Collinin

Periodontitis pathogenesis involves activation of host immune responses triggered by microbial dysbiosis. Therefore, controlling periodontal pathogens in-vivo is a main goal of periodontal therapy. New antimicrobials might help to control periodontal infection and improve treatment outcomes at "the dark times" of increasing antibiotic resistance. Here, we determined the biological activity of collinin and isocollinin against 8 bacterial strains. Antimicrobial activity of collinin and isocollinin, chlorhexidine digluconate (CHX) and sodium hypochlorite (NaClO) was evaluated against clinically relevant periodontal bacteria, like Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Fusobacterium nucleatum, Prevotella intermedia, Dialister pneumosintes strains and superinfectants like Escherichia coli, Staphylococcusaureus, and Pseudomonasaeruginosa strains. A broth microdilution test was carried out to determine the minimum inhibitory concentration of collinin and isocollinin against those strains, and bacterial viability was determined by resazurin assay at diverse concentration and exposure times. P. gingivalis was the most susceptible strain to collinin and isocollinin (MIC 2.1 μg/mL and 4.2 μg/mL respectively). Other periodontal pathogens showed MICs <17 μg/mL for collinin and MICs between 20 and 42 μg/mL for isocollinin, whereas CHX and NaClO showed MICs of 62 and 326 μg/mL, respectively. Collinin and isocollinin also exhibited antimicrobial activity against superinfectant bacteria (MIC < 21 and < 42 μg/mL, respectively). Overall, collinin and isocollinin showed a remarkable antibacterial activity against relevant periodontal and superinfective bacteria, especially against P. gingivalis (MIC 2.1 μg/mL and 4.2 μg/mL respectively) and the highly virulent P. aeruginosa (MIC 5.2 and 20.8 μg/mL, respectively).

Background: Tuberculosis is a very serious infectious disease that threatens humanity, and the emergence of multidrug-resistant (MDR), extensively drug-resistant (XDR) strains resistant to drugs suggests that new drug development is urgent. In order to develop new tuberculosis drug, we have conducted in vitro anti-tubercular tests on thousands of plant-derived substances and finally found collinin extracted from the leaves of Zanthoxylum schinifolium, which has an excellent anti-tuberculosis effect. Purpose: To isolate an anti-tubercular bioactive compound from the leaves of Z. schinifolium and evaluate whether this agent demonstrates any potential in vitro characteristics suitable for the development of future anti-tubercular drugs to treat MDR and XDR Mycobacterium tuberculosis. Methods: The methanolic extracts of the leaves of Z. schinifolium were subjected to bioassay-guided fractionation against M. tuberculosis using a microbial cell viability assay. In addition, following cell cytotoxicity assay, an intracellular anti-mycobacterial activity of the most active anti-tubercular compound was investigated after it was purified. Results: The active compound with anti-tubercular activity isolated from leaves of Z. schinifolium was identified as a collinin. The extracted collinin showed anti-tubercular activity against both drug-susceptible and -resistant strains of M. tuberculosis at 50% minimum inhibitory concentrations (MIC50s) of 3.13-6.25 µg/ml in culture broth and MIC50s of 6.25-12.50 µg/ml inside Raw264.7 and A549 cells. Collinin had no cytotoxicity against human lung pneumocytes up to a concentration of 100 µg/ml (selectivity index > 16-32). Conclusions: Collinin extracted from the leaves of Z. schinifolium significantly inhibits the growth of MDR and XDR M. tuberculosis in the culture broth. In addition, it also inhibits the growth of intracellular drug-susceptible and drug-resistant tuberculosis in Raw264.7 and A549 cells. To our knowledge, this is the first report on the in vitro anti-tubercular activity of collinin, and our data suggest collinin as a potential drug to treat drug-resistant tuberculosis. Further studies are warranted to assess the in vivo efficacy and therapeutic potential of collinin.

Nine terpenylated coumarins, namely 7-[(E)-3',7'-dimethyl-6'-oxo-2',7'-octadienyl]oxy-coumarin (1), schinilenol (2), schinindiol (3), collinin (4), 7-[(E)-7'-hydroxy-3',7'-dimethy-locta-2',5'-dienyloxy]-coumarin (5), 8-methoxyanisocoumarin (6), 7-(6'R-hydroxy-3',7'-dimethyl-2'E,7'-octadienyloxy)coumarin (7), (E)-4-methyl-6-(coumarin-7'-yloxy)hex-4-enal (8), and aurapten (9), along with a 4-quinolone alkaloid (10) and integrifoliodiol (11), were isolated from the leaves of Zanthoxylum schinifolium. Of the isolates, compounds 4 and 7 potentially inhibited NO production in lipopolysaccharide (LPS)-stimulated macrophage RAW264.7 cells, with IC50 values of 5.9 ± 0.8 and 18.2 ± 1.8 μM, respectively. Furthermore, compounds 4 and 7 dose-dependently reduced the LPS-induced iNOS expression. Moreover, pre-incubation of cells with 4 and 7 significantly suppressed LPS-induced COX-2 protein expression. In addition, compounds 4, 7, 8, and 10 showed strong α-glucosidase inhibitory effects, with IC50 values of 92.1 ± 0.7, 90.6 ± 0.9, 78.2 ± 0.2, and 82.4 ± 0.8 μM, respectively. Compounds 1, 5, and 11 displayed moderate effects with IC50 values of 161.6 ± 0.3, 164.4 ± 1.1, and 155.4 ± 0.9 μM, while acarbose, a positive control, possessed an IC50 value of 121.5 ± 1.0 μM. This is the first investigation on the α-glucosidase inhibitory effect of components from Zanthoxylum schinifolium. Further studies should be made on active compounds.