Plants are known to have numerous phytochemicals and other secondary metabolites with numerous pharmacological and biological properties. Among the various compounds, polyphenols, flavonoids, anthocyanins, alkaloids, and terpenoids are the predominant ones that have been explored for their biological potential. Among these, chalcones and bis-chalcones are less explored for their biological potential under in vitro experiments, cell culture models, and animal studies. In the present study, we evaluated six synthetic bis-chalcones that were different in terms of their aromatic cores, functional group substitution, and position of substitutions. The results indicated a strong antioxidant property in terms of DPPH and ABTS radical-scavenging potentials and ferric-reducing properties. In addition, compounds 1, 2, and 4 exhibited strong antibacterial activities against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonella enteritidis. The disc diffusion assay values were indicative of the antibacterial properties of these compounds. Overall, the study indicated the antioxidant and antimicrobial properties of the compounds. Our preliminary studies point to the potential of this class of compounds for further in vivo investigation.

Plant secondary metabolites are important sources of biologically active compounds with wide pharmacological potentials. Among the different classes, the chalcones form integral pharmacologically active agents. Natural chalcones and bis-chalcones exhibit high antioxidant and anti-inflammatory properties in various experiments. Studies are also underway to explore more biologically active bis-chalcones by chemical synthesis of these compounds. In this study, the effects of six synthetic bis-chalcones were evaluated in intestinal epithelial cells (IEC-6); further, the anti-inflammatory potentials were studied in lipopolysaccharide-induced cytokine production in macrophages. The synthesized bis-chalcones differ from each other first of all by the nature of the aromatic cores (functional group substitution, and their position) and by the size of a central alicycle. The exposure of IEC-6 cells to peroxide radicals reduced the cell viability; however, pre-treatment with the bis-chalcones improved the cell viability in these cells. The mechanism of action was observed to be the increased levels of glutathione and antioxidant enzyme activities. Further, these bis-chalcones also inhibited the LPS-stimulation-induced inflammatory cytokine production in RAW 264.7 macrophages. Overall, the present study indicated the cytoprotective and anti-inflammatory abilities of synthetic bis-chalcones.

Rivers and the estuarine regions play crucial roles in the environment by controlling the nutrient cycling, waste disposal, and also in supporting biodiversity. However, the estuarine regions of rivers are highly susceptible to disruptive changes by anthropogenic pollutants and eutrophication. Bacterioplankton diversity is the best indicators of the pollution level and eutrophication status of the rivers. The present study evaluated the eutrophication status and bacterioplankton diversity of the estuarine regions of Chaliyar and the Anjarakkandi originated from the Western Ghats. The present study observed the presence of increased incidence of bacterioplankton comprising of proteobacteria, actinobacteria and cyanobacteria in the estuarine regions of Anjarakkandi river compared to that of Chaliyar river. Further, the percentage incidence of faecal bacteria including Bacillus subtilis and E. coli, were also found to be in high in the Anjarakkandi river; in corroborating with this, the diversity of nitrogen metabolizing bacteria was also higher in the estuarine samples of Anjarakkandi river. Corroborating with this, the levels of water nutrients including nirates, nitrites and phosphates were high in the Anjarakkandi compared to the Chaliyar river. Together, it is possible that there might be increased faecal contamination and subsequent increased eutrophication in the estuarine regions of Anjarakkandi river. Altogether, the study concludes that the Anjarakkandi river may be more polluted and which is partly contributed by faecal contaminants and also responsible for the change in the bacterioplankton community of the estuaries.