecture, while the EDX mapping provides evidence of the incorporation of dopants inside various inorganic-organic composite mats. The viscoelastic properties of the microfibrous mats as measured by a nano-DMA test show a higher damping factor non-uniform tan-delta value. The maximum ultimate tensile strength and toughness are recorded for fish collagen with copper doped bioactive glass microfibers while the least values are demonstrated by microfibers with cobalt dopant. In vitro results demonstrate excellent cell-cell and cell-material interactions when human dermal fibroblasts (HDFs) were cultured over the microfibers for 48 h. When these mats were applied over full-thickness diabetic wounds in the rabbit model, early wound healing is attained with Fcol/CuBAG, Fcol/CoBAG, and Fcol/CuCoBAG microfibers. Notably, these microfibers-treated wounds demonstrate a significantly (p < 0.01) higher density of blood vessels by CD-31 immunostaining than control, Duoderm, and Fcol/BAG treated wounds. Mature collagen deposition and excellent ECM remodeling are also evident in wounds treated with fish collagen/ion-doped bioactive glass microfibers suggesting their positive role in diabetic wound healing.

Serial histological changes in the cartilaginous eustachian tube in the rat following balloon dilation

Although balloon dilation has shown promising results in the treatment of dilatory Eustachian tube (ET) dysfunction, the histological effects of ET balloon dilation (ETBD) is unknown because histological examination of the whole human cartilaginous ET is impossible. Animal studies are needed to elucidate the effect of ETBD so we evaluated the histological changes after ETBD in a rat model. The left ET of 20 Wistar rats was dilated with a balloon catheter and the right ET was used as a control. Five rats were sacrificed immediately after ETBD, at 1, 4 and 12 weeks after the procedure for histological examination. The epithelial cells, presence of epithelial hyperplasia, and the proportion of the goblet cells in the epithelium; the vascular structures and dimensions of the submucosa; and presence of cartilage fracture and the area of the ET lumen were evaluated and compared between the groups. Desquamation of nearly all epithelial cells and the fracture of tubal cartilages were observed immediately after ETBD. At 1-week post-ETBD, the ciliated epithelial cells started to recover with epithelial hyperplasia. The goblet cells recovered by 4 weeks post-ETBD and epithelial hyperplasia decreased but was still present at 12 weeks post-ETBD. The depth of the submucosa increased and neovascularization in this region was observed at 1-week post-ETBD and persisted up to 12 weeks post-ETBD. The lumen of the cartilaginous ET increased immediately after ETBD but decreased at 1-week post-ETBD. The cartilaginous ET lumen recovered to the normal value at 4 weeks post-ETBD. This study is the first to describe the serial histological changes to the cartilaginous ET after ETBD and helps our understanding of the histological changes that occur after an ETBD intervention for intractable ET dysfunction.

Evaluation of pro-angiogenic properties of an inorganic silica gel fibre fleece

Hard-to-heal wounds represent an increasing health and economic burden on society. At present, therapy options for hard-to-heal wounds are often unsatisfactory, and the development of more effective wound treatments is urgently needed. We have shown that orthosilicic acid-releasing silica fibre fleece (SIFIB), via its pronounced anti-inflammatory properties, exhibited a significantly enhanced effect on wound closure kinetics in a porcine wound model in vivo. In this present study, we have examined in vitro the impact of the pro-angiogenic potential of SIFIB. Using an in vitro angiogenesis assay we describe for the first time how an inorganic biodegradable silica-based material significantly improved endothelial microvessel-like structure formation. We further demonstrate that the molecular mechanism of this pro-angiogenic activity of SIFIB is based on a significantly increased and tumour necrosis factor (TNF)α-dependent VEGF protein expression. In conclusion, due to its positive effects on angiogenesis, our results further indicate that decomposition products of silica-based biodegradable inorganic materials might represent very relevant therapeutic components of modern wound dressings for the treatment of hard-to-heal wounds.

Microencapsulated rhEGF to facilitate epithelial healing and prevent scar formation of cesarean wound: A randomized controlled trial

OBJECTIVE

Cesarean section (CS) is a major surgical intervention that affects women at childbearing age. Scarring from CS potentially causes discomfort and psychological distress. Emerging evidence indicates that epidermal growth factor (EGF) plays crucial roles in wound healing with the potential of minimizing scar formation. This study aims to investigate the effect of microencapsulated recombinant human EGF (Me-EGF) in scar prevention. Silicone gel was incorporated as part of the routine scar treatment.

MATERIALS AND METHODS

Healthy women scheduled for cesarean delivery were enrolled and randomized to three groups: (1) no scar treatment, (2) silicone gel only, or (3) silicone gel plus Me-EGF. Vancouver Scar Scale (VSS: vascularity, pigmentation, elasticity, and height) was used for scar assessment at the 6th month and 9th month after CS.

RESULTS

A total of 60 women were enrolled, but one patient withdrew due to noncompliance with the follow-up visit requirement. Me-EGF-containing treatment group consistently scored the lowest on every parameter in the VSS scale, followed by silicone gel group, and the group with no scar treatment. Kruskal-Wallis tests indicated significant differences (p < 0.05) between Me-EGF-containing treatment group and the other two groups in vascularity, pigmentation, elasticity, and the VSS total score, at either 6th month, 9th month, or both time points. The only parameter not showing any significant between-group difference was scar height, but the pattern still remained the same, in which Me-EGF group scored better in both month 6 and 9.

CONCLUSION

Surgical incisions in lower abdomen posed challenge in scar management. Our findings suggest that Me-EGF is a potential therapeutic option for better wound healing and scar prevention.

Cryptotanshinone enhances wound healing in type 2 diabetes with modulatory effects on inflammation, angiogenesis and extracellular matrix remodelling

CONTEXT

Cryptotanshinone (CT) is a diterpene quinone compound from Salvia miltiorrhiza Bge. Labiatae has been widely used in cardio-cerebral vascular diseases, which could be potentially effective in treating diabetic wounds.

OBJECTIVE

This study evaluates the wound healing activity of CT by employing an excisional wound splinting model in db/db mice.

MATERIALS AND METHODS

Wounds were induced at the dorsum of non-diabetic (db/+) and diabetic (db/db) mice and treated with sodium carboxymethyl cellulose (CMC-Na) or 300 mg/kg/d CT for 16 days. Wound closure was measured every two days. Body weight, fasting blood glucose, re-epithelialization, granulation, leukocyte infiltration, capillary density, collagen deposition and expressions of CXCL1, CXCL2, VEGF, Ang-1, p-eNOS, eNOS, α-SMA, MMP2 and MMP9 were analysed. Expression of VEGF and tube formation was measured in vitro with human umbilical vein endothelial cells (HUVECs).

RESULTS

CT significantly accelerated rate of wound closure, as the contraction ratio increased from 68% (non-treated group) to 83% (CT-treated group) at days 16 post-injury. A significant increase was observed in re-epithelialization and granulation tissue formation. Mechanistically, CT suppressed leukocyte infiltration and CXCL1 and CXCL2 expression. CT treatment also increased blood vessel density and expression level of VEGF, Ang-1 and p-eNOS. In vitro, CT boosted expression of VEGF and tube formation of endothelial cells. Moreover, extracellular matrix (ECM) remodelling was enhanced by CT via promoting fibroblast transformation and inhibiting MMP2 and MMP9.

CONCLUSIONS

Our study provides evidence that CT could be developed as a potential therapeutic agent for the treatment of chronic diabetic wound healing.

Oxygen and nutrient delivery in tissue engineering: Approaches to graft vascularization

The field of tissue engineering is making great strides in developing replacement tissue grafts for clinical use, marked by the rapid development of novel biomaterials, their improved integration with cells, better-directed growth and differentiation of cells, and improved three-dimensional tissue mass culturing. One major obstacle that remains, however, is the lack of graft vascularization, which in turn renders many grafts to fail upon clinical application. With that, graft vascularization has turned into one of the holy grails of tissue engineering, and for the majority of tissues, it will be imperative to achieve adequate vascularization if tissue graft implantation is to succeed. Many different approaches have been developed to induce or augment graft vascularization, both in vitro and in vivo. In this review, we highlight the importance of vascularization in tissue engineering and outline various approaches inspired by both biology and engineering to achieve and augment graft vascularization.

Drug therapies and delivery mechanisms to treat perturbed skin wound healing

Acute wound healing is an orderly process of four overlapping events: haemostasis, inflammation, proliferation and remodelling. A drug delivery system with a temporal control of release could promote each of these events sequentially. However, acute wound healing normally proceeds very well in healthy individuals and there is little need to promote it. In the elderly and diabetics however, healing is often slow and wounds can become chronic and we need to promote their healing. Targeting the events of acute wound healing would not be appropriate for a chronic wound, which have stalled in the proinflammatory phase. They also have many additional problems such as poor circulation, low oxygen, high levels of leukocytes, high reactive oxygen species, high levels of proteolytic enzymes, high levels of proinflammatory cytokines, bacterial infection and high pH. The future challenge will be to tackle each of these negative factors to create a wound environment conducive to healing.

Hyperbaric Oxygen Therapy: Exploring the Clinical Evidence

GENERAL PURPOSE

To provide information about hyperbaric oxygen therapy (HBOT), its mechanisms, indications and safe applications based on clinical evidence.

TARGET AUDIENCE

This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care.

LEARNING OBJECTIVES/OUTCOMES

After participating in this educational activity, the participant should be better able to:1. Recall the physiology of wound healing and the mechanisms of action of HBOT.2. Identify current applications of HBOT based on clinical evidence as well as its risks and contraindications.

ABSTRACT

Treating chronic wounds and infections are challenging medical problems worldwide. Hyperbaric oxygen therapy (HBOT), the administration of 100% oxygen at pressures greater than 1.4 atmosphere absolute in a series of treatments, can be used as an adjunctive therapy in many wound care settings because it improves oxygenation and neovascularization and decreases inflammation in chronic wounds. A growing number of studies support the benefits of HBOT for enhancing wound healing and decreasing the likelihood of negative events such as amputation. However, many practitioners are unfamiliar with HBOT. This article provides a general introduction to HBOT, reviews the physiology and mechanisms of behind HBOT, discusses all the indications for HBOT, and explores in-depth the clinical evidence for HBOT in the treatment of arterial insufficiencies, diabetic ulcers, delayed radiation injury, and chronic refractory osteomyelitis.

Effect of Propolis on Experimental Cutaneous Wound Healing in Dogs

This study evaluates clinically the effect of propolis paste on healing of cutaneous wound in dogs. Under general anesthesia and complete aseptic conditions, two full thickness skin wounds (3 cm diameter) were created in each side of the chest in five dogs, one dorsal and one ventral, with 10 cm between them. These wounds were randomly allocated into two groups, control group (10 wounds) and propolis group (10 wounds). Both groups were represented in each dog. The wounds were cleaned with normal saline solution and dressed with macrogol ointment in control group and propolis paste in propolis group, twice daily till complete wound healing. Measurement of the wound area (cm(2)) was monitored planimetrically at 0, 7, 14, 21, 28, and 35 days after injury. The data were analyzed statistically. The results revealed a significant reduction in the wound surface area in the propolis group after 14 and 21 days compared to control group. The wound reepithelization, contraction, and total wound healing were faster in propolis group than in control group during five weeks of study. In conclusion, propolis paste has a positive impact on cutaneous wound healing and it may be suggested for treating various types of wounds in animals.

Indoxyl sulfate predicts cardiovascular disease and renal function deterioration in advanced chronic kidney disease

BACKGROUND AND AIMS

Indoxyl sulfate, a protein-bound uremic toxin, was found to be accumulated in kidney tissues with a reduction in renal function. This, in turn, not only leads to kidney fibrosis and endothelial dysfunction but also to adverse clinical effects. We investigated the adverse effects of indoxyl sulfate on clinical outcomes in a study involving human subjects.

METHODS

Seventy pre-dialysis patients were enrolled from a single medical center. Serum indoxyl sulfate and biochemistry data were measured concurrently. Clinical outcomes including dialysis event, cardiovascular event and all-cause mortality were recorded during a 36-month follow-up.

RESULTS

Multivariate Cox regression analysis showed that age (HR: 0.95, p = 0.05), serum creatinine (HR: 1.29, p = 0.04) and indoxyl sulfate (HR: 1.06, p = 0.02) were independently associated with dialysis event; age (HR: 1.16, p = 0.01), serum phosphate (HR: 3.03, p = 0.05) and indoxyl sulfate level (HR: 1.11, p = 0.04) reached significant correlation with cardiovascular events after adjusting for other confounding factors. Kaplan-Meier analysis revealed that indoxyl sulfate level was significantly associated with cardiovascular and dialysis event (log rank p <0.01, log rank p = 0.01, respectively). In addition, serum indoxyl sulfate concentration was significantly increased in patients with dialysis and cardiovascular event (p <0.01, p <0.01, respectively).

CONCLUSIONS

Our results suggest that serum indoxyl sulfate level was a valuable marker in predicting cardiovascular disease and renal function decline in patients with advanced chronic kidney disease.