A new strategy for the skin delivery of bioactive compounds has been developed, using enzymes involved in the maintenance of the epidermal barrier function and the enzymatic transformation of corresponding precursors. This new strategy... more
A new strategy for the skin delivery of bioactive compounds has been developed, using enzymes involved in the maintenance of the epidermal barrier function and the enzymatic transformation of corresponding precursors. This new strategy has been tested with regard to two enzymatic activities of the skin barrier: extracellular glucosidase and esterase/lipase. An analysis of the requirements for the glycosidic bond hydrolysis of any glycoconjugate by beta-glucocerebrosidase indicates that the release of the moiety linked to the glucose unit is obtained as long as the glycosidic bond being broken is not hindered, and as long as the leaving group property of the released moiety is good enough. This strategy was first applied to the release of the antioxidant delta-tocopherol. It was then extended to retinoic acid by introducing a spacer between the glucose unit and the bioactive moiety. This spacer was either a good leaving group such as hydroquinone, or a structure akin to a ceramide, n...
The phenolic glycoside arbutin and its metabolite with uroantiseptic activity hydroquinone occur naturally in the leaves of various medicinal plants and spices. In this study, an extraction procedure coupled with gas chromatography-mass... more
The phenolic glycoside arbutin and its metabolite with uroantiseptic activity hydroquinone occur naturally in the leaves of various medicinal plants and spices. In this study, an extraction procedure coupled with gas chromatography-mass spectrometry (GC-MS) was developed to determine arbutin and hydroquinone content in strawberry tree (Arbutus unedo L., Ericaceae) leaves. The method showed good linearity (R
Objective: Arbutin (p-hydroxyphenyl-β-D-glucopyranoside) possesses beneficial functions including antioxidant, anti-inflammatory, and anti-tumoral activities. Due to the important role of oxidative stress and apoptosis in the successful... more
Objective: Arbutin (p-hydroxyphenyl-β-D-glucopyranoside) possesses beneficial functions including antioxidant, anti-inflammatory, and anti-tumoral activities. Due to the important role of oxidative stress and apoptosis in the successful treatment of cancer, understanding mechanisms that lead to apoptosis in cancer cells, is essential. The purpose of the current study was to evaluate the effect of arbutin on tert-butyl hydroperoxide (t-BHP)-induced oxidative stress and the related mechanisms in fibroblast and Lymph Node Carcinoma of the Prostate (LNCaP) cells. Materials and Methods: In this experimental study, the LNCaP and fibroblast cell lines were pre-treated with arbutin (50, 250 and 1000 μM). After 24 hours, t-BHP (30 and 35 μM) was added to the cells. Viability was measured (at 24 and 48 hours) using MTT assay. The antioxidant effect of arbutin was measured by FRAP assay. The mRNA expression of P53 and BAX/BCL-2 ratio were measured using quantitative polymerase chain reaction (PCR). The percentage of apoptotic or necrotic cells was determined using a double staining annexin V fluorescein isothiocyanate (FITC) apoptosis detection kit. Results: Arbutin pre-treatment increased the total antioxidative power and cell viability in the MTT assay and reduced BAX/BCL-2 ratio, P53 mRNA expression and necrosis in fibroblasts exposed to the oxidative agent (P<0.001). In addition, our results showed that arbutin can decrease cell viability, induce apoptosis and increase BAX/BCL-2 ratio in LNCaP cells at some specific concentrations (P<0.001). Conclusion: Arbutin as a potential functional β-D-glucopyranoside has strong ability to selectively protect fibroblasts against t-BHP-induced cell damage and induce apoptosis in LNCaP cells.
Arbutin is a glycosylated hydroquinone found at high concentrations in certain plants capable of surviving extreme and sustained dehydration. In this paper, we examine a potential role of this molecule in anhydrobiosis. We have studied... more
Arbutin is a glycosylated hydroquinone found at high concentrations in certain plants capable of surviving extreme and sustained dehydration. In this paper, we examine a potential role of this molecule in anhydrobiosis. We have studied its effects on the physical properties of phospholipids and on preservation of liposomes during drying. Arbutin depresses the gel to liquid crystalline phase transition temperature of dry phospholipids, as measured by differential scanning calorimetry, with a pattern similar to that seen in phospholipids dried with the disaccharide trehalose. Unlike trehalose, however, arbutin does not protect dry liposomes from leaking their contents. Also, using Fourier transform infrared spectroscopy, we found an increase in the vibrational frequency of the phosphate asymmetric stretch in partially hydrated phospholipids in the presence of arbutin. Trehalose, by contrast, depresses the frequency of the phosphate in dry phospholipids, indicating that the modes of in...
A new arbutin derivative, madhuglucoside (1), along with three known arbutin derivatives were isolated from the seeds of Madhuca latifolia in addition to seven other known constituents. Their structures were established on the basis of... more
A new arbutin derivative, madhuglucoside (1), along with three known arbutin derivatives were isolated from the seeds of Madhuca latifolia in addition to seven other known constituents. Their structures were established on the basis of spectral analysis. Compounds 1a, 2a and 3a were obtained in a pure state after acetylation of the mother fraction and characterized as their acetyl derivatives.
The effect of arbutin, a 4-hydroxyphenyl-beta-glucopyranoside, on dimyristoylphosphatidylcholine (DMPC) bilayers was studied by turbidimetry, EPR and FTIR spectroscopies. The disruption of DMPC multilamellar vesicles... more
The effect of arbutin, a 4-hydroxyphenyl-beta-glucopyranoside, on dimyristoylphosphatidylcholine (DMPC) bilayers was studied by turbidimetry, EPR and FTIR spectroscopies. The disruption of DMPC multilamellar vesicles (MLV&amp;amp;#39;s) with monomyristoylphosphatidylcholine (lysoPC), a product of hydrolysis of phospholipase A(2) (PLA(2)), is more efficient at 18 degrees C, where DMPC MLV&amp;amp;#39;s are known to be in the ripple P(beta&amp;amp;#39;) phase, than at 10 degrees C (L(beta&amp;amp;#39;) flat gel phase). Disruption at 18 degrees C was inhibited by increasing concentrations of arbutin in the solution. This inhibition was correlated with the disappearance of the ripple phase in MLV&amp;amp;#39;s when arbutin is present. Shifts in FTIR carbonyl bands caused by arbutin or by temperature changes allow us to propose a model. It is interpreted that the changes in the water-hydrocarbon interface caused by arbutin, forcing a reaccommodation of the carbonyl groups, eliminate the topological defects in the lattice due to mismatches among regions with different area per lipid where lysoPC can insert.
The objective of this study was to develop and characterize a liposome delivery system coencapsulating two cosmeceutical ingredients, avobenzone (AVO) and arbutin (AR). Two different liposome preparation methods, that is, thin film... more
The objective of this study was to develop and characterize a liposome delivery system coencapsulating two cosmeceutical ingredients, avobenzone (AVO) and arbutin (AR). Two different liposome preparation methods, that is, thin film hydration and reverse-phase evaporation, were evaluated. To obtain the optimal formulation, various ratios of lipid to AVO or AR were tested. The effects of liposome formulation and preparation method on particle size, entrapment efficiency (EE), and skin permeation rate were studied. The mean particle size of the liposome formulations obtained by the thin film hydration method was smaller than that obtained by the reverse-phase evaporation method. The EE of AR and AVO in liposomes prepared by the thin film method, however, was lower than that prepared by the reverse-phase evaporation method. No differences in membrane permeation were observed between the two preparation methods. A large portion of AR permeated through the membrane into the receptor chamb...
The effect of arbutin, a 4-hydroxyphenyl-beta-glucopyranoside, on dimyristoylphosphatidylcholine (DMPC) bilayers was studied by turbidimetry, EPR and FTIR spectroscopies. The disruption of DMPC multilamellar vesicles... more
The effect of arbutin, a 4-hydroxyphenyl-beta-glucopyranoside, on dimyristoylphosphatidylcholine (DMPC) bilayers was studied by turbidimetry, EPR and FTIR spectroscopies. The disruption of DMPC multilamellar vesicles (MLV&amp;amp;#39;s) with monomyristoylphosphatidylcholine (lysoPC), a product of hydrolysis of phospholipase A(2) (PLA(2)), is more efficient at 18 degrees C, where DMPC MLV&amp;amp;#39;s are known to be in the ripple P(beta&amp;amp;#39;) phase, than at 10 degrees C (L(beta&amp;amp;#39;) flat gel phase). Disruption at 18 degrees C was inhibited by increasing concentrations of arbutin in the solution. This inhibition was correlated with the disappearance of the ripple phase in MLV&amp;amp;#39;s when arbutin is present. Shifts in FTIR carbonyl bands caused by arbutin or by temperature changes allow us to propose a model. It is interpreted that the changes in the water-hydrocarbon interface caused by arbutin, forcing a reaccommodation of the carbonyl groups, eliminate the topological defects in the lattice due to mismatches among regions with different area per lipid where lysoPC can insert.
Abstract: From the aerial parts of Salvia mexicana var. mexicana, two C-10 epimers (α and β) of salvimexicanolide were isolated. Our interpretation of the data, especially the 13 C NMR, led us to conclude that the previously described 13... more
Abstract: From the aerial parts of Salvia mexicana var. mexicana, two C-10 epimers (α and β) of salvimexicanolide were isolated. Our interpretation of the data, especially the 13 C NMR, led us to conclude that the previously described 13 C-NMR spectrum of the α- ...
Insecticides based on botanical sources have taken on increased attention due to differing modes of action from current insecticides in use and the view that they may be environmentally friendly. Thymoquinone, a component in the essential... more
Insecticides based on botanical sources have taken on increased attention due to differing modes of action from current insecticides in use and the view that they may be environmentally friendly. Thymoquinone, a component in the essential oil of incense cedar heartwood, has been shown to have insecticidal action against adult mosquitoes. This study evaluated relative toxicities of thymoquinone, selected derivatives of thymoquinone, hydroquinone, and arbutin to determine if any had similar or better activity. The intrinsic toxicities of hydroquinone and thymohydroquinone were not significantly different from thymoquinone, while libocedrol and arbutin were significantly less toxic.
