AVALIACAO DO EFEITO DO VENENO DE APIS MELLIFERA EM CULTURAS DE E. COLI, S. TYPHIMURIUM E Y. ENTEROCOLITICA TRATADAS COM BLEOMICINA

Apis mellifera bee venom (Africanized honey bee) was tested for the ability to protect against the lethal effect of bleomycin, an antibiotic and antineoplastic agent. Since the radioprotective effect of the venom has been observed on the other biological systems, in the present study the venom was applied to cultures of enterobacteria treated with bleomycin, a radiomimetic agent. The venom did not act as a protective agent against bleomycin in E. coli, S. typhimurium or Y. enterocolitica.

Effects of crude extracts of Agaricus blazei on DNA damage and on rat liver carcinogenesis induced by diethylnitrosamine

The effects of crude extracts of the mushroom Agaricus blazei Murrill (Agaricaceae) on both DNA damage and placental form glutathione S-transferase (GST-P)-positive liver foci induced by diethylnitrosamine (DEN) were investigated. Six groups of adult male Wistar rats were used. For two weeks, animals of groups 3 to 6 were treated with three aqueous solutions of A. blazei (mean dry weight of solids being 1.2, 5.6, 11.5 and 11.5 mg/ml, respectively). After this period, groups 2 to 5 were given a single ip injection 200 mg/kg DEN and groups 1 and 6 were treated with 0.9% NaCl. All animals were subjected to 70% partial hepatectomy at week five and sacrificed 4, 24 and 48 h or 8 weeks after DEN or 0.9% NaCl treatments (10th week after the beginning of the experiment). The alkaline comet assay and GST-P-positive liver foci development were used to evaluate the influence of the mushroom extracts on liver cell DNA damage and on the initiation of liver carcinogenesis, respectively. Previous treatment with the highest concentration of A. blazei (11.5 mg/ml) significantly reduced DNA damage, indicating a protective effect against DEN-induced liver cytotoxicity/genotoxicity. However, the same dose of mushroom extract significantly increased the number of GST-P-positive liver foci.

Periapical tissue healing after post space preparation with or without use of a protection plug and root canal exposure to the oral environment. Study in dogs

The purpose of this study was to evaluate the influence of coronal leakage on the healing of dogs' periapical tissues after root canal filling, post space preparation and protection or not with a temporary sealer plug. Forty root canals of dogs' teeth were instrumented and filled by the lateral condensation technique with gutta-percha points and Endomethasone or CRCS sealers. After post space preparation, the remaining filling material was protected or not with a plug of temporary Coltosol sealer and exposed to the oral environment for 90 days. Thereafter, the animals were sacrificed and the specimens were removed and prepared for histomorphological and histobacteriological analysis. The findings revealed 35% of microbial leakage in the groups without plugs and 15% of leakage in the groups with plugs. Statistical analysis showed that the use of a Coltosol plug improved significantly the histomorphological results regardless of the type of root canal sealer (p=0.05) and that CRCS and Endomethasone sealers showed similar results (p>0.05).

Response of human dental pulp capped with MTA and calcium hydroxide powder

Objectives: To compare the response of human dental pulp capped with a mineral trioxide aggregate (MTA) and Ca(OH) 2 powder. Methods and Material: Pulp exposures were performed on the occlusal floor of 40 permanent premolars. The pulp was then capped with either Ca(OH) 2 powder (CH) or MTA and restored with resin composite. After 30 days (groups CH30 and MTA30) and 60 days (groups CH60 and MTA60), the teeth were extracted and processed for HE and categorized in a histological score system. The data were subjected to Kruskal-Wallis and Conover tests (α=0.05). Results: In regard to dentin bridge formation, CH30 showed a tendency towards superior performance compared to MTA30 (p>0.05), although the products showed comparable results at day 60. In the item Inflammation and General State of the Pulp (p>0.05), CH showed a tendency towards presenting a higher inflammatory response. In the item Other Pulpal Findings, MTA and Ca(OH) 2 showed equal and excellent performance after 30 and 60 days (p>0.05). Conclusion: After 30 days, Ca(OH) 2 powder covered with calcium hydroxide cement showed faster hard tissue bridge formation compared to MTA. After 60 days, Ca(OH) 2 powder or MTA materials showed a similar and excellent histological response with the formation of a hard tissue bridge in almost all cases with low inflammatory infiltrate. © Operative Dentistry, 2008.

Flavonoids with gastroprotective activity

Peptic ulcers are a common disorder of the entire gastrointestinal tract that occurs mainly in the stomach and the proximal duodenum. This disease is multifactorial and its treatment faces great difficulties due to the limited effectiveness and severe side effects of the currently available drugs. The use of natural products for the prevention and treatment of different pathologies is continuously expanding throughout the world. This is particularly true with regards to flavonoids, which represent a highly diverse class of secondary metabolites with potentially beneficial human health effects that is widely distributed in the plant kingdom and currently consumed in large amounts in the diet. They display several pharmacological properties in the gastroprotective area, acting as anti-secretory, cytoprotective and antioxidant agents. Besides their action as gastroprotectives, flavonoids also act in healing of gastric ulcers and additionally these polyphenolic compounds can be new alternatives for suppression or modulation of peptic ulcers associated with H. pylori. In this review, we have summarized the literature on ninety-five flavonoids with varying degrees of antiulcerogenic activity, confirming that flavonoids have a therapeutic potential for the more effective treatment of peptic ulcers.

Gastroprotective mechanisms of the chloroform and ethyl acetate phases of Praxelis clematidea (Griseb.) R.M.King & H.Robinson (Asteraceae)

Flavonoid-rich Praxelis clematidea (Griseb.) R.M.King & H.Robinson (Asteraceae) is a native plant of South America. This study evaluates the gastroprotective activity and possible mechanisms for both the chloroform (CHCl3P) and ethyl acetate phases (AcOEtP) obtained from aerial parts of the plant. The activity was investigated using acute models of gastric ulcer. Gastric secretion biochemical parameters were determined after pylorus ligature. The participation of cytoprotective factors such as mucus, nitric oxide (NO), sulfhydryl (SH) groups, prostaglandin E2 (PGE 2), reduced glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), reduction of lipid peroxidation (malondialdehyde level), and polymorphonuclear infiltration (myeloperoxidase activity), was also investigated. CHCl3P (125, 250, and 500 mg/kg) and AcOEtP (62.5, 125, and 250 mg/kg) showed significant gastroprotective activity, reducing the ulcerative index by 75, 83, 88 % and 66, 66, 81 % for ethanol; 67, 67, 56 % and 56, 53, 58 % for a non-steroidal anti-inflammatory drug (NSAID); and 74, 58, 59 % and 64, 65, 61 % for stress-induced gastric ulcer, respectively. CHCl3P (125 mg/kg) and AcOEtP (62.5 mg/kg) significantly reduced the ulcerative area by 78 and 83 %, respectively, for the ischemia-reperfusion model. They also did not alter the biochemical parameters of gastric secretion, the GSH level or the activities of SOD, GPx or GR. They increased the quantity of gastric mucus, not dependent on NO, yet dependent on SH groups, and maintained PGE2 levels. The P. clematidea phases demonstrated gastroprotective activity related to cytoprotective factors. © 2012 The Japanese Society of Pharmacognosy and Springer.

Ação do metabólito secundário 5-hidroxi-2-hidroximetil gama-pirona isolado de fungos do gênero Aspergillus sobre monócitos humanos in vitro

O 5-hidroxi-2-hidroximetil-gama-pirona (HMP) é um metabólito secundário sintetizado por algumas espécies de fungos dos gêneros Aspergillus, Penicillium Acetobac-ter. O HMP tem várias aplicações, sendo utilizado como antioxidante, inibidor da tirosinase, agente protetor contra a radiação e antitumoral. Recentemente, foi também demonstrado que esse metabólito atua como ativador de macrófagos. No entanto, o efeito do HMP em mo-nócitos humanos é desconhecido. Assim, o objetivo deste estudo foi avaliar os efeitos de HMP sobre a viabilidade e diferenciação celular de monócitos do sangue humano in vi-tro. Leucócitos humanos do sangue periférico foram obtidos a partir de bolsas de san-gue doadas pela Fundação Centro de Hemoterapia e Hematologia do Pará (HEMOPA). O isolamento das células foi realizado por meio de gradiente de densidade com Histopaque ®1077. Os monócitos foram tratados durante 24, 48 e 72 horas com 50 e 100 μg / mL de HMP. A análise ultraestrutural dos monócitos tratados revelou que essas células apresen-tam maior espraiamento, elevado número de projeções citoplasmáticas e vacúolos, caracterís-ticas que são frequentemente observadas em células ativadas. A análise da expressão da proteína de superfície específica para macrófago (F4/80) por imunofluorescência, de-monstrou que os monócitos humanos tratados com 50 e 100 μg / mL de HMP por 48 e 72 horas, mostrou um padrão de expressão semelhante ao verificado em macrófagos humanos originados de monócitos tratados com o M-CFS. Os testes de viabilidade utilizados (Método thiazolyl blue, Potencial de membrana mitocondrial, Vermelho Neutro e Azul de Tripan) mostraram que o HMP não tem nenhum efeito citotóxico em monócitos humanos quando tra-tados com 50 e 100 μg/ mL do bioproduto. Estes resultados demonstram um novo papel pa-ra HMP como um agente imunomodulador, induzindo a diferenciação de monócitos em macrófagos.

Physical exercise and pancreatic islets Acute and chronic actions on insulin secretion

Diabetes mellitus (DM) is a great public health problem, which attacks part of the world population, being characterized by an imbalance in body glucose homeostasis. Physical exercise is pointed as a protective agent and is also recommended to people with DM. As pancreatic islets present an important role in glucose homeostasis, we aim to study the role of physical exercise (chronic adaptations and acute responses) in pancreatic islets functionality in Wistar male rats. First, animals were divided into two groups: sedentary (S) and aerobic trained (T). At the end of 8 weeks, half of them (S and T) were submitted to an acute exercise session (exercise until exhaustion), being subdivided as acute sedentary (AS) and acute trained (AT). After the experimental period, periepididymal, retroperitoneal and subcutaneous fat pads, blood, soleus muscle and pancreatic islets were collected and prepared for further analysis. From the pancreatic islets, total insulin content, insulin secretion stimulated by glucose, leucine, arginine and carbachol were analyzed. Our results pointed that body adiposity and glucose homeostasis improved with chronic physical exercise. In addition, total insulin content was reduced in group AT, insulin secretion stimulated by glucose was reduced in trained groups (T and AT) and insulin secretion stimulated by carbachol was increased in group AT. There were no significant differences in insulin secretion stimulated by arginine and leucine. We identified a possible modulating action on insulin secretion, probably related to the association of chronic adaptation with an acute response on cholinergic activity in pancreatic islets.

Quali-quantitative study of the phenolic and polyphenolic compounds and their antioxidant capacity in vegetal matrix processed with different technologies

Food technologies today mean reducing agricultural food waste, improvement of food security, enhancement of food sensory properties, enlargement of food market and food economies. Food technologists must be high-skilled technicians with good scientific knowledge of food hygiene, food chemistry, industrial technologies and food engineering, sensory evaluation experience and analytical chemistry. Their role is to apply the modern vision of science in the field of human nutrition, rising up knowledge in food science. The present PhD project starts with the aim of studying and improving frozen fruits quality. Freezing process in very powerful in preserve initial raw material characteristics, but pre-treatment before the freezing process are necessary to improve quality, in particular to improve texture and enzymatic activity of frozen foods. Osmotic Dehydration (OD) and Vacuum Impregnation (VI), are useful techniques to modify fruits and vegetables composition and prepare them to freezing process. These techniques permit to introduce cryo-protective agent into the food matrices, without significant changes of the original structure, but cause a slight leaching of important intrinsic compounds. Phenolic and polyphenolic compounds for example in apples and nectarines treated with hypertonic solutions are slightly decreased, but the effect of concentration due to water removal driven out from the osmotic gradient, cause a final content of phenolic compounds similar to that of the raw material. In many experiment, a very important change in fruit composition regard the aroma profile. This occur in strawberries osmo-dehydrated under vacuum condition or under atmospheric pressure condition. The increment of some volatiles, probably due to fermentative metabolism induced by the osmotic stress of hypertonic treatment, induce a sensory profile modification of frozen fruits, that in some way result in a better acceptability of consumer, that prefer treated frozen fruits to untreated frozen fruits. Among different processes used, a very interesting result was obtained with the application of a osmotic pre-treatment driven out at refrigerated temperature for long time. The final quality of frozen strawberries was very high and a peculiar increment of phenolic profile was detected. This interesting phenomenon was probably due to induction of phenolic biological synthesis (for example as reaction to osmotic stress), or to hydrolysis of polymeric phenolic compounds. Aside this investigation in the cryo-stabilization and dehydrofreezing of fruits, deeper investigation in VI techniques were carried out, as studies of changes in vacuum impregnated prickly pear texture, and in use of VI and ultrasound (US) in aroma enrichment of fruit pieces. Moreover, to develop sensory evaluation tools and analytical chemistry determination (of volatiles and phenolic compounds), some researches were bring off and published in these fields. Specifically dealing with off-flavour development during storage of boiled potato, and capillary zonal electrophoresis (CZE) and high performance liquid chromatography (HPLC) determination of phenolic compounds.

Studies of the mechanism of daunorubicin carcinogenesis: Modulation by vitamin E

Daunorubicin (DNR) is an anthracycline antibiotic used as a cancer chemotherapeutic agent. However, it causes mammary adenocarcinomas in female Sprague-Dawley (SD) rats. Vitamin E (E) has been found to reduce DNR carcinogenicity. I investigated the mechanism of DNR carcinogenicity and its interaction with E in SD rats by studying DNR-DNA adduct formation and the influence of E status on DNR clearance and free radical producing and detoxifying enzymes.^ The hypothesis was that DNR exerts its tumorigenic effect via free radicals generated during redox cycling and production of reactive intermediates capable of forming DNA adducts. E was postulated to act as a protective agent through a combination of its antioxidant property, modulation of drug clearance and levels of free radical producing and detoxifying enzymes.^ DNA adduct formation was measured by the nuclease P1 $\sp{32}$P-post labeling assay. In vitro, DNR was activated by rat liver microsomes and either NADPH or cumene hydrogen peroxide (CuOOH). Rat liver DNA incubated with this mixture formed two adducts when the cofactor was NADPH and three adducts when CuOOH was used. In vivo, SD rats were treated with i.v. doses of DNR. No detectable DNR-DNA adducts were formed in liver or mammary DNA in vivo, although there was an intensification of endogenous DNA adducts.^ Groups, 1, 2, 3 and 4 of weanling female SD rats were fed 0, 100, 1,000 and 10,000 mg $\alpha$-tocopheryl acetate/kg diet respectively. A comparison of Groups 1 and 4 showed no effect of E status on clearance of 10 mg tritiated DNR/kg body weight over 72 hours. However, liver cleared DNR at a faster rate than mammary epithelial cells (MEC).^ Xanthine oxidase, which catalyzes DNR redox cycling, was significantly decreased in liver and MEC of rats in group 4 compared to groups 1, 2, and 3. Detoxifying enzymes were not dramatically affected by E supplementation. Quinone reductase in MEC was significantly increased in group 4 compared to other groups. Overall, the liver had higher levels of free radical detoxifying enzymes compared to MEC.^ These data support a role of free radicals in DNR carcinogenicity because (1) endogenous DNA adducts formed due to free radical insult are further intensified by DNR treatment in vivo, (2) MEC, the specific target of DNR carcinogenicity, cannot rapidly clear DNR and have a lower free radical detoxifying capability than liver, (3) E supplementation caused lowering of free radical generating potential via xanthine oxidase, and increased DNR detoxification due to elevation of quinone reductase in MEC. ^

Participação da conexina 32 na fisiopatogênese da doença hepática gordurosa não alcoólica em camundongos

A doença hepática gordurosa não alcoólica (DHGNA) abrange alterações desde esteatose até esteato-hepatite não alcoólica (EHNA), podendo evoluir para fibrose, cirrose e carcinoma hepatocelular. A DHGNA é considerada a doença hepática mais comum na atualidade e com prevalência mundial alarmante. Esta doença caracteriza-se, basicamente, pela deposição de triglicérides nos hepatócitos, podendo evoluir com inflamação e fibrose, e está intimamente associada com resistência à insulina (RI), diabetes mellitus tipo 2 e obesidade. Os hepatócitos representam as principais células hepáticas e se comunicam através de junções do tipo gap, formadas principalmente por conexina 32 (Cx32). Esta proteína apresenta importante função no controle da homeostase tecidual, regulando processos fisiológicos e tem sido associada como agente protetor na hepatocarcinogênese e outros processos patológicos, porem pouco se sabe sobre sua participação na DHGNA. Sendo assim, o objetivo deste trabalho foi avaliar a participação da Cx32 na fisiopatogênese da DHGNA, utilizando camundongos knockout para Cx32 (Cx32-KO) submetidos a uma dieta hiperlipídica deficiente em colina. Foram analisados dados biométricos, histopatológicos, função hepática, RI, citocinas inflamatórias, adipocinas, estresse oxidativo, peroxidação lipídica e a expressão de genes envolvidos na DHGNA. Os animais Cx32-KO apresentaram maior acumulo de triglicérides hepáticos em relação aos animais selvagens e, consequentemente, maior peso absoluto e relativo do fígado. Adicionalmente, apresentaram maior inflamação hepática demonstrado pela exacerbação da citocina TNF-α e supressão da IL-10, maior dano hepatocelular indicado pelo aumento das enzimas AST e ALT, aumento da peroxidação lipídica e alterações na expressão de genes chaves na fisiopatogênese da DHGNA, como SREBP1c. No entanto, não houve diferença nos marcadores histopatológicos, RI e estresse oxidativo hepático. Por fim, os animais Cx32-KO apresentaram maior produção de leptina e adiponectina no tecido adiposo. Todos esses resultados revelam que a Cx32 pode atuar como um agente protetor ao desenvolvimento da DHGNA, sugerindo seu potencial como novo alvo terapêutico

Antitumor activity of 3-ingenyl angelate: Plasma membrane and mitochondrial disruption and necrotic cell death

Options for skin cancer treatment currently include surgery, radiotherapy, topical chemotherapy, cryosurgery, curettage, and electrodes-sication. Although effective, surgery is costly and unsuitable for certain patients. Radiotherapy can leave a poor cosmetic effect, and current chemotherapy is limited by low cure rates and extended treatment schedules. Here, we describe the preclinical activity of a novel topical chemotherapeutic agent for the treatment of skin cancer, 3-ingenyl angelate (PEP005), a hydrophobic diterpene ester isolated from the plant Euphorbia peplus. Three daily topical applications of 42 nmol (18 mug) of PEP005 cured a series of s.c. mouse tumors (B16 melanoma, LK2 UV-induced squamous cell carcinoma, and Lewis lung carcinoma; it = >14 tumors/group) and human tumors (DO4 melanoma, HeLa cervical carcinoma, and PC3 and DU145 prostate carcinoma; it = >4 tumors/group) previously established (5-10 mm(3)) on C57BL/6 or Fox1(nu) mice. The treatment produced a mild, short-term erythema and eschar formation but, ultimately, resulted in excellent skin cosmesis. The LD90 for PEP005 for a panel of tumor cell lines was 180-220 muM. Electron microscopy showed that treatment with PEP005 both ill vitro (230 tot) and ill vivo (42 nmol) rapidly caused swelling of mitochondria and cell death by primary necrosis. Cr-51 release, uptake of propidium iodide, and staining with the mitochondria dye JC1, revealed that PEP005 (230 muM) treatment of tumor cells ill vitro resulted in a rapid plasma membrane perturbation and loss of mitochondrial membrane potential. PEP005 thus emerges as a new topical anti-skin cancer agent that has a novel mode of action involving plasma membrane and mitochondrial disruption and primary necrosis, ultimately resulting in an excellent cosmetic outcome.

Evaluation of Protective Effect of a Water-In-Oil Microemulsion Incorporating Quercetin Against UVB-Induced Damage in Hairless Mice Skin

Purpose. Histological aspects were considered in order to evaluate the in vivo photoprotective effect of a w/o microemulsion containing quercetin against UVB irradiation-induced dermal damages. The toxicity in cell culture and the potential skin irritation resulting from topical application of this formulation were investigated. Methods. Mouse dorsal surfaces were treated topically with 300 mg of the unloaded and quercetin-loaded (0.3%, w/w) microemulsions before and after exposure to UVB (2.87 J/cm(2)) irradiation. The untreated control groups irradiated and non-irradiated were also evaluated. UVB-induced histopathological changes as well as the photoprotective effect of this formulation were evaluated considering the parameters of infiltration of inflammatory cells, epidermis thickening (basale and spinosum layers) and collagen and elastic fiber contents. The cytotoxicity of the reported formulation was evaluated in L929 mice fibroblasts by MTT assay and the skin irritation was investigated after topical application of both unloaded and quercetin-loaded microemulsions once a day for 15 days. Results. The results demonstrated that the w/o microemulsion containing quercetin reduced the incidence of histological skin alterations, mainly the connective-tissue damage, induced by exposure to UVB irradiation. This suggests that protective effects of this formulation against UV-induced responses are not secondary to the interference of UV transmission (i.e., blocking the UVB radiation from being absorbed by the skin), as is usually implied with UVB absorbers and sunscreens, but is instead due to different biological effects of this flavonoid. Furthermore, by evaluating the cytotoxic effect on L929 cells and histological aspects such as infiltration of inflammatory cells and epidermis thickness of hairless mice, the present study also demonstrated the lack of toxicity of the proposed system. Conclusion. Based on these mice models, a detailed characterization of the w/o microemulsion incorporating quercetin effects as a photochemoprotective agent on human skin is presented.

Protective effect of (-)-epigallocatechin gallate on ultraviolet b-induced skin damage in hairless mice

Purpose: To investigate the protective effect of green tea (-)-epigallocatechin gallate (EGCg) on ultraviolet B (UV-B)-induced skin damages in hairless mice in order to develop a natural sunscreen compound for use in skin care products and cosmetics. Methods: EGCg was dissolved in acetone at concentrations of 1.0, 10.0 and 50.0 mg/mL, and topically applied to the skin of hairless mice at doses of 0.2 mL/cm2, with acetone as control. The mice were then irradiatd m2 UV-B for 30 min daily. EGCg treatment and UV-B irradiation were carried out daily for 28 consecutive days. The mice were then sacrificed and their dorsal skin examined by transmission electron microscopy (TEM) on the 28th day. Results: UV-B irradiation induced severe macroscopic skin damage including chapping, cracking and abnormal desquamation in the treated hairless mice. EGCg showed dose-dependent protective effects against UV-B induced damage on the skin. Treatments with 10.0 and 50.0 mg/mL EGCg alleviated UVB-induced skin damage by suppressing both keratinocyte apoptosis and mitochondrial dysfunction, along with inhibiting the production of melanin pigment. Conclusion: Topical application of green tea EGCg shows dose-dependent protective effect against UV-B-induced damage on hairless mouse skin. Thus, the plant compound can potentially be used as an alternative agent for photoprotection against UV-B exposure.

Protective effect of Calendula officinalis extract against UVB-induced oxidative stress in skin: Evaluation of reduced glutathione levels and matrix metalloproteinase secretion

Background and purpose: Calendula officinalis flowers have long been employed time in folk therapy, and more than 35 properties have been attributed to decoctions and tinctures from the flowers. The main uses are as remedies for burns (including sunburns), bruises and cutaneous and internal inflammatory diseases of several origins. The recommended doses are a function both of the type and severity of the condition to be treated and the individual condition of each patient. Therefore, the present study investigated the potential use of Calendula officinalis extract to prevent UV irradiation-induced oxidative stress in skin. Methods: Firstly, the physico-chemical composition of marigold extract(ME) (hydroalcoholic extract)was assessed and the in vitro antioxidant efficacy was determined using different methodologies. Secondly, the cytotoxicity was evaluated in L929 and HepG2 cells with the MTT assay. Finally, the in vivo protective effect of ME against UVB-induced oxidative stress in the skin of hairless mice was evaluated by determining reduced glutathione (GSH) levels and monitoring the secretion/activity of metalloproteinases. Results and conclusions: The polyphenol, flavonoid, rutin and narcissin contents found in ME were 28.6 mg/g, 18.8 mg/g, 1.6 mg/g and 12.2 mg/g, respectively and evaluation of the in vitro antioxidant activity demonstrated a dose-dependent effect of ME against different radicals. Cytoxicity experiments demonstrated that ME was not cytotoxic for L929 and HepG2 cells at concentrations less than or equal to of 15 mg/mL However, concentrations greater than or equal to 30 mg/mL, toxic effects were observed. Finally, oral treatment of hairless mice with 150 and 300 mg/kg of ME maintained GSH levels close to non-irradiated control mice. In addition, this extract affects the activity/secretion of matrix metalloproteinases 2 and 9 (MMP-2 and -9) stimulated by exposure to UVB irradiation. However, additional studies are required to have a complete understanding of the protective effects of ME for skin. (C) 2009 Elsevier Ireland Ltd. All rights reserved.