Effects of diode laser application on inflammation and mpo in periodontal tissues in a rat model.

OBJECTIVE: In this study, we aimed to histologically and immunologically evaluate the effect of diode laser treatment when applied adjunctive to scaling and root planing (SRP) in an experimental periodontitis model. MATERIALS AND METHODS: We used Wistar-Albino rats (n=60) with average weight of 230 g. Experimental periodontitis was induced by ligature at the right and left first mandibular molar teeth in all rats. After 11 days, the ligature was removed and rats were divided into two groups. The control group (n=30) received only SRP treatment, while the laser group (n=30) received a diode laser (GaAlAs, 810 nm, 1 W, 10 J, 20 s) treatment adjunctive to SRP. Ten rats in each group were sacrificed after 7, 15, and 30 days. Histopathological examination was performed in the left mandible of rats. Myeloperoxidase (MPO) was evaluated by western blot in the gingival specimens from the right mandible. RESULTS: MPO levels in the laser group were statistically significantly lower compared with the control group (p≤0.05). There was no statistically significance at any time between MPO levels in the control group (p>0.05). MPO levels in the laser group at the 7th day were statistically significantly higher compared to the 15th (p≤0.05) and the 30th day (p≤0.05). Inflammatory cell infiltration decreased over time in both groups and was statistically significantly lower in the laser group than in the control group at all times (p≤0.01). CONCLUSIONS: Within the limits of this study, we suggest that diode laser application is an adjunctive treatment because it reduced inflammation and MPO when applied in addition to SRP. On the other hand, more studies are needed for the assessment of the effects of diode laser application to periodontal tissues.

[THE USE OF OZONATED SEA BUCKTHORN OIL IN THE PREVENTION AND TREATMENT OF TOBACCO DEPENDENCE PERIODONTITIS IN THE EXPERIMENT].

Therapeutic and prophylactic properties ozonated of sea buckthorn oil in the experiment on the model of generalized periodontitis in Wistar rats induced by action of extracted products of incomplete combustion of tobacco smoke was investigated. It is proved that the proposed method of ozone therapy in combination with fitooil prevents and corrects metabolic disturbances in the periodontal tissues, caused a by high therapeutic effect of the drug.

Histone deacetylase inhibitors and periodontal bone loss.

BACKGROUND AND OBJECTIVE: Bone loss caused by enhanced osteoclast activity is a significant feature of periodontitis. Histone deacetylase inhibitors (HDACi) can suppress osteoclast-mediated bone loss in vitro and in vivo. This study investigated whether HDACi can suppress bone loss in experimental periodontitis. MATERIAL AND METHODS: Experimental periodontitis was induced in mice by oral inoculation with Porphyromonas gingivalis bacteria. Mice were treated orally with olive oil alone, with olive oil and a novel compound - 1179.4b - which targets both Class I and Class II histone deacetylases (HDACs) or with olive oil and MS-275, which targets Class I HDACs. Micro-computed tomography scans of live mice, stereo imaging and histological analyses were used to detect changes in bone. RESULTS: In the absence of treatment there was a 13.2% increase in bone volume in controls compared with a 7.4% decrease in P. gingivalis-inoculated mice. 1179.4b significantly reduced bone loss, with a 3.4% increase in bone volume (p < 0.01). MS-275 did not have a significant effect on P. gingivalis-induced bone loss. Histological analysis revealed that 1179.4b reduced bone loss despite having no effect on inflammation. CONCLUSION: HDACi were found to effectively suppress bone loss in the mouse model of periodontitis. 1179.4b - the inhibitor of Class I and Class II HDACs - was more effective at suppressing bone loss than MS-275, which targets Class I HDACs only. These compounds may therefore have the potential to be used for the management of periodontitis.

[Effects of Bushenguchiwan on expression of matrix metalloproteinase-13 in rats' periodontium].

OBJECTIVE: To investigate the influence of Bushenguchiwan on expression of matrix metalloproteinase-13 (MMP-13) in periodontium of rats with experimental periodontitis. METHODS: The model of experimental periodontitis of rats was established and treated by Bushenguchiwan with different doses. The periodontal tissues from groups of different doses were immunohistochemically stained by antibody of MMP-13. The expression of MMP-13 was examined and semi-quantitative analysis of signals performed by integrated absorbance. RESULTS: MMP-13 was intensely positive in gingival epithelial cells and periodontal fibroblasts in periodontitis models and negative in normal rat periodontal tissues. After 30 days of Bushenguchiwan treatment with high dose, middle dose and low dose, the expression of MMP-13 (2.9103 ± 0.5534, 3.6588 ± 0.4330, 4.4550 ± 0.4255) was down-regulated respectively compared with model rats (5.3233 ± 0.7993), P < 0.05. After 60 days of treatment the expression of MMP-13 (2.1855 ± 0.5381, 2.8558 ± 0.4759, 3.8980 ± 0.5885) was down-regulated more significantly. with model rats (6.2693 ± 0.4538), P < 0.05. CONCLUSIONS: Bushenguchiwan could down-regulate the expression of MMP-13 in rats' periodontium and the high dose group had better effect.

Cranberry proanthocyanidins inhibit MMP production and activity.

Matrix metalloproteinases (MMPs) produced by resident and inflammatory cells in response to periodontopathogens play a major role in periodontal tissue destruction. Our aim was to investigate the effects of A-type cranberry proanthocyanidins (AC-PACs) on: (i) the production of various MMPs by human monocyte-derived macrophages stimulated with Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS), and (ii) the catalytic activity of recombinant MMP-1 and MMP-9. The effects of AC-PACs on the expression of 5 protein kinases and the activity of nuclear factor-kappa B (NF-kappaB) p65 in macrophages stimulated with LPS were also monitored. Our results indicated that AC-PACs inhibited the production of MMPs in a concentration-dependent manner. Furthermore, the catalytic activity of MMP-1 and MMP-9 was also inhibited. The inhibition of MMP production was associated with reduced phosphorylation of key intracellular kinases and the inhibition of NF-kappaB p65 activity. AC-PACs thus show potential for the development of novel host-modulating strategies to inhibit MMP-mediated tissue destruction during periodontitis.

Acid-base status and fructose diphosphatase activity in rats exposed to fluoride and induced periodontitis.

This study was conducted to evaluate acid-base status and fructose diphosphatase (FDPase) activity in 40 (4 groups of 10) male Wistar rats. One group of rats was left untreated as control, fed a standard diet, and given distilled water. Periodontitis model induced with 5 mg/kg NH4Cl (group 1), exposed to sodium fluoride (NaF) at the concentration 5 mg/l (group 2), exposed to NaF (5 mg/l) and supplemented with minerals and vitamins (group 3). At the termination of experimental period (30 days) the pH and pCO2 value of arterial blood were analysed. Then, the FDPase activity in the hemogenized heart, kidney liver, mandible, pelvis, and teeth were determined by measuring inorganic phosphate that converts from fructose-1.6-diphosphate and using spectrophotometer at 350 nm. The differences in the acid-base status and FDPase activity in the groups 1 and 2 were statistically significant in comparison with the control and group 3 (P < 0.001). Increased FDPase activities are associated with acid-base status. The minerals and vitamins supplementation proved to restore acid-base balance, reduce toxicity and establish steady enzyme activity, which has not been previously reported.

The effects of selective COX-2 inhibitor/celecoxib and omega-3 fatty acid on matrix metalloproteinases, TIMP-1, and laminin-5gamma2-chain immunolocalization in experimental periodontitis.

BACKGROUND: Matrix metalloproteinases (MMPs) play important roles in tissue-destruction mechanisms-associated periodontitis. MMP-8 and -13 are the predominant collagenases that are important in the extracellular matrix degradation in periodontal tissues. MMP-14 is a membrane-type MMP, whereas laminin-5 indicates basal membrane modification and epithelial induction. The purpose of the present study was to evaluate the effects of celecoxib and omega-3 fatty acid administration on the gingival tissue expression of MMP-8, -13, and -14, tissue inhibitor of MMP (TIMP)-1, and laminin (Ln)-5gamma2-chain in rat experimental periodontitis induced by Escherichia coli endotoxin (lipopolysaccharide [LPS]). METHODS: Experimental periodontitis was induced in rats by repeated LPS injection. Fifty-one adult male Sprague-Dawley rats were divided into six study groups: saline control, LPS, LPS + celecoxib, LPS + therapeutic omega-3 (TO3), prophylactic omega-3 + LPS + omega-3 (P+TO3), and LPS + celecoxib + omega-3 fatty acid. Celecoxib and omega-3 fatty acid were given as a single agent or as combination therapy for 14 days. On day 15, all rats were sacrificed, and gingival tissues were analyzed immunohistochemically for the expression of MMP-8, -13, and -14, TIMP-1, and Ln-5gamma2-chain. Alveolar bone loss was evaluated morphometrically under a stereomicroscope. Data were tested statistically by Kruskal-Wallis and Mann-Whitney tests and Spearman correlation analysis. RESULTS: Alveolar bone loss was significantly higher in all study groups compared to the saline control group (all P <0.01). MMP-8 expression was significantly higher in the LPS group than in the saline group (P = 0.001). Very low expression of MMP-8 was found in the celecoxib, P+TO3, and combination groups. TO3 increased TIMP-1 expression significantly compared to the LPS group (P <0.05). Individual celecoxib and P+TO3 administration increased MMP-14 significantly compared to saline control and LPS groups (P <0.05). No significant differences were found among the study groups with regard to Ln-5gamma2-chain and MMP-13 expressions (P >0.05). CONCLUSIONS: Selective cyclooxygenase-2 inhibitor, prophylactic omega-3 fatty acid, and a combination of these two agents can inhibit gingival tissue MMP-8 expression. Moreover, the individual administration of therapeutic omega-3 may increase gingival TIMP-1 expression in contrast to no effect on MMP-8, -13, and -14 expressions in experimental periodontitis. These experimental findings in a rat model of LPS-induced periodontitis need to be verified by clinical human studies.

[Activity of salivary glutathione-dependent enzymes in patients with periodontitis].

Forty-five patients aged 20-47 years who had mild, moderate, or severe periodontitis and 32 healthy individuals (a control group) were studied during 10-15-day treatment with traditional therapy and combined therapy including the traditional approach and the antihomotoxic agent Traumeel S ointment as a supplement. Increased free radical generation and lipid peroxidation were considered to play an important role in the pathogenesis of periodontitis. Salivary indices are a reflection of a patient's metabolic state and have clinical diagnostic values in patients with oral tissue inflammation. The activities of antioxidative enzymes (glutathione reductase, glutathione-S-transferase, glucose-6-phosphate dehydrogenase) and the content of reduced glutathione (GSH) were determined in the saliva of patients with periodontitis during traditional and complex (traditional + Traumeel S) therapies. Inflammation led to metabolic disturbances and antioxidative defense system imbalance in patients with periodontitis. The findings suggest that the complex therapy with Traumeel S restored antioxidative defense balance and it was more effective than the traditional therapy in patients with periodontitis. An analysis showed a direct correlation between the activity of antioxidative enzymes and clinical characteristics of the disease. These results reflect the activity of a pathological process and the imbalance of antioxidative defense in patients with periodontitis.

The effects of the initial treatment phase and of adjunctive low-dose doxycycline therapy on clinical parameters and MMP-8, MMP-9, and TIMP-1 levels in the saliva and peripheral blood of patients with chronic periodontitis.

INTRODUCTION: The treatment of periodontal disease can consist of bacterial plaque reduction, risk factor elimination, and metalloproteinase inhibitor medication. The level of matrix metalloproteinases (MMPs) are regulated by endogenous tissue inhibitors of metalloproteinases (TIMPs) as well as therapeutic low-dose doxycycline. The aim of the study was to evaluate the effect of the initial phase of periodontal treatment and the effect of doxycycline on clinical parameters and the MMP-8, MMP-9, and TIMP-1 concentrations in the saliva and peripheral blood of patients with chronic periodontitis. MATERIALS AND METHODS: The study group consisted of 33 patients with chronic periodontitis. Conventional periodontal treatment (scaling and root planing) was conducted on all the patients and doxycycline (20 mg orally) was administered twice daily for three months. Thirty-three controls received the conventional treatment only. Clinical scores (PI, BI, PD, CAL) were recorded before and three months after the treatment. MMP-8, MMP-9, and TIMP-1 concentrations in saliva and peripheral blood were measured by ELISA before and after the treatment of 20 patients from the study group and 13 of the controls. RESULTS: The application of doxycycline 20 mg resulted in significant improvement in clinical parameters compared with the conventional periodontal treatment. Doxycycline did not produce significant reductions in MMP-8 and MMP-9 levels in saliva observed after the conventional treatment. The study revealed increases in the TIMP-1 concentration and the MMP-8/TIMP-1 and MMP-9/TIMP-1 ratios in saliva and blood after treatment with doxycycline. CONCLUSIONS: The study confirmed the modulating effect of doxycycline on the host response in chronic periodontitis.

Effects of Tempol, a membrane-permeable radical scavenger, in a rodent model periodontitis.

BACKGROUND: Recent studies have demonstrated that Tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl), a cell membrane-permeable radical scavenger, exerts protective effects in various models of inflammation and shock. Reactive oxygen species (ROS) plays a pivotal role in the induction of genes involved in physiological processes as well as in the response to inflammation. AIM: We have investigated the effect of Tempol in a rat model of periodontitis. MATERIALS AND METHODS: Periodontitis was induced in rats by placing a 2/0 braided silk ligature around the lower left first molar. At day 8, the gingivomucosal tissue encircling the mandibular first molar was removed for evaluation of neutrophils infiltration, tissue permeability, nitrotyrosine formation, poly-(ADP-ribose) polymerase (PARP) activation, radiography and histology. RESULTS AND CONCLUSIONS: Legation significantly induced an increased neutrophil infiltration and a positive staining for nitrotyrosine formation and PARP activation. Ligation significantly increased Evans blue extravasation in gingivomucosal tissue and alveolar bone erosion as evaluated by radiography analysis. Intraperitonial injection of Tempol (10 mg/kg daily for 8 days) significantly decreased all of the parameters of inflammation as described above. This suggests that antioxidant therapies, which interfere with ROS, may be of benefit in the treatment of periodontitis.

Evaluation of the inhibitory effect of triphala on PMN-type matrix metalloproteinase (MMP-9).

BACKGROUND: This study evaluated the inhibitory activity of triphala on PMN-type matrix metalloproteinase (MMP-9) expressed in adult periodontitis patients and compared its activity with another ayurvedic drug, kamillosan, and doxycycline, which has known inhibitory activity. METHODS: Matrix metalloproteinases (MMPs) were extracted from gingival tissue samples from 10 patients (six males, four females) with chronic periodontitis. Tissue extracts were treated with the drug solutions, the inhibition was analyzed by gelatin zymography, and the percentage of inhibition was determined by a gel documentation system. RESULTS: The activity of MMPs was significantly decreased with the use of the drugs. Triphala showed a 76.6% reduction of MMP-9 activity, whereas kamillosan showed a 46.36% reduction at a concentration of 1,500 microg/ml (crude extract) and doxycycline showed a 58.7% reduction at a concentration of 300 microg/ml (pure drug). CONCLUSION: The present study showed the strong inhibitory activity of triphala on PMN-type MMPs involved in the extracellular matrix (ECM) degradation during periodontitis.

Effects of a vegetable extract from Lupinus albus (LU105) on the production of matrix metalloproteinases (MMP1, MMP2, MMP9) and tissue inhibitor of metalloproteinases (TIMP1, TIMP2) by human gingival fibroblasts in culture.

This study examined the effects of a vegetable extract from Lupinus albus (LU105) on MMPs and TIMPs secreted by human gingival fibroblasts in culture. LU105 was extracted from seeds of L. albus and is freely soluble in water. Gelatin zymography showed that control human gingival fibroblasts maintained in culture for 48 h express pro-MMP2 (progelatinase A) in the culture medium while the active form of MMP2 (gelatinase A), the active form of MMP9 (gelatinase B), and pro-MMP9 (progelatinase B) are not detected. Fibroblasts derived from inflamed gingiva expressed in the culture medium increased amounts of pro-MMP2 (progelatinase A) compared with controls and significant amounts of pro-MMP9 (progelatinase B). LU105 diminished the expression by gingival fibroblasts derived from inflamed tissue of both pro-MMP2 and pro-MMP9. Furthermore LU105 did not modify the amount of TIMP2 expressed in culture by controls or by gingival fibroblasts derived from inflamed tissue. TIMP1 and MMP1 significantly decreased when LU105 was added in the culture media of gingival fibroblasts derived from inflamed tissue compared with control fibroblasts. Thus LU105 seems to offer an opportunity to restore a correct balance between MMP2, MMP9, MMP1, and their natural inhibitors, i.e., TIMP1 and TIMP2 in human inflamed gingiva.

Inhibitory effect of procyanidin oligomer from elm cortex on the matrix metalloproteinases and proteases of periodontopathogens.

OBJECTIVES: The purpose of this study was to evaluate a partially purified extract (elm extract) from the Ulmi cortex (Ulmi macrocarpa Hance) and its active ingredient, a mix of procyanidin oligomers (3 to 12 flavan-3-ol monomers, an average molecular weight of 1,518 with an average polymerization degree of 5.3) for a possible inhibitory effect against proteases. BACKGROUND: Host-derived matrix metalloproteinases (MMPs) and bacterial proteases play important roles in the gingival tissue destruction that is a characteristic of periodontitis. The inhibitors of these proteases may be developed into therapeutic agents against periodontitis. METHODS: The inhibitory effects were assessed by gelatin zymography. The MMPs tested were originated from the gingival crevicular fluid (GCF) of adult periodontitis patients and from the conditioned media of cultured periodontal ligament (PDL) cells, which provided the proMMP-2 and activated MMP-2 when treated with a periodontopathogen, Treponema lecithinolyticum. Bacterial enzymes tested were secreted forms from two major periodontopathogens, Porphyromonas gingivalis and Treponema denticola. In addition, the inhibitory effects on trypsin-like enzymes from these two periodontopathogens were assayed by the n-benzoyl-DL-arginine-naphthylamide (BANA) test. RESULTS: The elm extract and the procyanidin oligomer (100-1,000 microg/ml) exhibited potent inhibitory effects on the MMPs in GCF (chiefly MMP-8 and MMP-9), the pro and active forms of MMP-2, and secreted and trypsin-like enzymes from T. denticola and P. gingivalis. CONCLUSIONS: These results suggest that elm cortex should be considered as a potential agent against periodontal diseases, due to its inhibitory action on MMPs and the proteases of periodontopathogens.

Adjunctive benefits of subantimicrobial dose doxycycline in the management of severe, generalized, chronic periodontitis.

BACKGROUND: Severe, generalized periodontitis is a form of chronic periodontitis that appears to be associated with an exaggerated host response. Little information is available on the benefits of using adjunctive host modulation in the management of this form of periodontal disease. METHODS: Thirty subjects < or = 45 years of age with severe, generalized periodontitis received subgingival debridement and oral hygiene instructions each week for 4 weeks, plus 6 months of adjunctive subantimicrobial doxycycline (SDD) or placebo. Periodontal status was monitored at baseline, and at 1, 3, 5.25, and 8.25 months following completion of the hygiene sessions. Maintenance therapy was performed at 3, 5.25, and 8.25 months for both groups. RESULTS: Ten subjects in each group completed all phases of the study. Subgingival debridement plus adjunctive SDD reduced deep pockets (> or =7 mm at baseline) by an average of 3.02 mm after 9 months versus 1.42 mm for the placebo group. A significant clinical response was seen in both groups as soon as 1 month, but the response was always clinically and statistically greater in the SDD group. In the SDD group, nearly 40% of 237 pockets > or =7 mm were reduced by > or =4 mm, and 55% were reduced by > or =3 mm. In addition, only 2 pockets deepened by > or =4 mm in the SDD group versus 10 in the placebo group. CONCLUSIONS: The supplementation of hygienist-delivered full mouth subgingival and supragingival debridement with a host-modulating agent, SDD, provides clinically and statistically significant benefits in the reduction of deep pockets in patients with severe, generalized periodontitis. In addition, adjunctive SDD is more effective than a placebo in preventing further increases in probing depth.

Effect of avocado and soybean unsaponifiables on gelatinase A (MMP-2), stromelysin 1 (MMP-3), and tissue inhibitors of matrix metalloproteinase (TIMP- 1 and TIMP-2) secretion by human fibroblasts in culture.

BACKGROUND: In inflamed periodontal tissues, gingival fibroblasts are able to express matrix metalloproteinases (MMPs) and their natural inhibitors, tissue inhibitors of matrix metalloproteinases (TIMPs). They can also respond to growth factors and cytokines. In this study, the in vitro effects of avocado and soybean unsaponifiable residues (ASU), their fractions (avocado unsaponifiable [ASF] or soy unsaponifiable [SSF]) on MMP-2 and MMP-3, and the activity and secretion of their inhibitors TIMP-1 and TIMP-2 were investigated using cultured human gingival fibroblasts. METHODS: Gingival fibroblasts were cultured for 72 hours with ASU, ASF, and SSF at concentrations of 0. 1, 0.5, 2.5, 5, and 10 microgram/ml of culture medium, after pretreatment or no pretreatment for 1 hour with interleukin-1beta (IL-1beta). MMP-2 and MMP-3 were detected and quantified in the culture media after zymography and image analysis. TIMP-1, TIMP-2, MMP-2, and MMP-3 were also evidenced by dot blotting and quantified by image analysis. RESULTS: In the absence of IL-1beta, a slight decrease in the secretion of MMP-2 was observed with lower doses of ASU, ASF, and SSF. The decrease of MMP-3 secretion was clearly marked with all fractions especially at low concentrations (0.1 and 2.5 microgram/ml). A slight decrease in TIMP-2 secretion was seen for low doses of ASU, ASF, and SSF, while a small increase was seen at higher concentrations. Concerning TIMP-1, no significant variation was observed in culture medium for low concentrations, and a decrease was noted for 5 and 10 microgram/ml of ASU, ASF, and SSF. As anticipated, IL-1beta induced a marked release of MMP-2, MMP-3, and TIMP-1, but no variation for TIMP-2 was seen. ASU, ASF, and SSF reversed the IL-1beta effect on gingival fibroblasts for MMP-2 and MMP-3, particularly with doses varying from 0.1 to 2.5 microgram/ml and for TIMP-1, particularly with doses varying from 2.5 to 10 microgram/ml. CONCLUSIONS: These findings suggest a potential role for avocado and soy unsaponifiable extracts to prevent the deleterious effects of IL-1beta that occur during periodontal diseases.

Evaluation of Periostat for patient management.

The cause of adult periodontitis involves complex bacteria-host interactions, with modifying influences exerted by genetic and environmental factors. Current thinking indicates that successful, long-term management of adult periodontitis requires a treatment approach that takes into account the various etiologic components of the disease. Recently, a formulation containing a subantimicrobial dose of doxycycline (Periostat) was approved for use as an adjunct to scaling and root planing (SRP) in the treatment of adult periodontitis. As an inhibitor of matrix metalloproteinases that have been implicated in the pathologic degradation of connective tissue collagen in periodontal support structures, Periostat in conjunction with SRP was shown to significantly improve clinical attachment and reduce probing depth compared with placebo in conjunction with SRP. This article reviews the clinical trial results leading to US Food and Drug Administration approved of Periostat and discusses the potential use of this host-modulatory agent as a complementary systemic pharmacotherapy in periodontal management programs.

[Effect of biogenic stimulators--aloe extract and biotrite--on lipid peroxidation processes in saliva in inflammatory periodontal disease]. / Vliianie biogennykh stimuliatorov--ékstrakta aloé i biotrita--na protsessy peroksidatsii lipidov v sliune pri vospalitetl'nykh zabolevaniiakh parodonta.

The influence of biostimulators of vegetative origin, such as aloes and biotritis, on the process of lipid peroxidation in parodontium tissues, was studied. Biotritis has a more considerable parodontoprotective effect than aloes.

Inhibitory effect of tea catechins on collagenase activity.

A major purpose of this study was to examine inhibitory effect of the catechin derivatives from Japanese green tea Camellia sinensis on collagenase activity. The crude tea catechins, which contain (+)-catechin (C), (-)-epicatechin (EC), (+)-gallocatechin (GC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg), and (-)-epigallocatechin gallate (EGCg), were tested for their ability to inhibit the prokaryotic and eukaryotic cell derived collagenase activities. Among the tea catechins tested, ECg and EGCg showed the most potent inhibitory effect on collagenase activity when an optimal concentration of tea catechins (100 micrograms/ml) was added to reaction mixture containing collagenase and collagen. Preincubation of collagenase with tea catechins reduced the collagenase activity as well. In contrast to ECg and EGCg, the other four tea catechins (C, EC, EGC, and GC) did not show any collagenase inhibitory effect. Our results suggest that the steric structure of 3-galloyl radical is important for the inhibition of collagenase activity. The collagenase activity in the gingival crevicular fluid from highly progressive adult periodontitis was completely inhibited by the addition of tea catechins. These results demonstrated that tea catechins containing galloyl radical possess the ability to inhibit both eukaryotic and prokaryotic cell derived collagenase.

[The effect of gu chi wan on enzyme histochemistry changes in diabetic rats with experimental periodontal disease].

This study observed the effect of Gu Chi Wan on the enzyme histochemistry changes of diabetic rats with experimental periodontal disease. The results indicate that the experimental group has not the decrease of oxidase-reductase and alkaline phosphatase as seen in control group and demonstrate the protective effect of Gu Chi Wan perhaps acts through regulating metabolism of periodontium of rats with experimental periodontal disease, and then improving the immune response of the host.