In vivo anti-ageing activity of cream containing niosomes loaded with purple glutinous rice (Oryza sativa Linn.) extract.

OBJECTIVE: To evaluate the anti-ageing activity of cream containing the methanolic purple glutinous rice extract loaded in niosomes. METHODS: The in vitro biological activities of the purple glutinous rice extracted by methanol maceration were determined. The extract loaded in niosomes and the cream containing the niosomes were developed. The in vivo anti-ageing activity in 20 human volunteers including skin hydration, pigmentation, roughness and elasticity after daily application for 28 days compared to at initial was evaluated by Corneometer, Mexameter, Visiometer and Cutometer, respectively. RESULTS: The purple glutinous rice extract showed free radical scavenging (SC50 ), lipid peroxidation inhibition (IPC50 ), metal ion chelating (CC50 ) and tyrosinase inhibition (IC50 ) values at 32.31 ± 1.28, 57.40 ± 2.12, 85.05 ± 5.43 and 43.89 ± 2.14 mg/mL which were 0.00031, 0.011, 0.0078 and 0.0016 times of the standards (0.01 ± 0.00, 0.62 ± 0.14, 0.66 ± 0.05 and 0.07 ± 0.01), respectively. The purple glutinous rice extract contained 0.35 µg of anthocyanin/1 mg of the extract determined by HPLC. After loaded in niosomes, the solubility of the extract was not only increased in various solvents, but also the chemical stability in different environments (weak base, reducing agent and acid salt) was improved. The cream formulation containing niosomes loaded with 1%w/v of the purple glutinous rice extract indicated the anthocyanin remaining percentages after 6 cycles of heating and cooling test at 52.28% of the initial. For in vivo anti-ageing activities, cream containing niosomes loaded with the extract gave significant decreased melanin index and skin roughness reduction of -14.05 and -9.95% of the initial, respectively. The % changes of the increased skin hydration, skin elastic extension and skin elastic recovery when applied on human volunteers' skin with this formulation were +48.73, -24.51 and +35.98%, respectively. CONCLUSION: The cream containing niosomes loaded with the 1%w/v methanolic purple glutinous rice extract gave not only the suitable in vitro antioxidant activity and physical stability of the active anthocyanin, but also the superior in vivo anti-ageing activity on human skin compared to the cream base and before application which can be further developed as a novel anti-ageing cosmeceutical product.

OBJECTIF: Evaluer l'activité anti-âge d'une crème contenant de l'extrait de riz gluant violet méthanolique chargé en niosomes. MÉTHODES: Les activités biologiques in vitro de l'extrait du riz gluant violet par macération au méthanol ont été déterminées. L'extrait chargé en niosomes et la crème contenant les niosomes ont été développés. L'activité anti-âge in vivo sur 20 volontaires humains, y compris de l'hydratation de la peau, la pigmentation, la rugosité et l'élasticité après une application quotidienne pendant 28 jours a été évaluée par comparaison avec T0 par cornéomètre, mexamètre, visiomètre et cutomètre, respectivement. RÉSULTATS: L'extrait de riz gluant violet a montré des valeurs de piégeage des radicaux libres (SC50), d'inhibition de la peroxydation lipidique (IPC50), de chélation des ions métalliques (CC50) et d'inhibition de la tyrosinase (IC50) à 32,31 ± 1,28, 57,40 ± 2,12, 85,05 ± 5,43 et 43,89 ± 2,14 mg / ml qui étaient 0,00031, 0,011, 0,0078 et 0,0016 fois des standards respectivement (0,01 ± 0,00, 0,62 ± 0,14, 0,66 ± 0,05 et 0,07 ± 0,01). L'extrait de riz gluant violet contenait 0.35 pg d'anthocyanine / 1 mg de l'extrait déterminé par HPLC. Après avoir été chargé dans les niosomes, la solubilité de l'extrait a non seulement été augmentée dans divers solvants, mais aussi la stabilité chimique dans différents environnements (base faible, agent réducteur et sel d'acide) a été améliorée. La formulation de crème contenant des niosomes chargés avec 1% p / v de l'extrait de riz gluant violet a indiqué les pourcentages d'anthocyanine restants après 6 cycles de test de chauffage et de refroidissement à 52,28% de la valeur initiale. Pour les activités anti-âge in vivo, la crème contenant des niosomes chargés de l'extrait a donné une réduction significative de l'indice de mélanine et de la rugosité cutanée de -14,05 et -9,95% de la valeur initiale, respectivement. Les pourcentages de variation de l'hydratation accrue de la peau, de l'extension élastique de la peau et de la récupération de l'élasticité de la peau lors de l'application sur la peau de volontaires humains avec cette formulation étaient respectivement de +48,73, -24,51 et + 35,98%. CONCLUSION: La crème contenant des niosomes chargée avec l'extrait de riz gluant violet méthanolique à 1% p / v a donné non seulement une activité antioxydante in vitro appropriée et une stabilité physique de l'anthocyanine active, mais également une activité anti-vieillissement in vivo supérieure sur la peau humaine par rapport à la base de la crème et avant application, qui peut être développée en tant que nouveau produit cosméceutique anti-âge. Mots clés: riz gluant violet, niosomes, antioxydant, inhibition de la tyrosinase, efficacité anti-âge in vivo, produit cosméceutique.

Potent and prolonged hypoglycemic activity of an oral insulin--Tat mixture in diabetic mice.

Trans-activator of transcription (Tat) is a cell penetrating peptide which can translocate and carry macromolecular cargoes through cell membranes. This study investigated the hypoglycemic activity of orally delivered insulin - Tat mixture in alloxan-induced diabetic mice. The mixtures of insulin and Tat at 1:1, 1:3 and 1:6 molar ratios were given orally at the insulin doses ranging from 1-200 IU/kg. The fasting blood glucose (FBG) levels were measured at initial, 1, 2, 4, 6, and 12 h after administration. At 1:3 molar ratio of the mixture and after 12 h of administration, insulin at 200 IU/kg showed the highest with prolonged hypoglycemic activity of 74.0±10.3% FBG reduction (2.18 folds of subcutaneously injected (SC) insulin). Free insulin administered orally did not show any hypoglycemic activity. The mixtures at the insulin doses of 100 and 50 IU/kg also showed potent FBG reduction of 73.8±8.2 and 71.3±16.9% at 12 h after administration (2.18 and 2.10 folds of SC insulin, respectively). After incubation with Mono-Mac-6 cells, only the -mixtures but not the free insulin showed intra-cellular insulin uptake, indicating the insulin penetration through the cell membranes via Tat. In simulated gastric fluid, the insulin content in the mixture was not found, demonstrating the degradation of insulin in the gastric environments. Insulin may be absorbed at upper gastrointestinal tract facilitated by Tat. The potent and prolonged hypoglycemic activity of insulin co-administered orally with Tat can be further developed as an effective oral insulin delivery system.

Low cytotoxic elastic niosomes loaded with salmon calcitonin on human skin fibroblasts.

A low cytotoxic elastic niosomal formulation loaded with salmon calcitonin was developed. The elastic niosomes were prepared from Tween 61 mixed with cholesterol at various concentrations of the edge activators (sodium cholate (NaC) and sodium deoxycholate (NaDC); 0.25, 0.5, 2.5, 5 and 10% mole) or ethanol (10-30% v/v). The effects of the niosomal concentrations (5, 10 and 20 mM) and phosphate buffer at pH 7.0 (5, 10, 20 and 30 mM) on the physical characteristics of niosomes were investigated. The 5 mM elastic niosomes in 5 mM phosphate buffer containing calcitonin 0.22 mg/mL gave the highest elasticity (deformability index (DI)) at 6.79 ± 2.03 determined by the extrusion method. The blank elastic niosomes comprised 2.5% mole NaDC, 5% mole NaC or 20% v/v ethanol showed the highest elasticity. The 5% mole NaC elastic niosomes loaded with calcitonin gave the highest DI (21.59 ± 0.91) and percentages of calcitonin entrapment efficiency (60.11 ± 4.98). This study has demonstrated that this NaC elastic niosome did not only reduce the cytotoxicity of the loaded calcitonin but also gave superior cell viability to the ethanolic elastic niosome as well.