1,721,110 research outputs found
A general hypothesis of multistable systems in pathophysiology
No full textDespite intensive investigations numerous diseases remain etiologically puzzling and recalcitrant to treatments. A hypothesis is proposed here assuming that these difficulties are due to an unsuitable approach to the mechanisms of life, which is subjugated by an apparent complexity and fails to grasp the uniformity that lays behind. The stability of metabolism, despite the enormous complex of chemical reactions, suggests that reciprocal control is a prerequisite of life. Negative feedback loops have been known for a long time to maintain homeostasis, while more recently, different life processes involved in transitions or changes have been modeled by positive loops giving rise to bistable switches, also including various diseases. The present hypothesis makes a generalization, by assuming that any functional element of a biological system is involved in a positive or a negative feedback loop. Consequently, the hypothesis holds that the starting mechanism of any disease that affects a healthy human can be conceptually reduced to a bistable or multistationary loop system, thus providing a unifying model leading to the discovery of critical therapeutic targets
Therapeutic Potential of Temperate Forage Legumes: A Review
No full textThe discovery of bioactive molecules from botanical sources is an expanding field, preferentially oriented to plants having
a tradition of use in medicine and providing high yields and availability. Temperate forage legumes are Fabaceae species
that include worldwide-important crops. These plants possess therapeutic virtues that have not only been used in
veterinary and folk medicine, but have also attracted the interest of official medicine. We have examined here Medicago
sativa (alfalfa), Trifolium pratense and T. repens (clovers), Melilotus albus and M. officinalis (sweet clovers), Lotus
corniculatus (birdsfoot trefoil), Onobrychis viciifolia (sainfoin), Lespedeza capitata (roundhead lespedeza), and Galega
officinalis (goat’s rue). The phytochemical complexes of these species contain secondary metabolites whose
pharmacological potentials deserve investigation. Major classes of compounds include alkaloids and amines, cyanogenic
glycosides, flavonoids, coumarins, condensed tannins, and saponins. Some of these phytochemicals have been related to
antihypercholesterolemia, antidiabetic, antimenopause, anti-inflammatory, antiedema, anthelmintic, and kidney protective
effects. Two widely prescribed drugs have been developed starting from temperate forage legumes, namely, the
antithrombotic warfarin, inspired from sweet clover’s coumarin, and the antidiabetic metformin, a derivative of sainfoin’s
guanidine. Available evidence suggests that temperate forage legumes are a potentially important resource for the
extraction of active principles to be used as nutraceuticals and pharmaceuticals
Wound healing properties of jojoba liquid wax: An in vitro study
No full textAim of the study: The wound healing properties of jojoba (Simmondsia chinensis) liquid wax (JLW) were studied in vitro on HaCaT keratinocytes and human dermal fibroblasts, which are involved in wounded skin repair. Materials and methods: JLW cytotoxicity was evaluated by the crystal violet staining and the neutral red uptake endpoint. Induction of wound healing by JLW was assessed by scratch wound assay on cell monolayers. The involvement of signaling pathways was evaluated by the use of the Ca2+chelator BAPTA and of kinase inhibitors, and by Western blot analysis of cell lysates using anti-phospho antibodies. Collagen and gelatinase secretion by cells were assayed by in-cell ELISA and zymography analysis, respectively. Results: Cytotoxicity assays showed that the toxic effects of JLW to these cells are extremely low. Scratch wound experiments showed that JLW notably accelerates the wound closure of both keratinocytes and fibroblasts. The use of inhibitors and Western blot revealed that the mechanism of action of JLW is strictly Ca2+dependent and requires the involvement of the PI3K-Akt-mTOR pathway and of the p38 and ERK1/2 MAPKs. In addition, JLW was found to stimulate collagen I synthesis in fibroblasts, while no effect was detected on the secretion of MMP-2 and MMP-9 gelatinases by HaCaT or fibroblasts. Conclusions: Taken together, data provide a pharmacological characterization of JLW properties on skin cells and suggest that it could be used in the treatment of wounds in clinical settings. © 2011 Elsevier Ireland Ltd
Honey in dermatology and skin care: a review
No full textHoney is a bee-derived, supersaturated solution composed mainly by fructose and glucose, and containing proteins and amino acids, vitamins, enzymes, minerals, and other minor components. Historical records of honey skin uses date back to the earliest civilizations, showing that honey has been frequently used as a binder or vehicle, but also for its therapeutic virtues. Antimicrobial properties are pivotal in dermatological applications, owing to enzymatic H2O2 release or the presence of active components, like methylglyoxal in Manuka, while medical-grade honey is also available. Honey is particularly suitable as a dressing for wounds and burns, and has also been included in treatments against pityriasis, tinea, seborrhoea, dandruff, diaper dermatitis, psoriasis, hemorroids, and anal fissure. In cosmetic formulations it exerts emollient, humectant, soothing, and hair conditioning effects, keeps the skin juvenile and retard wrinkle formation, regulates pH and prevents pathogen infections. Honey-based cosmetic products include lip ointments, cleansing milks, hydrating creams, after sun, tonic lotions, shampoos and conditioners. The used amounts range between 1-10%, but concentrations up to 70% can be reached by mixing with oils, gel and emulsifiers, or polymer entrapment. Intermediate-moisture, dried, and chemically-modified honeys are also used. Mechanisms of action on skin cells are deeply conditioned by the botanical sources, and include antioxidant activity, the induction of cytokines and matrix metalloproteinase expression, as well as epithelial-mesenchymal transition in wounded epidermis. Future achievements, throwing light on honey chemistry and pharmacological traits, will open the way to new therapeutic approaches and add considerable market value to the product
Biological activities of the legume crops Melilotus officinalis and Lespedeza capitata for skin care and pharmaceutical applications
No full textThe search for natural principles is attracting much interest in the field of skin care. Fabaceae are major
agricultural crops and potential sources of bioactive compounds with possible applications in human
health and skin care. This study concerns the biological activities of the legume crops Melilotus officinalis
(L.) Pall. and Lespedeza capitata Michx. for their potential use in skin care applications. The effects
of plant ethanolic extracts at doses ranging from 0.25 to 50 g/mL (from 1 to 5000 g/mL in cell viability
assays) were evaluated using in vitro tests on HaCaT human keratinocytes, 46BR.1N fibroblasts,
and adipocyte cell cultures, and on matrix-degrading enzymes. MTT assay revealed weak effects on cell
viability (IC50 > 1000 g/mL) and significant increase of fibroblast growth rate with both extracts. Similar
induction of cell motility by the two extracts was observed on keratinocytes, while on fibroblasts
M. officinalis induced a stronger effect with respect to L. capitata. Cell-free enzymatic assays showed
stronger collagenase inhibition by L. capitata, while an ELISA assay revealed more efficient stimulation of
fibroblast collagen production by M. officinalis. Oil-Red-O adipocyte staining showed more pronounced
lipolytic effect of M. officinalis with respect to L. capitata. Both extracts showed the ability of stimulating
skin cells in order to promote tissue regeneration, prevent skin aging, and reduce fat deposition. In
most cases, different patterns of activation/inhibition were observed. Data indicate that these legume
crops could be profitably exploited in skin care applications, possibly in combined formulations for the
development of antiaging and anticellulite products
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