Oral microbiota in cancer: could the bad guy turn good with application of polyphenols?

The human oral cavity is comprised of dynamic and polynomial microbes which uniquely reside in the microenvironments of oral cavities. The cumulative functions of the symbiotic microbial communities maintain normal homeostasis; however, a shifted microbiota yields a dysbiosis state, which produces local and systemic diseases including dental caries, periodontitis, cancer, obesity and diabetes. Recent research reports claim that an association occurs between oral dysbiosis and the progression of different types of cancers including oral, gastric and pancreatic ones. Different mechanisms are proposed for the development of cancer, such as induction of inflammatory reactions, production of carcinogenic materials and alteration of the immune system. Medications are available to treat these associated diseases; however, the current strategies may further worsen the disease by unwanted side effects. Natural-derived polyphenol molecules significantly inhibit a wide range of systemic diseases with fewer side effects. In this review, we have displayed the functions of the oral microbes and we have extended the report regarding the role of polyphenols in oral microbiota to maintain healthy conditions and prevention of diseases with emphasis on the treatment of oral microbiota-associated cancer.

Transdermal Delivery of Curcumin-Loaded Solid Lipid Nanoparticles as Microneedle Patch: an In Vitro and In Vivo Study.

Curcumin is well known for its neuroprotective effect, and also able to alleviate Parkinsonian features. Clinical application of curcumin is limited due to its low bioavailability. Hence, we hypothesized that the microneedles (MN) containing drug-loaded solid lipid nanoparticles (SLNs) may be able to improve its bioavailability and efficacy. The SLNs were prepared with microemulsion technique using glyceryl monostearate as a lipid and tween 80 as a stabilizer. The particle size, polydispersity index, zeta potential, and entrapment efficiency of prepared SLNs were determined. The optimized formulation was incorporated into microneedle arrays using micromolding technique and fabricated microneedle patch were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, optical microscopy, ex vivo permeation studies, histology studies, and fluorescent microscopy. The fabricated microneedle patch was also evaluated for neuroprotective activity and skin irritation potential. Fourier transform infrared spectroscopy studies of SLNs and microneedles confirmed the chemical compatibility of excipients with curcumin. The developed microneedles were also found to be non-irritant with decreased degree of bradykinesia, high motor coordination, and balance ability. The study provided a theoretical basis for the use of novel microneedle containing curcumin-loaded solid lipid nanoparticles as a useful tool for the treatment of Parkinson's disease.

Systematic review: Effectiveness of herbal oral care products on ventilator-associated pneumonia.

Ventilator-associated pneumonia (VAP) resulting from bacterial infection is a prevalent medical problem in intensive care units (ICUs). The purpose of this study was to systematically review available studies on oral products employed to control and reduce VAP in patients undergoing tracheal intubation. This study was based on a systematic review of clinical trial data from science databases such as PubMed, Cochrane, Scopus, and Web of science. Articles were reviewed and selected according to defined criteria and assessed by the primary evaluation checklist. After a critical review of 3,143 search hits, only 18 relevant articles were finally selected for discussion. Our assessment revealed that chlorhexidine and some other oral herbal medications are beneficial in preventing VAP. Chlorhexidine oral dosage forms provide a remarkable role in oral health and prevention of VAP by decreasing the microbial flora in the mouth. Because of similar benefits and comparable effects, some herbal medicines can be suggested as a practical alternative to chlorhexidine.

Neuroprotective effects of methyl-3-O-methyl gallate against sodium fluoride-induced oxidative stress in the brain of rats.

Methyl-3-O-methyl gallate (M3OMG) is a rare natural product that showed promising in vitro antioxidant activities. In this study, the protective role of synthetic M3OMG against sodium fluoride (NaF)-induced oxidative stress in rat brain was evaluated. Animals were treated with either M3OMG (10 and 20 mg/kg i.p.), vitamin C (10 mg/kg i.p.) as the standard antioxidant or the vehicle (5 % dimethyl sulfoxide; 1 ml/kg) for 1 week. Oxidative stress was induced in the brain by adding 600 ppm NaF in the drinking water for 7 days. At the end of the treatment period, the levels of thiobarbituric acid reactive substances (TBARS), reduced glutathione and the activities of antioxidant enzymes (superoxide dismutase and catalase) were evaluated in brain homogenates. M3OMG treatment mitigated the NaF-induced oxidative stress through normalization of the level of TBARS, reduced levels of glutathione and by the restoration of the diminished antioxidant enzyme activities. In conclusion, M3OMG could have a potential for treating neurotoxicity induced by fluoride or related environmental pollutants.

Protective effect of gallic acid isolated from Peltiphyllum peltatum against sodium fluoride-induced oxidative stress in rat's kidney.

In the present study, the nephroprotective effect of gallic acid isolated from Peltiphyllum peltatum was examined in sodium fluoride (NaF) treated rats. Nephrotoxicity was induced by 1-week intoxication of NaF at 600 ppm through drinking water. The levels of thiobarbituric acid reactive substances, reduced glutathione as well as activities of superoxide dismutase and catalase in renal tissues homogenates were determined. The serum biochemical markers of renal injuries including creatinine, serum urea, blood urea nitrogen, uric acid levels as well as the levels of phosphate and calcium were also assessed. Intoxication with NaF caused a significant increase in the levels of thiobarbituric acid reactive substances (46 % versus to control) and reduced the glutathione concentration (47 %) and the activities of superoxide dismutase (46 %) and catalase (41 %) in renal tissues homogenates. NaF intoxication also induced significant alterations in the kidney biochemical markers increasing the levels of urea, uric acid, blood urea nitrogen, creatinine, and phosphate and decreasing the levels of calcium. Daily administration of gallic acid (20 mg/kg) for 1 week before NaF intoxication brought the antioxidant-oxidant balance similar to the NaF-untreated group. Silymarin, used a standard antioxidant agent, also showed a nephroprotective activity. We concluded that NaF caused nephrotoxicity and oxidative stress in renal tissues and daily administration of gallic acid for 1 week prior to intoxication inhibited toxicity and oxidative stress.

DihydrofolateReductase (DHFR) Inhibitors: A Comprehensive Review.

BACKGROUND: Dihydrofolate reductase (DHFR) is an indispensable enzyme required for the survival of most prokaryotic and eukaryotic cells as it is involved in the biosynthesis of essential cellular components. DHFR has attracted a lot of attention as a molecular target for various diseases like cancer, bacterial infection, malaria, tuberculosis, dental caries, trypanosomiasis, leishmaniasis, fungal infection, influenza, Buruli ulcer, and respiratory illness. Various teams of researchers have reported different DHFR inhibitors to explore their therapeutic efficacy. Despite all the progress made, there is a strong need to find more novel leading structures, which may be used as better and safe DHFR inhibitors, especially against the microorganisms which are resistant to the developed drug candidates. OBJECTIVE: This review aims to pay attention to recent development, particularly made in the past two decades and published in this field, and pay particular attention to promising DHFR inhibitors. Hence, an attempt has been made in this article to highlight the structure of dihydrofolate reductase, the mechanism of action of DHFR inhibitors, most recently reported DHFR inhibitors, diverse pharmacological applications of DHFR inhibitors, reported in-silico study data and recent patents based on DHFR inhibitors to comprehensively portray the current scenery for researchers interested in designing novel DHFR inhibitors. CONCLUSION: A critical review of recent studies revealed that most novel DHFR inhibitor compounds either synthetically or naturally derived are characterized by the presence of heterocyclic moieties in their structure. Non-classical antifolates like trimethoprim, pyrimethamine, and proguanil are considered excellent templates to design novel DHFR inhibitors, and most of them have substituted 2,4-diamino pyrimidine motifs. Targeting DHFR has massive potential to be investigated for newer therapeutic possibilities to treat various diseases of clinical importance.

Ameliorative effects of quercetin on sodium fluoride-induced oxidative stress in rat's kidney.

OBJECTIVE: The in vivo nephroprotective effect of quercetin against sodium fluoride (NaF)-induced damage was studied. METHODS: Renal injury was induced by daily administration of NaF (600 ppm) through drinking water for 1 week. The levels of reduced glutathione (GSH), lipid peroxidation as well as superoxide dismutase and catalase activity of kidney homogenates were determined. The serum markers of glomerular damage, including creatinine, serum urea, and blood urea nitrogen levels, were also assessed. RESULTS: The study revealed that administration of fluoride resulted in a significant downregulation of antioxidant defenses coupled with an increased serum level of glomerular damage markers. The administration of quercetin prior to fluoride reversed the antioxidant-oxidant balance to control (fluoride-untreated) level. The level of protection obtained for the 20 mg/kg quercetin treatment was equivalent to the positive control, ascorbic acid (10 mg/kg). The therapeutic implication of antioxidants in fluoride-induced nephrotoxicity is discussed. CONCLUSIONS: This study showed that NaF intoxication caused renal damage by increasing oxidative stress, and quercetin and vitamin C administration gave protection against fluoride-induced oxidative stress to some degree.

Cytoprotective effects of curcumin on sodium fluoride-induced intoxication in rat erythrocytes.

Curcumin is well known for its potent antioxidant activity. The result of numerous studies showed that antioxidants can protect against fluoride-induced toxicity. In the present study, protective effects of curcumin against sodium fluoride-induced toxicity in rat erythrocytes were evaluated. Curcumin (10 and 20 mg/kg) and vitamin C (10 mg/kg) were administrated intraperitoneally for 1 week followed by sodium fluoride (600 ppm) treatment for next week. Erythrocytes were isolated and superoxide dismutase and catalase activities as well as the levels of reduced glutathione, and lipid peroxidation were measured. The level of malondialdehyde in sodium fluoride treated rats (595.13 ± 20.23 nmol/g Hb) increased compared to the normal rats (315.44 ± 9.76 nmol/g Hb). Animals which were pretreated with curcumin at 20 mg/kg for 1 week prior to sodium fluoride intoxication showed significant reduction in the malondialdehyde level (320.22 ± 9.28 nmol/g Hb). Also, pretreated with curcumin (20 mg/kg) and vitamin C restored the superoxide dismutase and catalase activities and modified the level of reduced glutathione compared with control group (p > 0.01).

Protective role of gallic acid on sodium fluoride induced oxidative stress in rat brain.

Gallic acid is known as a potent antioxidant active compound of the edible and medicinal plant Peltiphyllum peltatum. The main objective of this study was to evaluate the neuroprotective effects of gallic acid against sodium fluoride induced oxidative stress in rat brain. Gallic acid (10 and 20 mg/kg) and vitamin C (10 mg/kg) were intraperitoneally administrated for 1 week prior to sodium fluoride intoxication. After the treatment period, brain tissues were collected and homogenized, and antioxidant parameters were measured in the homogenates. The level of thiobarbituric acid reactive substances in sodium fluoride intoxicated rats (42.04 ± 2.14 nmol MDA eq/g tissue, p < 0.01 vs. normal) increased compared to the normal rats (35.99 ± 1.08 nmol MDA eq/g tissue). Pretreatment with gallic acid at 20 mg/kg was exhibited significant reduction in the thiobarbituric acid reactive substances level (37.06 ± 1.4 nmol MDA eq/g tissue, p > 0.05 vs. normal). This increasing in thiobarbituric acid reactive substances level was accompanied with a decrease in the level of reduced glutathione (6.74 ± 0.28 µg/mg of protein, p < 0.001 vs. normal), superoxide dismutase (53.24 ± 1.62 U/mg of protein, p < 0.001 vs. normal) and catalase (70.73 ± 2.94 µmol/min/mg of protein p < 0.001 vs. normal) activities in sodium fluoride intoxicated rat. Gallic acid at 20 mg/kg was significantly modified the level of reduced glutathione (11.02 ± 0.53 µg/mg of protein, p < 0.05 vs normal) and catalase activity (89.22 ± 3.67 µmol/min/mg of protein, p > 0.05 vs. normal) in rat brain. However, gallic acid at 20 mg/kg was significantly more effective in retrieving superoxide dismutase (124.78 ± 5.7 U/mg of protein) activity than vitamin C (115.5 ± 4.97 U/mg of protein).

Mitigating role of quercetin against sodium fluoride-induced oxidative stress in the rat brain.

CONTEXT: Quercetin is a well known aglycone flavonoid that is widely found in different food sources. OBJECTIVE: In this study, the in vivo neuroprotective potential of quercetin against sodium fluoride-induced oxidative stress was evaluated. MATERIALS AND METHODS: Wistar rats were divided into five treatment groups and then subjected to daily intraperitoneally treatment with quercetin (at 10 and 20 mg/kg body weight), vitamin C (at 10 mg/kg), or vehicle. After a 1 week treatment period, all groups except saline treated (normal group), were intoxicated with sodium fluoride (NaF) for 1 week. Rat brains were then removed and homogenized for measurement of antioxidant markers including superoxide dismutase (SOD), reduced glutathione, catalase, and lipid peroxidation final products. RESULTS: The thiobarbituric acid reactive substances (TBARS) levels in the heart homogenate of sodium fluoride treated rats (42.04 ± 2.14 nmol MDA eq/g tissue) increased compared to the normal rats (35.99 ± 1.08 nmol MDA eq/g tissue). Animals which were pretreated with quercetin at 20 mg/kg for 1 week prior to sodium fluoride intoxication showed significant reduction in the TBARS level (36.13 ± 1.12 nmol MDA eq/g tissue). Also, pretreatment with quercetin (20 mg/kg) restored the SOD and catalase activities and modified the level of reduced glutathione compared with the control group (p > 0.05). DISCUSSION AND CONCLUSION: The present study revealed a potent neuroprotective potential of quercetin against NaF-induced toxicity.

In vivo protective effects of gallic acid isolated from Peltiphyllum peltatum against sodium fluoride-induced oxidative stress in rat erythrocytes.

Gallic acid has been identified as an antioxidant component of the edible and medicinal plant Peltiphyllum peltatum. The present study examined its potential protective role against sodium fluoride (NaF)-induced oxidative stress in rat erythrocytes. Oxidative stress was induced by NaF administration through drinking water (1030.675 mg m(-3) for one week). Gallic acid at 10 mg kg(-1) and 20 mg kg(-1) and vitamin C for positive controls (10 mg kg(-1)) were administered daily intraperitoneally for one week prior to NaF administration. Thiobarbituric acid reactive substances, antioxidant enzyme activities (superoxide dismutase and catalase), and the level of reduced glutathione were evaluated in rat erythrocytes. Lipid peroxidation in NaF-exposed rats significantly increased (by 88.8%) when compared to the control group (p<0.05). Pre-treatment with gallic acid suppressed lipid peroxidation in erythrocytes in a dose-dependent manner. Catalase and superoxide dismutase enzyme activities and glutathione levels were reduced by NaF intoxication by 54.4%, 63.69%, and 42% (p<0.001; vs. untreated control group), respectively. Pre-treatment with gallic acid or vitamin C significantly attenuated the deleterious effects. Gallic acid isolated from Peltiphyllum peltatum and vitamin C mitigated the NaF-induced oxidative stress in rat erythrocytes.

Prophylactic effects of methyl-3-O-methyl gallate against sodium fluoride-induced oxidative stress in erythrocytes in vivo.

OBJECTIVES: The purpose of this study was to demonstrate the effect of methyl-3-O-methyl gallate (M3OMG), a rare polyphenolic natural product with a potent in-vitro antioxidant effect, against sodium fluoride (NaF)-induced oxidative stress in rat erythrocytes in vivo. METHODS: Male Wistar rats were treated daily with either M3OMG (10 and 20 mg/kg) obtained through synthesis, vitamin C (10 mg/kg) or vehicle intraperitoneally for 7 days. Oxidative stress was then induced by exposing animals to NaF (600 ppm) through drinking water for 7 days. At the end of intoxication period, rats were killed and erythrocytes isolated. The activity of antioxidant enzymes (catalase and superoxide dismutase) and levels of reduced glutathione and thiobarbituric acid reactive substances were measured in erythrocyte haemolysates. RESULTS: NaF intoxication resulted in a 1.9-fold increase in erythrocyte lipid peroxidation associated with significant (P < 0.001) depletion of reduced glutathione level. Superoxide dismutase and catalase activity was suppressed by NaF treatment by 3.069 and 2.3 fold when compared with untreated control groups. Pretreatment of rats with M3OMG or vitamin C afforded protection against NaF-induced oxidative stress as assessed through the measured oxidant/antioxidant markers. CONCLUSION: This finding provided in-vivo evidence for the therapeutic potential of M3OMG in combating fluoride-induced oxidative damage in cellular systems.

Protective effect of quercetin against sodium fluoride induced oxidative stress in rat's heart.

The antioxidative and cardioprotective properties of quercetin were investigated against sodium fluoride (NaF) induced oxidative stress in rat hearts. Experimental rats were divided into five groups. The first group served as the untreated (normal) control. The second group received NaF at a dose of 600 ppm through drinking water for 1 week, and served as the toxin control. The third and fourth groups were exposed to quercetin (at the dose of 10 and 20 mg kg(-1) intraperitoneally (i.p.) for 1 week) prior to NaF intoxication, and the fifth group was treated with vitamin C at a dose of 10 mg kg(-1) i.p., for 1 week prior to NaF intoxication and served as the positive control in the study. The activities of various antioxidant enzymes, superoxide dismutase and catalase, level of reduced glutathione and lipid peroxidation end product were determined in the cardiac tissues of all the experimental animals. NaF intoxication significantly altered all the indices related to the pro-oxidant-antioxidant status of the heart; treatment with the active constituents prior to NaF administration, however, prevented these alterations. The combined results suggest that quercetin protects rat hearts from NaF-induced oxidative stress, probably via its antioxidant properties.

Protective effects of curcumin against sodium fluoride-induced toxicity in rat kidneys.

In the present study, the protective effect of curcumin against sodium fluoride-induced nephrotoxicity was evaluated in rats. Renal injury was induced by daily administration of 600 ppm sodium fluoride in drinking water for 1 week. One week before the administration of fluoride, the animals selected as study group were given curcumin (10 and 20 mg/kg body weight, intraperitoneally). After 1 week, lipid peroxidation level, activities of superoxide dismutase, catalase, and level of glutathione in kidney homogenate were measured. Blood serum samples were examined for creatinine, serum urea, and blood urea nitrogen levels. Another group of rats received vitamin C (10 mg/kg) as standard antioxidant. The results show that curcumin and vitamin C treatment prior to fluoride administration normalized the levels of serum creatinine, serum urea, and blood urea nitrogen. Moreover, curcumin and vitamin C administrations prevented the antioxidant enzyme decreasing and lipid peroxidation levels imbalance. In conclusion, curcumin treatment at the doses of 10 and 20 mg/kg (intraperitoneally) showed significant nephroprotective effects.