Allantoin may modulate aging impairments, symptoms and cancers.

Allantoin increases in different stress conditions and environment such as physical activity, amniotic fluids and oxidative stress. So, we inspired to explore the role of allantoin as a metabolic by-product in health improvement and protection using irradiation as simulator for oxidative stress. Allantoin was injected i.p. (100 mg/kg) in senile male rats in irradiated and non-irradiated groups in comparison to sham operated group. The studied parameters were superoxide dismutase, Glutathione reductase, Glutathione, total antioxidant capacity, collagenase, urea, creatine kinase, alanine transaminase, aspartate aminotransferase, triglycerides, total cholesterol, and HDL and LDL cholesterol. Allantoin in vitro antitumor activity was MTT assayed for some age dependent cancers. Allantoin showed improvement in all in vivo studied oxidative stress parameters. Allantoin showed an increase in lipogenesis was recorded as a hepatic energy targeting muscles. Allantoin improves aging process indicated by its collagenase inhibitory effect. Allantoin showed cytotoxicity against prostate, colon, intestinal ovarian and breast cancers and weak inhibitory against larynx cancer. Allantoin may be the possible mysterious key factor involved in health and aging improvement and cancer protection in stress conditions such as physically activity and radiation hazards.

Herbal Infusions as a Valuable Functional Food.

Herbal infusions are an underestimated and easy to intake a source of biologically active natural compounds (polyphenols), which, in the dissolved form, are more easily absorbed. Therefore, this study aimed to assess the potential of herbal infusions as a functional food to reduce postprandial hyperglycemia (inhibition of α-amylase and α-glucosidase) and to reduce the effects of increased blood glucose level (antioxidant effect-DPPH, CUPRAC, and Fe2+ chelating assays, as well as anti-inflammatory activity-inhibition of collagenase). We showed that polyphenols are present in the examined aqueous herbal infusions (including chlorogenic and gallic acids). Subsequently, our research has shown that herbal infusions containing cinnamon bark, mulberry leaves, and blackberry fruits most strongly inhibit glucose release from complex carbohydrates, and that all herbal infusions can, to different degrees, reduce the effects of elevated blood sugar. In conclusion, infusions prepared from herbal blends could be recommended to prevent type II diabetes.

The role of statins in the differentiation and function of bone cells.

BACKGROUND: Statins are 3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors blocking cholesterol biosynthesis in hepatic cells, thereby causing an increase in low-density lipoprotein (LDL) receptors resulting in enhanced uptake and clearance of atherogenic LDL-cholesterol (LDL-C) from the blood. Accordingly, statins decrease the risk of developing atherosclerosis and its acute complications, such as acute myocardial infarction and ischaemic stroke. Besides the LDL-C-lowering impact, statins also have other so-called pleiotropic effects. Among them, the ability to modulate differentiation and function of bone cells and exert direct effects on osteosynthesis factors. Specifically, earlier studies have shown that statins cause in vitro and in vivo osteogenic differentiation. DESIGN: The most relevant papers on the bone-related 'pleiotropic' effects of statins were selected following literature search in databases and were reveiwed. RESULTS: Statins increase the expression of many mediators involved in bone metabolism including bone morphogenetic protein-2 (BMP-2), glucocorticoids, transforming growth factor-beta (TGF-ß), alkaline phosphatase (ALP), type I collagen and collagenase-1. As a result, they enhance bone formation and improve bone mineral density by modulating osteoblast and osteoclast differentiation. CONCLUSION: This review summarizes the literature exploring bone-related 'pleiotropic' effects of statins and suggests an anabolic role in the bone tissue for this drug class. Accordingly, current knowledge encourages further clinical trials to assess the therapeutic potential of statins in the treatment of bone disorders, such as arthritis and osteoporosis.

Inhibitory activity of Podospermum canum and its active components on collagenase, elastase and hyaluronidase enzymes.

Present study is aimed to investigate in vitro inhibitory effects of the extract prepared from the aerial parts of Podospermum canum (syn: Scorzonera cana var. jacquiniana) (Asteraceae) on hyaluronidase, collagenase, and elastase enzymes using a bioassay-guided fractionation. Inhibitory effects of the extract, sub-extracts, fractions obtained by column chromatography, and isolated compounds on collagenase, elastase, and hyaluronidase were performed by using in vitro enzyme inhibitory assays based on spectrophotometric evaluation. The methanolic extract obtained from P. canum exhibited strong inhibitory activities on elastase and collagenase while the insignificant activity was observed on hyaluronidase. Through bioactivity-guided fractionation, the ethyl acetate and remaining water sub-extracts obtained from the methanolic extract displayed significant inhibitory activities on collagenase and elastase, while petroleum ether and chloroform extracts did not show any inhibitory activity. Eleven known compounds: arbutin, 6́-O-caffeoylarbutin, cichoriin, 3,5-dicaffeoylquinic acid methyl ester, apigenin 7-O-ß-glucoside, luteolin 7-O-ß-glucoside, apigenin 7-O-ß-rutinoside, isoorientin, orientin, vitexin, procatechuic acid, and new compound 4-hydroxy-benzoic acid 4-(6-O-α-rhamnopyranosyl-ß-glucopyranosyl) benzyl ester have been obtained from ethyl acetate sub-extract. Results of the present study have revealed that apigenin 7-O-ß-glucoside, luteolin 7-O-ß-glucoside, apigenin 7-O-ß-rutinoside, and isoorientin showed potent enzyme inhibitory activities. However, methanolic extract of P. canum displayed a greater inhibitory activity than fractions and isolated compounds both on collagenase and elastase.

Absolute Configuration of Mycosporine-Like Amino Acids, Their Wound Healing Properties and In Vitro Anti-Aging Effects.

Mycosporine-like amino acids (MAAs) are water-soluble metabolites, reported to exhibit strong UV-absorbing properties. They have been found in a wide range of marine organisms, especially those that are exposed to extreme levels of sunlight, to protect them against solar radiation. In the present study, the absolute configuration of 14 mycosporine-like-amino acids was determined by combining the results of electronic circular dichroism (ECD) experiments and that of advanced Marfey's method using LC-MS. The crystal structure of a shinorine hydrate was determined from single crystal X-ray diffraction data and its absolute configuration was established from anomalous-dispersion effects. Furthermore, the anti-aging and wound-healing properties of these metabolites were evaluated in three different assays namely the inhibition of collagenase, inhibition of advanced glycation end products (AGEs) and wound healing assay (scratch assay).

Thai plants with high antioxidant levels, free radical scavenging activity, anti-tyrosinase and anti-collagenase activity.

BACKGROUND: Ultraviolet radiation from sunlight induces overproduction of reactive oxygen species (ROS) resulting in skin photoaging and hyperpigmentation disorders. Novel whitening and anti-wrinkle compounds from natural products have recently become of increasing interest. The purpose of this study was to find products that reduce ROS in 14 Thai plant extracts. METHODS: To determine total phenolic and flavonoid content, antioxidant activity, anti-tyrosinase activity and anti-collagenase activity, we compared extracts of 14 Thai plants prepared using different solvents (petroleum ether, dichloromethane and ethanol). Antioxidant activities were determined by DPPH and ABTS assays. RESULTS: Total phenolic content of the 14 Thai plants extracts was found at the highest levels in ethanol followed by dichloromethane and petroleum ether extracts, respectively, while flavonoid content was normally found in the dichloromethane fraction. Scavenging activity ranged from 7 to 99% scavenging as assessed by DPPH and ABTS assays. The ethanol leaf extract of Ardisia elliptica Thunb. had the highest phenolic content, antioxidant activity and collagenase inhibition, while Cassia alata (L.) Roxb. extract had the richest flavonoid content. Interestingly, three plants extracts, which were the ethanolic fractions of Annona squamosa L., Ardisia elliptica Thunb. and Senna alata (L.) Roxb., had high antioxidant content and activity, and significantly inhibited both tyrosinase and collagenase. CONCLUSION: Our finding show that the ethanol fractions of Annona squamosa L., Ardisia elliptica Thunb. and Senna alata (L.) Roxb. show promise as potential ingredients for cosmetic products such as anti-wrinkle agents and skin whitening products.

Discovery of a Potent Inhibitor Class with High Selectivity toward Clostridial Collagenases.

Secreted virulence factors like bacterial collagenases are conceptually attractive targets for fighting microbial infections. However, previous attempts to develop potent compounds against these metalloproteases failed to achieve selectivity against human matrix metalloproteinases (MMPs). Using a surface plasmon resonance-based screening complemented with enzyme inhibition assays, we discovered an N-aryl mercaptoacetamide-based inhibitor scaffold that showed sub-micromolar affinities toward collagenase H (ColH) from the human pathogen Clostridium histolyticum. Moreover, these inhibitors also efficiently blocked the homologous bacterial collagenases, ColG from C. histolyticum, ColT from C. tetani, and ColQ1 from the Bacillus cereus strain Q1, while showing negligible activity toward human MMPs-1, -2, -3, -7, -8, and -14. The most active compound displayed a more than 1000-fold selectivity over human MMPs. This selectivity can be rationalized by the crystal structure of ColH with this compound, revealing a distinct non-primed binding mode to the active site. The non-primed binding mode presented here paves the way for the development of selective broad-spectrum bacterial collagenase inhibitors with potential therapeutic application in humans.

Inhibition of Shedding of Low-Density Lipoprotein Receptor-Related Protein 1 Reverses Cartilage Matrix Degradation in Osteoarthritis.

OBJECTIVE: The aggrecanase ADAMTS-5 and the collagenase matrix metalloproteinase 13 (MMP-13) are constitutively secreted by chondrocytes in normal cartilage, but rapidly endocytosed via the cell surface endocytic receptor low-density lipoprotein receptor-related protein 1 (LRP-1) and subsequently degraded. This endocytic system is impaired in osteoarthritic (OA) cartilage due to increased ectodomain shedding of LRP-1. The aim of this study was to identify the LRP-1 sheddase(s) in human cartilage and to test whether inhibition of LRP-1 shedding prevents cartilage degradation in OA. METHODS: Cell-associated LRP-1 and soluble LRP-1 (sLRP-1) released from human cartilage explants and chondrocytes were measured by Western blot analysis. LRP-1 sheddases were identified by proteinase inhibitor profiling and gene silencing with small interfering RNAs. Specific monoclonal antibodies were used to selectively inhibit the sheddases. Degradation of aggrecan and collagen in human OA cartilage was measured by Western blot analysis using an antibody against an aggrecan neoepitope and a hydroxyproline assay, respectively. RESULTS: Shedding of LRP-1 was increased in OA cartilage compared with normal tissue. Shed sLRP-1 bound to ADAMTS-5 and MMP-13 and prevented their endocytosis without interfering with their proteolytic activities. Two membrane-bound metalloproteinases, ADAM-17 and MMP-14, were identified as the LRP-1 sheddases in cartilage. Inhibition of their activities restored the endocytic capacity of chondrocytes and reduced degradation of aggrecan and collagen in OA cartilage. CONCLUSION: Shedding of LRP-1 is a key link to OA progression. Local inhibition of LRP-1 sheddase activities of ADAM-17 and MMP-14 is a unique way to reverse matrix degradation in OA cartilage and could be effective as a therapeutic approach.

In Vitro Chondroprotective Potential of Extracts Obtained from Various Phyllantus Species.

Phyllanthus amarus has been proven to exhibit chondroprotection. Regarding the morphological similarities among Phyllanthus species, we were attracted to evaluate the chondroprotective potential of Phyllanthus species including P. amarus obtained from Chiang Mai and Phuket, Phyllanthus urinaria L., Phyllanthus urinaria subsp. chamaepeuce, Phyllanthus debilis, and Phyllanthus airy-shawii using interleukin-1ß-induced degradation of cartilage explants. The ethanolic extracts of the plants were evaluated for major lignans, phyllanthin, and hypophyllanthin by HPLC and further measurements of the total contents of flavonoids and phenolic compounds along with the assays for antioxidant and anti-collagenase activities. The interleukin-1ß-induced cartilage explant degradation was performed with/without the extracts at concentrations of 50-250 µg/mL. After 4-14 days of incubation, the medium was assayed for the level of sulfated glycosaminoglycans while the explants were measured for the remaining content of uronic acid. Proteoglycan intensity in the explants was determined by safranin O staining. Diacerein, the antiarthritic agent, was used as the positive control. Although the two major lignans were found in P. amarus from Chiang Mai, P. amarus from Phuket, and P. urinaria L. extracts, similar chondroprotective activities were observed in all Phyllanthus extracts. Total phenolic content and total flavonoid content of the extracts showed a correlation with antioxidation, whereas the total phenolic content correlated with anti-collagenase activity. Among the six extracts, P. airy-shawii showed the greatest antioxidant and collagenase inhibitory activities. The results revealed that chondroprotective activities of all of the extracts of Phyllanthus species might result from an additive or synergistic influence of some constituents of these plants, which could be considered for antiarthritic purposes.

Discovery of N-(4-Fluoro-3-methoxybenzyl)-6-(2-(((2S,5R)-5-(hydroxymethyl)-1,4-dioxan-2-yl)methyl)-2H-tetrazol-5-yl)-2-methylpyrimidine-4-carboxamide. A Highly Selective and Orally Bioavailable Matrix Metalloproteinase-13 Inhibitor for the Potential Treatment of Osteoarthritis.

Matrix metalloproteinase-13 (MMP-13) is a zinc-dependent protease responsible for the cleavage of type II collagen, the major structural protein of articular cartilage. Degradation of this cartilage matrix leads to the development of osteoarthritis. We previously have described highly potent and selective carboxylic acid containing MMP-13 inhibitors; however, nephrotoxicity in preclinical toxicology species precluded development. The accumulation of compound in the kidneys mediated by human organic anion transporter 3 (hOAT3) was hypothesized as a contributing factor for the finding. Herein we report our efforts to optimize the MMP-13 potency and pharmacokinetic properties of non-carboxylic acid leads resulting in the identification of compound 43a lacking the previously observed preclinical toxicology at comparable exposures.

Effect of phosphoric acid on the degradation of human dentin matrix.

This study determined if dentin proteases are denatured by phosphoric acid (PA) used in etch-and-rinse dentin adhesives. Dentin beams were completely demineralized with EDTA for 30 days. We "acid-etched" experimental groups by exposing the demineralized dentin beams to 1, 10, or 37 mass% PA for 15 sec or 15 min. Control beams were not exposed to PA but were incubated in simulated body fluid for 3 days to assay their total endogenous telopeptidase activity, by their ability to solubilize C-terminal crosslinked telopeptides ICTP and CTX from insoluble dentin collagen. Control beams released 6.1 ± 0.8 ng ICTP and 0.6 ± 0.1 ng CTX/mg dry-wt/3 days. Positive control beams pre-incubated in p-aminophenylmercuric acetate, a compound known to activate proMMPs, released about the same amount of ICTP peptides, but released significantly less CTX. Beams immersed in 1, 10, or 37 mass% PA for 15 sec or 15 min released amounts of ICTP and CTX similar to that released by the controls (p > 0.05). Beams incubated in galardin, an MMP inhibitor, or E-64, a cathepsin inhibitor, blocked most of the release of ICTP and CTX, respectively. It is concluded that PA does not denature endogenous MMP and cathepsin activities of dentin matrices.

Tratamento de queimadura de segundo grau superficial em face e pescoço com heparina tópica: estudo comparativo, prospectivo e randomizado / Treatment of superficial second degree burn of face and neck with topical heparin: a comparative, prospective and randomized study

INTRODUÇÃO: Novas opções terapêuticas para o tratamento de lesões térmicas são constantemente buscadas, especialmente se reduzirem tempo de cicatrização e dor, sem aumentar as taxas de infecção das queimaduras. Estudos recentes sugerem que o uso tópico de heparina pode alcançar esses objetivos. Este estudo tem o objetivo de avaliar tempo de epitelização, dor e taxa de infecção, comparando o uso de heparina tópica ao uso de colagenase no tratamento de queimadura de segundo grau superficial de face e pescoço. MÉTODO: No total, 20 pacientes foram randomizados em dois grupos: grupo tratado com heparina sódica e grupo tratado com colagenase (controle). Os critérios de exclusão foram: história de sangramento, discrasia sanguínea, alergias ao produto, úlcera péptica ativa e queimadura há mais de 24 horas. O teste de Mann-Whitney foi utilizado para avaliar os resultados. A dor foi avaliada pela necessidade do uso de analgésicos opioides. RESULTADOS: A heparina não foi efetiva em diminuir o tempo de epitelização ou o uso de opioides, e a taxa de infecção não apresentou diferença estatística entre os grupos. CONCLUSÕES: A heparina pode ser usada com segurança no tratamento de queimadura de segundo grau superficial em face e pescoço, mas seus efeitos benéficos ainda precisam ser comprovados.

BACKGROUND: New treatment options for thermal injuries are very desirable, especially if they reduce healing time and pain without increase of infection rates. Recent studies suggest that heparin topical use can achieve those goals. This study has the objective to evaluate healing time, pain and infection rate comparing topical use of heparin and collagenase in the treatment of superficial second degree burns of face and neck. METHODS: Twenty patients were randomized into 2 groups: group treated with topical heparin and group treated with collagenase (control group). The exclusion criteria were: history of bleeding, blood discrasia, allergies to the product, active peptic ulcer and burns with more than 24 hours. Mann-Whitney test was applied to evaluate the results. The pain was measured by the use of opioid analgesics. RESULTS: The heparin was not effective in decrease of healing time nor the use of opioids, and the infection rate didn't present significant difference between the groups. CONCLUSIONS: The heparin can be used safely in treatment of superficial second degree burn of face and neck, but its beneficial effects need to be proven.

The effects of tacrolimus on colonic anastomotic healing in rats.

AIM: The aim of this experimental study is to investigate the effects of tacrolimus on colonic anastomotic healing after subcutaneous administration. MATERIALS AND METHODS: Forty Albino-Wistar male rats were divided into two groups, with two equal subgroups each. They all underwent colonic resection followed by a single-layer, inverted colon anastomosis and were injected subcutaneously with either 1 ml of 0.9% NaCl solution or tacrolimus (0.1 mg/kg body weight) depending on their group. Half of the rats were sacrificed on the fourth postoperative day, while the remaining half were sacrificed on the eighth postoperative day. Macroscopical and histological assessment was performed, while anastomotic bursting pressures and the tissue concentrations in hydroxyproline and collagenase I were evaluated. RESULTS: On the fourth postoperative day, the bursting pressures (217.00 ± 11.12, p < 0.001), the fibroblast activity (2.80 ± 0.42, p = 0.022), the neoangiogenesis (2.10 ± 0.32, p = 0.007) and the tissue hydroxyproline concentration (254.23 ± 67.10, p = 0.001) were significantly higher in the tacrolimus-treated animals. Furthermore, tacrolimus significantly decreased the inflammatory cell infiltration (1.50 ± 0.53, p < 0.001) and the tissue collagenase I concentration (4.16 ± 0.76, p = 0.002). On the eighth day, the bursting pressure (264.00 ± 32.61, p < 0.001) and the hydroxyproline tissue concentration (331.04 ± 55.56, p = 0.002) were significantly higher in the tacrolimus subgroups. The inflammatory cell infiltration (1.20 ± 0.42, p < 0.001) and the collagenase I concentration (1.61 ± 0.83, p < 0.001) were significantly lower. In addition, the adhesion formation score was significantly lower (1.20 ± 0.92, p = 0.065). CONCLUSION: Tacrolimus, when injected subcutaneously, promotes healing of colonic anastomoses in rats. It impairs not only inflammatory response but also collagen degradation, resulting to increased anastomotic strength on the fourth as well as on the eighth postoperative day.

The effects of iloprost on colonic anastomotic healing in rats.

PURPOSE: The purpose of this experimental study is to investigate the effects of iloprost on colonic anastomotic healing in rats, after intraperitoneal administration. METHODS: Forty male Albino-Wistar rats were randomized into two groups of twenty animals each. They all underwent colonic resection followed by an inverted anastomosis. The rats of Group A (control) received 3 ml of NaCl intraperitoneally, while those of Group B (iloprost) received iloprost (2 µg/kg body weight), immediately postoperatively and daily until killed. Each group was further divided into two equal subgroups, depending on the day of killing. The animals of subgroups 1 were killed on the fourth postoperative day, while those of subgroups 2 on the eighth. Macroscopical and histological assessments were performed. Besides, anastomotic bursting pressures and the tissue concentrations in hydroxyproline and collagenase I were also evaluated. RESULTS: No anastomotic dehiscence was noted. The mean bursting pressure was higher in the iloprost group compared with the control group, but a significant difference was revealed only on the fourth postoperative day. Furthermore, iloprost significantly increased the new vessel formation on the fourth, as well as on the eighth postoperative day. CONCLUSION: Iloprost enhances the early phase of colonic anastomotic healing in rats.

Sublethal doses of surfactants induce premature senescence in normal human skin cells.

We evaluated the cytotoxicity of surfactants in human cells. Synthetic surfactants showed different cytotoxicity levels depending on their structures. The cytotoxicity of commercial washing products was determined mainly by the contents of surfactants. All of them induced premature senescence in normal cells, but not in tumor-derived or immortalized cells, under sublethal conditions. Residual surfactants might be a risk factor for skin aging.

Irbic acid, a dicaffeoylquinic acid derivative from Centella asiatica cell cultures.

3,5-O-dicaffeoyl-4-O-malonilquinic acid (1) (irbic acid) has been isolated for the first time from cell cultures of Centella asiatica and till now it has never been reported to be present in the intact plant. Evidence of its structure was obtained by spectroscopic analyses (MS/NMR). Besides 1, cell cultures produce also the known 3,5-O-dicaffeoylquinic acid, chlorogenic acid, and the triferulic acid 2 (4-O-8'/4'-O-8″-didehydrotriferulic acid). Biological activities were evaluated for compound 1, which showed to have a strong radical scavenging capacity, together with a high inhibitory activity on collagenase. This suggests a possible utilization of this substance as a topical agent to reduce the skin ageing process.

Effect of lanthanides on Porphyromonas gingivalis proteases.

Host and bacterial proteases play a vital role in periodontitis. Inhibitors of these proteases are necessary for control of this disease. The purpose of this study was to evaluate the effect of lanthanides on proteins from Porphyromonas gingivalis, a major pathogen in periodontitis. Benzoyl-L-Arg-p-nitroanilide (BAPNA); H-Gly-Pro-pNA x HCl and gelatin were used to evaluate the activity of P. gingivalis proteins in the presence of lanthanides. Proteins extracted from cell surfaces and culture media of P. gingivalis were assessed for activity in the presence of different lanthanides by BAPNA assay. Only gadolinium chloride was used for H-Gly-Pro-pNA x HCl assay and gelatin-zymography. Concentration-dependent reduction of absorbance was observed in the presence of lanthanides with BAPNA and a similar observation was made with gadolinium chloride using H-Gly-Pro-pNa. Collagenolytic activity in cell surface extracts and culture media-precipitated proteins was absent in the presence of gadolinium chloride. These results suggest that the lanthanide gadolinium can be a potential inhibitor of P. gingivalis proteases.

Effect of smoking, abstention, and nicotine patch on epidermal healing and collagenase in skin transudate.

Delayed wound healing may explain postoperative tissue and wound dehiscence in smokers, but the effects of smoking and smoking cessation on the cellular mechanisms remain unclear. Suction blisters were raised in 48 smokers and 30 never smokers. The fluid was retrieved and the epidermal roof was excised. Transepidermal water loss (TEWL) was measured after 2, 4, and 7 days. Then, the smokers were randomized to continuous smoking or abstinence with a transdermal nicotine patch or a placebo by concealed allocation. The sequence was repeated after 4, 8, and 12 weeks in all smokers and abstainers and in 6 never smokers. Matrix metalloproteinase (MMP)-8 and MMP-1 levels in suction blister fluid were assessed by an enzyme-linked immunosorbent assay. Random-effects models for repeated measurements were applied and p< or =0.05 was considered significant. One week after wounding the TEWL was 17.20 (14.47-19.92) g/cm(2) hour (mean, 95% CI) in smokers and 13.89 (9.46-18.33) in never smokers (p<0.01). In abstinent smokers TEWL was 18.95 (15.20-22.70)(p<0.01, when compared with smokers). In smokers, MMP-8 was 36.4 (24.3-48.5) ng/mL (mean, 95% CI) and 15.2 (1.4-30.2) ng/mL in never smokers (p<0.01). Abstinent smokers' MMP-8 level was 21.2 ng/mL (6.6-43.0) (p=0.02, when compared with smokers). MMP-1 was unaffected by smoking and abstention. Transdermal nicotine patch did not affect any parameter. We conclude that smoking attenuates epidermal healing and may enhance extracellular matrix degradation. Three months of abstinence from smoking does not restore epidermal healing, whereas 4 weeks of abstinence normalizes suction blister MMP-8 levels. These findings suggest sustained impaired wound healing in smokers and potential reversibility of extracellular matrix degradation.

Subantimicrobial-dose doxycycline modulates gingival crevicular fluid biomarkers of periodontitis in postmenopausal osteopenic women.

BACKGROUND: We recently demonstrated that a 2-year subantimicrobial-dose doxycycline (SDD) regimen (double-masked, placebo-controlled clinical trial) in postmenopausal (PM) women exhibiting mild systemic bone loss (osteopenia) and local bone loss (periodontitis) reduced the progression of periodontal attachment loss (intent-to-treat analysis) and the severity of gingival inflammation and alveolar bone loss (subgroups) without producing antibiotic side effects. We now describe SDD effects on biomarkers of collagen degradation and bone resorption in the gingival crevicular fluid (GCF) of the same vulnerable subjects. METHODS: GCF was collected from SDD- and placebo-treated PM subjects (n=64 each) at the baseline and 1- and 2-year appointments; the volume was determined; and the samples were analyzed for collagenase activity (using a synthetic peptide as substrate), relative levels of three genetically distinct collagenases (Western blot), a type-1 collagen breakdown product/bone resorption marker (a carboxyterminal telopeptide cross-link fragment of type I collagen [ICTP]; radioimmunoassay), and interleukin-1beta (enzyme-linked immunosorbent assay). Statistical analyses were performed using generalized estimating equations; primary analyses were intent-to-treat. RESULTS: Collagenase activity was significantly reduced by SDD treatment relative to placebo based on intent-to-treat (P=0.01). ICTP showed a similar pattern of change during SDD treatment, and GCF collagenase activity and ICTP were positively correlated at all time periods (P<0.001). Matrix metalloproteinase (MMP)-8 accounted for approximately 80% of total collagenase in GCF, with much less MMP-1 and -13, and SDD reduced the odds of elevated MMP-8 by 60% compared to placebo (P=0.006). CONCLUSION: These observations support the therapeutic potential of long-term SDD therapy to reduce periodontal collagen breakdown and alveolar bone resorption in PM women; effects on serum biomarkers of systemic bone loss in these subjects are being analyzed.

Nitric oxide enhances aggrecan degradation by aggrecanase in response to TNF-alpha but not IL-1beta treatment at a post-transcriptional level in bovine cartilage explants.

OBJECTIVE: The objective of this study was to determine the role of nitric oxide (NO) in tumor necrosis factor alpha (TNF-alpha)-induced matrix damage, compared to interleukin 1 beta (IL-1beta), in bovine cartilage explant cultures. METHODS: Cartilage explants were subjected to treatment with TNF-alpha (100ng/ml), IL-1beta (10 ng/ml) and to the nitric oxide synthase inhibitor, N-methyl-arginine (L-NMA; 1.25 mM) for 26, 50 or 120 h (5 days). The collected medium was analyzed for sulfated glycosaminoglycan (sGAG), nitrate and nitrite, matrix metalloproteinase (MMP) activity by zymography, and aggrecan degradation by immunoblotting of aggrecan-G1 and aggrecan-G1-NITEGE fragments. RNA was extracted from the 26 and 50 h treated explants for real time quantitative PCR analyses. RESULTS: TNF-alpha and IL-1beta treatment caused a 3-5 fold increase in sGAG release with an increase in aggrecanase-specific aggrecan breakdown and an increase in nitrate and nitrite production. L-NMA treatment inhibited almost 50% of the sGAG release caused by TNF-alpha treatment, with concomitant decrease in the aggrecanase-specific-NITEGE neo-epitope of aggrecan released into the medium. No L-NMA effect was identified with IL-1beta. TNF-alpha and IL-1beta both increased a disintegrin and matrix metalloproteinase with thrombospondin motif (ADAMTS)4 and ADAMTS5 transcription with no effect by L-NMA, suggesting that NO regulates aggrecanase activity at a post-transcriptional level in response to TNF-alpha. TNF-alpha and IL-1beta both caused an increase in protease transcription (MMP-3, MMP-13, ADAMTS4 and ADAMTS5) and in pro-inflammatory enzymes, inducible nitric oxide synthase and cyclooxygenase (COX)-2, as well as a decrease in matrix protein transcription, including collagen II, aggrecan, fibromodulin and link protein (IL-1beta only), and an increase in MMP-3 and MMP-9 secretion. L-NMA had no effect on gene transcription or MMP secretion. CONCLUSION: NO regulates aggrecanase activity at a post-transcriptional level in response to TNF-alpha treatment while having no effect on IL-1beta treated cartilage explants.