Potentiating cutaneous wound healing in young and aged skin with nutraceutical collagen peptides.

BACKGROUND: Chronic wounds continue to be a burden to healthcare systems, with ageing linked to increased prevalence of chronic wound development. Nutraceutical collagen peptides have been shown to reduce signs of skin ageing, but their therapeutic potential for cutaneous wound healing remains undefined. AIM: To determine the potential for nutraceutical collagen peptides to promote cutaneous wound healing in vitro in the context of age. METHODS: The potential for bovine- or porcine-derived nutraceutical collagen peptides to promote wound healing of primary cutaneous fibroblasts and keratinocytes derived from young and aged individuals in vitro was assessed by two-dimensional scratch and cell-viability assays and by immunofluorescence for the cell proliferation marker, Ki67. The achievement of peptide concentrations in vivo, equivalent to those exerting a beneficial effect on wound healing in vitro, was confirmed by pharmacokinetic studies of hydroxyproline, a biomarker for collagen peptide absorption, following peptide ingestion by healthy individuals over a wide age range. RESULTS: Results demonstrated significant nutraceutical collagen peptide-induced wound closure of both young and aged fibroblasts and keratinocytes, mediated by enhanced cellular proliferation and migration. Analysis of blood levels of hydroxyproline in young and aged individuals following porcine collagen peptide ingestion revealed peak serum/plasma levels after 2 h at similar concentrations to those exerting beneficial effects on wound healing in vitro. CONCLUSION: These data demonstrate the capacity for nutraceutical collagen peptides to promote cutaneous wound closure in vitro, at pharmacologically achievable concentrations in vivo, thereby offering a potential novel therapeutic strategy for the management of cutaneous wounds in young and aged individuals.

Microbiota and their role in the pathogenesis of oral mucositis.

Oral mucositis in patients undergoing cancer therapy is a significant problem. Its prevalence ranges between 20 and 100%, depending on treatment type and protocols and patient-based variables. Mucositis is self-limiting when uncomplicated by infection. Unfortunately, the incidence of developing a local or systemic infection during the course of the treatment is very high. At this stage, it is unclear which role oral microbiota play in the onset, duration, and severity of oral mucositis. Nevertheless, there is growing interest in this underexplored topic, and new studies are being undertaken to unravel their impact on the pathogenesis of mucositis.

Development of in vitro models for investigating spatially fractionated irradiation: physics and biological results.

We present different in vitro experimental models which allow us to evaluate the effect of spatially fractionated dose distributions on metabolic activity. We irradiated a monolayer of MCF-7/6 human breast cancer cells with a steep and a smooth 6 MV x-ray dose gradient. In the steep gradient model, we irradiated the cells with three separate small fields. We also developed two smooth gradient models. In the first model, the cells are cultured in a T25 flask and irradiated with a smooth dose gradient over the length of the flask, while in the second one, the cells are cultured in a 96-well plate and also irradiated over the length of the plate. In an attempt to correlate the spatially fractionated dose distributions with metabolic activity, the effect of irradiation was evaluated by means of the MTT assay. This assay is used to determine the metabolic activity by measuring the amount of formazan formed after the conversion of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) by cellular dehydrogenases. The results obtained with our different models suggest a dose-specific effect on metabolic activity, characterized by an increased formazan optical density occurring in the dose range 1.0-4.0 Gy in the steep dose gradient model and in the dose ranges 4.2-6.5 Gy and 2.3-5.1 Gy in the two smooth dose gradient models. The corresponding times for maximal formazan accumulation were 5-7 days in the steep dose gradient model and day 9-13 and day 9-11 in the smooth dose gradient models. Altogether, our results suggest that the MTT assay may be used as a biological dose-response meter to monitor the radiotherapeutic effectiveness.

Plant polyphenolics as anti-invasive cancer agents.

Because invasion is, either directly or via metastasis formation, the main cause of death in cancer patients, development of efficient anti-invasive agents is an important research challenge. We have established a screening program for potentially anti-invasive compounds. The assay is based on organotypic confronting cultures between human invasive cancer cells and a fragment of normal tissue in three dimensions. Anti-invasive agents appeared to be heterogeneous with regard to their chemical nature, but plant alkaloids, polyphenolics and some of their synthetic congeners were well represented. Even within this group, active compounds were quite diverse: (+)-catechin, tangeretin, xanthohumol and other prenylated chalcones, 3,7-dimethoxyflavone, a pyrazole derivative, an isoxazolylcoumarin and a prenylated desoxybenzoin. The data gathered in this system are now applied in two projects. Firstly, structure-activity relationships are explored with computer models using an artificial neural network approach, based on quantitative structural descriptors. The aim of this study is the prediction and design of optimally efficient anti-invasive compounds. Secondly, the metabolism of orally ingested plant polyphenolics by colonic bacteria is studied in a simulator of the human intestinal microbial ecosystem (SHIME) and in human intervention trials. This method should provide information on the final bioavailability of the active compounds in the human body, with regard to microbial metabolism, and the feasibility of designing pre- or probiotics that increase the generation of active principles for absorption in the gastro-intestinal tract. The final and global aim of all these studies is to predict, synthesize and apply in vivo molecules with an optimal anti-invasive, and hence an anti-metastatic activity against cancer.

Deguelin inhibits expression of IkappaBalpha protein and induces apoptosis of B-CLL cells in vitro.

We investigated if deguelin, a naturally occurring rotenoid, was able to inhibit nuclear factor kappa B (NF-kappaB)-binding protein (IkappaBalpha) expression and to induce apoptosis in B-cell chronic lymphocytic leukemia (B-CLL) cells in vitro. Deguelin-induced cell death in the majority of B-CLL cells and was found to be more toxic toward B-CLL cells than to the normal mononuclear or B-cells, suggesting selectivity towards the malignant cells. Deguelin was found to reduce IkappaBalpha protein expression, and thus interacts with the NFkappaB pathway. The induced apoptosis was characterized by processing of caspase-9 and -3 and poly-(ADP)-ribose-polymerase cleavage. Exposure of B-CLL cells to deguelin resulted in Bcl2-associated protein (Bax) conformational changes and downregulation of the key survival protein myeloid cell leukemia sequence 1 (Mcl-1), which is associated with response to treatment in B-CLL patients. Deguelin retained its ability to induce apoptosis in B-CLL cells in the presence of interleukin-4, a pro-survival cytokine in B-CLL, and when cultured with 50% human serum. These data indicate that deguelin is able to induce apoptosis in B-CLL cells in the presence of pro-survival signals and thus merits further investigation for clinical application either as a single agent or in combination with other anticancer agents.

Tibolone and its metabolites inhibit invasion of human mammary carcinoma cells in vitro.

UNLABELLED: Tibolone is used in postmenopausal women to alleviate menopausal symptoms and to prevent osteoporosis, but it does not stimulate the endometrium and the breast. Up to date, little data are available on the effect of tibolone on breast cancer initiation and progression. OBJECTIVE: In the present in vitro study, we investigated the effect of tibolone and its metabolites (3alpha-OH tibolone, 3beta-OH tibolone, the Delta4 isomer and the sulphated isoform) on invasion of human breast cancer cells. METHODS: The effect on invasion was evaluated in the chick heart invasion assay using MCF-7/6 cells and in the collagen type I invasion assay using T47-D cells. Furthermore, the compounds were tested in aggregation and migration assays. RESULTS: We observed that, at a concentration of 100 microM, tibolone and its 3beta-OH metabolite possess anti-invasive activities in the two different invasion assays. However, this was neither due to effects on cell-cell adhesion nor on motility. In an attempt to probe the mechanism underlying the anti-invasive effect, we found that pro-MMP-9 release was markedly reduced in the supernatant of MCF-7/6 breast cancer cells treated with tibolone, 3alpha-OH tibolone and the Delta4 isomer but, interestingly, not with the sulphated metabolite. CONCLUSION: We conclude that tibolone and its 3beta-OH metabolite have an anti-invasive effect on the tested breast cancer cell lines in vitro. This effect on invasion is not correlated with an effect on cell-cell adhesion or motility but coincides with a decreased release of pro-MMP-9 in the medium.