Oral dose of citrus peel extracts promotes wound repair in diabetic rats

Antioxidative, Metabolic and Vascular Medicinal Potentials of Natural Products in the Non-Edible Wastes of Fruits Belonging to the Citrus and Prunus Genera: A Review

Diabetes mellitus and related metabolic and vascular impairments are notable health problems. Fruits and vegetables contain phenolics that are beneficial to metabolic and oxidative health and useful in preventing associated disease. Scientific evidence has shown that some bioactive phenolics are more abundant in the non-edible parts (especially the peels) of many fruits than in their respective edible tissues. Fruits belonging to the Citrus and Prunus genera are commonly consumed worldwide, including in South Africa, and their non-edible wastes (peel and seed) have been shown to have antioxidative, metabolic and vascular pharmacological potentials and medicinal phytochemistry. It is therefore imperative to evaluate the pharmacological actions and phytochemical properties of the non-edible wastes of these fruits and understand how they could potentially be of medicinal relevance in oxidative, metabolic and vascular diseases, including diabetes, oxidative stress, obesity, hypertension and related cardiovascular impairments. In the absence of a previous review that has concomitantly presented the medicinal potentials of fruits wastes from both genera, this review presents a critical analysis of previous and recent perspectives on the medicinal potential of the non-edible wastes from the selected Citrus and Prunus fruits in metabolic, vascular and oxidative health. This review further exposes the medicinal phytochemistry, while elucidating the underlying mechanisms through the fruit wastes potentiates their therapeutic effects. A literature search was carried out on "PubMed" to identify peer-reviewed published (mostly 2015 and beyond) studies reporting the antidiabetic, antioxidative, antihypertensive, anti-hyperlipidemic and anti-inflammatory properties of the non-edible parts of the selected fruits. The data of the selected studies were analyzed to understand the bioactive mechanisms, bioactive principles and toxicological profiles. The wastes (seed and peel) of the selected fruits had antioxidant, anti-obesogenic, antihypertensive, anti-inflammatory, antidiabetic and tissue protective potentials. Some phenolic acids and terpenes, as well as flavonoids and glycosides such as narirutin, nobiletin, hesperidin, naringin, naringenin, quercetin, rutin, diosmin, etc., were the possible bioactive principles. The peel and seed of the selected fruits belonging to the Citrus and Prunus genera are potential sources of bioactive compounds that could be of medicinal relevance for improving oxidative, metabolic and vascular health. However, there is a need for appropriate toxicological studies.

Phytotherapy in Diabetic Foot Ulcers: A Promising Strategy for Effective Wound Healing

Despite the advancement in wound care, the effective therapy of chronic diabetic ulcers continues to be a challenge. Wound healing is a highly controlled process, which involves a sequence of complex overlapping steps. This healing pathway comprises of hemostasis, inflammation, proliferative, and remodeling phases. Recent evidence suggests that phytomedicines can prevent or repair different kinds of destructive cellular damage, including chronic wounds. Several phytochemicals such as polyphenols, alkaloids, flavonoids, terpenoids, and glycosides have pleiotropic effects, including stimulation of fibroblast proliferation, the main step in wound healing. Besides, the mechanism involves induction of collagen synthesis, migration, and reepithelization and their antimicrobial, antioxidant, anti-inflammatory, and immunomodulatory actions. Similarly, the use of phytochemicals alone or as an adjuvant with standard therapy has demonstrated promising results in managing complications in the diabetic foot. For instance, the extract of Carica papaya has been shown antioxidant, antimicrobial, and anti-inflammatory, and immunomodulatory effects, which, together with proteolytic enzymatic activity, contributes to its wound healing property. It is generally believed that phytotherapy has no or minimal toxicity than synthetic therapeutic agents, favoring its use in diabetic foot ulcer management. The current review highlights the selected phytochemicals and their sources; and potential application in diabetic foot ulcer management.Key teaching points and nutritional relevanceCurrently, phytochemicals have been shown wide potential in disease. management including alleviating clinical manifestations, preventing degenerative disease, and curing illness.Increased evidence of phytochemical as anti-infective and anti-inflammatory suggests its role in the management of diabetic foot ulcer(DFU).Potential benefit along with minimal adverse effect favors its application as adjuvant therapy.Further research is needed to standardize its dose and formulation to enhance its clinical application in DFU management.

Diosmin-Loaded Nanoemulsion-Based Gel Formulation: Development, Optimization, Wound Healing and Anti-Inflammatory Studies

The wound-healing process is complex and prone to interruption or failure, which can result in the development of chronic wounds that never heal. This can be overcome by seeking prompt medical attention, which will reduce the likelihood of complications and speed up the healing of the cutaneous wound. It has been established that functionalized engineered biomaterials are a possible strategy for starting skin wound care. The purpose of the current study is to develop a diosmin (DSM)-loaded nanoemulsion (NE)-based gel formulation and to investigate its wound healing and anti-inflammatory activity on rats. The DSM-loaded NEs (F1-F17) were developed and optimized with the help of Box-Behnken Design Expert. The DSM-Nes were developed using lauroglycol 90 (LG90^®) as oil, Tween-80 as surfactant and transcutol-HP (THP) as co-surfactant. The optimized Nes showed globule size (41 ± 0.07 nm), polydispersity index (PDI) (0.073 ± 0.008) and percentage of entrapment efficiency (%EE) (87 ± 0.81%). This optimized DSM-loaded NEs (F1) was further evaluated and incorporated into 1% carbopol 940 gel. F1-loaded gel was then characterized for drug content, spreadability, in vitro release, wound healing, and anti-inflammatory studies. The developed gel of DSM was found to show significantly better (p < 0.05) wound-healing and anti-inflammatory activity.

The biological effect of orange (Citrus sinensis L.) by-products on metabolic biomarkers: A systematic review

Industrial processing of citrus fruits generates an important amount of wastes that evoke environmental damage. Orange is the main citrus fruit consumed worldwide, and after its use, approximately more than a half of the fruit remains as by-products, which comprise important bioactive compounds useful for the development of promising nutraceuticals for the treatment of non-communicable diseases. This study aimed to gather scientific evidence about the biological effects of orange by-products using a systematic review. A total of 14 studies that were carried out in rodent models in the last 10 years were retrieved from PubMed and ScienceDirect databases. Studies that used another animal species, another type of citrus, or a combination of orange with other citrus were excluded. The risk of bias was assessed by using the SYRCLE RoB tool, and the results obtained are shown in an informative table, which showed that most of the studies used a pathological model of chronic diseases. We found that the peel is the most used agri-food by-product, and that it has the potential of reducing the levels of triglycerides, total cholesterol, glucose, and systolic blood pressure. However, to clinically assess these effects, these results need to be tested in future in humans. The included studies on the use of orange by-products strengthen the global sustainable food agenda. It is important to consider new research directions about the use of citrus fruit residues since it not only impacts the problem of its disposal but also provides solutions to eliminate the resulting contamination.

Crisaborole Loaded Nanoemulsion Based Chitosan Gel: Formulation, Physicochemical Characterization and Wound Healing Studies

The development of an effective gel capable of treating eczema remains a challenge in medicine. Because of its greater retention in the affected area, good absorption of wound exudates, and induction of cell growth, nanogel is widely investigated as a topical preparation. Chitosan gel based on nanoemulsions has received much attention for its use in wound healing. In this study, four formulae (CRB-NE1-CRB-NE4) of crisaborole-loaded nanoemulsions (CRB-NEs) were developed using lauroglycol 90 as an oil, Tween-80 as a surfactant, and transcutol-HP (THP) as a co-surfactant. The prepared NEs (CRB-NE1-CRB-NE4) were evaluated for their physicochemical properties. Based on vesicle size (64.5 ± 5.3 nm), polydispersity index (PDI) (0.202 ± 0.06), zeta potential (ZP, −36.3 ± 4.16 mV), refractive index (RI, 1.332 ± 0.03), and percent transmittance (% T, 99.8 ± 0.12) was optimized and further incorporated into chitosan (2%, w/w) polymeric gels. The CRB-NE1-loaded chitosan gel was then evaluated for its drug content, spreadability, in-vitro release, flux, wound healing, and anti-inflammatory studies. The CRB-NE1-loaded chitosan gel exhibited a flux of 0.211 mg/cm²/h, a drug release of 74.45 ± 5.4% CRB released in 24 h with a Korsmeyer-Peppas mechanism release behavior. The CRB-NE1-loaded gel exhibited promising wound healing and anti-inflammatory activities.

Chondroprotection of fruit peels in a monosodium iodoacetate-induced osteoarthritis rat model via downregulation of Col1A1

The potential of the fruit peels of mango, orange, cantaloupe, and pomegranate in the treatment of osteoarthritis (OA) was evaluated in a rat model. Their metabolic profiles were characterized using ultrahigh-performance liquid chromatography (UPLC)-electrospray ionization-mass spectroscopy and 66 albino rats were intra-articularly injected with monosodium iodoacetate in the knee joints. The extracts were orally administered at doses of 200 and 400 mg/kg for 28 days. Serum levels of IL-6 and tissue levels of cyclooxygenase-2 (COX-2), peroxisome proliferator-activated receptor-gamma (PPARγ), and alpha-smooth muscle actin (α-SMA) were measured using ELISA. COL1A1 expression was measured by quantitative polymerase chain reaction. Histopathological changes in the joints were examined. In the extracts, 85 metabolites were annotated, and the levels of interleukin (IL)-6, COX-2, α-SMA, malondialdehyde, and nitric oxide were significantly reduced, while PPARγ and glutathione levels were significantly raised in all treated groups compared to the OA group. All extracts downregulated the cartilage mRNA expressions for COL1A1 dose-dependently. Mango peel extract exhibited the best chondroprotective effect. The in silico study showed the link between mango extract metabolites and COX-2.

In vivo wound-healing and antioxidant activity of aqueous extract of Roylea elegans leaves against physically induced burn model in Wistar albino rats

Roylea elegans Wall. ex Benth. is a lemon-scented hoary shrub belonging to the mint family (Lamiaceae). Traditionally, a local tribe of the Himalayan region uses leaves for scabs and skin infections. The aerial parts and leaves are widely used to cure various skin ailments. The plant is well known for two furanoid diterpenes, royeleganin and royelegafuran. The aqueous extract of Roylea elegans (AERE) leaves was investigated for wound-healing effects in rats using a physically induced burn model by assessing different parameters. Animals were divided into four groups (six rats in each group). Group I animals were considered as disease control and topically given base cream. Group II was considered as standard control and treated topically with Framycetin sulphate cream (1% w/w). Group III and IV animals were treated topically with creams containing 5 or 10% of AERE, respectively. Several parameters such as wound contraction rate, epithelialization period, and enzymatic and non-enzymatic antioxidant markers along with pro- and anti-inflammatory cytokines were studied followed by histopathological studies. The animals treated with AERE cream exhibited significant declination in the wound area and increased collagen content as compared to the disease control group. The results showed that the lower dose (5%) of AERE produced a significant decrease in the epithelialization period, wound contraction rate, and collagen content. Increased levels of cytokine production may be one of the mechanisms in accelerating the wound-healing process. The study established the traditional claim as an antioxidant and wound-healing potential of Roylea elegans by promoting the accelerated wound-healing activity against the physically induced burn model.

The Anti-Obesity Effects of Lemon Fermented Products in 3T3-L1 Preadipocytes and in a Rat Model with High-Calorie Diet-Induced Obesity

Lemon (Citrus limon) has antioxidant, immunoregulatory, and blood lipid-lowering properties. This study aimed to determine the effect of the lemon fermented product (LFP) which is lemon fermented with Lactobacillus OPC1 to prevent obesity. The inhibition of lipid accumulation in 3T3-L1 adipocytes is examined using a Wistar rat model fed a high-fat diet to verify the anti-obesity efficacy and mechanism of LFP. Here, it was observed that LFP reduced cell proliferation and inhibited the lipid accumulation (8.3%) of 3T3-L1 adipocytes. Additionally, LFP reduced body weight (9.7%) and fat tissue weight (25.7%) of rats; reduced serum TG (17.0%), FFA (17.9%), glucose (29.3%) and ketone body (6.8%); and increased serum HDL-C (17.6%) and lipase activity (17.8%). LFP regulated the mRNA expression of genes related to lipid metabolism (PPARγ, C/EBPα, SREBP-1c, HSL, ATGL, FAS, and AMPK). Therefore, LFP reduces body weight and lipid accumulation by regulating the mRNA expression of genes related to lipid metabolism. Overall, our results implicate LFP as a potential dietary supplement for the prevention of obesity.

Limited Treatment Options for Diabetic Wounds: Barriers to Clinical Translation Despite Therapeutic Success in Murine Models

Significance: Millions of people worldwide suffer from diabetes mellitus and its complications, including chronic diabetic wounds. To date, there are few widely successful clinical therapies specific to diabetic wounds beyond general wound care, despite the vast number of scientific discoveries in the pathogenesis of defective healing in diabetes. Recent Advances: In recent years, murine animal models of diabetes have enabled the investigation of many possible therapeutics for diabetic wound care. These include specific cell types, growth factors, cytokines, peptides, small molecules, plant extracts, microRNAs, extracellular vesicles, novel wound dressings, mechanical interventions, bioengineered materials, and more. Critical Issues: Despite many research discoveries, few have been translated from their success in murine models to clinical use in humans. This massive gap between bench discovery and bedside application begs the simple and critical question: what is still missing? The complexity and multiplicity of the diabetic wound makes it an immensely challenging therapeutic target, and this lopsided progress highlights the need for new methods to overcome the bench-to-bedside barrier. How can laboratory discoveries in animal models be effectively translated to novel clinical therapies for human patients? Future Directions: As research continues to decipher deficient healing in diabetes, new approaches and considerations are required to ensure that these discoveries can become translational, clinically usable therapies. Clinical progress requires the development of new, more accurate models of the human disease state, multifaceted investigations that address multiple critical components in wound repair, and more innovative research strategies that harness both the existing knowledge and the potential of new advances across disciplines.

Antioxidant and Wound Healing Potential of Essential Oil from Citrus reticulata Peel and Its Chemical Characterization

BACKGROUND

Fruit peels are considered as waste and contribute to a major proportion of the biomass. They can be a good source of various therapeutic benefits. Peels biomass of citrus fruits is usually considered as garbage. Such peels may have many important and valuable medicinal components with pharmacological activities. Citrus reticulata, (Rutaceae family, local name tangerine) is a local seasonal fruit in Pakistan, a very good example of wastage of its peels.

OBJECTIVE

The study is based on the exploration of a citrus fruit peel derived essential oil, its chemical characterization, identification of various bioactive components and the exploration of pharmacological potentials (antibacterial and wound healing activity).

METHODS

Essential oil was recovered by hydro-distillation of freshly collected peels. Chemical constituents of oil were determined by Gas Chromatography-Mass Spectroscopy (GC-MS) analysis. Antioxidant activities were evaluated by total phenolic contents, total flavonoid content, DPPH scavenging activity and reducing power assay. Antibacterial activity was determined using disc diffusion assay. In vivo wound healing potential was determined in rabbits after topical administration of oil. Wound scoring was calculated followed by histological study.

RESULTS

GC-MS analysis showed the presence of various components with the greatest proportion of D-Limonene (89.31%). Total flavonoid and phenolic contents were found to be 14.63 ± 0.95 mg CE/g and 17.03 ± 3.24 mg GAE/g respectively, while DPPH activity was found to be 73.32%. A better antibacterial activity was shown against E. coli. In vivo studies showed significant reduction in wound diameter in essential oil treatment groups. Further, the essential oil was found non-irritant in draize scoring.

CONCLUSION

The study concluded that essential oil of this fruit peel might be used for antibacterial and wound healing purposes.

Evaluation of the Wheat Germ Oil Topical Formulations for Wound Healing Activity in Rats

Wheat Germ Oil (WGO), the flour-milling by-product of wheat has essential constituents for skin health care as vitamin E, B-complex, squalene and unsaturated fatty acids. Incorporate WGO into polymers of the cream and ointment bases and evaluate the wound healing potential of these WGO formulations in the rat-animal model. <b>Materials and Methods:</b> WGO creams and ointments were prepared in two concentrations, 10 and 20% and evaluated for storage stability, homogeneity and compatibility using Fourier Transform Infrared (FT-IR) spectrometry. An amount of 0.5 g of the WGO formulations was applied daily to the injured area of the rats back. Wounds were observed for any clinical changes and healing compared to the control animal group. <b>Results:</b> The WGO was compatible with the cream and ointment bases and physically stables over 60 days of storage. The formulations of WGO have induced dose-dependent wound healing properties however the ointment formulations were demonstrating wound healing activity significantly better than the creams at all the intervals of the treatment. Within three weeks, 20% WGO ointment has induced a 90%reduction in the wound size diameter. Also, wounds recovered by 50% in 10 and 14 days of treatment with 20% WGO ointment and cream, respectively. <b>Conclusion:</b> The results revealed that WGO is a potential wound-healing agent from the scope that WGO is a common cosmetic ingredient and available at affordable prices.

Citrus limon Peel Essential Oil-Induced Type IV Hypersensitivity Reaction

Background

Several studies have shown anti-inflammatory, anti-microbial, antifungal, and antioxidant effects from Citrus limon–peel essential oil (Cl-PEO). Cl-PEO can be developed as topical drugs for oral ulceration because of its potential active components. There have been no studies on the topical application of Cl-PEO inducing type IV hypersensitivity reaction.

Purpose

To investigate the potential of Cl-PEO from Batu City to induce type IV hypersensitivity reactions based on clinical changes, lymphocytes, macrophages, IFNγ, andIL10 expression.

Methods

This study was adapted from a guinea pig maximization-test method in Indonesia and the guidance of ISO 10,993-10:2010, and conducted on 20 guinea pigs (Cavia cobaya) divided into a control group and a treatment group. The treatment group was given Cl-PEO and the control group CMC-Na. Clinical changes were observed, then tissue specimens taken for hematoxylin–eosin and immunohistochemistry staining.

Results

There were no clinical changes after exposure. Lymphocyte and macrophage numbers and IFNγ and IL10 expression increased in the treatment group compared to the control group (p=0).

Conclusion

Cl-PEO can induce type IV hypersensitivity reactions in guinea pigs based on cellular and molecular cytokines, but there are no clinical changes after topical application.

Natural Products Derived from the Mediterranean Diet with Antidiabetic Activity: from Insulin Mimetic Hypoglycemic to Nutriepigenetic Modulator Compounds

BACKGROUND

The Mediterranean diet is a healthy eating pattern that protects against the development of Type 2 diabetes mellitus (T2DM), a metabolic disease characterized by elevated blood sugar levels due to pancreatic beta-cell functional impairment and insulin resistance in various tissues. Inspired by the ancient communities, this diet emphasizes eating primarily plant-based foods, including vegetables, legumes, fruits, cereals, and nuts. Importantly, virgin olive oil is used as the principal source of fat. Red meat is consumed in low amounts while wine and fish are consumed moderately.

OBJECTIVE

Here, we review the most beneficial components of the Mediterranean Diet and tentative mechanisms of action for prevention and/or management of T2DM, based on research conducted within the last decade.

METHODS

The references over the last five years have been reviewed and they have been selected properly according to inclusion/ exclusion criteria.

RESULTS

Several bioactive diet components were evaluated to prevent inflammation and cytokine-induced oxidative damage, reduce glucose concentration, carbohydrate absorption and increase insulin sensitivity and related gene expression.

CONCLUSION

The adherence to a healthy lifestyle, including diet, exercise and habits remains the best approach for the prevention of diabetes as well as frequent check-ups and education. Though diabetes has a strong genetic component, in recent years many reports strongly point to the critical role of lifestyle specific epigenetic modifications in the development of T2DM. It remains to be established how different components of the Mediterranean Diet interact and influence the epigenetic landscape to prevent or treat the disease.

Preparation and Comparison of Effects of Different Herbal Oil Ointments as Wound-Healing Agents

Wound healing is a complex process and some agents have been reported to accelerate it. The aim of this study was to evaluate the healing effect of Eucerin-based ointments of lemon, sesame and olive oils on infected full-thickness wounds in rats. Wounds were created on the dorsal surface of Male Albino Wistar rats (n = 12). Wounds were treated with an Eucerin-based ointment containing either of lemon, sesame or olive oils (33% w/w) twice a day for 14 days. Histopathology results showed that contraction of wounds treated with lemon and sesame oils was higher than in the olive oil and control groups on days 10 and 14. In the lemon- and sesame-oil treated groups, on day 14, 50% of rat lesions were completely healed. Total number of inflammatory cells in lemon oil treatment group was significantly smaller than that of others on day 14 (p < 0.001). Also, thickness of the epidermal layer and rejuvenation of the hair follicles and other skin appendages was normal in lemon and sesame oil treated groups. The lemon and sesame oil ointments accelerated the healing process of wounds in macroscopic, morphological and morphmetrical analyses. Therefore, lemon and sesame oil ointments could be considered as alternative dressings for infected full-thickness wounds because of improved wound healing characteristics.

Diabetic Foot Ulcers: Current Advances in Antimicrobial Therapies and Emerging Treatments

Diabetic foot ulcers (DFUs) are very important diabetes-related lesions that can lead to serious physical consequences like amputations of limbs and equally severe social, psychological, and economic outcomes. It is reported that up to 25% of patients with diabetes develop a DFU in their lifetime, and more than half of them become infected. Therefore, it is essential to manage infection and ulcer recovery to prevent negatives outcomes. The available information plays a significant role in keeping both physicians and patients aware of the emerging therapies against DFUs. The purpose of this review is to compile the currently available approaches in the managing and treatment of DFUs, including molecular and regenerative medicine, antimicrobial and energy-based therapies, and the use of plant extracts, antimicrobial peptides, growth factors, ozone, devices, and nano-medicine, to offer an overview of the assessment of this condition.

Effects on Glycemic Control in Impaired Wound Healing in Spontaneously Diabetic Torii (SDT) Fatty Rats

Introduction

Impaired diabetic wound healing is an important issue in diabetic complications. The present study aims to evaluate the protective effect on glycemic control against impaired diabetic wound healing using a diabetic rat model. We investigated the wound healing process and effect on the impaired wound repair by glycemic control in the Spontaneously Diabetic Torii (SDT) fatty rat, which is a new animal model of obese type 2 diabetes and may be a good model for study impaired wound healing.

Material and methods

Male SDT fatty rats at 15 weeks of age were administered orally with sodium glucose co-transporter (SGLT) 2 inhibitor for 3 weeks. Wounds were induced at 2 weeks after SGLT 2 inhibitor treatment, and the wound areas were periodically examined in morphological and histological analyses.

Results

The SDT fatty rats showed a delayed wound healing as compared with the normal rats, but a glycemic control improved the impaired wound healing. In histological analysis in the skin of SDT fatty rats showed severe infiltration of inflammatory cell, hemorrhage and many bacterial masses in the remaining and slight fibrosis of crust on skin tissue. Thought that this results skin performance to be a delay of crust formation and regeneration of epithelium; however, these findings were ameliorated in the SGLT 2 inhibitor treated group.

Conclusion

Glycemic control is effective for treatment in diabetic wounds and the SDT fatty rat may be useful to investigate pathophysiological changes in impaired diabetic wound healing.

Hesperidin, a plant flavonoid accelerated the cutaneous wound healing in streptozotocin-induced diabetic rats: Role of TGF-ß/Smads and Ang-1/Tie-2 signaling pathways

Background: Delayed wound healing is a diverse, multifactorial, complex and inter-related complication of diabetes resulting in significant clinical morbidity. Hesperidin possesses potent antidiabetic and wound healing activity.

Aim: To evaluate the potential of hesperidin against experimentally induced diabetes foot ulcers.

Methods: Diabetes was induced experimentally by streptozotocin (STZ, 55 mg/kg, i.p.) in Sprague Dawley rats (180-220 g) and wounds were created on the dorsal surface of the hind paw of rats. Hesperidin (25, 50 and 100 mg/kg, p.o.) was administered for 21 days after wound stabilization. Various biochemical, molecular and histopathological parameters were evaluated in wound tissue.

Results: STZ-induced decrease in body weight and increase in blood glucose, food, and water intake was significantly (p < 0.05) inhibited by hesperidin (50 and 100 mg/kg) treatment. It showed a significant increase (p < 0.05) in percent wound closure and serum insulin level. The STZ-induced decrease in SOD and GSH level, as well as elevated MDA and NO levels, were significantly (p < 0.05) attenuated by hesperidin (50 and 100 mg/kg) treatment. Intraperitoneal administration of STZ caused significant down-regulation in VEGF-c, Ang-1, Tie-2, TGF-β and Smad 2/3 mRNA expression in wound tissues whereas hesperidin (50 and 100 mg/kg) treatment showed significant up-regulation in these mRNA expressions. STZ-induced alteration in would architecture was also attenuated by hesperidin (50 and 100 mg/kg) treatment.

Conclusion: Together, treatment with hesperidin accelerate angiogenesis and vasculogenesis via up-regulation of VEGF-c, Ang-1/Tie-2, TGF-β and Smad-2/3 mRNA expression to enhance wound healing in chronic diabetic foot ulcers.

Anticarcinogenic Effects of Dried Citrus Peel in Colon Carcinogenesis Due to Inhibition of Oxidative Stress

Colorectal cancer is one of the leading causes of death worldwide. Reactive oxygen species produce oxidative stress and contribute to colorectal carcinogenesis. Because dietary citrus has been shown to reduce oxidative stress, we investigated the effects of citrus peel extract at dilutions of 1/200-1/500 on the activity of oxidative-stress-related transcription factors, including AP-1, NF-κB, NRF2, p53, and STAT3, in human colon cancer cell line HCT116 cells using a luciferase reporter gene assay. NRF2 transcriptional activities were 1.8- to 2.0-fold higher than the untreated control value. In addition, NF-κB, p53, and STAT3 transcriptional activities were 12-26% lower than the untreated control value. Administration of dried citrus peel in the diet of F344 rats at a dose of 1,000 ppm prevented the formation of azoxymethane-induced precancerous aberrant crypt foci (ACF) in the colon. The total number of ACF in rats fed with dried citrus peel was reduced to 75% of the control value. Moreover, the levels of oxidative-stress-related markers, reactive carbonyl species, in the serum of F344 rats were significantly reduced following the administration of dried citrus peel. These data suggest that citrus peel possesses an ability to suppress cellular oxidative stress through induction of NRF2, thereby preventing azoxymethane-induced colon carcinogenesis.