Involvement of lipid peroxidation in necrosis of skin flaps and its suppression by ellagic acid

Ellagic acid inhibits dihydrotestosterone-induced ferroptosis and promotes hair regeneration by activating the wnt/β-catenin signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Androgenic alopecia (AGA) is the most prevalent form of hair loss in clinical practice and affects the physical and psychological well-being of adolescents. Paeonia lactiflora Pallas (PL), which is widely used in traditional Chinese medicine, enhances blood function and promotes hair growth, and ellagic acid (EA), a polyphenol in PL extract, shows strong antioxidant, anti-aging, and anti-inflammatory properties and also plays a role in the treatment of various skin conditions. However, its role and mechanism of action in AGA remain unclear.

AIM OF THE STUDY

To determine whether EA can rescue slow hair regeneration by regulating dihydrotestosterone (DHT)-induced ferroptosis in AGA mice and clarify the effect of EA on DHT-induced ferroptosis in dermal papilla cells (DPCs).

MATERIALS AND METHODS

Male C57BL/6 mice were used to establish a DHT-induced AGA mouse model, whereas DPCs were used to establish a DHT-induced cellular model. Thereafter, we investigated the therapeutic mechanism of action of EA via immunofluorescence, western blot analysis, immunohistochemistry, electron microscopy, and molecular docking.

RESULTS

EA stimulated hair regeneration in mice and reversed DHT-induced increases in iron content, lipid peroxidation, and DHT-induced mitochondrial dysfunction by activating the Wnt/β-catenin signaling pathway. Further, β-catenin knockdown suppressed the inhibitory effect of EA on DHT-induced ferroptosis in DPCs.

CONCLUSION

EA inhibits DHT-induced ferroptosis and promotes hair regrowth in mice by activating the Wnt/β-catenin signaling pathway. Thus, it has potential for use as a treatment option for AGA.

Pharmacotherapeutic potential of pomegranate in age-related neurological disorders

Age-related neurological disorders [AND] include neurodegenerative diseases [NDDs] such as Alzheimer's disease [AD] and Parkinson's disease [PD], which are the most prevalent types of dementia in the elderly. It also includes other illnesses such as migraine and epilepsy. ANDs are multifactorial, but aging is their major risk factor. The most frequent and vital pathological features of AND are oxidative stress, inflammation, and accumulation of misfolded proteins. As AND brain damage is a significant public health burden and its incidence is increasing, much has been done to overcome it. Pomegranate (Punica granatum L.) is one of the polyphenol-rich fruits that is widely mentioned in medical folklore. Pomegranate is commonly used to treat common disorders such as diarrhea, abdominal pain, wound healing, bleeding, dysentery, acidosis, microbial infections, infectious and noninfectious respiratory diseases, and neurological disorders. In the current review article, we aimed to summarize the data on the pharmacotherapeutic potentials of pomegranate in ANDs.

Therapeutic Effects of Medicinal Plants on Cutaneous Wound Healing in Humans: A Systematic Review

The pharmaceutical industry has made great strides in providing drugs that are able to stimulate the healing process, but only 1-3% of all drugs that are listed in Western pharmacopoeias are intended for use on the skin or cutaneous wounds. Of these, at least one-third are obtained from plants. We sought to review the therapeutic effects of medicinal plants on human skin lesions. For this systematic review, we searched the PubMed, Scopus, and Web of Science databases to identify clinical trials that were published from 1997 to 2017. We reviewed studies that described the use of medicinal plants for the treatment of skin lesions in humans. Ten studies were selected, eight of which were published from 2007 to 2016, with a total of 503 patients. Among the plant species that were used for the treatment of human skin lesions, 12 belonged to 11 families and were included in the analysis. All of the plant species that were studied presented high therapeutic potential for the treatment of cutaneous lesions.

Pharmacologic overview of systemic chlorogenic acid therapy on experimental wound healing

Chlorogenic acid (CGA) is a well-known natural antioxidant in human diet. To understand the effects of CGA on wound healing by enhancing antioxidant defense in the body, the present study sought to investigate the potential role of systemic CGA therapy on wound healing and oxidative stress markers of the skin. We also aimed to understand whether chronic CGA treatment has side effects on pivotal organs or rat bone marrow during therapy. Full-thickness experimental wounds were created on the backs of rats. CGA (25, 50, 100, 200 mg/kg) or vehicle was administered intraperitoneally for 15 days. All rats were sacrificed on the 16th day. Biochemical, histopathological, and immunohistochemical examinations were performed. Possible side effects were also investigated. The results suggested that CGA accelerated wound healing in a dose-dependent manner. CGA enhanced hydroxyproline content, decreased malondialdehyde and nitric oxide levels. and elevated reduced glutathione, superoxide dismutase, and catalase levels in wound tissues. Epithelialization, angiogenesis, fibroblast proliferation, and collagen formation increased by CGA while polymorph nuclear leukocytes infiltration decreased. CGA modulated matrix metalloproteinase-9 and tissue inhibitor-2 expression in biopsies. Otherwise, high dose of CGA increased lipid peroxidation of liver and kidney without affecting the heart and muscle samples. Chronic CGA increased micronuclei formation and induced cytotoxicity in the bone marrow. In conclusion, systemic CGA has beneficial effects in improving wound repair. Antioxidant, free radical scavenger, angiogenesis, and anti-inflammatory effects of CGA may ameliorate wound healing. High dose of CGA may induce side effects. In light of these observations, CGA supplementation or dietary CGA may have benefit on wound healing.

Neuroprotective effects of a variety of pomegranate juice extracts against MPTP-induced cytotoxicity and oxidative stress in human primary neurons

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is an environmental toxin which selectively induces oxidative damage and mitochondrial and proteasomal dysfunctions to dopaminergic neurons in the substantia nigra leading to Parkinsonian syndrome in animal models and humans. MPTP is one of the most widely used in vitro models to investigate the pathophysiology of Parkinson's disease (PD) and, screen for novel therapeutic compounds that can slow down or ameliorate this progressive degenerative disease. We investigated the therapeutic effect of pomegranate juice extracts (PJE), Helow, Malasi, Qusum, and Hamadh against MPTP-induced neurotoxicity in primary human neurons by examining extracellular LDH activity, intracellular NAD⁺ and ATP levels, and endogenous antioxidant levels including lipid peroxidation products, catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, and reduced glutathione (GSH) levels. MPTP induced a reduction in SOD and GPx activities and intracellular NAD⁺, ATP, and GSH levels parallel to an increase in extracellular LDH and CAT activities, although lipid peroxidation was not altered. We report that helow and malasi can ameliorate MPTP-induced neurotoxicity by attenuating the observed changes in redox function to a greater extent than qusum and hamedh. Selected PJE varieties may exhibit properties which may be of therapeutic value to slow down age-related degeneration and neurodegeneration in particular.

The rare sugar D-allose has a reducing effect against ischemia-reperfusion injury on the rat abdominal skin island flap model

BACKGROUND

Recently, one of the rare sugars, D-allose, has received attention from many researchers because of its availability for mass production and its various physiological functions. Among these, an antioxidative effect has been strongly suggested. In this study, we investigated whether this effect is also applicable to the field of skin surgery.

METHODS

In ischemia-reperfusion injury model using the rat abdominal skin island flap (male Wistar rats, n = 110), D-allose was injected intravenously 15 min before 8-h ischemia. The survival area (%) was measured by digital photographic assessment 1 wk after surgery, and multiple comparisons (Fisher's protected least significant difference) were carried out. Histopathological examination (neutrophilic infiltration into dermis in hematoxylin and eosin stain) and immunostaining (of ectodermal dysplasia-1 (ED1)-positive cells/flap) were assessed. Myeloperoxidase (MPO) activity in the skin flap (sampling at the time of 8 h after reperfusion) was measured spectrophotometrically, and Student t-test was performed.

RESULTS

D-allose extended the survival of the remaining flaps, and a dose greater than 30 mg (0.1 mg/g) was necessary to be effective. The flap survival rates in the 30, 60, and 150 mg groups were significantly higher than that in the control (saline) group: 75.87 ± 5.90, 79.27 ± 7.81, and 77.87 ± 6.20 versus 50.53 ± 9.66, respectively (P < 0.05). ED1-positive cells/flap in 60 mg of D-allose and control (saline) were 78 ± 25.7 versus 124 ± 15.8, respectively (P = 0.08). The MPO activity in the D-allose 60 mg group was 0.40 ± 0.04, and that in the control (saline) was 0.72 ± 0.12. D-allose significantly reduced the skin tissue MPO activity (P < 0.05) compared with that in the control (saline) group.

CONCLUSIONS

We proved that D-allose has a reducing effect against ischemia-reperfusion injury on the skin island flap model, and the mechanism is related to inhibiting the activity of neutrophils in the skin tissues. Compared with chemo-synthetic materials, rare sugars are safer for our bodies as well as the environment; therefore, this rare sugar project is expected to lead to the development of a safer antioxidant for skin flap surgery.

1-(2,4-Dihydroxyphenyl)-3-(2,4-dimethoxy-3-methylpheny)propane inhibits melanin synthesis by dual mechanisms

BACKGROUND

1-(2,4-Dihydroxyphenyl)-3-(2,4-dimethoxy-3-methylpheny)propane (DP) was reported as a novel tyrosinase inhibitor by Nesterov et al. In previous study, we showed that DP is an antioxidant and accelerates the fading of UVB-induced tan in human skin but details of inhibiting mechanism of DP in melanogenesis remain incomplete.

OBJECTIVE

To clarify additional mechanisms of DP inhibition of melanogenesis, we studied the effect of DP on tyrosinase processing and degradation.

METHODS

Tyrosinase inhibition was assessed using mushroom and human tyrosinase. The effect of DP on mRNA and protein levels as well as glycosylation and degradation of tyrosinase was examined using normal human epidermal melanocytes (NHEM).

RESULTS

DP was 200 times more potent than that of kojic acid in inhibiting mushroom tyrosinase activity. In contrast, DP (IC(50)=200μM) was significantly less effective at inhibiting tyrosinase from NHEM. DP decreased melanin content in cultured NHEM after 7th day (IC(50)=10μM). The IC(50) for DP against human tyrosinase activity was found to be at least 20 times higher than that of melanin synthesis. At a non-cytotoxic concentration DP did not decrease tyrosinase mRNA however protein level decreased by 46% after 48h treatment. DP did not alter the ratio of mature and immature tyrosinase assayed by endo H cleavage. Tyrosinase degradation assays revealed that DP accelerated tyrosinase degradation in NHEM.

CONCLUSIONS

We found that DP acts through dual mechanisms to reduce melanin synthesis; by inhibition of tyrosinase activity via an anti-oxidant effect, and, more importantly, by the acceleration of tyrosinase degradation.

Prunella vulgaris extract and rosmarinic acid prevent UVB-induced DNA damage and oxidative stress in HaCaT keratinocytes

Solar radiation is a very important exogenous factor in skin pathogenesis and can lead to the development of a number of skin disorders. UVB irradiation is known to induce oxidative stress, inflammation and especially DNA lesions in exposed cells. It is important, therefore, to identify agents that can offer protection against UVB-caused skin damage. Natural compounds have been studied for their possible ability to control/modulate various lifestyle-related diseases. The application of plant compounds/extracts with screening, antioxidant and anti-inflammatory activities may also successfully protect the skin against UV-caused injury. We assessed the potency of Prunella vulgaris extract (PVE) and its main phenolic acid component, rosmarinic acid (RA), to suppress UVB-induced (295-315 nm) alterations to human keratinocytes HaCaT using a solar simulator. Pre- and post-treatment of HaCaT cells with PVE (5-50 mg/l) and RA (0.18-1.8 mg/l) reduced breakage together with the apoptotic process. PVE and RA also significantly eliminated ROS production and diminished IL-6 release. Taken together, both PVE and RA prevent UVB-caused injury to keratinocytes. However their efficacy needs to be demonstrated in vivo.

Effects of Alchemilla vulgaris and glycerine on epithelial and myofibroblast cell growth and cutaneous lesion healing in rats

Wound-healing properties have been suggested for Alchemilla vulgaris. Since epithelial and myofibroblast cell growth is required for wound healing, the effects of A. vulgaris on cell growth were investigated in Chang liver and Madin Darby Bovine Kidney (MDBK) epithelial cell lines and rat aortic myofibroblast cultures. Putative healing properties were investigated on dorsal circular 8 mm excisional skin lesions in adult male rats. Cell numbers increased with 0.1-1% A. vulgaris, attaining 21.3 +/- 2.1%, 15.5 +/- 2.25% and 10.6 +/- 0.6% in MDBK, myofibroblast and Chang liver cells, respectively (p < 0.005). No morphological changes or cytotoxicity were noted. In rats A. vulgaris (3%)-treated lesions were significantly decreased in diameter by 10.0 +/- 0.7% (p < 0.005) after 2 days of treatment. On day 3 of treatment, the lesion diameter was significantly reduced by 15.9 +/- 1.1% in glycerine vehicle-treated rats compared with distilled water (p < 0.005), whereas that in A. vulgaris-treated rats was reduced further by 23.2 +/- 1.4% (p < 0.005). Glycerine alone significantly reduced the lesion diameter between days 3 and 5 but complete healing occurred a day earlier in A. vulgaris-treated rats. The results demonstrate wound-healing properties of A. vulgaris associated with promitotic activity in epithelial cells and myofibroblasts.

Inhibitory effect of an ellagic acid-rich pomegranate extract on tyrosinase activity and ultraviolet-induced pigmentation

A pomegranate extract (PE) from the rind containing 90% ellagic acid was tested for its skin-whitening effect. PE showed inhibitory activity against mushroom tyrosinase in vitro, and the inhibition by the extract was comparable to that of arbutin, which is a known whitening agent. PE, when administered orally, also inhibited UV-induced skin pigmentation on the back of brownish guinea pigs. The intensity of the skin-whitening effect was similar between guinea pigs fed with PE and those fed with L-ascorbic acid. PE reduced the number of DOPA-positive melanocytes in the epidermis of UV-irradiated guinea pigs, but L-ascorbic acid did not. These results suggest that the skin-whitening effect of PE was probably due to inhibition of the proliferation of melanocytes and melanin synthesis by tyrosinase in melanocytes. PE, when taken orally, may be used as an effective whitening agent for the skin.

The effects of ellagic acid and vitamin E succinate on antioxidant enzymes activities and glutathione levels in different brain regions of rats after subchronic exposure to TCDD

Ellagic acid (EA) and vitamin E succinate (VES) were previously shown to protect against 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD)-induced reactive oxygen species (ROS) overproduction in certain brain regions of rats after subchronic exposure. The current study was designed to assess the modulation of antioxidant enzyme activities and glutathione (GSH) levels as protective measures for VES and EA against TCDD-induced ROS overproduction in four regions of rat brain. TCDD was administered to groups of rats at a daily dose of 46 ng/kg for 90 d. EA and VES were administered to some other groups of rats either alone or simultaneously with TCDD, every other day for 90 d. At the end of the treatment period, animals were sacrificed and brain regions were dissected, including cerebral cortex (Cc), hippocampus (H), cerebellum (C), and brainstem (Bs), for assay of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities, as well as GSH levels. While treatment of rats with VES alone or in combination with TCDD resulted in significant increases in SOD and CAT activities in different brain regions, treatment with EA resulted in a significant rise in total GSH levels and GSH-Px activity in those regions. Results may suggest antioxidant modulation by VES and EA as a mechanism for the previously observed protection by these compounds against TCDD-induced ROS overproduction in brain. Data also indicate there are two different pathways in the protection provided by the two antioxidants.

Beware of Pomegranates Bearing 40% Ellagic Acid

A recent profusion of pomegranate nutraceutical products, "standardized to 40% ellagic acid," has appeared in the marketplace. This Perspective reviews the chemical and functional studies of pomegranate as well as the virtues and dangers of ellagic acid, and concludes that synergy among the various pomegranate fractions and phytochemicals is the most important factor for assessing strength of pomegranate nutraceutical preparations, and not simply the concentration of ellagic acid. Ellagic acid concentration in final products is likely to have an optimal therapeutic range, which very likely is less than 40%. The wisdom of designing and engineering pomegranate nutraceutical products to maximize therapeutic or chemopreventive synergy is suggested, as opposed to preparations that are designed and engineered simply to maximize the concentration of a single phytochemical. The implications of this strategy may be generalized for the optimization of nutraceutical preparations from other medicinal plants as well.

Treatment of Aphthous Stomatitis with Topical Alchemilla vulgaris in Glycerine

BACKGROUND AND OBJECTIVE

Recurrent aphthous ulceration is the most common oral mucosal disease known. It presents as three types: minor (most prevalent), major and herpetiform. However, there are no well established effective and reliable treatments of this condition. Alchemilla vulgaris (Lady's Mantle) has traditionally been used in oral hygiene and was recently shown to accelerate wound healing when used in combination with glycerine. The objective of this study was to determine whether this combination is effective in the treatment of the most prevalent form of aphthous ulcers.

METHODS

An open-label study was conducted in 48 otherwise healthy male and female patients aged 4-44 years to determine the putative healing properties and tolerability of a standard 3% extract of A. vulgaris in glycerine (Aphtarine) on common minor oral ulcers. Patients with major or herpetiform ulcers were excluded from the study.

RESULTS

Topical application three times daily of Aphtarine gel to minor mouth ulcers relieved discomfort and produced complete healing in the majority of patients (60.4%) within 2 days and in 75% within 3 days, compared with 10.4% and 33.3%, respectively, without treatment and 15% and 40%, respectively, with commonly available treatments. Most patients appreciated the product's ease of application, taste and texture. Aphtarine was well tolerated locally and most patients rated the product good to excellent overall.

CONCLUSION

Aphtarine is a safe, well tolerated and highly effective promising new treatment for healing common mouth ulcers.

Pomegranate extracts potently suppress proliferation, xenograft growth, and invasion of human prostate cancer cells

We completed a multicenter study of the effects of pomegranate cold-pressed (Oil) or supercritical CO(2)-extracted (S) seed oil, fermented juice polyphenols (W), and pericarp polyphenols (P) on human prostate cancer cell xenograft growth in vivo, and/or proliferation, cell cycle distribution, apoptosis, gene expression, and invasion across Matrigel, in vitro. Oil, W, and P each acutely inhibited in vitro proliferation of LNCaP, PC-3, and DU 145 human cancer cell lines. The dose of P required to inhibit cell proliferation of the prostate cancer cell line LNCaP by 50% (ED(50)) was 70 microg/mL, whereas normal prostate epithelial cells (hPrEC) were significantly less affected (ED(50) = 250 g/mL). These effects were mediated by changes in both cell cycle distribution and induction of apoptosis. For example, the androgen-independent cell line DU 145 showed a significant increase from 11% to 22% in G(2)/M cells (P <.05) by treatment with Oil (35 microg/mL) with a modest induction of apoptosis. In other cell lines/treatments, the apoptotic response predominated, for example, in PC-3 cells treated with P, at least partially through a caspase 3-mediated pathway. These cellular effects coincided with rapid changes in mRNA levels of gene targets. Thus, 4-hour treatment of DU 145 cells with Oil (35 microg/mL) resulted in significant 2.3 +/- 0.001-fold (mean +/- SEM) up-regulation of the cyclin-dependent kinase inhibitor p21((waf1/cip1)) (P <.01) and 0.6 +/- 0.14-fold down-regulation of c-myc (P <.05). In parallel, all agents potently suppressed PC-3 invasion through Matrigel, and furthermore P and S demonstrated potent inhibition of PC-3 xenograft growth in athymic mice. Overall, this study demonstrates significant antitumor activity of pomegranate-derived materials against human prostate cancer.

The effect of short- versus long-term administration of alpha tocopherol on the survival of random flaps in experimental diabetes mellitus

The effects of short- versus long-term alpha tocopherol administration on oxidative stress and survival of dorsal random flaps were studied in diabetic rats. Seven groups, with 20 rats in each, were constructed: (1) control, (2) noncontrolled diabetes, (3) noncontrolled diabetes+short-term alpha tocopherol, (4) noncontrolled diabetes+long-term alpha tocopherol, (5) insulin treatment, (6) insulin+short-term alpha tocopherol, and (7) insulin+long-term alpha tocopherol. After 3 months of diabetes, dorsal McFarlane flaps were raised. Flap viability and free-radical measurements with histopathological examination were investigated. Mean flap survival in Groups I to VII were 84.0+/-2.2%, 55.0+/-2.4%, 57.0+/-2.5%, 57.8+/-3.7%, 64.1+/-4.1%, 70.0+/-4.9%, and 77.0+/-6.6%, respectively. Free-radical concentration, as assessed with luminol- and lucigenin-enhanced chemiluminiscence, was inversely correlated with flap survival. The results for viability and free-radical concentrations were significant between Groups 1, 2, 5, 6, and 7. Random flaps in diabetic animals showed significantly greater necrosis compared with controls. Among the diabetic animals, group receiving combination of insulin and long-term alpha tocopherol treatment had the greatest flap viability and least tissue free-radical concentration. Histopathological studies showed a hyalinization of arterioles in diabetics with long-term alpha tocopherol treatment protecting the vessel wall. In conclusion, random flaps in experimental diabetes mellitus show greater tissue oxidative stress and necrosis, which is only partially corrected with insulin treatment. Long-term antioxidant supplementation as an adjunct to insulin further lowers the oxidative stress, protects vessel structure and function, and therefore increases flap survival.

The curcuma antioxidants: pharmacological effects and prospects for future clinical use. A review

In agreement with the predictions of the oxygen-stress theory of aging and age-related degenerative diseases, diet supplementation with a number of phenolic or thiolic antioxidants has been able to increase the life span of laboratory animals, protect against senescent immune decline and preserve the respiratory function of aged mitochondria. In addition to the above, more recent data reviewed here suggest that the polyphenolic compound curcumin and related non-toxic antioxidants from the rhizome of the spice plant Curcuma longa have a favorable effect on experimental mouse tumorigenesis as well as on inflammatory processes such as psoriasis and ethanol-caused hepatic injury. Our own research has focused on the effects of diet supplementation with an antioxidant-rich hydroalcoholic extract of the curcuma rhizome on key risk factors of atherogenesis and related cardiovascular disease. Our reviewed data show that, in human healthy subjects, the daily intake of 200 mg of the above extract results in a decrease in total blood lipid peroxides as well as in HDL and LDL-lipid peroxidation. This anti-atherogenic effect was accompanied by a curcuma antioxidant-induced normalization of the plasma levels of fibrinogen and of the apo B/apo A ratio, that may also decrease the cardiovascular risk. The reviewed literature indicates that curcumin and related plant co-antioxidants are powerful anti-inflammatory agents. Further, since they potentiate the anti-atherogenic effect of alpha-tocopherol, more extensive clinical testing of their probable usefulness in cardiovascular risk reduction seems justified.

The modulatory effects of ellagic acid and vitamin E succinate on TCDD-induced oxidative stress in different brain regions of rats after subchronic exposure

The effects of ellagic acid (EA) and vitamin E succinate (VES) on 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced oxidative stress in different brain regions of rats have been studied after subchronic exposure to the compounds. TCDD was administered to groups of rats at a dose of 46 ng/kg/day for 90 days. EA and VES were administered to groups of rats, either separately or simultaneously with TCDD, every other day for 90 days. At the end of the treatment period, animals were sacrificed and brains were dissected to cerebral cortex (Cc), hippocampus (H), cerebellum (C), and brain stem (Bs), and were assayed for production of superoxide anion (SA), lipid peroxidation (LP), and DNA single-strand breaks (SSBs). While TCDD administration to rats resulted in significant production of SA, LP, and DNA SSBs in Cc and H, simultaneous administration of VES or EA with the xenobiotics resulted in significant protection against those effects. The results also indicate that VES provided a better protyection against TCDD-induced effects in brains when compared with EA.

Comportamento do estresse oxidativo e da capacidade antioxidante total em ratos submetidos a retalhos cutâneos isquêmicos

OBJETIVO: Estudar o comportamento do estresse oxidativo (MDA) e da defesa antioxidante (CAT), em fragmentos de retalhos cutâneos randômicos isquêmicos em ratos. MÉTODOS: Foram utilizados 18 ratos adultos jovens, machos (Wistar EPM-1, 290 a 350g), submetidos à elevação de retalho cutâneo de base cranial no dorso, divididos em três grupos (N=6) em função do tempo pós-operatório: imediato (POI), terceiro e sétimo dias (PO3 e PO7, respectivamente). Ao final, foram coletadas amostras de sangue periférico e fragmentos de tecido do retalho e de área cutânea normal fora do retalho para dosagem de MDA e de CAT. RESULTADOS: Para MDA no soro, o grupo POI apresentou valores significativamente menores que os grupos PO3 e PO7, os quais não diferiram entre si. Não foi encontrada diferença entre os valores das amostras cutâneas em nenhum dos três grupos estudados. Para os valores da capacidade antioxidante total (CAT) não houve diferença significante entre os três grupos, quando analisado o soro dos animais, no entanto, para as amostras de fragmentos cutâneos, os valores diminuíram significativamente em função do tempo. CONCLUSÃO: A inexistência de diferença para os valores de MDA nas amostras cutâneas entre os grupos e a diminuição dos valores da CAT ao longo do tempo sugere que a presença de necrose na porção distal dos retalhos dos animais do grupo PO7 decorra, não somente da agressão oxidativa, mas também da diminuição da capacidade de defesa antioxidante local.

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

BACKGROUND

Curcumin, isolated from turmeric, has been known to possess many pharmacologic properties. It has been proven to exhibit remarkable anticarcinogenic, anti-inflammatory, and antioxidant properties. Turmeric curcumin may be a good potential agent for wound healing.

METHODS

To further understand its therapeutic mechanisms on wound healing, the antioxidant effects of curcumin on hydrogen peroxide (H2O2) and hypoxanthine-xanthine oxidase induced damage to cultured human keratinocytes and fibroblasts were investigated. Cell viability was assessed by colorimetric assay and quantification of lactate dehydrogenase release.

RESULTS

Exposure of human keratinocytes to curcumin at 10 microg/mL showed significant protective effect against hydrogen peroxide. Interestingly, exposure of human dermal fibroblasts to curcumin at 2.5 microg/mL showed significant protective effects against hydrogen peroxide. No protective effects of curcumin on either fibroblasts or keratinocytes against hypoxanthine-xanthine oxidase induced damage were found in our present studies.

CONCLUSION

The findings indicate that curcumin indeed possessed powerful inhibition against hydrogen peroxide damage in human keratinocytes and fibroblasts.

Anti-oxidant effects of the extracts from the leaves of Chromolaena odorata on human dermal fibroblasts and epidermal keratinocytes against hydrogen peroxide and hypoxanthine–xanthine oxidase induced damage

In cutaneous tissue repair, oxidants and antioxidants play very important roles. In local acute and chronic wounds, oxidants are known to have the ability to cause as cell damage and may function as inhibitory factors to wound healing. The administration of anti-oxidants or free radical scavengers is reportedly helpful, notably in order to limit the delayed sequelae of thermal trauma and to enhance the healing process. Extracts from the leaves of Chromolaena odorata have been shown to be beneficial for treatment of wounds. Studies in vitro of these extracts demonstrated enhanced proliferation of fibroblasts, endothelial cells and keratinocytes, stimulation of keratinocyte migration in an in vitro wound assay, up-regulation of production by keratinocytes of extracellular matrix proteins and basement membrane components, and inhibition of collagen lattice contraction by fibroblasts. In this study, the anti-oxidant effects of both total ethanol and polyphenolic extracts from the plant leaves on hydrogen peroxide and hypoxanthine-xanthine oxidase induced damage to human fibroblasts and keratinocytes were investigated. Cell viability was monitored by a colorimetric assay. The results showed that for fibroblasts, toxicity of hydrogen peroxide or hypoxanthine xanthine oxidase on cells was dose-dependent. Total ethanol extract (TEE) at 400 and 800 microg/ml showed maximum and consistent protective cellular effect on oxidant toxicity at low or high doses of oxidants. The 50 microg/ml concentration of TEE also had significant and slightly protective effects on fibroblasts against hydrogen peroxide and hypoxanthine-xanthine oxidase induced damage, respectively. For keratinocytes, a dose-dependent relationship of oxidant toxicity was only seen with hydrogen peroxide but the protective action of the extract correlated with oxidant dosage. TEE at 400 and 800 microg/ml showed dose-dependent effects with both low and high concentration of oxidants. TEE at 50 microg/ml had no effect on keratinocytes. Pre-treatment with the extracts did not show a protective effect on cells. Polyphenolic extract exhibited a slight anti-oxidant effect. Protection of cells against destruction by inflammatory mediators may be one of the ways in which the extracts from the plant, C. odorata, contribute to wound healing.

Therapeutic potential of dietary phase 2 enzyme inducers in ameliorating diseases that have an underlying inflammatory component

Many diseases associated with ageing have an underlying oxidative stress and accompanying inflammatory component, for example, Alzheimer's disease or atherosclerosis. Reviewed in this manuscript are: the role of oxidative stress in activating the transcription factor nuclear factor kappa B (NFκB), the role of NFκB in activating pro-inflammatory gene transcription, strong oxidants produced by cells, anti-oxidant defense systems, the central role of phase 2 enzymes in the anti-oxidant defense, dietary phase 2 enzyme inducers and evidence that dietary phase 2 enzymes decrease oxidative stress. It is likely that a diet containing phase 2 enzyme inducers may ameliorate or even prevent diseases that have a prominent inflammatory component to them. Research should be directed into the potential therapeutic effects of dietary phase 2 enzyme inducers in ameliorating diseases with an underlying oxidative stress and inflammatory component to them.Key words: Alzheimer's disease, atherosclerosis, diet, glutathione, inflammation, stroke.

An hydroalcoholic extract of curcuma longa lowers the apo B/apo A ratio. Implications for atherogenesis prevention

It is generally accepted that free-radical induced blood lipid peroxidation and especially peroxidized LDL play a central role in the pathogenesis of atherosclerosis and related cardiovascular disease. Moreover, recent research highlights the key contribution of apolipoprotein B (apo B) to atherogenesis as the main inductor of one of its earlier steps, i.e. macrophage proliferation. This has led us to investigate the apo B response to a very effective phenolic lipid-antioxidant, namely an hydroalcoholic extract of Curcuma longa, which according to our previous work does not show any toxic effects and decreases the levels of blood lipid peroxides, oxidized lipoproteins and fibrinogen. The present study shows that a daily oral administration of the extract decreases significantly the LDL and apo B and increases the HDL and apo A of healthy subjects. This and recent data on the increased anti-atherogenic action of the physiological antioxidant tocopherol in the presence of phenolic co-antioxidants (which eliminate the tocopheroxyl radical), justifies planned clinical research to test the usefulness of the curcuma extract as a co-antioxidant complement to standard treatments to prevent or retard atherosclerosis.

Effects of the antioxidant turmeric on lipoprotein peroxides: Implications for the prevention of atherosclerosis

Extracts from the rhyzome of Curcuma longa are widely used as food additives in India and other Asiatic and Central American countries. It has been shown that these extracts ("turmeric"), as well as "curcumin" and related phenolic compounds isolated from Curcuma, have a powerful antioxidant action when tested in in vitro systems. Moreover, previous research from our laboratories has shown significant decreases in the levels of lipid peroxides in the blood of both mice and human subjects administered "turmeric." Our present research complements the previous data, showing that a daily intake of turmeric equivalent to 20 mg of the phenolic antioxidant curcumin for 60 days decreases the high levels of peroxidation of both the HDL and the LDL, in vivo, in 30 healthy volunteers ranging in age from 40 to 90 years. The effect was quite striking in the persons with high baseline values of peroxidized compounds in these lipoproteins, while no apparent change took place in the persons having low baseline values. In view of current concepts on the atherogenic role played by peroxidized HDL, and especially by peroxidized LDL, as inducers of foam and smooth cell proliferation in the arterial wall, this preliminary experiment suggests that the Curcuma phenolic antioxidants, because of their high antioxidant activity and lack of toxicity, might be a useful complement to standard hypo-lipidemic drugs in the prevention and treatment of atherosclerosis.

Possible contributions of mastocytosis, apoptosis, and hydrolysis in pathophysiology of randomized skin flaps in humans and guinea pigs

To understand better the pathophysiology of random skin flaps, randomized skin flaps of human (3 cases) and guinea pig (53 cases) were investigated. Proximal (normal), proximomedial (viable), mediodistal (between viable and necrotic parts), and distal (necrosis) locations of the skin flaps were biopsied. Lipid peroxidase, hydrolytic enzymes of cytosol (Ca(2+)-dependent cysteine protease: calpain), and lysosome (acid phosphatase) of skin were used as markers. Measurements were taken of the flap blood flow; the numbers of capillaries, postcapillary venules, pericapillary arterioles, leukocytes, and mast cells per unit square of dermis. Apoptotic cells were identified by specific staining. Flaps were sampled at postoperative weeks 1 and 3 (human) and hours 1 and 6, and days 1 to 7 (guinea pig). The values for normal skin were regarded as the control. Obstruction (by leukocytes) of venous microvessels, rather than arterial microvessels, was the major cause of temporary hypoxia in the proximomedial location, constant hypoxia (venous stasis) in the mediodistal location, and ischemia in the distal location. Increases in the number of mast cells (mastocytosis) and microvessels (angiogenesis) were significant only in the viable parts of the flaps. This phenomenon and the rate of blood flow increased with time in viable locations (guinea pig). Epidermal necrosis, dermal fibrosis, and apoptosis were evident mostly in the mediodistal location. Elevated levels of leukocytes, lipid peroxidase, acid phosphatase, and calpain, combined with necrotic changes, were seen mostly in the distal skin location. There is a strong possibility that the following factors are involved: lipid piroxidation and hydrolysis in necrosis of the distal flap location after ischemia; constant hypoxia in fibrosis and apoptosis in the mediodistal location; and initial or temporary hypoxia in mastocytosis-induced angiogenesis in the viable location. The results presented here indicate that guidelines for further investigations include combined suppression of leukotaxis, lipid peroxidase, and hydrolysis, or the application of mast cell growth factors in an effort to salvage the flap maximally.