Development of trans-Chalcone loaded pectin/casein biodegradable microcapsules: Efficacy improvement in the management of experimental colitis.

Improved therapies for inflammatory bowel diseases are sorely needed. Novel therapeutic agents and the development of controlled release systems for targeted tissue delivery are interesting approaches to overcome these barriers. We investigated the activity of trans-chalcone (T) in acetic acid-induced colitis in mice and developed, characterized, and determined the therapeutic effect of pectin/casein polymer microcapsules containing T (MT) in a colitis mouse model. In vitro, compound release was achieved in simulated intestinal fluid but not in the simulated gastric fluid. In vivo, since T at the dose of 3 mg/kg but not 0.3 mg/kg ameliorated colitis, we next tested the effects of MT at 0.3 mg/kg (non-effective dose). MT, but not free T at 0.3 mg/kg, significantly improved colitis outcomes such as neutrophil recruitment, antioxidant capacity, cytokine production, and NF-kB activation. This translated into reduced macro and microscopic damage in the colon. T release from the microcapsules is mediated by a pH-dependent and pectinase-regulated mechanism that provide controlled and prolonged release of T. Moreover, MT lowered the required dose for T therapeutic effect, indicating that could be a suitable pharmaceutical approach to colitis treatment. This is the first demonstration that T or MT is effective at reducing the signs of colitis.

Pimenta pseudocaryophyllus (Gomes) Landrum extract inhibits inflammatory pain in mice: targeting neutrophil recruitment, oxidative stress, and cytokine production.

Pimenta pseudocaryophyllus (Gomes) Landrum is a Brazilian native plant. The mechanisms by which it promotes analgesia are unknown. We demonstrated the analgesic effect of P. pseudocaryophyllus dried extract (3 mg/kg; i.p.) in the following models of inflammatory pain (maximal inhibition): phenyl-p-benzoquinone (89%), formalin (72% - 1st phase and 96% - 2nd phase for flinches, and 50% - 1st phase and 71% - 2nd phase for licking behavior), complete Freund's adjuvant (95% - flinches and 33% - licking behavior), and carrageenin (56% - mechanical and 85% - thermal hyperalgesia) without motor impairment. Its analgesic effect depends on inhibiting neutrophil recruitment (95% - histopathology, 83% - myeloperoxidase activity, and 80% - LysM-eGFP mice), oxidative stress (86% - GSH and 98% - superoxide anion), and cytokine production (35% - IL-33, 80% - TNF-α, and 95% - IL-1ß). The present study advances in understanding the analgesic mechanisms of P. pseudocaryophyllus.

Protection against UVB deleterious skin effects in a mouse model: effect of a topical emulsion containing Cordia verbenacea extract.

Cordia verbenacea DC (Boraginaceae) is a flowering shrub found along the Brazilian Atlantic Forest, Brazilian coast, and low areas of the Amazon. The crude extract of its leaves is widely used in Brazilian folk medicine as an anti-inflammatory, both topically and orally. The aim of this study is to evaluate the activity of C. verbenacea ethanolic leaves extract (CVE) against UVB-triggered cutaneous inflammation and oxidative damage in hairless mice. CVE treatment recovered cutaneous antioxidant capacity demonstrated by scavenging ABTS+ free radical and iron-reducing antioxidant potential evaluated by FRAP. CVE also controlled the following UV-triggered events in the skin: reduced glutathione (GSH) depletion, catalase activity decrease, and superoxide anion (O⋅-) build-up. Furthermore, mice treated with CVE exhibited less inflammation, shown by the reduction in COX-2 expression, TNF-α, IL-1ß, IL-6, edema, and neutrophil infiltration. CVE also regulated epidermal thickening and sunburn cells, reduced dermal mast cells, and preserved collagen integrity. The best results were obtained using 5% CVE-added emulsion. The present data demonstrate that topical administration of CVE presents photochemoprotective activity in a mouse model of UVB inflammation and oxidative stress. Because of the intricate network linking inflammation, oxidative stress, and skin cancer, these results also indicate the importance of further studies elucidating a possible role of C. verbenacea in the prevention of UVB-induced skin cancer and evaluating a potential synergy between CVE and sunscreens in topical products against UVB damaging effects to the skin.

Protective effect of oral treatment with Cordia verbenacea extract against UVB irradiation deleterious effects in the skin of hairless mouse.

Photochemoprotection of the skin can be achieved by inhibiting inflammation and oxidative stress, which we tested using Cordia verbenacea extract, a medicinal plant known for its rich content of antioxidant molecules and anti-inflammatory activity. In vitro antioxidant evaluation of Cordia verbenacea leaves ethanolic extract (CVE) presented the following results: ferric reducing antioxidant power (886.32 µM equivalent of Trolox/g extract); IC50 of 19.128 µg/ml for scavenging 2,2-diphenyl-1-picrylhydrazyl; IC50 of 12.48 µg/mL for scavenging 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid); decrease of hydroperoxides from linoleic acid (IC50 of 10.20 µg/mL); inhibition of thiobarbituric acid reactive substances (IC50 8.90 µg/mL); iron-chelating ability in bathophenanthroline iron assay (IC50 47.35 µg/mL); chemiluminescence triggered by free radicals in the H2O2/horseradish peroxidase/luminol (IC50 0.286 µg/mL) and xanthine/xanthine oxidase/luminol (IC50 0.42 µg/mL) methods. CVE (10-100 mg per kg, 30 min before and immediately after UVB exposure) treatment was performed by gavage in hairless mice. CVE inhibited skin edema, neutrophil infiltration, and overproduction of MMP-9; reduced levels of TNF-α, IL-1ß, and IL- 6; numbers of skin mast cells, epidermal thickening, number of epidermal apoptotic keratinocytes, and collagen degradation. CVE increased the skin's natural antioxidant defenses as observed by Nrf-2, NAD(P)H quinone oxidoreductase 1, and heme oxygenase 1 mRNA expression enhancement. Furthermore, CVE inhibited lipid peroxidation and superoxide anion production and recovered antioxidant reduced glutathione, catalase activity, and ROS scavenging capacity of the skin. Concluding, CVE downregulates the skin inflammatory and oxidative damages triggered by UVB, demonstrating its potentialities as a therapeutic approach.

Analgesic activity and mechanism of action of a Beta vulgaris dye enriched in betalains in inflammatory models in mice.

Evidence demonstrates the pronounced anti-inflammatory activity of a beetroot (Beta vulgaris) dye enriched in betalains obtained using precipitation with ethanol. Herein, we expand upon our previous observations and demonstrate the analgesic and antioxidant effect of betalains. Betalains [10-1000 mg/kg; intraperitoneal route (i.p.)] diminished acetic acid- and PBQ-induced abdominal contortions, and the overt pain-like behaviour induced by complete Freund`s adjuvant (CFA) and formalin (intraplantar; i.pl.) injection. Moreover, betalains (100 mg/kg) administered by various routes [i.p. or subcutaneous (s.c.)] or as a post-treatment reduced carrageenin- or CFA-induced hyperalgesia. Mechanistically, betalains mitigated carrageenin-induced tumour necrosis factor-alpha (TNF-α), interleukin (IL)-1ß, superoxide anion levels, and lipid peroxidation. Betalains also stopped the depletion of reduced glutathione (GSH) levels and ferric reducing ability produced by carrageenin, as well as upregulated Nrf2 and Ho1 transcript expression in the plantar tissue of mice. Furthermore, betalains showed hydroxyl radical, 2,2'-azino-di-(3-ethylbenzthiazoline-6-sulphonic acid) radical (ABTS+), and 2,2-diphenyl-1-picryl-hydrazyl radical (DPPH•) scavenging ability and iron-chelating activity (bathophenantroline assay), and inhibited iron-independent and iron-dependent lipid peroxidation (LPO) in vitro. Finally, betalains-treated bone marrow-derived macrophages exhibited lower levels of cytokines (TNF-α and IL-1ß), and superoxide anion levels and nuclear factor kappa B (NF-κB) activation following lipopolysaccharide (LPS) stimulation. Therefore, this betalain-rich dye extracted using a novel precipitation approach presents prominent analgesic effect in varied models of pain by mechanisms targeting cytokines and oxidative stress.

Optimization of ultrasound-assisted extraction of grape-seed oil to enhance process yield and minimize free radical formation.

BACKGROUND: Grape seeds are a relatively abundant source of oil and bioactive compounds. To use this byproduct, the current work aimed to optimize the ultrasound-assisted extraction (UAE) of grape-seed oil to obtain greater process yield and minimize free radical formation in the oil. RESULTS: The optimal condition was 15 °C with an ultrasonic wave amplitude of 42 µm, leading to a process yield of 82.9% and content of free radicals of 14.7 × 1017 kg-1 and 3.4 × 1018 kg-1 for samples stored for 7 and 30 days, respectively. No significant differences in fatty acid composition and acidity and iodine values were observed between samples. The oil obtained by ultrasound had greater phenolic compound content and antioxidant activity by ferric reduction than the control sample (without ultrasound application). However, higher content of free radicals and peroxide value was observed. CONCLUSION: Sonication improved extraction yield when compared to the process without ultrasound application. Moreover, UAE favored the extraction of phenolic compounds. As it enhanced process yield with the minimum formation of free radicals, UAE is a promising oil-extraction technology. © 2018 Society of Chemical Industry.

Antinociceptive Effect of Tephrosia sinapou Extract in the Acetic Acid, Phenyl-p-benzoquinone, Formalin, and Complete Freund's Adjuvant Models of Overt Pain-Like Behavior in Mice.

Tephrosia toxicaria, which is currently known as Tephrosia sinapou (Buc'hoz) A. Chev. (Fabaceae), is a source of compounds such as flavonoids. T. sinapou has been used in Amazonian countries traditional medicine to alleviate pain and inflammation. The purpose of this study was to evaluate the analgesic effects of T. sinapou ethyl acetate extract in overt pain-like behavior models in mice by using writhing response and flinching/licking tests. We demonstrated in this study that T. sinapou extract inhibited, in a dose (1-100 mg/kg) dependent manner, acetic acid- and phenyl-p-benzoquinone- (PBQ-) induced writhing response. Furthermore, it was active via intraperitoneal, subcutaneous, and peroral routes of administration. T. sinapou extract also inhibited formalin- and complete Freund's adjuvant- (CFA-) induced flinching/licking at 100 mg/kg dose. In conclusion, these findings demonstrate that T. sinapou ethyl acetate extract reduces inflammatory pain in the acetic acid, PBQ, formalin, and CFA models of overt pain-like behavior. Therefore, the potential of analgesic activity of T. sinapou indicates that it deserves further investigation.

Anti-inflammatory activity of betalain-rich dye of Beta vulgaris: effect on edema, leukocyte recruitment, superoxide anion and cytokine production.

We have recently developed betalain-rich beetroot (Beta vulgaris) dye (betalain) to be used in food products. Betalain (30-300 mg/kg) intraperitoneal (i.p.) treatment diminished carrageenan (100 µg/paw)-induced paw edema and neutrophil migration to the paw skin tissue. Betalain (100 mg/kg) treatment by subcutaneous or per oral routes also inhibited the carrageenan-induced paw edema. Importantly, the post-treatment with betalain (100 mg/kg, i.p.) significantly inhibited carrageenan- and complete Freund's adjuvant (10 µl/paw)-induced paw edema. Betalain (100 mg/kg) also reduced carrageenan (500 µg/cavity)-induced recruitment of total leukocytes, including mononuclear cells and neutrophils, as well as increasing vascular permeability in the peritoneal cavity. Furthermore, betalain significantly reduced carrageenan-induced superoxide anion, tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-1ß levels in the peritoneal fluid, as well as augmenting IL-10 levels. Therefore, this compound presents prominent anti-inflammatory effect on carrageenan-induced paw edema and peritonitis by reducing the production of superoxide anion and the cytokines TNF-α and IL-1ß, in addition to increasing IL-10 levels. These results suggest that betalain shows therapeutic potential that could be utilized in the treatment of inflammation-associated diseases.

The ruthenium nitric oxide donor, [Ru(HEDTA)NO], inhibits acute nociception in mice by modulating oxidative stress, cytokine production and activating the cGMP/PKG/ATP-sensitive potassium channel signaling pathway.

Nitric oxide plays an important role in various biological processes including antinociception. The control of its local concentration is crucial for obtaining the desired effect and can be achieved with exogenous nitric oxide-carriers such as ruthenium complexes. Therefore, we evaluated the analgesic effect and mechanism of action of the ruthenium nitric oxide donor [Ru(HEDTA)NO] focusing on the role of cytokines, oxidative stress and activation of the cyclic guanosine monophosphate/protein kinase G/ATP-sensitive potassium channel signaling pathway. It was observed that [Ru(HEDTA)NO] inhibited in a dose-dependent (1-10 mg/kg) manner the acetic acid-induced writhing response. At the dose of 1 mg/kg, [Ru(HEDTA)NO] inhibited the phenyl-p-benzoquinone-induced writhing response, and formalin- and complete Freund's adjuvant-induced licking and flinching responses. Systemic and local treatments with [Ru(HEDTA)NO] also inhibited the carrageenin-induced mechanical hyperalgesia and increase of myeloperoxidase activity in paw skin samples. Mechanistically, [Ru(HEDTA)NO] inhibited carrageenin-induced production of the hyperalgesic cytokines tumor necrosis factor-α and interleukin-1ß, and decrease of reduced glutathione levels. Furthermore, the inhibitory effect of [Ru(HEDTA)NO] in the carrageenin-induced hyperalgesia and myeloperoxidase activity was prevented by the treatment with ODQ (soluble guanylyl cyclase inhibitor), KT5823 (protein kinase G inhibitor) and glybenclamide (ATP-sensitive potassium channel inhibitor), indicating that [Ru(HEDTA)NO] inhibits inflammatory hyperalgesia by activating the cyclic guanosine monophosphate/protein kinase G/ATP-sensitive potassium channel signaling pathway, respectively. These results demonstrate that [Ru(HEDTA)NO] exerts its analgesic effect in inflammation by inhibiting pro-nociceptive cytokine production, oxidative imbalance and activation of the nitric oxide/cyclic guanosine monophosphate/protein kinase G/ATP-sensitive potassium channel signaling pathway in mice.

Topical formulations containing Pimenta pseudocaryophyllus extract: In vitro antioxidant activity and in vivo efficacy against UV-B-induced oxidative stress.

Pimenta pseudocaryophyllus is a Brazilian native plant that presents high concentrations of flavonoids and other polyphenolic compounds. Herein, we evaluated: (1) the chemical properties of P. pseudocaryophyllus ethanolic extract (PPE), (2) the in vitro antioxidant activity (AA) of PPE and of two different topical formulations (F1 and F2) containing PPE, (3) physico-chemical and functional stability, (4) in vitro release of PPE, and (5) in vivo capacity of formulations to prevent UV-B irradiation-induced skin damage. Results show that the polyphenol and flavonoid contents in PPE were 199.33 and 28.32 mg/g, respectively, and HPLC results show the presence of eugenol, tannic acid, and rutin. Evaluation of the in vitro AA of PPE demonstrated a dose-dependent effect and an IC50 of 4.75 µg/mL in 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 3.0 µg/mL in 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. The ferric-reducing antioxidant power (FRAP assay) was 0.046 µmol/L trolox equivalent/µg/mL of extract. Among the AA, only the capacity to scavenge DPPH radical of PPE was maintained in F1 and F2. In addition, both formulations satisfactorily released the extract. The evaluation of the functional stability of F1 and F2 did not demonstrate loss of activity by storage at room temperature and at 4°C/6 months. In irradiated mice, treatment with F1 and F2 added with PPE significantly increased the capacity to scavenge ABTS radical and the FRAP of skin compared to vehicle-treated mice. In conclusion, the present results suggest that formulations containing PPE may be a topical source of antioxidant compounds to decrease oxidative damages of the skin.

Protective effect of fermented soybean dried extracts against TPA-induced oxidative stress in hairless mice skin.

This study evaluated the chemical properties (polyphenol and genistein contents) of soybean extracts obtained by biotransformation and dried by spray dryer at different conditions and their in vivo ability to inhibit 12-O-tetradecanoylphorbol-13-acetate- (TPA-) induced biochemical alterations in the skin of hairless mice. By comparing the obtained data with that of the well-known active soybean extract Isoflavin beta, we evaluated the influence of the fermentation and drying process in the extracts efficacy. The results demonstrated that inlet gas temperature and adjuvant concentration for the extract drying process have significantly affected the total polyphenol contents and, to a minor degree, the genistein contents. However, the effect of topical stimulus with TPA, an oxidative stress inducer, which caused significant depletion of reduced glutathione (GSH) and catalase, with increased levels of H2O2 and lipid peroxidation (MDA) in the skin of hairless mice, was significantly prevented by the soybean extracts treatment. These results indicate that the spray drying processing resulted in a product capable of limiting the oxidative stress with possible therapeutic applicability as an antioxidant in pharmaceutical forms.

Efficacy of topical formulations containing Pimenta pseudocaryophyllus extract against UVB-induced oxidative stress and inflammation in hairless mice.

Plants rich in antioxidant substances may be a promising strategy for preventing UV-induced oxidative and inflammatory damage of the skin. Pimenta pseudocaryophyllus is native to Brazil and presents flavonoids and other polyphenolic compounds in high concentration. Thus, the present study evaluated the possible effects of topical formulations containing P. pseudocaryophyllus ethanolic extract (PPE) at inhibiting UV-B irradiation-induced oxidative stress and inflammation. PPE was administered on the dorsal skin of hairless mice using two formulations: F1 (non-ionic emulsion with high lipid content) and F2 (anionic emulsion with low lipid content) before and after UV-B irradiation. The following parameters were evaluated in skin samples: edema, myeloperoxidase activity, cytokines levels, matrix metalloprotease-9 (MMP-9) secretion/activity, reduced glutathione (GSH), superoxide anion and lipid peroxidation levels, and mRNA expression for glutathione reductase and gp91phox. The UV-B irradiation increased all parameters, except for IL-10 levels and glutathione reductase mRNA expression, which were not altered, and GSH levels, which were reduced by exposure to UV-B light. Treatments with F1 and F2 containing PPE inhibited UV-B-induced edema formation (89% and 86%), myeloperoxidase activity (85% and 81%), IL-1ß production (62% and 82%), MMP-9 activity (71% and 74%), GSH depletion (73% and 85%), superoxide anion (83% and 66%) and TBARS (100% and 100%) levels, increased glutathione reductase (2.54 and 2.55-fold) and reduced gp91phox (67% and 100%) mRNA expression, respectively. F2 containing PPE also increased IL-10 levels. Therefore, this study demonstrates the effectiveness of topical formulations containing PPE in inhibiting UV-B irradiation-induced inflammation and oxidative stress of the skin.

Tephrosia sinapou ethyl acetate extract inhibits inflammatory pain in mice: opioid receptor dependent inhibition of TNFα and IL-1ß production.

UNLABELLED: CONTEXT. Tephrosia toxicaria is currently known as Tephrosia sinapou (Buc'hoz) A. Chev. (Fabaceae) and is a source of compounds such as flavonoids that inhibit inflammatory pain. OBJECTIVE: To investigate the analgesic effect and mechanisms of the ethyl acetate extract of T. sinapou in inflammatory pain in mice. MATERIALS AND METHODS: Behavioral responses were evaluated using mechanical (1-24 h) and thermal hyperalgesia (0.5-5 h), writhing response (20 min) and rota-rod (1-5 h) tests. Neutrophil recruitment (myeloperoxidase activity), cytokines (tumor necrosis factor [TNF]α and interleukin [IL]-1ß), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) serum levels were determined by colorimetric assays. Pharmacological treatments were opioid receptor antagonist (naloxone, 0.1-1 mg/kg) and control opioid (morphine, 5 mg/kg). Inflammatory stimuli were carrageenin (100 µg/paw), complete Freund's adjuvant (CFA, 10 µl/paw), prostaglandin E2 (PGE2, 100 ng/paw) and acetic acid (0.8%). RESULTS: The intraperitoneal pre-treatment with extract inhibited in a dose-dependent (30-300 mg/kg) dependent manner the mechanical hyperalgesia induced by carrageenin (up to 93% inhibition). The post-treatment (100 mg/kg) inhibited CFA-induced hyperalgesia (up to 63% inhibition). Naloxone (1 mg/kg) prevented the inhibitory effect of the extract over carrageenin-induced mechanical (100%) and thermal (100%) hyperalgesia, neutrophil recruitment (52%) and TNFα (63%) and IL-1ß (98%) production, thermal threshold in naïve mice (99%), PGE2-induced mechanical hyperalgesia (88%) and acetic acid-induced writhing response (49%). There was no significant alteration in the rota-rod test, and AST and ALT serum levels by extract treatment. Discussion and conclusion. Tephrosia sinapou ethyl acetate extract reduces inflammatory pain by activating an opioid receptor-dependent mechanism.

The ruthenium NO donor, [Ru(bpy)2(NO)SO3](PF6), inhibits inflammatory pain: involvement of TRPV1 and cGMP/PKG/ATP-sensitive potassium channel signaling pathway.

The activation of nitric oxide (NO) production is an analgesic mechanism shared by drugs such as morphine and diclofenac. Therefore, the controlled release of low amounts of NO seems to be a promising analgesic approach. In the present study, the antinociceptive effect of the ruthenium NO donor [Ru(bpy)2(NO)SO3](PF6) (complex I) was investigated. It was observed that complex I inhibited in a dose (0.3-10mg/kg)-dependent manner the acetic acid-induced writhing response. At the dose of 1mg/kg, complex I inhibited the phenyl-p-benzoquinone-induced writhing response and formalin- and complete Freund's adjuvant-induced licking and flinch responses. Additionally, complex I also inhibited transient receptor potential cation channel subfamily V member 1 (TRPV1)-dependent overt pain-like behavior induced by capsaicin. Complex I also inhibited the carrageenin-induced mechanical hyperalgesia and increase of myeloperoxidase activity (MPO) in paw skin samples. The inhibitory effect of complex I in the carrageenin-induced hyperalgesia, MPO activity and formalin was prevented by the treatment with ODQ, KT5823 and glybenclamide, indicating that complex I inhibits inflammatory hyperalgesia by activating the cGMP/PKG/ATP-sensitive potassium channel signaling pathway. The present study demonstrates the efficacy of a novel ruthenium NO donor and its analgesic mechanisms.

Preparation and characterization of microcapsules based on biodegradable polymers: pectin/casein complex for controlled drug release systems.

Controlled release of drugs is an important strategy to diminish the drug dose and adverse side effects. Aqueous mixtures of polysaccharides and proteins are usually unstable above a certain biopolymer concentration and phase separation occurs either because of repulsive (segregative) or attractive (associative) interactions. Herein, pectin/casein microcapsules were prepared by complex coacervation aiming at prolonged drug release. The morphological characteristics, particle size, distribution, and release kinetics of microcapsules were studied using as a model the hydrophilic drug acetaminophen. It was detected that complexation of pectin/casein particles occurs at pH values lower than 6, resulting in the formation of spherical particles after spray drying. Microcapsules had a mean diameter of 3.138 and 4.929 µm without drug, and of 4.680 and 5.182 µm with drug using USP and 8003 pectin, respectively. The in vitro release of acetaminophen from microcapsules was slow and the drug release mechanism was controlled by diffusion following first-order kinetics. There was greater release of acetaminophen in simulated gastric fluid than simulated intestinal fluid conditions. Concluding, the polymeric system present herein seemed to be appropriate for a prolonged release of acetaminophen throughout the gastrointestinal tract. Nevertheless, it is likely that it is a promising pectin/casein complex for lipossoluble drugs, which merits further investigation.

Evaluation of in vivo efficacy of topical formulations containing soybean extract.

In the present study it was evaluated the: (i) functional stability of the soybean extract as a raw material and dispersed in two different topical formulations, (ii) skin retention using modified Franz diffusion cells, and (iii) in vivo activity of these formulations to inhibit 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced hydrogen peroxide (H(2)O(2)) and malondialdehyde (MDA) increases in the skin of hairless mice. The physico-chemical stability was evaluated by pH, globule size and centrifugation test. Furthermore, functional stability was also evaluated by antilipoperoxidative activity. The two topical formulations were stored at 4 degrees C, 30 degrees C/60% RH and 40 degrees C/70% RH for 6 months. The evaluation of the antiperoxidative stability of soybean extract itself and incorporated in formulations did not demonstrate loss of activity by storage at 4 degrees C/6 months. During 6 months of the study in different storage conditions the formulations 1 and 2 added or not with soybean extract were stable to physico-chemical tests. The effect of antioxidant compounds detected by the inhibition of MDA formation was time-dependent for formulation 2 as detected in the skin retention study. Pretreatment with formulation 1 or 2 significantly diminished TPA-induced H(2)O(2) and MDA generation. In conclusion, the present results suggest for the first time that formulations containing soybean extract may be a topical source of antioxidant compounds that decrease oxidative damages of the skin.

Evaluation of the antioxidant activity of different flavonoids by the chemiluminescence method.

The objective of the present investigation was to study the antioxidant action of different flavonoids (quercetin, glabridin, red clover, and Isoflavin Beta, an isoflavones mixture) in order to determine if they could be added to a topical formulation used to treat damage caused by free radicals. Samples of 10 microL of the test compounds at different concentrations were mixed with 0.1 M phosphate buffer, pH 7.4, and a luminol solution was added to yield a final concentration of 0.113 mM. Hydrogen peroxide was then added at a final concentration of 0.05 mM. The reaction was started by introducing the horseradish peroxidase enzyme at a final concentration of 0.2 IU/mL, in a final volume of 1.0 mL. Chemiluminescence was measured for 10 minutes at room temperature, and dimethylsulfoxide (DMSO) was used as a control. All samples showed marked inhibition of oxidative stress, with a concentration-dependent action for quercetin and Isoflavin Beta. The highest inhibition was observed with glabridin and the dry red clover extract. All flavonoids proved to be adequate for addition to topical formulations because of their high antioxidant activity.