ABSTRACT
OBJECTIVE: To study the permeation of liquiritigenin (LQG) and liquiritin (LQ) as licorice flavonoids into the skin, we prepared ceramide liposome-in-cellulose hydrogel complex system. METHODS: Liposome-in-hydrogel complex systems were developed by incorporating ceramide liposomes into cellulose hydrogels by the swelling method. We evaluated their physical and chemical properties, encapsulation efficiency and skin permeability using Franz Diffusion Cell. It was visually seen by CLSM images analysis. RESULTS: The ceramide liposome, consisting of biocompatible lipid membranes, remained stable for over 3 weeks. Encapsulation efficiencies for liquiritigenin and liquiritin-loaded liposome-in-hydrogel were 69.39% and 64.71%, respectively. Liposome-in-hydrogel complex systems (LQG: 56.55%, LQ: 66.99%) had greater skin permeability than control (LQG: 4.92%, LQ: 5.30%) or a single liposome systems (LQG: 43.34%, LQ: 48.97%) and hydrogel systems (LQG: 38.21%, LQ: 55.07%). CONCLUSION: Liposome-in-hydrogel system can be a potential drug delivery system for topical delivery of antioxidants such as licorice flavonoids to construct antioxidative skin barrier.
Subject(s)
Drug Delivery Systems/methods , Epidermis/physiology , Flavanones/physiology , Hydrogel, Polyethylene Glycol Dimethacrylate/pharmacology , Liposomes/pharmacology , Administration, Cutaneous , Glucosides , Humans , Hydrogel, Polyethylene Glycol Dimethacrylate/administration & dosage , Liposomes/administration & dosage , Microscopy, Confocal , PermeabilityABSTRACT
In Rhizobium leguminosarum bv. viciae, NodD, as a member of the LysR-type transcriptional regulators (LTTRs), exerts auto-regulation and activates transcription of other nod genes in the presence of naringenin. LTTRs were typically composed of N-terminal DNA-binding domain and C-terminal regulatory domain. In this study, by systematic insertion mutation, a region of 12 amino acids in length of NodD was identified as functional domain. Insertion mutants in this region appeared to acquire the ability of constitutively activating nodA gene and retained their auto-regulation properties. This identified region was shown to be a hinge of NodD as revealed through the model built using Swiss- PDB Viewer software. It is the first time to report that as a member of LysR family, NodD has been shown to contain a short intramolecular domain that influences its performance.
Subject(s)
Bacterial Proteins/genetics , Flavanones/genetics , Genome, Bacterial/physiology , Mutation , Rhizobium leguminosarum/genetics , Bacterial Proteins/physiology , Flavanones/physiology , Gene Expression Regulation, Bacterial , Plant Roots/microbiology , Symbiosis , Transcriptional ActivationABSTRACT
Flavonoids are thought to function in the plant stress response and male fertility in some, but not all, species. We examined the effects of a self-fertile chalcone synthase null allele, a, for the effects of heat and light stress on fertilization success and flower production in Ipomoea purpurea. Pollen recipients and pollen donors of both homozygous genotypes exhibit reduced fertilization success at high temperatures, indicating that high temperature acts as a stress-lowering fertilization success. Homozygous aa individuals exhibit reduced male and female fertilization success, compared to AA individuals, at high temperatures but not at low temperatures. In addition, aa individuals produce fewer flowers than AA individuals at low temperatures, but not at high temperatures. These results suggest that flavonoids alleviate heat stress on fertilization success. They also suggest that pleiotropic effects at the A locus may explain the low frequency of the a allele in natural populations.
