Protective effects of curcumin against oxidative damage on skin cells in vitro: its implication for wound healing

Evidence of curcumin and curcumin analogue effects in skin diseases: A narrative review

Curcumin, a natural polyphenolic and yellow pigment obtained from the spice turmeric, has strong antioxidative, anti-inflammatory, and antibacterial properties. Due to these properties, curcumin has been used as a remedy for the prevention and treatment of skin aging and disorders such as psoriasis, infection, acne, skin inflammation, and skin cancer. Curcumin has protective effects against skin damage caused by chronic ultraviolet B radiation. One of the challenges in maximizing the therapeutic potential of curcumin is its low bioavailability, limited aqueous solubility, and chemical instability. In this regard, the present review is focused on recent studies concerning the use of curcumin for the treatment of skin diseases, as well as offering new and efficient strategies to optimize its pharmacokinetic profile and increase its bioavailability.

Novel Antibacterials: Alternatives to Traditional Antibiotics

With the advent of the global antimicrobial resistance (AMR) crisis, our arsenal of effective antibiotics is diminishing. The widespread use and misuse of antibiotics in human and veterinary medicine, compounded by the lack of novel classes of antibiotic in the pharmaceutical pipeline, has left a hole in our antibiotic armamentarium. Thus, alternatives to traditional antibiotics are being investigated, including two major groups of antibacterial agents, which have been extensively studied, phytochemicals and metals. Within these groups, there are several subclasses of compound/elements, including polyphenols and metal nanoparticles, which could be used to complement traditional antibiotics, either to increase their potency or extend their spectrum of activity. Alone or in combination, these antibacterial agents have been shown to be effective against a vast array of human and animal bacterial pathogens, including those resistant to licensed antibacterials. These alternative antibacterial agents could be a key element in our fight against AMR and provide desperately needed options, to veterinary and medical clinicians alike.

Polyphenol uses in biomaterials engineering

Polyphenols are micronutrients obtained from diet that have been suggested to play an important role in health. The health benefits of polyphenols and their protective effects in food systems as antioxidant compounds are well known and have been extensively investigated. However, their functional roles as a "processing cofactor" in tissue engineering applications are less widely known. This review focuses on the functionality of polyphenols and their application in biomaterials. Polyphenols have been used to stabilize collagen and to improve its resistance to degradation in biological systems. Therefore, they have been proposed to improve the performance of biomedical devices used in cardiovascular systems by improving the mechanical properties of grafted heart valves, enhancing microcirculation through the relaxation of the arterial walls and improving the capillary blood flow and pressure resistance. Polyphenols have been found to stimulate bone formation, mineralization, as well as the proliferation, differentiation, and the survival of osteoblasts. These effects are brought about by the stimulatory effect of polyphenols on osteoblast cells and their protective effect against oxidative stress and inflammatory cytokines. In addition, polyphenols inhibit the differentiation of the osteoclast cells. Collectively, these actions lead to promote bone formation and to reduce bone resorption, respectively. Moreover, polyphenols can increase the cross-linking of dentine and hence its mechanical stability. Overall, polyphenols provide interesting properties that will stimulate further research in the bioengineering field.

Encapsulation of Curcumin Nanoparticles with MMP9-Responsive and Thermos-Sensitive Hydrogel Improves Diabetic Wound Healing

Impaired wound healing in diabetics usually leads to life-threatening complications. To develop a system for fastening skin wound healing efficiently and safely in diabetics, thermos-sensitive hydrogel containing the nanodrug, loaded in the form of gelatin microspheres (GMs), was designed to deliver curcumin (Cur) as a therapeutic drug. Cur is a naturally existing polyphenolic compound with a broad range of biological functions useful for potential therapies. Because Cur molecule has weakness in both bioavailability and in vivo stability, delivery of Cur requires assistance from other molecules to act as carrier vehicles in a sustained manner for therapeutic use. At first, self-assembly of Cur nanoparticles (CNPs) was done to improve bioavailability. The CNPs were further enclosed into GMs for responding to the matrix metalloproteinases (MMPs) that usually overexpress at diabetic nonhealing wound sites. The GMs containing CNPs were loaded into the thermos-sensitive hydrogel and were finally proved for the capacity of specially induced drug release at the wound bed, which promoted the efficacy in healing the standardized skin wounds in streptozotocin-induced diabetic mice. Our results indicated that the successfully developed CNP delivery system had the capacity to significantly promote skin wound healing, which suggested that it could have the potential to become a wound dressing with the properties of antioxidants and promotions of cell migration.

Oral curcumin for radiation dermatitis: a URCC NCORP study of 686 breast cancer patients

PURPOSE

Despite advances in medical technology, radiation dermatitis occurs in 95% of patients receiving radiation therapy (RT) for cancer. Currently, there is no standard and effective treatment for the prevention or control of radiation dermatitis. The goal of the study was to determine the efficacy of oral curcumin, one of the biologically active components in turmeric, at reducing radiation dermatitis severity (RDS) at the end of RT, using the RDS scale, compared to placebo.

METHODS

This was a multisite, randomized, double-blinded, placebo-controlled trial of 686 breast cancer patients. Patients took four 500-mg capsules of placebo or curcumin three times daily throughout their prescribed course of RT until 1 week post-RT.

RESULTS

A total of 686 patients were included in the final analyses (87.5% white females, mean age = 58). Linear mixed-model analyses demonstrated that curcumin did not reduce radiation dermatitis severity at the end of RT compared to placebo (B (95% CI) = 0.044 (- 0.101, 0.188), p = 0.552). Fewer curcumin patients with RDS > 3.0 suggested a trend toward reduced severity (7.4 vs. 12.9%, p = 0.082). Patient-reported changes in pain, symptoms, and quality of life were not statistically significant between arms.

CONCLUSIONS

Oral curcumin did not significantly reduce radiation dermatitis severity compared to placebo. The skin rating variation and broad eligibility criteria could not account for the undetectable therapeutic effect. An objective measure for radiation dermatitis severity and further exploration for an effective treatment for radiation dermatitis is warranted.

Curcumin accelerates cutaneous wound healing via multiple biological actions: The involvement of TNF-α, MMP-9, α-SMA, and collagen

Curcumin, a constituent of the turmeric plant, has antitumor, anti-inflammatory, and antioxidative effects, but its effects on wound healing are unclear. We created back wounds in 72 mice and treated them with or without topical curcumin (0.2 mg/mL) in Pluronic F127 gel (20%) daily for 3, 5, 7, 9, and 12 days. Healing in wounds was evaluated from gross appearance, microscopically by haematoxylin and eosin staining, by immunohistochemistry for tumour necrosis factor alpha and alpha smooth muscle actin, and by polymerase chain reaction amplification of mRNA expression levels. Treatment caused fast wound closure with well-formed granulation tissue dominated by collagen deposition and regenerating epithelium. Curcumin increased the levels of tumour necrosis factor alpha mRNA and protein in the early phase of healing, which then decreased significantly. However, these levels remained high in controls. Levels of collagen were significantly higher in curcumin-treated wounds. Immunohistochemical staining for alpha smooth muscle actin was increased in curcumin-treated mice on days 7 and 12. Curcumin treatment significantly suppressed matrix metallopeptidase-9 and stimulated alpha smooth muscle levels in tumour necrosis factor alpha-treated fibroblasts via nuclear factor kappa B signalling. Thus, topical curcumin accelerated wound healing in mice by regulating the levels of various cytokines.

PLGA based drug delivery systems: Promising carriers for wound healing activity

Wound treatment remains one of the most prevalent and economically burdensome healthcare issues in the world. Current treatment options are limited and require repeated administrations which led to the development of new therapeutics to satisfy the unmet clinical needs. Many potent wound healing agents were discovered but most of them are fragile and/or sensitive to in vivo conditions. Poly(lactic-co-glycolic acid) (PLGA) is a widely used biodegradable polymer approved by food and drug administration and European medicines agency as an excipient for parenteral administrations. It is a well-established drug delivery system in various medical applications. The aim of the current review is to elaborate the applications of PLGA based drug delivery systems carrying different wound healing agents and also present PLGA itself as a wound healing promoter. PLGA carriers encapsulating drugs such as antibiotics, anti-inflammatory drugs, proteins/peptides, and nucleic acids targeting various phases/signaling cycles of wound healing, are discussed with examples. The combined therapeutic effects of PLGA and a loaded drug on wound healing are also mentioned.

Combinatorial drug delivery strategy employing nano-curcumin and nano-MiADMSA for the treatment of arsenic intoxication in mouse

Chelation therapy is the mainstream treatment for heavy metal poisoning. Apart from this, therapy using antioxidant/herbal extracts are the other strategies now commonly being tried for the treatment. We have previously reported individual beneficial efficacy of nanoparticle mediated administration of an antioxidant like 'curcumin' and an arsenic chelator 'monoisoamyl 2,3-dimercaptosuccinic acid (MiADMSA)' for the treatment of arsenic toxicity compared to bulk drugs. The present paper investigates our hypothesis that a combination drug delivery therapy employing two nanosystems, a chelator and a strong antioxidant, may produce more pronounced therapeutic effects compared to individual effects in the treatment of arsenic toxicity. An in-vivo study was conducted wherein arsenic as sodium arsenite (100 ppm) was administered in drinking water for 5 months to Swiss albino mice. This was followed by a treatment protocol comprising of curcumin encapsulated chitosan nanoparticles (nano-curcumin, 15 mg/kg, orally for 1 month) either alone or in combination with MiADMSA encapsulated polymeric nanoparticles (nano-MiADMSA, 50 mg/kg for last 5 days) to evaluate the therapeutic potential of the combination treatment. Our results demonstrated that co-treatment with nano-curcumin and nano-MiADMSA provided beneficial effects in a synergistic way on the adverse changes in oxidative stress parameters and metal status induced by arsenic.

Role of Curcumin in Disease Prevention and Treatment

Treatment based on traditional medicine is very popular in developing world due to inexpensive properties. Nowadays, several types of preparations based on medicinal plants at different dose have been extensively recognized in the diseases prevention and treatment. In this vista, latest findings support the effect of Curcuma longa and its chief constituents curcumin in a broad range of diseases cure via modulation of physiological and biochemical process. In addition, various studies based on animal mode and clinical trials showed that curcumin does not cause any adverse complications on liver and kidney function and it is safe at high dose. This review article aims at gathering information predominantly on pharmacological activities such as anti-diabetic, anti-microbial, hepato-protective activity, anti-inflammatory, and neurodegenerative diseases.

Induction of apoptosis in HeLa cancer cells by an ultrasonic-mediated synthesis of curcumin-loaded chitosan-alginate-STPP nanoparticles

Natural herbal compounds have been widely introduced as an alternative therapeutic approach in cancer therapy. Despite potent anticancer activity of curcumin, its clinical application has been limited because of low water solubility and resulting poor bioavailability. In this study, we designed a novel ultrasonic-assisted method for the synthesis of curcumin-loaded chitosan–alginate–sodium tripolyphosphate nanoparticles (CS-ALG-STPP NPs). Furthermore, antitumor effect of curcumin-loaded NPs was evaluated in vitro. Field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM) were used to characterize the properties of NPs. Antitumor activity of curcumin-loaded NPs was assessed by using MTT and quantitative real-time polymerase chain reaction (qRT-PCR). FE-SEM and AFM data revealed the spherical morphology, and the average size of NPs was <50 nm. In vitro cytotoxicity assay suggested that curcumin-loaded CS-ALG-STPP NPs displayed significant antitumor activity compared with the free curcumin. Gene expression level analyses showed that curcumin NPs significantly increased the apoptotic gene expression. Collectively, our results suggest that curcumin-loaded NPs significantly suppressed proliferation and promoted the induction of apoptosis in human cervical epithelioid carcinoma cancer cells, which might be regarded as an effective alternative strategy for cancer therapy.

Efficacy of thermosensitive chitosan/β-glycerophosphate hydrogel loaded with β-cyclodextrin-curcumin for the treatment of cutaneous wound infection in rats

Wound infection has been a persistent problem that is common and costly. Thermosensitive hydrogel has been demonstrated to be a suitable dressing candidate due to its high moldability, easy administration and ability to maintain a moist topical environment at the wound bed. In the present study, a novel thermosensitive hydrogel was successfully prepared and characterized to have a porous inner structure and a sustained curcumin-releasing profile. The wound healing ability of the hydrogel was investigated in a wound infection model in rats. On analysis, it was observed that the hydrogel complex-dressed wounds exhibited a faster wound closure rate compared with gauze-covered wounds, which was paralleled with improved histological outcomes that were observed. Additionally, the results of in vitro antimicrobial, anti-oxidant, western blot analysis and reverse transcription-quantitative polymerase chain reaction assays indicated that the hydrogel complex had distinct anti-oxidative, antimicrobial and anti-nuclear factor-κB-signaling capacities. These results suggest that this novel hydrogel may be a suitable candidate for facilitating the healing of infected cutaneous wounds in rats.

Chitosan-based polymer hybrids for thermo-responsive nanogel delivery of curcumin

The purpose of this study is to design and develop thermoresponsive nano-sized hydrogel particles from a natural polymer, chitosan, as smart material platforms for curcumin delivery. Chitosan was used as the backbone material to be grafted with poly-(N-isopropylacrylamide) (pNIPAM) using an EDC/NHS coupling reaction. The conjugated products were characterized by ¹H NMR and TGA. Chitosan-grafted pNIPAM (CS-g-pN) nanogels were prepared by a sonication method. The loading of curcumin into the CS-g-pN nanogels was achieved using an incubation method. Size, morphology of nanogels, amounts of curcumin loaded to the nanogels and cellular uptake were investigated by DLS, TEM, fluorescent spectroscopy and confocal microscopy techniques, respectively. A CellTiter-Blue^® cell viability assay was performed in NIH-3T3 and HeLa cells to assess the safety while MTT assay was carried out in MDA-231, Caco-2, HepG2, and HT-29 cells for determining cytotoxic effects. Results showed that CS-g-pN with 3-60% degree of modification were simply assembled into spherical nanogel particles with submicron sizes, in which curcumin was encapsulated. The thermoresponsive behavior of each CS-g-pN nanogel formulation differed due to the grafted pNIPAM length and density. The CS-g-pN nanogel formulations were non-toxic towards NIH-3T3 and HeLa cells. Each curcumin-loaded CS-g-pN nanogel formulation could be up taken into NIH-3T3 cell lines and showed the dose-dependent cytotoxicity against tested cell lines. Successful development of this curcumin-loaded nanogel will lead to advanced materials that can be functionalized and optimized for targeted therapy and controlled delivery of small molecules and/or biomolecules for biomedical applications.

The Effects of Curcumin on Wound Healing in a Rat Model of Nasal Mucosal Trauma

We explored the effects of topical curcumin on the healing of nasal mucosal wounds. A total of 32 Sprague-Dawley Albino rats were randomized in equal numbers into four groups, and unilateral nasal wounds were created using an interdental brush. Group 1 (the sham-control group) contained untreated rats with traumatized right-side nasal cavities; Group 2 and 3 rats were similarly traumatized and treated with topical curcumin (5 and 10 mg/mL) dissolved in dimethyl sulfoxide daily for 7 days after trauma; Group 4 rats were treated with topical dimethyl sulfoxide only. All rats were decapitated on day 15 and the healing sites evaluated by blinded observers in terms of the presence of cellular hyperplasia, goblet cell hypertrophy and degeneration, leucocytic infiltration, ciliary loss and degeneration, edema, and vascular dilation. On histopathological evaluation, all of cellular hyperplasia, leukocytic infiltration, and edema were significantly reduced in Group 3 compared with Group 1 (p = 0.001, p = 0.004, and p = 0.008, resp.). Thus, curcumin reduced the inflammatory response and significantly accelerated wound healing.

Curcumin ameliorates diclofenac sodium-induced nephrotoxicity in male albino rats

Exposure to drugs often results in toxicity in the kidney which represents the major control system maintaining homeostasis of the body and thus is especially susceptible to xenobiotics. Nephrotoxicity is a life-threatening side-effect of nonsteroidal anti-inflammatory drugs (NSAIDs). Diclofenac is one of the most frequently prescribed NSAIDs and have been reported to cause multiple organs damage. Curcumin (CUR) exhibits nephroprotective properties. Therefore, rats were divided into four groups; rats of groups 3 and 4 received diclofenac (100 mg/kg, i.m.), whereas rats of groups 2 and 4 received CUR (100 mg/kg, p.o.) for 3 days. Diclofenac revealed a significant increase in urea and creatinine levels and malondialdehyde concentration and marked reduction in catalase activity and reduced glutathione concentration. Histopathologically, diclofenac produced fatty changes and eosinophilic casts were detected in the renal tubules, those were attenuated by administration of CUR prior diclofenac.

Investigating the use of curcumin-loaded electrospun filaments for soft tissue repair applications

Electrospun filaments represent a new generation of medical textiles with promising applications in soft tissue repair. A potential strategy to improve their design is to combine them with bioactive molecules. Curcumin, a natural compound found in turmeric, is particularly attractive for its antioxidant, anti-inflammatory, and antimicrobial properties. However, investigating the range of relevant doses of curcumin in materials designed for tissue regeneration has remained limited. In this paper, a wide range of curcumin concentrations was explored and the potential of the resulting materials for soft tissue repair applications was assessed. Polydioxanone (PDO) filaments were prepared with various amounts of curcumin: 0%, 0.001%, 0.01%, 0.1%, 1%, and 10% (weight to weight ratio). The results from the present study showed that, at low doses (≤0.1%), the addition of curcumin has no influence on the spinning process or on the physicochemical properties of the filaments, whereas higher doses lead to smaller fiber diameters and improved mechanical properties. Moreover, filaments with 0.001% and 0.01% curcumin stimulate the metabolic activity and proliferation of normal human dermal fibroblasts (NHDFs) compared with the no-filament control. However, this stimulation is not significant when compared to the control filaments (0%). Highly dosed filaments induce either the inhibition of proliferation (with 1%) or cell apoptosis (with 10%) as a result of the concentrations of curcumin found in the medium (9 and 32 μM, respectively), which are near or above the known toxicity threshold of curcumin (~10 μM). Moreover, filaments with 10% curcumin increase the catalase activity and glutathione content in NHDFs, indicating an increased production of reactive oxygen species resulting from the large concentration of curcumin. Overall, this study suggested that PDO electrospun filaments loaded with low amounts of curcumin are more promising compared with higher concentrations for stimulating tissue repair. This study also highlighted the need to explore lower concentrations when using polymers as PDO, such as those with polycaprolactone and other degradable polyesters.

Therapeutic effect of topical application of curcumin during treatment of radiation burns in a mini-pig model

Curcumin protects the skin against radiation-induced epidermal damage and prevents morphological changes induced by irradiation skin, thereby maintaining the epidermal thickness and cell density of basal layers. In this study, the effects of topical curcumin treatment on radiation burns were evaluated in a mini-pig model. Histological and clinical changes were observed five weeks after radiation exposure to the back (⁶⁰Co gamma-radiation, 50 Gy). Curcumin was applied topically to irradiated skin (200 mg/cm²) twice a day for 35 days. Curcumin application decreased the epithelial desquamation after irradiation. Additionally, when compared to the vehicle-treated group, the curcumin-treated group showed reduced expression of cyclooxygenase-2 and nuclear factor-kappaB. Furthermore, irradiation prolonged healing of biopsy wounds in the exposed area, whereas curcumin treatment stimulated wound healing. These results suggest that curcumin can improve epithelial cell survival and recovery in the skin and therefore be used to treat radiation burns.

Wound Healing Activity of Extracts and Formulations of Aloe vera, Henna, Adiantum capillus-veneris, and Myrrh on Mouse Dermal Fibroblast Cells

Background:

Among the most important factors in wound healing pathways are transforming growth factor beta1 and vascular endothelial growth factor. Fibroblasts are the main cell in all phases wound closure. In this study, the extracts of plant materials such as Adiantum capillus-veneris, Commiphora molmol, Aloe vera, and henna and one mixture of them were used to treatment of normal mouse skin fibroblasts.

Methods:

Cytotoxic effects of each extract and their mixture were assessed on mouse skin fibroblasts cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. We performed migration assays to assess migration properties of mouse skin fibroblasts cells in response to the extracts. Changes in the gene expression of the Tgfβ1 and Vegf-A genes were monitored by real-time polymerase chain reaction.

Results:

A. capillus-veneris, C. molmol and henna extract improved the expression of Tgfβ1 gene. All used extracts upregulated the expression of Vegf-A gene and promoted the migration of mouse fibroblast cells in vitro.

Conclusions:

The present study demonstrated that the mentioned herbal extracts might be effective in wound healing, through the improvement in the migration of fibroblast cells and regulating the gene expression of Tgfβ1 and Vegf-A genes in fibroblast cells treated with extracts.

The Anti-Inflammatory and Antioxidant Effects of Curcumin in Middle Ear Infection

AIM

To investigate and analyze the anti-inflammatory and antioxidant efficacy of curcumin in experimentally induced middle ear infection.

METHOD

Twenty-four Wistar albino rats with otomicroscopic examination findings within normal limits were included in the study. Study groups were established after Streptococcus pneumoniae was inoculated into the middle ear cavity of all rats. No medication was administered to Group 1, the control group. Group 2 was administered 50 mg/kg/day amoxicillin intraperitoneally. Group 3 was administered 50 mg/kg/day amoxicillin together with 30 mg/kg/day curcumin intraperitoneally. Blood specimens and temporal bones were collected on the 10th day of medication from the 22 rats in which acute otitis media developed. Serum glutathione peroxidase and superoxide dismutase activities and malondialdehyde levels were measured. Inflammatory cell infiltration, vascular proliferation, and epithelial proliferation were assessed histopathologically in middle ear mucosa specimens, and the results were compared among the groups.

RESULTS

Malondialdehyde levels in the group given curcumin were significantly lower than those of the control group, while serum glutathione peroxidase activity was also lower compared to that of the control group. No significant difference was observed among the groups in terms of superoxide dismutase activity. Although there were no significant findings in terms of histopathological data, epithelial proliferation in the groups receiving antibiotherapy was suppressed compared to the control group. Similarly, curcumin was observed to have a positive effect on inflammatory cell infiltration. No significant changes were observed in terms of vascular proliferation.

CONCLUSION

With its wide and safe dose range, curcumin represents grounds for optimism in terms of anti-inflammatory treatment in acute otitis media.

Antibiotic-non-antibiotic combinations for combating extremely drug-resistant Gram-negative 'superbugs'

The emergence of antimicrobial resistance of Gram-negative pathogens has become a worldwide crisis. The status quo for combating resistance is to employ synergistic combinations of antibiotics. Faced with this fast-approaching post-antibiotic era, it is critical that we devise strategies to prolong and maximize the clinical efficacy of existing antibiotics. Unfortunately, reports of extremely drug-resistant (XDR) Gram-negative pathogens have become more common. Combining antibiotics such as polymyxin B or the broad-spectrum tetracycline and minocycline with various FDA-approved non-antibiotic drugs have emerged as a novel combination strategy against otherwise untreatable XDR pathogens. This review surveys the available literature on the potential benefits of employing antibiotic-non-antibiotic drug combination therapy. The apex of this review highlights the clinical utility of this novel therapeutic strategy for combating infections caused by 'superbugs'.

Enhancement of curcumin wound healing ability by complexation with 2-hydroxypropyl-γ-cyclodextrin in sacran hydrogel film

Curcumin is one of promising agents to accelerate the wound-healing process. However, the efficacy of curcumin is limited due to its poor water solubility and stability. To enhance the properties of curcumin, 2-hydroxypropyl-γ-cyclodextrin (HP-γ-CyD) can be used through complexation. Recently, we revealed that sacran has the potential to form a hydrogel film (HGF) as a wound dressing material. Therefore, in the present study, we investigated the wound healing ability of curcumin/HP-γ-CyD (Cur/HP-γ-CyD) complex in sacran-based HGF (Sac-HGF). We prepared the Cur/HP-γ-CyD complex in Sac-HGF without surface roughness. Additionally, the amorphous form in the Cur/HP-γ-CyD complex in Sac-HGF were observed. In contrast, the curcumin in Sac-HGF and curcumin/HP-γ-CyD physical mixture in Sac-HGF formed inhomogeneous films due to crystallization of curcumin. Furthermore, HP-γ-CyD played an important role to increase the elastic modulus of the Sac-HGF with high re-swelling ability. The Cur/HP-γ-CyD complex in Sac-HGF maintained antioxidant properties of curcumin. Curcumin was gradually released from the HP-γ-CyD complex in Sac-HGF. Notably, the Cur/HP-γ-CyD complex in Sac-HGF provided the highest wound healing ability in hairless mice. These results suggest that the Cur/HP-γ-CyD complex in Sac-HGF has the potential for use as a new transdermal therapeutic system to promote the wound-healing process.

EGF and curcumin co-encapsulated nanoparticle/hydrogel system as potent skin regeneration agent

Wound healing is a complex multifactorial process that relies on coordinated signaling molecules to succeed. Epidermal growth factor (EGF) is a mitogenic polypeptide that stimulates wound repair; however, precise control over its application is necessary to reduce the side effects and achieve desired therapeutic benefits. Moreover, the extensive oxidative stress during the wound healing process generally inhibits repair of the injured tissues. Topical applications of antioxidants like curcumin (Cur) could protect tissues from oxidative damage and significantly improve tissue remodeling. To achieve much accelerated wound healing effects, we designed a novel dual drug co-loaded in situ gel-forming nanoparticle/hydrogel system (EGF-Cur-NP/H) which acted not only as a supportive matrix for the regenerative tissue, but also as a sustained drug depot for EGF and Cur. In the established excisional full-thickness wound model, EGF-Cur-NP/H treatment significantly enhanced wound closure through increasing granulation tissue formation, collagen deposition, and angiogenesis, relative to normal saline, nanoparticle/hydrogel (NP/H), Cur-NP/H, and EGF-NP/H treated groups. In conclusion, this study provides a biocompatible in situ gel-forming system for efficient topical application of EGF and Cur in the landscape of tissue repair.

In Vitro Antibacterial Activity of Curcumin-Polymyxin B Combinations against Multidrug-Resistant Bacteria Associated with Traumatic Wound Infections

Bacterial infections resulting from nonsurgical traumatic wounds can be life threatening, especially those caused by multidrug-resistant (MDR) bacteria with limited therapeutic options. The antimicrobial activity of polymyxin B (1) and curcumin (2) alone and in combination was determined versus MDR bacterial isolates associated with traumatic wound infections. Cytotoxicity assays for 1 and 2 were undertaken in keratinocyte cell lines. Minimum inhibitory concentrations of 1 were significantly reduced in the presence of 2 (3- to 10-fold reduction), with synergy observed. Time-kill assays showed the combinations produced bactericidal activity. Cytotoxicity assays indicate the toxicity of 2 was reduced in the presence of 1.

Phytochemicals in Wound Healing

Significance: Traditional therapies, including the use of dietary components for wound healing and skin regeneration, are very common in Asian countries such as China and India. The increasing evidence of health-protective benefits of phytochemicals, components derived from plants is generating a lot of interest, warranting further scientific evaluation and mechanistic studies. Recent Advances: Phytochemicals are non-nutritive substances present in plants, and some of them have the potential to provide better tissue remodeling when applied on wounds and to also act as proangiogenic agents during wound healing. Critical Issues: In this review, we briefly discuss the current understanding, important molecular targets, and mechanism of action(s) of some of the phytochemicals such as curcumin, picroliv, and arnebin-1. We also broadly review the multiple pathways that these phytochemicals regulate to enhance wound repair and skin regeneration. Future Directions: Recent experimental data on the effects of phytochemicals on wound healing and skin regeneration establish the potential clinical utility of plant-based compounds. Additional research in order to better understand the exact mechanism and potential targets of phytochemicals in skin regeneration is needed. Human studies a2nd clinical trials are pivotal to fully understand the benefits of phytochemicals in wound healing and skin regeneration.

Santosomes as natural and efficient carriers for the improvement of phycocyanin reepithelising ability in vitro and in vivo

New biocarriers, named santosomes, were formulated using Santolina insularis essential oil and hydrogenated phosphatidylcholine. They were modified by adding propylene glycol, a hydrophylic penetration enhancer, and loaded with phycocyanin, a protein found in cyanobacteria, which possesses antioxidant and antiinflammatory properties. The essential oil was expected to modify the bilayer structure and improve the delivery and efficacy of the protein due to a synergistic effect of the phospholipid and S. insularis terpenes. Santosomes were small in size (∼118nm), unilamellar and with polyhedral shape. SAXS patterns showed that phycocyanin strongly interacted with the polar heads of the vesicle bilayer. Phycocyanin-loaded vesicles did not show any toxic effect in vitro: cell viability was ∼100% in endothelial cells and ∼120% in keratinocytes, at all the concentrations tested. In addition, phycocyanin-loaded vesicles protected the cells against free radical damage. In vivo studies were performed to evaluate the ability of santosomes to inhibit chemically-induced oedema and inflammation in mice. Results demonstrated that the application of phycocyanin-loaded santosomes produced an evident amelioration of the skin lesion, confirming their great potential for wound healing.

Phycocyanin-encapsulating hyalurosomes as carrier for skin delivery and protection from oxidative stress damage

The phycobiliprotein phycocyanin, extracted from Klamath algae, possesses important biological properties but it is characterized by a low bioavailability due to its high molecular weight. To overcome the bioavailability problems, phycocyanin was successfully encapsulated, using an environmentally-friendly method, into hyalurosomes, a new kind of phospholipid vesicles immobilised with hyaluronan sodium salt by the simple addition of drug/sodium hyaluronate water dispersion to phospholipids. Liposomes were used as a comparison. Vesicles were small in size and homogeneously dispersed, being the mean size always smaller than 150 nm and PI never higher than 0.31. Liposomes were unilamellar and spherical, the addition of the polymer slightly modify the vesicular shape which remain spherical, while the addition of PEG improve the lamellarity of vesicles being multilamellar vesicles. In all cases phycocyanin was encapsulated in good amount especially using hyalurosomes and PEG hyalurosomes (65 and 61% respectively). In vitro penetration studies suggested that hyalurosomes favoured the phycocyanin deposition in the deeper skin layers probably thanks to their peculiar hyaluronan-phospholipid structure. Moreover, hyalurosomes were highly biocompatible and improved phycocyanin antioxidant activity on stressed human keratinocytes respect to the drug solution.

Soothing and anti-itch effect of quercetin phytosome in human subjects: a single-blind study

BACKGROUND

We evaluated the ability of quercetin, a natural antioxidant formulated in a specific delivery system, to reduce skin inflammation induced by a variety of stimuli, including UV radiation, stimulation with a histamine solution, or contact with chemical irritants. In particular, we tested the soothing and anti-itch effect of Quercevita(®), 1% cream for external use, a formulation characterized by a phospholipids-based delivery system.

PATIENTS AND METHODS

The study was a monocentric, single blind trial that enrolled a group of 30 healthy volunteers. The back of each subject was examined to identify four quadrants with no previous skin damage or naevi that were treated in order to induce a controlled and reversible form of skin stress. The areas were treated as follows: no product; Quercevita(®) 1% cream, 2 mg/cm(2); placebo; positive control (a commercially available topical formulation containing 1% dexchlorpheniramine).

RESULTS

Only quercetin phospholipids 1% and dexchlorpheniramine 1% achieved a significant reduction in erythema with comparable results: (-10.05% [P=0.00329] for quercetin phospholipids 1% vs -14.05% [P=0.00046] for the positive control). Moreover, quercetin phospholipids 1% and dexchlorpheniramine 1% were both associated with a significant decrease in mean wheal diameter: (-13.25% and -12.23% for dexchlorpheniramine 1%, respectively). Similar findings were reported for the other tested parameters.

CONCLUSION

Quercetin has a skin protective effect against damage caused by a variety of insults, including UV radiation, histamine, or contact with toxic chemical compounds. Indeed, quercetin is able to reduce redness, itching, and inflammation of damaged skin; it may also help restore skin barrier function, increasing hydration, and reducing water loss.

Current concepts on burn wound conversion-A review of recent advances in understanding the secondary progressions of burns

Burn wound conversion describes the process by which superficial partial thickness burns convert into deeper burns necessitating surgical intervention. Fully understanding and thus controlling this phenomenon continues to defy burn surgeons. However, potentially guiding burn wound progression so as to obviate the need for surgery while still bringing about healing with limited scarring is the major unmet challenge. Comprehending the pathophysiologic background contributing to deeper progression of these burns is an essential prerequisite to planning any intervention. In this study, a review of articles examining burn wound progression over the last five years was conducted to analyze trends in recent burn progression research, determine changes in understanding of the pathogenesis of burn conversion, and subsequently examine the direction for future research in developing therapies. The majority of recent research focuses on applying therapies from other disease processes to common underlying pathogenic mechanisms in burn conversion. While ischemia, inflammation, and free oxygen radicals continue to demonstrate a critical role in secondary necrosis, novel mechanisms such as autophagy have also been shown to contribute affect significantly burn progression significantly. Further research will have to determine whether multiple mechanisms should be targeted when developing clinical therapies.

Dietary curcumin supplementation attenuates 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neurotoxicity in C57BL mice

Studies in vivo and in vitro suggest that curcumin is a neuroprotective agent. Experiments were conducted to determine whether dietary supplementation with curcumin has neuroprotective effects in a mouse model of Parkinson’s disease (PD). Treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) significantly induced the loss of dopaminergic cells in the substantia nigra and deletion of dopamine in the striatum, which was attenuated by long-term (7 weeks) dietary supplementation with curcumin at a concentration of 0.5% or 2.0% (w/w). Although curcumin did not prevent the MPTP-induced apoptosis of neuroblasts in the subventricular zone (SVZ), it promoted the regeneration of neuroblasts in the anterior part of the SVZ (SVZa) at 3 days after MPTP treatment. Furthermore, curcumin enhanced the MPTP-induced activation of microglia and astrocytes in the striatum and increased the expression of glial cell line-derived neurotrophic factor (GDNF) and transforming growth factor-β1 (TGFβ1) in the striatum and SVZ. GDNF and TGFβ1 are thought to play an important role in protecting neurons from injury in the central and peripheral nervous systems. These results suggest that long-term administration of curcumin blocks the neurotoxicity of MPTP in the nigrostriatal dopaminergic system of the mouse and that the neuroprotective effect might be correlated with the increased expression of GDNF and TGFβ1. Curcumin may be effective in preventing or slowing the progression of PD.

Anti-oxidative effect of turmeric on frying characteristics of soybean oil

Curcumin, the active principle of turmeric, is known to act as an anti-oxidant, anti-mutagen and anti-carcinogen. This study aimed to find out the thermal and oxidative stability of soybean oil when potatoes marinated with turmeric were deep fried in the oil. Two sets of experiment were carried out. In one set, 1 L of oil was heated for 24 h (8 h daily for 3 consecutive days) and 200 g of potato chips without any marination were fried each time twice daily. Foods were fried in batches to replicate the commercial practice of the food industries. The temperature maintained during the whole experiment was at 180-190 °C i.e. at the frying temperature. About 50 ml of the oil sample was collected after every 4 h. In the second set, another 1 L of soybean oil was heated for 24 h in the similar manner and potato chips marinated with turmeric was fried twice daily. Oil samples were collected as before and comparative studies were done. The chemical parameters like acid value, peroxide value, content of 4-hydroxy-2-trans-nonenal (HNE) and fatty acid composition for all the oil samples of each set were determined. The comparative studies on peroxide value and content of HNE revealed that the antioxidant property of curcumin in turmeric helped in reducing the oxidation of the oil initially, but with increase in duration of time, the antioxidant potency got gradually reduced. The loss of unsaturated fatty acids were calculated from the fatty acid composition and it was found that loss of unsaturation in soybean oil where turmeric marinated potatoes were fried was 6.37 % while the controlled one showed 7.76 % loss after 24 h of heating. These results indicated higher thermal and oxidative stability of the soybean oil in presence of turmeric. However, the antioxidant effect gradually decreased with increase in duration of heating.

Intravenous curcumin efficacy on healing and scar formation in rabbit ear wounds under nonischemic, ischemic, and ischemia-reperfusion conditions

Curcumin, a spice found in turmeric, is widely used in alternative medicine for its purported anti-inflammatory and antioxidant activities. The goal of this study was to test the curcumin efficacy on rabbit ear wounds under nonischemic, ischemic, and ischemia-reperfusion conditions. Previously described models were utilized in 58 New Zealand White rabbits. Immediately before wounding, rabbits were given intravenous crude or pure curcumin (6 μg/kg, 30 μg/kg, or 60 μg/kg) dissolved in 1% ethanol. Specimens were collected at 7-8 days to evaluate the effects on wound healing and at 28 days to evaluate the effects on hypertrophic scarring. Student's t test was applied to screen difference between any treatment and control group, whereas analysis of variance was applied to further analyze for all treatment groups in aggregate in some specific experiments. Treatment with crude curcumin suggested accelerated wound healing that reached significance for reepithelialization in lower and medium doses and granulation tissue formation in lower dose. Purified curcumin became available and was used for all later experiments. Treatment with pure curcumin suggested accelerated wound healing that reached significance for reepithelialization in lower and medium doses and granulation tissue formation in lower dose. Treatment with pure curcumin significantly promoted nonischemic wound healing in a dose-response fashion compared with controls as judged by increased reepithelialization and granulation tissue formation. Improved wound healing was associated with significant decreases in pro-inflammatory cytokines interleukin (IL)-1 and IL-6 as well as the chemokine IL-8. Curcumin also significantly reduced hypertrophic scarring. The effects of curcumin were examined under conditions of impaired healing including ischemic and ischemia-reperfusion wound healing, and beneficial effects were also seen, although the dose response was less clear. Systemically administrated pure curcumin significantly promotes nonischemic wound healing and reduces hypertrophic scarring. Improvements in wound healing were associated with decreased inflammatory markers in wounds. Further study is needed to optimize dosing in ischemic and ischemia-reperfusion wound healing. In aggregate, the studies strongly support the systemic administration of curcumin to improve wound healing.

Curcumin affords protection against valproic acid induced teratogenicity by curtailing oxidative stress and inhibiting CYP2C9 activity

The toxic metabolite (E)-2,4-diene-VPA is involved in generation of oxidative stress subsequently contributing in induction of malformations and anomalies and that curcumin affords dose dependent amelioration of the anomalies exerted by VPA.

Identification and nanoentrapment of polyphenolic phytocomplex from Fraxinus angustifolia: in vitro and in vivo wound healing potential

The aim of the present study was to elucidate the polyphenolic composition of Fraxinus angustifolia leaf and bark extracts, and to evaluate their efficacy in wound healing. Quercetin, catechin, rutin and tannic acid were identified as the main components of the extracts. In order to improve their skin bioavailability, the polyphenolic phytocomplexes were incorporated in different nanovesicles, namely ethosomes and phospholipid vesicles containing Transcutol(®) P (Trc) or ethylene glycol (EG). The latter had never been used before as a component of phospholipid vesicles, and it was found to play a key role in improving extract efficacy in wound healing. Results of cryogenic transmission electron microscopy (cryo-TEM), Photon Correlation Spectroscopy (PCS) and Small-Angle X-ray Scattering (SAXS) showed that ethosomes and EG-PEVs were small, monodispersed, unilamellar vesicles, while Trc-PEVs were larger, less homogeneously dispersed and multilamellar, with a large bilayer thickness. Free extracts did not show relevant ability to protect in vitro human keratinocytes from H2O2 damages, while when entrapped in nanovesicles, they significantly inhibited H2O2 stress damages, probably related to a higher level of cell uptake. On the other hand, in vivo results showed that the highest antioxidant and anti-inflammatory effects were provided by the phytocomplexes in EG-PEVs, which favoured wound healing. Moreover, non-entrapped F. angustifolia extracts showed a marginal effect, comparable to that of free quercetin dispersion (control). In conclusion, our results depict that these extracts may find potential applications in biomedicine.

Improvement of quercetin protective effect against oxidative stress skin damages by incorporation in nanovesicles

Quercetin was incorporated in glycerosomes, new phospholipid-glycerol vesicles, and their protective effect against oxidative stress skin damages was extensively evaluated. In particular, the concentration-dependent effect of glycerol (from 10 to 50%) on vesicle suitability as cutaneous carriers of quercetin was carefully assessed. All vesicles were unilamellar and small in size (∼80-110 nm), as confirmed by cryo-TEM observation, with a drug incorporation efficiency ranging between 81 and 91%. SAXS studies, performed to investigate the bilayer arrangement, indicated a strong, dose-dependent interaction of glycerol with the polar portions of the phospholipid molecules, while quercetin did not significantly change the bilayer packing. In vitro studies on newborn pig skin underlined the concentration-dependent ability of glycerosomes to promote quercetin accumulation in the different layers, also confirmed by confocal microscopic observation of skin treated with fluorescent vesicles. Quercetin incorporated into liposomal and glycerosomal nanoformulations showed a strong ability to scavenge free radicals (DPPH test) and protect human keratinocytes in vitro against hydrogen peroxide damage. Moreover, quercetin-loaded vesicles were avidly taken up by keratinocytes in vitro. Overall, results indicate 40 and 50% glycerosomes as promising nanosystems for the improvement of cutaneous quercetin delivery and keratinocyte protection against oxidative stress damage.

Curcumin as a wound healing agent

Turmeric (Curcuma longa) is a popular Indian spice that has been used for centuries in herbal medicines for the treatment of a variety of ailments such as rheumatism, diabetic ulcers, anorexia, cough and sinusitis. Curcumin (diferuloylmethane) is the main curcuminoid present in turmeric and responsible for its yellow color. Curcumin has been shown to possess significant anti-inflammatory, anti-oxidant, anti-carcinogenic, anti-mutagenic, anti-coagulant and anti-infective effects. Curcumin has also been shown to have significant wound healing properties. It acts on various stages of the natural wound healing process to hasten healing. This review summarizes and discusses recently published papers on the effects of curcumin on skin wound healing. The highlighted studies in the review provide evidence of the ability of curcumin to reduce the body's natural response to cutaneous wounds such as inflammation and oxidation. The recent literature on the wound healing properties of curcumin also provides evidence for its ability to enhance granulation tissue formation, collagen deposition, tissue remodeling and wound contraction. It has become evident that optimizing the topical application of curcumin through altering its formulation is essential to ensure the maximum therapeutical effects of curcumin on skin wounds.

Combined administration of curcumin and gallic acid inhibits gallic acid-induced suppression of steroidogenesis, sperm output, antioxidant defenses and inflammatory responsive genes

In this study, we investigated the effects of administration of gallic acid (Gal) with or without curcumin (Cur) on the sperm output, steroid level and antioxidant defenses in rat testis in vivo and the expression of inflammatory responsive genes in vitro. Male Wistar rats were divided randomly into four groups and given oral Gal (100mg/kg/day) and Cur (100mg/kg/day) alone or in combination for four weeks. The sperm quality was impaired following Gal treatment, while Cur prevented this and also improved the sperm count as well as the efficiency of sperm production (DSP/gm testis). The inhibitory effects of Gal on plasma testosterone level, glutathione levels, activities of glutathione peroxidase, catalase, superoxide dismutase and steroidogenic enzymes, 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-HSD in the rat testis was blocked by Cur. Interestingly, the level of testosterone and the activities of the steroidogenic enzymes were significantly increased after treatment with Cur alone. Malondialdehyde concentration was unchanged following Gal treatment, while a significant decrease in malondialdehyde level was observed following treatment with Cur alone or in combination with Gal. We further analyzed the effects of Cur and Gal (25-100 μM) on the 93RS2 Sertoli cell-lines and observed that Cur blocked the Gal-induced suppression of inflammatory mediators such as TNF-α and IL-6, while Gal blocked the suppressive effect of Cur on IL-1α expression. Furthermore, the stimulatory or inhibitory effects of Gal on the expressions Tgf-β1 and CD-14 was concentration-dependent and could be blocked by Cur. When cultures of primary Sertoli cells were exposed to both Cur and Gal for 24h, p-JNK/SAPK expression remain stable, whereas Gal-induced p-p65 (NF-κB) expression and IκBα degradation was seen to be blocked by Cur but not Gal-induced expression of pERK1/2. Overall, Cur has stimulatory reproductive effects and could protect the testis from the toxic effects of Gal by mechanisms that could not be explained by its effects on the expressions of inflammatory cytokines but by its anti-oxidant properties.

Topical application of a sandal wood oil and turmeric based cream prevents radiodermatitis in head and neck cancer patients undergoing external beam radiotherapy: a pilot study

OBJECTIVE

The study objective was to assess the effectiveness of a turmeric- and sandal wood oil-containing cream [Vicco(®) turmeric cream (VTC); Vicco Laboratories, Parel, India] on radiodermatitis in patients with head and neck cancer undergoing radiotherapy.

METHODS

A total of 50 patients with head and neck cancer requiring >60 Gy of curative radiotherapy/chemoradiotherapy were enrolled in the study. The volunteers were randomly divided into two groups of 25 patients. Group 1 was assigned to a topical application of Johnson's(®) baby oil (Johnson & Johnson Ltd, Baddi, India) and Group 2 for VTC. Prophylactic application of the cream was initiated on Day 1 and continued every day until 2 weeks after the end of treatment. Both agents were symmetrically applied within the irradiated field five times a day, and the acute skin reactions were assessed twice weekly in accordance with the Radiation Therapy Oncology Group scores by an investigator who was unaware of the details.

RESULTS

The incidence of radiodermatitis increased with the exposure to radiation and was the highest in both groups at Week 7. However, a significant reduction in grades of dermatitis were seen in cohorts applying VTC at all time points, including 2 weeks post radiotherapy (p < 0.015 to p < 0.001). The occurrence of Grade 3 dermatitis was lower in the cohorts using VTC and was statistically significant (p < 0.01). Additionally, follow-up observations 2 weeks after the completion of radiotherapy also showed a reduced degree of radiodermatitis in cohorts applying VTC, which was significant (p = 0.015).

CONCLUSION

VTC is shown to be effective in preventing radiodermatitis and needs to be validated in larger double-blind trials.

ADVANCES IN KNOWLEDGE

For the first time, this study shows that the turmeric- and sandal oil-based cream was effective in preventing radiation-induced dermatitis.

Fabrication of quercetin and curcumin bionanovesicles for the prevention and rapid regeneration of full-thickness skin defects on mice

In the present work biocompatible quercetin and curcumin nanovesicles were developed as a novel approach to prevent and restore skin tissue defects on chronic cutaneous pathologies. Stable and suitable quercetin- and curcumin-loaded phospholipid vesicles, namely liposomes and penetration enhancer-containing vesicles (PEVs), were prepared. Vesicles were made from a highly biocompatible mixture of phospholipids and alternatively a natural polyphenol, quercetin or curcumin. Liposomes were obtained by adding water, while PEVs by adding polyethylene glycol 400 and Oramix®CG110 to the water phase. Transmission electron microscopy, cryogenic-transmission electron microscopy and small- and wide-angle X-ray scattering showed that vesicles were spherical, oligo- or multilamellar and small in size (112-220 nm). In vitro and in vivo tests underlined a good effectiveness of quercetin and curcumin nanovesicles in counteracting phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) induced lesions and inflammation. Myeloperoxydase activity, used to gauge inflammation, was markedly inhibited by quercetin liposomes (59%) and curcumin liposomes and polyethylene glycol (PEG)-PEVs (∼ 68%). Histology showed that PEG-PEVs provided an extensive re-epithelization of the TPA-damaged skin, with multiple layers of thick epidermis. In conclusion, nanoentrapped polyphenols prevented the formation of skin lesions abrogating the various biochemical processes that cause epithelial loss and skin damage.

Turmeric (curcumin) remedies gastroprotective action

The purpose of this review is to summarize the pertinent literature published in the present era regarding the antiulcerogenic property of curcumin against the pathological changes in response to ulcer effectors (Helicobacter pylori infection, chronic ingestion of non-steroidal anti-inflammatory drugs, and exogenous substances). The gastrointestinal problems caused by different etiologies was observed to be associated with the alterations of various physiologic parameters such as reactive oxygen species, nitric oxide synthase, lipid peroxidation, and secretion of excessive gastric acid. Gastrointestinal ulcer results probably due to imbalance between the aggressive and the defensive factors. In 80% of the cases, gastric ulcer is caused primarily due to the use of non-steroidal anti-inflammatory category of drug, 10% by H. pylori, and about 8-10% by the intake of very spicy and fast food. Although a number of antiulcer drugs and cytoprotectants are available, all these drugs have side effects and limitations. In the recent years a widespread search has been launched to identify new antiulcer drugs from synthetic and natural resources. An Indian dietary derivative (curcumin), a yellow pigment found in the rhizome of Curcuma longa, has been widely used for the treatment of several diseases. Epidemiologically, it was suggested that curcumin might reduce the risk of inflammatory disorders, such as cancer and ulcer. These biological effects are attributed to its anti-inflammatory and antioxidant activities. It can, therefore, be reported from the literature that curcumin PRevents gastrointestinal-induced ulcer and can be recommended as a novel drug for ulcer treatment.

Skin regenerative potentials of curcumin

Curcumin, an active constituent of the spice turmeric, is well known for its chemopreventive properties and is found to be beneficial in treating various disorders including skin diseases. Curcumin protects skin by quenching free radicals and reducing inflammation through the inhibition of nuclear factor-kappa B. Curcumin also affects other signaling pathways including transforming growth factor-β and mitogen-activated protein kinase pathway. Curcumin also modulates the phase II detoxification enzymes which are crucial in detoxification reactions and for protection against oxidative stress. In the present review, the biological mechanisms of the chemopreventive potential of curcumin in various skin diseases like psoriasis, vitiligo, and melanoma is discussed. The application of curcumin in skin regeneration and wound healing is also elucidated. We also explored the recent innovations and advances involved in the development of transdermal delivery systems to enhance the bioavailability of curcumin, particularly in the skin. Recent clinical trials pertaining to the use of curcumin in skin diseases establishes its benefits and also the need for additional clinical trials in other diseases are discussed.