An update on possible alternative therapeutics for future periodontal disease management.

Periodontitis is an inflammatory disease caused by microbial infections of the gum. At an advanced stage, periodontitis can even destroy the alveolar bone. Fusobacterium nucleatum, Prevotella intermedia, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Capnocytophaga gingivalis, and Pr. nigrescens are the major pathogens in periodontitis. Scaling and root planning are used together with local or systemic antibiotics to treat periodontitis. The difficulty in complete eradication of periodontal pathogens frequently leads to the relapse of the disease. As not many new antibiotics are available in the market, many researchers are now focusing on developing alternative strategies against periodontal microbes. This review provides an overview of the possible use of bacteriophages, lysins, honey, plant extracts, metallic salts, nanoparticles, and vaccines as alternative therapeutic agents against periodontal infections. The information provided here could help in designing alternative therapeutics for the treatment of periodontal infections.

A new approach against Helicobacter pylori using plants and its constituents: A review study.

Helicobacter pylori is a Gram-negative, spiral-shaped bacillus that colonizes 50% of the world population and is considered a class 1 carcinogen by the World Health Organization. This pathogen is the most common cause of infection-related cancers. Apart from cancer, it also causes several gastric and extra gastric diseases. Eradication of H. pylori using antibiotics is a global challenge because of its drug resistance. Alternative treatment options are gaining more attention to tackle drug-resistant H. pylori infections. Several medicinal plants and their isolated compounds have been reported for their antimicrobial activity against H. pylori. The mechanism of action of many of these plant extracts and plant-derived compounds is different from that of conventional antibiotics. Therefore they are shown to be effective against drug-resistant strains of H. pylori. They act by inhibiting bacterial enzymes, adhesions with gastric mucosa, suppression of nuclear factor-κB and by inhibition of oxidative stress. Extracts from Pistacia lentiscus, Brassica oleracea, Glycyrrhiza glabra, Camellia sinensis, Cinnamomum cassia, Allium sativum and Nigella sativa plants and isolated phyto-compounds such as curcumin, resveratrol, quercetin, allicin and ellagic acid demonstrated antimicrobial activity against H. pylori under in vivo conditions. The plant extracts of Zingiber officinale, Glycyrrhiza glabra; and phytochemical allicin and berberine when combined with standard treatment, result in a dramatic increase in H. pylori eradication. In this review, we highlighted the therapeutic efficacy of different plant extracts and isolated phyto compounds against H. pylori infection and described their role in tackling H. pylori resistance to antibiotics.

Development of Mangifera indica leaf extract incorporated carbopol hydrogel and its antibacterial efficacy against Staphylococcus aureus.

Staphylococcus aureus is a major pathogen causing skin infections and currently treated with topical antibiotic preparations like bacitracin, triple antibiotic ointment (neomycin, polymixin B, and bacitracin), gentamicin or mupirocin. However, their efficacies are restricted when the infections are caused by drug resistant strains. There is an imperative need for new antibacterial compounds for the management of S. aureus topical infections. Maginfera indica (mango) is reported for its antibacterial efficacy in many traditional plant based medicines. In this study we tested the antibacterial efficacy of the methanol extract of mango leaf against SA113 and S. aureus clinical strains. Mango leaf extract (MLE) was found to be an effective anti-staphylococcal agent, non-mutagenic, and contains phytochemicals such as tannins, saponins, flavanoids, phenols, and coumarins. Further, the mango leaf extract (from stock MLE concentration of 130 mg/ml) containing carbopol hydrogel (MLEC) was prepared and characterized further for biocompatibility, rheological and anti-staphylococcal activities. The antibacterial activity of MLEC hydrogel against S. aureus strains was verified using in vitro and ex vivo porcine skin model. Our results demonstrated MLEC hydrogel formulation may act as superior alternative to currently available topical antiseptic/antibiotic formulations for the treatment of drug resistant staphylococcal infections.

Fucoidan coated ciprofloxacin loaded chitosan nanoparticles for the treatment of intracellular and biofilm infections of Salmonella.

Salmonella infections and their gallstone associated biofilm infections are difficult to treat due to poor penetration of antibiotics into the intracellular compartments of macrophages and within biofilms. Here we developed ciprofloxacin loaded chitosan nanoparticles (cCNPs) and fucoidan (Fu) coated cCNPs (Fu-cCNPs). Characterizations of these nanoparticles were carried out using Dynamic Light Scattering , Transmission electron microscopy and Fourier transform infrared spectroscopy. The prepared cCNPs and Fu-cCNPs have the size range of 124±7nm and 320±18nm, respectively. Both nanoparticles were found to be non-hemolytic and cytocompatible. In vitro sustained release of ciprofloxacin was observed from both cCNPs and Fu-cCNPs over a period of 2 weeks. The antimicrobial activity of cCNPs and Fu-cCNPs was tested under in vitro and in vivo conditions. The intracellular anti-Salmonella activity of Fu-cCNPs was 2 fold higher than cCNPs and 6 fold higher than ciprofloxacin alone. Fluorescence microscopic images confirmed enhanced delivery of Fu-cCNPs than the cCNPs within the intracellular compartment of macrophages. Both cCNPs and Fu-cCNPs are found to be equally effective in dispersing Salmonella Paratyphi A gallstone biofilms. The in vivo antibacterial activities of Fu-cCNPs were superior to cCNPs which we have validated using Salmonella Paratyphi A infected Drosophila melanogaster fly model. Our overall results showed that (1) Fu-cCNPs are more effective in eradicating Salmonella infections than cCNPs; (2) both cCNPs and Fu-cCNPs were equally effective in dispersing Salmonella gallstone biofilms.

Antibiotic resistance in Pseudomonas aeruginosa and alternative therapeutic options.

Pseudomonas aeruginosa is a leading cause of nosocomial infections and is responsible for ∼10% of all hospital-acquired infections worldwide. It continues to pose a therapeutic challenge because of the high rate of morbidity and mortality associated with it and the possibility of development of drug resistance during therapy. Standard antibiotic regimes against P. aeruginosa are increasingly becoming ineffective due to the rise in drug resistance. With the scope for developing new antibiotics being limited, alternative treatment options are gaining more and more attention. A number of recent studies reported complementary and alternative treatment options to combat P. aeruginosa infections. Quorum sensing inhibitors, phages, probiotics, anti-microbial peptides, vaccine antigens and antimicrobial nanoparticles have the potential to act against drug resistant strains. Unfortunately, most studies considering alternative treatment options are still confined in the pre-clinical stages, although some of these findings have tremendous potential to be turned into valuable therapeutics. This review is intended to raise awareness of several novel approaches that can be considered further for combating drug resistant P. aeruginosa infections.

Comparative efficacy of chloramphenicol loaded chondroitin sulfate and dextran sulfate nanoparticles to treat intracellular Salmonella infections.

Salmonella Paratyphi A is a food-borne Gram-negative pathogen and a major public health challenge in the developing world. Upon reaching the intestine, S. Paratyphi A penetrates the intestinal epithelial barrier; and infects phagocytes such as macrophages and dendritic cells. S. Paratyphi A surviving within macrophages is protected from the lethal action of antibiotics due to their poor penetration into the intracellular compartments. Hence we have developed chloramphenicol loaded chondroitin sulfate (CS-Cm Nps) and dextran sulfate (DS-Cm Nps) nanoparticles through ionotropic-gelation method for the intracellular delivery of chloramphenicol. The size of these nanoparticles ranged between 100 and 200 nm in diameter. The encapsulation efficiency of both the nanoparticles was found to be around 65%. Both the nanoparticles are found to be non-hemolytic and non-toxic to fibroblast and epithelial cells. The prepared nanoparticles exhibited sustained release of the drug of up to 40% at pH 5 and 20-25% at pH 7.0 after 168 h. The anti-microbial activities of both nanoparticles were tested under in vitro and ex vivo conditions. The delivery of DS-Cm Nps into the intracellular compartments of the macrophages was 4 fold more compared to the CS-Cm Nps which lead to the enhanced intracellular antimicrobial activity of Ds-Cm Nps. Enhanced anti-microbial activity of Ds-Cm Nps was further confirmed in an ex vivo chicken intestine infection model. Our results showed that Cm loaded DS Nps can be used to treat intracellular Salmonella infections.

Evaluation of antibacterial activity and cytocompatibility of ciprofloxacin loaded gelatin-hydroxyapatite scaffolds as a local drug delivery system for osteomyelitis treatment.

Surgical debridement of the dead bone and subsequent systemic antibiotic therapy is often ineffective in eliminating Staphylococcus aureus infections in osteomyelitic patients. The recurrence of S. aureus infection is mainly due to the intracellular growth of bacterial colonies within osteoblast cells that protect the organism from extracellular host defences and/or antibiotic therapy. In this study, porous gelatin-hydroxyapatite (HAP) scaffolds with various amounts of ciprofloxacin (1, 2, 5, and 10 wt%) were fabricated by freeze-drying technique and the release of the antibiotic was characterized, as was the efficacy of the released antibiotic against methicillin-sensitive and methicillin-resistant S. aureus. Furthermore, the impact of the released antibiotic on the viability and osteogenic differentiation of human adipose-derived mesenchymal stem cells (ADMSCs) cultured on the scaffolds were assessed. Finally, the efficacy of the released ciprofloxacin to enter the cells and abate intracellularly located S. aureus was evaluated. All the groups of CGHA scaffolds displayed sustained release of ciprofloxacin against S. aureus for 60 days above the minimum inhibitory concentration for the target species with zero-order kinetics and Korsmeyer-Peppas models. While comparing, the released antibiotic from CGHA5 scaffolds was found to be effective at reducing S. aureus through the study period, without detrimental effects on human ADMSC viability or osteogenic potential. When stem cells internalized with S. aureus were cultured onto the drug-loaded scaffolds, a significant reduction in the colony count of internalized bacteria was observed, resulting in the osteogenic differentiation capability of those cells. Our results clearly demonstrate that the ciprofloxacin incorporated gelatin-HAP scaffolds, which were cytocompatible and could target both intracellular and extracellular S. aureus, defining its potential to be used as local drug delivery system.

Antimicrobial drugs encapsulated in fibrin nanoparticles for treating microbial infested wounds.

PURPOSE: In vitro evaluation of antibacterial and antifungal drugs encapsulated fibrin nanoparticles to prove their potential prospect of using these nanocomponent for effective treatment of microbial infested wounds. METHODS: Surfactant-free oil-in-water emulsification-diffusion method was adopted to encapsulate 1 mg/ml each of antimicrobial drugs (Ciprofloxacin and Fluconazole) in 4 ml of aqueous fibrinogen suspension and subsequent thrombin mediated cross linking to synthesize drug loaded fibrin nanoparticles. RESULTS: Ciprofloxacin loaded fibrin nanoparticles (CFNPs) showed size range of 253 ± 6 nm whereas that of Fluconazole loaded fibrin nanoparticles (FFNPs) was 260 ± 10 nm. Physico chemical characterizations revealed the firm integration of antimicrobial drugs within fibrin nanoparticles. Drug release studies performed at physiological pH 7.4 showed a release of 16% ciprofloxacin and 8% of fluconazole while as the release of ciprofloxacin at alkaline pH 8.5, was 48% and that of fluconazole was 37%. The antimicrobial activity evaluations of both drug loaded systems independently showed good antibacterial activity against Escherichia coli (E.coli), Staphylococcus aureus (S. aureus) and antifungal activity against Candida albicans (C. albicans). The in vitro toxicity of the prepared drug loaded nanoparticles were further analyzed using Human dermal fibroblast cells (HDF) and showed adequate cell viability. CONCLUSION: The efficacies of both CFNPs and FFNPs for sustained delivery of encapsulated anti microbial drugs were evaluated in vitro suggesting its potential use for treating microbial infested wounds (diabetic foot ulcer).