ABSTRACT
Xanthorrhizol (XTZ), isolated from Curcuma xanthorrhiza, has potent antifungal and antibacterial activity. It shows very strong activity against Gram-positive bacteria, such as Streptococcus mutans and Staphylococcus aureus, but is generally not active against Gram-negative bacteria. In this study, we explored the possibility of using a combination strategy for expanding the antimicrobial spectrum of XTZ against Gram-negative bacteria. To take advantage of XTZ being a food-grade material, 10 food-grade or generally recognized as safe (GRAS) antimicrobial compounds with low toxicities were selected for combination therapy. In addition, polymyxin B nonapeptide (PMBN), which is less toxic than polymyxin B, was also selected as an outer membrane permeabilizer. The antibacterial activity of various double or triple combinations with or without XTZ were assayed in vitro against four Gram-negative bacterial species (Escherichia coli, Salmonella enterica serovar Typhi, Salmonella enterica serovar Typhimurium, and Vibrio cholerae), with synergistic combinations exhibiting clear activity subjected to further screening. The combinations with the greatest synergism were XTZ + PMBN + nisin, XTZ + PMBN + carvacrol, and XTZ + PMBN + thymol. These combinations also showed potent antimicrobial activity against Shigella spp., Yersinia enterocolitica, and Acinetobacter baumannii. In time-kill assays, the three combinations achieved complete killing of E. coli within 2 h, and S. Typhi and V. cholera within 15 min. This is the first report on expanding the activity spectrum of XTZ against Gram-negative bacteria through combination with PMBN and food-grade or GRAS substances, with the resulting findings being particularly useful for increasing the industrial and medical applications of XTZ.
Subject(s)
Anti-Bacterial Agents/pharmacology , Gram-Negative Bacteria/drug effects , Monoterpenes/pharmacology , Nisin/pharmacology , Phenols/pharmacology , Polymyxin B/analogs & derivatives , Acinetobacter baumannii/drug effects , Curcuma/metabolism , Cymenes , Drug Combinations , Drug Synergism , Escherichia coli/drug effects , Microbial Sensitivity Tests , Polymyxin B/pharmacology , Salmonella typhi/drug effects , Salmonella typhimurium/drug effects , Vibrio cholerae/drug effects , Yersinia enterocolitica/drug effectsABSTRACT
Periodontitis, an inflammatory disease of the gingival tissue, triggered by microbial-derived elements, such as lipopolysaccharide (LPS), collapses the periodontal tissues and resorbs the alveolar bone. This study evaluated the inhibitory effects of standardized Boesenbergia pandurata extract (BPE) and panduratin A (PAN) on periodontitis-induced inflammation and alveolar bone loss. Sprague-Dawley rats with LPS-induced periodontitis were orally administered BPE (50 and 200 mg/kg/day) and PAN (20 mg/kg/day) for 8 days. Histological analysis revealed that BPE- and PAN-administered groups showed decreased cell infiltration and alveolar bone resorption. Furthermore, the BPE and PAN significantly alleviated the mRNA and protein expression levels of nuclear factor kappa B (NF-κB), interleukin-1ß, matrix metalloproteinase (MMP)-2, and MMP-8. BPE and PAN also inhibited the expression of nuclear factor of activated T cells, cytoplasmic 1, c-Fos, and ostoclastogenesis-related enzymes, including cathepsin K and tartrate-resistant acid phosphatase (ALP). BPE and PAN not only upregulated the osteoblastogenesis-associated markers, such as collagen type I (COL1A1) and ALP, but also increased the ratio of osteoprotegerin to receptor activator of NF-κB ligand. Collectively, BPE and PAN efficiently prevent destruction of periodontal tissues and stimulating the loss of alveolar bone tissues, strongly indicative of their potential as natural antiperiodontitis agents.
Subject(s)
Alveolar Bone Loss/drug therapy , Chalcones/administration & dosage , Periodontal Diseases/drug therapy , Plant Extracts/administration & dosage , Zingiberaceae/chemistry , Alveolar Bone Loss/chemically induced , Alveolar Bone Loss/immunology , Animals , Chalcones/chemistry , Collagen Type I/genetics , Collagen Type I/immunology , Humans , Interleukin-1beta/genetics , Interleukin-1beta/immunology , Lipopolysaccharides/adverse effects , Male , Matrix Metalloproteinase 2/genetics , Matrix Metalloproteinase 2/immunology , NF-kappa B/genetics , NF-kappa B/immunology , Osteoprotegerin/genetics , Osteoprotegerin/immunology , Periodontal Diseases/chemically induced , Periodontal Diseases/immunology , Plant Extracts/chemistry , Rats , Rats, Sprague-DawleyABSTRACT
Periodontitis is an inflammatory disease caused by microbial lipopolysaccharide (LPS), destroying gingival tissues and alveolar bone in the periodontium. In the present study, we evaluated the anti-inflammatory and anti-osteoclastic effects of panduratin A, a chalcone compound isolated from Boesenbergia pandurata, in human gingival fibroblast-1 (HGF-1) and RAW 264.7 cells. Treatment of panduratin A to LPS-stimulated HGF-1 significantly reduced the expression of interleukin-1ß and nuclear factor-kappa B (NF-κB), subsequently leading to the inhibition of matrix metalloproteinase-2 (MMP-2) and MMP-8 compared with that in the LPS control (**p < 0.01). These anti-inflammatory responses were mediated by suppressing the mitogen-activated protein kinase (MAPK) signaling and activator protein-1 complex formation pathways. Moreover, receptor activator of NF-κB ligand (RANKL)-stimulated RAW 264.7 cells treated with panduratin A showed significant inhibition of osteoclastic transcription factors such as nuclear factor of activated T-cells c1 and c-Fos as well as osteoclastic enzymes such as tartrate-resistant acid phosphatase and cathepsin K compared with those in the RANKL control (**p < 0.01). Similar to HGF-1, panduratin A suppressed osteoclastogenesis by controlling MAPK signaling pathways. Taken together, these results suggest that panduratin A could be a potential candidate for development as a natural anti-periodontitis agent.
Subject(s)
Chalcones/antagonists & inhibitors , Inflammation , Mitogen-Activated Protein Kinases/drug effects , Osteogenesis/drug effects , Periodontitis/drug therapy , Plant Extracts/antagonists & inhibitors , Animals , Cathepsin K/metabolism , Cell Line , Cell Survival/drug effects , Chalcones/chemistry , Fibroblasts/metabolism , Humans , Interleukin-1beta/metabolism , Lipopolysaccharides/adverse effects , MAP Kinase Signaling System/drug effects , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 8/metabolism , Mice , NF-kappa B/metabolism , Osteoclasts/drug effects , RANK Ligand/metabolism , RAW 264.7 Cells , Signal Transduction/drug effects , Tartrate-Resistant Acid Phosphatase/metabolism , Transcription Factors/drug effects , Zingiberaceae/chemistryABSTRACT
Periodontitis, an infective disease caused by oral pathogens and the intrinsic aging process, results in the destruction of periodontal tissues and the loss of alveolar bone. This study investigated whether Boesenbergia pandurata extract (BPE) standardized with panduratin A exerted anti-periodontitis effects, using an aging model representative of naturally occurring periodontitis. In aged rats, the oral administration of BPE (200 mg·kg-1·day-1) for 8 weeks significantly reduced the mRNA and protein expression of interleukin-1ß, nuclear factor-kappa B, matrix metalloproteinase (MMP)-2, and MMP-8 in gingival tissues (p < 0.01). In alveolar bone, histological analysis with staining and micro-computed tomography revealed the attenuation of alveolar bone resorption in the BPE-treated aged group, which led to a significant reduction in the mRNA and protein expression of nuclear factor of activated T-cells c1 (NFATc1), c-Fos, tartrate-resistant acid phosphatase, and cathepsin K (p < 0.01). BPE not only increased the expression of osteoblast differentiation markers, such as alkaline phosphate, and collagen type I (COL1A1), but also increased the ratio of osteoprotegerin to RANKL. Collectively, the results strongly suggested that BPE is a natural resource for the prevention or treatment of periodontal diseases.
