Coumestrol is an isoflavonoid that exhibits antioxidant activity. In this study, hydrogels containing coumestrol-loaded nanoemulsions were designed to protect the skin against UVA/UVB light. The ...systems investigated were coumestrol-loaded nanoemulsions obtained by spontaneous emulsification procedure formulated in semisolid hydrogels composed of ionic (Carbopol 940®), cationic (chitosan) or non-ionic (hydroxyethylcellulose) gelling materials. Transmission electron microscopy images of formulations showed oil droplets exhibiting 200–300 nm. Hydrogels displayed non-Newtonian shear-thinning behavior. Coumestrol content in formulations remained close to 100 % (1 mg/mL) over time (up to 90 days). Regardless of the gelling material used, a lowering of coumestrol release rate was observed, in comparison with the release from nanoemulsion. The permeation and retention of coumestrol in porcine ear skin was evaluated using Franz-type diffusion cells. A higher retention of coumestrol in the epidermis was noticed (20 μg/g) from Carbopol 940-based formulation after 8 h of kinetics. No histological evidence of tissue damage was observed. The nanoemulsion containing coumestrol thickened with Carbopol 940® was selected for further studies. The formulation exhibited antioxidant potential as estimated by TRAP and TAR assays. The skin photoprotective effect was evidenced by means of TBARS, protein carbonylation, and protein thiol content experiments. Overall, our research suggests that the formulation is promising to protect skin against oxidative damage from UVA/UVB light.
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Recent studies have shown the effect of soy isoflavones in preventing skin photoaging and photocarcinogenesis, especially for genistein (GEN). Nanoemulsions have been proposed as a delivery system ...for GEN administration due to the low water solubility of this isoflavone. This article describes the validation of an isocratic liquid chromatography method to determine GEN in porcine ear skin layers from nanoemulsions before and after incorporation into hydrogels. The analyses are performed on a reversed-phase C18 column using a mobile phase composed of methanol-water (70:30, v/v) under acid conditions (at pH 3.0) and UV detection at 270 nm. The method is linear in the range of 0.1-10 µg/mL (r2 > 0.999) in the presence of skin extracts. The low limit of quantitation is estimated as 0.1 µg/mL. No interferences from formulation excipients or skin layer compounds are detected. The RSD values for intra- and inter-day precision are lower than 15%. Recovery ranged from approximately 90% to 110%. The method is applied to estimate GEN retention in the skin from formulations using Franz diffusion cells. The highest amount of GEN is detected in the epidermis (185 µg/cm2). In conclusion, the method proved to be specific, precise, and accurate in determining GEN amounts from formulations in skin retention studies.
3
-O
-Methylquercetin (3
O
MQ), a natural 3-
O-
methylflavonoid, was isolated from
Achyrocline satureioides
and purified using the high-performance counter current chromatography (HPCCC) on a ...semi-preparative scale. High-purity 3
O
MQ (98%) was obtained with excellent recovery (81.8% (w/w)) and good yield (190 mg/100 g of plant). Isolated 3
O
MQ was evaluated against the A375 human amelanotic melanoma cancer cell line and A375-derived with different degrees of aggressiveness (A375-A7, A375-G10, and A375-PCDNA3). The results showed that 3
O
MQ reduced the cell viability of all strains, demonstrating time- and dose-dependent responses. 3
O
MQ was used to obtain hydrogels for the topical treatment of melanoma. Thus, 3
O
MQ was incorporated into hypromellose hydrogels with/without different cyclodextrins (CDs). The 3
O
MQ formulations showed permeation/retention in all skin layers, namely stratum corneum, epidermis, and dermis. A significant amount of 3
O
MQ was found in the replication site of the melanoma cells (epidermis and dermis). Altogether, these results demonstrate that 3
O
MQ can be isolated from
Achyrocline satureioides
by HPCCC on a semi-preparative scale and exhibit cytotoxic activity against melanoma cells. Its incorporation into an HPMC hydrogel containing HP-β-CD yielded a formulation with excellent technological and biopharmaceutical characteristics for evaluating the topical management of melanoma.
Graphical abstract
Aqueous and hydro-ethanolic extracts of Bauhinia microstachya leaves (AEBM and HEBM) were investigated for their phenolic content and phytochemical profile (by spectrophotometry and HPLC), and for ...their antioxidant activities and free radical scavenging potential in different in vitro systems (TRAP, TEAC, TBARS, nitric oxide, superoxide and hydroxyl radical). HEBM presented a 27.4% higher content of phenolics when compared to AEBM and a distinct phytochemical profile was observed. Our work suggests that both extracts have potent antioxidant activities and that their antioxidant capacity and efficiency vary according to the radical-generating system. In general, HEBM was more effective than AEBM in avoiding ROS-generating damage and in scavenging the various radicals formed. Nevertheless, when results were normalized to total phenolic content, a different profile of antioxidant activities and free radical scavenging potential was observed, particularly against oxidative lipid damage and superoxide radical. B. microstachya extracts may be considered an interesting source of natural antioxidants as well as other phenolic-rich plants.
Achyrocline satureioides (Lam.) DC extract–loaded nanoemulsions have demonstrated potential for wound healing, with promising effects on keratinocyte proliferation. We carried out the first in vivo ...investigation of the wound healing activity of a hydrogel containing A. satureioides extract–loaded nanoemulsions. We prepared hydrogels by adding the gelling agent (Carbopolsup.® Ultrez) to extract-loaded nanoemulsions (~250 nm in diameter) obtained by spontaneous emulsification. The final flavonoid content in formulation was close to 1 mg/mL, as estimated by ultra-fast liquid chromatography. Permeation/retention studies using porcine ear skin showed that flavonoids reached deeper layers of pig ear skin when it was damaged (up to 3.2 µg/cm² in the dermis), but did not reach the Franz-type diffusion cell receptor fluid. For healing activity, we performed a dorsal wound model using Wistar rats, evaluating the lesion size, anti-inflammatory markers, oxidative damage, and histology. We found that extract-loaded formulations promoted wound healing by increasing angiogenesis by ~20%, reducing inflammation (tumor necrosis factor α) by ~35%, decreasing lipid damage, and improving the re-epithelialization process in lesions. In addition, there was an increase in the number of blood vessels and hair follicles for wounds treated with the formulation compared with the controls. Our findings indicate that the proposed formulation could be promising in the search for better quality healing and tissue reconstruction.
Objective: To evaluate the effect of different cyclodextrins (β-cyclodextrin β-CD, methyl-β-cyclodextrin Mβ-CD, or hydroxypropyl-β-cyclodextrin HPβ-CD) and/or hydrophilic polymers ...(carboxymethylcellulose, hydroxypropylmethylcellulose HPMC, polyethyleneglycol, or polyvinylpyrrolidone PVP) on daidzein solubility in water.
Materials and methods: The corresponding associations were characterized in aqueous media using phase-solubility studies. The morphology of daidzein/cyclodextrin freeze-dried complexes was characterized using scanning electron microscopy, and their spatial configuration was proposed by means of nuclear magnetic resonance spectroscopy.
Results and discussion: In the presence of 6 mM of cyclodextrins, the solubility of daidzein in water was significantly enhanced: 5.7-fold (β-CD), 7.2-fold (Mβ-CD), and 9.4-fold (HPβ-CD). The analysis of the three solid complexes proved that the formation of inclusion complexes occurred through the insertion of the B and C rings of daidzein molecule into the cyclodextrins cavity. The association of daidzein/cyclodextrin complexes to the hydrophilic polymers HPMC or PVP (1%, w/w) was able to improve the solubility of daidzein even further.
Conclusion: The highest solubilizing effect was obtained for daidzein/HPβ-CD/PVP ternary system (12.7-fold).
The present study was elaborated to comparatively evaluate the preventive effect of different peach-derived products obtained from preserved fruits (Syrup and Preserve Pulp Peach PPP) and from fresh ...peels and pulps (Peel and Fresh Pulp Peach FPP) in a model of liver/renal toxicity and inflammation induced by carbon tetrachloride (CCl4) in rats. Tissue damage (carbonyl, thiobarbituric acid reactive species and sulfhydril), antioxidant enzymes activity (catalase and superoxide dismutase) and inflammatory parameters tumor necrosis factor (TNF)-α and interleukin (IL)-1β levels, and receptor for advanced glycation end-products (RAGE) and nuclear factor (NF)κB-p65 immunocontent were investigated. Our findings demonstrated that Peel, PPP and FPP (200 or 400 mg/kg) daily administration by oral gavage for 30 days conferred a significant protection against CCl4-induced antioxidant enzymes activation and, most importantly, oxidative damage to lipids and proteins as well as blocked induction of inflammatory mediators such as TNF-α, IL-1β, RAGE and NFκB. This antioxidant/anti-inflammatory effect seems to be associated with the abundance of carotenoids and polyphenols present in peach-derived products, which are enriched in fresh-fruit-derived preparations (Peel and FPP) but are also present in PPP. The Syrup — which was the least enriched in antioxidants — displayed no protective effect in our experiments. These effects cumulated in decreased levels of transaminases and lactate dehydrogenase leakage into serum and maintenance of organ architecture. Therefore, the herein presented results show evidence that supplementation with peach products may be protective against organ damage caused by oxidative stress, being interesting candidates for production of antioxidant-enriched functional foods.
This article describes the development of topical hydrogels containing genistein-loaded nanoemulsions, obtained by means of spontaneous emulsification. This procedure yielded monodisperse ...nanoemulsions in a sub 250 nm range exhibiting negative zeta-potential and low viscosity. The formulations were incorporated into acrylic-acid hydrogels in order to have their viscosity adjusted for topical application. The semisolid formulations exhibit non-Newtonian pseudoplastic behavior. The skin permeation/retention of genistein from formulations was carried out using porcine ear skin mounted in Franz diffusion cells under sink conditions. The results showed a slow flow of genistein through the skin. Higher amount of genistein was detected into the skin from the formulation composed by medium chain triglycerides as oily core when compared to the octyldodecanol one. The overall results show that hydrogels containing genistein-loaded nanoemulsions could be considered as a promising formulation to delivery isoflavones into the skin.
Lactobionic acid and its salts are substances that have several applications in the pharmaceutical area. These products were obtained by bioconversion through the enzymatic complex ...glucose-fructose-oxidoreductase (GFOR)/gluconolactonase (GL) present in calcium alginate immobilized cells of Zymomonas mobilis. In the reactions catalyzed by this enzyme system, the medium pH must be controlled at slightly acid values. For this purpose, NaOH, KOH, or Ca(OH)2 were used, and as a result, the respective salts were formed. The kinetic study on the formation of sodium, potassium and calcium lactobionates was followed by the steps of purification and characterization aiming the potential use of these compounds in the pharmaceutical area. In the assays for the bioproduction of sodium, potassium or calcium lactobionates, yields of 74, 77 and 84% were obtained, respectively. In the salts purification step, purity levels of approximately 95% were achieved. The structural identities of the lactobionate salts were determined by high resolution mass spectrometry, in addition to the 13C and 1H NMR analysis. The characterization demonstrates the selectivity of the enzymatic reaction of GFOR/GL of Z. mobilis, in the production of lactobionic acid and its salts.
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