Superior even skin tone and anti-ageing benefit of a combination of 4-hexylresorcinol and niacinamide.

OBJECTIVES: To demonstrate the synergistic effect of 4-hexylresorcinol (4-HR) with niacinamide in boosting anti-melanogenic efficacy in vitro and establish the in vivo efficacy and safety of the combination in a human trial. METHODS: Primary human epidermal melanocytes and 3D pigmented skin equivalents were treated with 4-HR, niacinamide, and their combinations for their effect on pigmentation. This was followed by a randomized, double-blind, split-face clinical study in Chinese subjects, and effects on skin tone, hyperpigmentation, fine lines and wrinkles, hydration, and skin firmness were measured for a 12-week study period. RESULTS: In vitro tyrosinase enzyme activity studies showed that 4-HR is one of the most potent tyrosinase inhibitors. The combination of 4-HR and niacinamide showed a synergistic reduction in melanin production in cultured melanocytes and lightened the 3D skin equivalent model. In vitro as well as in the human trial, the combination of 4-HR and niacinamide showed significantly improved efficacy over niacinamide alone on hyperpigmentation spots as measured by L*, the visual appearance of fine lines and wrinkles in crow's feet and perioral area and skin firmness, with no product-related adverse events. CONCLUSIONS: A formulation containing a combination of 4-HR and niacinamide delivered superior skin tone and anti-ageing benefits significantly better than niacinamide alone with no adverse events. This study demonstrates that a product designed to affect multiple pathways of melanogenesis, inflammation, and ageing may provide an additional treatment option, beyond hydroquinone and retinoids, for hyperpigmentation and ageing.

OBJECTIFS: Démontrer l'effet synergique du 4-hexylrésorcinol (4-HR) associé au niacinamide pour stimuler in vitro l'efficacité antimélanogène, et établir l'efficacité et la sécurité d'emploi in vivo de cette association dans un essai chez l'homme. MÉTHODES: Des mélanocytes épidermiques humains primaires et des équivalents cutanés pigmentés en 3D ont été traités avec du 4-HR, du niacinamide et leurs combinaisons pour leur effet sur la pigmentation. Ceci a été suivi d'une étude clinique randomisée, en double aveugle en hémi-visage chez des sujets chinois, et les effets sur le teint, l'hyperpigmentation, les rides et ridules, l'hydratation et la fermeté de la peau ont été mesurés pendant une durée d'étude de 12 semaines. RÉSULTATS: Les études in vitro sur l'activité enzymatique de la tyrosinase ont montré que le 4-HR est l'un des inhibiteurs de la tyrosinase les plus puissants. L'association du 4-HR et du niacinamide a montré une réduction synergique de la production de mélanine dans les mélanocytes de culture et donné de la luminosité au modèle cutané 3D équivalent. Également in vitro avec l'étude chez l'homme, l'association du 4-HR et du niacinamide a fait ressortir une efficacité significativement plus élevée qu'avec le niacinamide seul sur les taches d'hyperpigmentation mesurées par L*, l'aspect visuel des rides et ridules des pattes d'oie et de la zone périorale, et la fermeté de la peau, sans événements indésirables liés au produit. CONCLUSIONS: Une formulation contenant une association de 4-HR et de niacinamide a permis d'obtenir un teint et un effet anti-âge nettement supérieurs à ceux du niacinamide seul, sans événements indésirables. Cette étude démontre qu'un produit conçu pour toucher plusieurs voies de mélanogenèse, d'inflammation et de vieillissement peut constituer une nouvelle option thérapeutique, au-delà de l'hydroquinone et des rétinoïdes, pour l'hyperpigmentation et le vieillissement.

Effects of Danggui Sini decoction on neuropathic pain: experimental studies and clinical pharmacological significance of inhibiting glial activation and proinflammatory cytokines in the spinal cord
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AIM: Neuropathic pain responds poorly to drug treatments. Partial relief is achieved in only about half of the patients. Danggui Sini decoction (DSD), an aqueous extract of Angelica sinensis, Ramulus Cinnamomi, and Radix Puerariae, has been used extensively in China to treat inflammatory and ischemic diseases. The current study examined the putative effects of DSD on neuropathic pain. METHOD: We used two commonly-used animal models: chronic constriction injury (CCI) and diabetic neuropathy for the study. And we examined effects of DSD on pain response, activation of microglia and astroglia in spinal dorsal horn, and expression of proinflammatory cytokines in the spinal cord. RESULTS: Consecutive intragastric administration of DSD (25 - 100 mg/kg) for 10 days inhibited the mechanical and thermal nociceptive response induced by CCI and diabetes without interfering with the normal pain response. Meanwhile, in both models, DSD inhibited the over-expression of specific markers for microglia (Iba-1) and astroglia (GFAP) activation in the spinal dorsal horn. DSD also reduced the elevated nuclear NF-κB level and inhibited the up-regulation of proinflammatory cytokines, such as IL-6, IL-1ß, and TNF-α, in the spinal cord. CONCLUSION: DSD can alleviate CCI and diabetes-induced neuropathic pain, and its effectiveness might be due to the inhibition of neuroinflammation in the spinal dorsal horn. The anti-inflammation effect of DSD may be related to the suppression of spinal NF-κB activation and/or cytokines expression.
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Preparation of activated carbon by chemical activation under vacuum.

Activated carbons especially used for gaseous adsorption were prepared from Chinesefir sawdust by zinc chloride activation under vacuum condition. The micropore structure, adsorption properties, and surface morphology of activated carbons obtained under atmosphere and vacuum were investigated. The prepared activated carbons were characterized by SEM, FTIR, and nitrogen adsorption. It was found that the structure of the starting material is kept after activation. The activated carbon prepared under vacuum exhibited higher values of the BET surface area (up to 1079 m2 g(-1)) and total pore volume (up to 0.5665 cm3 g(-1)) than those of the activated carbon obtained under atmosphere. This was attributed to the effect of vacuum condition that reduces oxygen in the system and limits the secondary reaction of the organic vapor. The prepared activated carbon has well-developed microstructure and high microporosity. According to the data obtained, Chinese fir sawdust is a suitable precursor for activated carbon preparation. The obtained activated carbon could be used as a low-cost adsorbent with favorable surface properties. Compared with the traditional chemical activation, vacuum condition demands less energy consumption, simultaneity, and biomass-oil is collected in the procedure more conveniently. FTIR analysis showed that heat treatment would result in the aromatization of the carbon structure.