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The root-knot nematode Meloidogyne incognita is one of the most damaging plant-parasitic nematodes and is responsible for significant crop losses worldwide. Rising human health and environmental concerns have led to the withdrawal of commonly used chemical nematicides. There has been a tremendous demand for eco-friendly bio-nematicides with beneficial properties to the nematode hosting plants, which encourages the need for alternative nematode management practices. The current study was undertaken to determine the nematicidal potential of cotton seed cake (CSC) against second-stage juvenile (J2) hatching, J2 mortality, and J2 penetration of M. incognita in tomato plants in vitro. J2s and egg masses of M. incognita were exposed to four concentrations (250, 500, 750, and 1000 mg/L) of CSC extracts. The higher J2 mortality and inhibition of J2 hatching were found at 1000 mg/L, while the least effective result was observed at 250 mg/L of the CSC extract. The CSC extract applied with the concentrations mentioned above also showed inhibition of J2 penetration in tomato roots; 1000 mg/L showed the highest inhibition of penetration, while 250 mg/L displayed the least inhibition. Using gas chromatography-mass spectroscopy, we identified 11 compounds, out of which 9,12-Octadecadienoic acid, Hexadecanoic acid, and Tetradecanoic acid were found as major compounds. Subsequently, in silico molecular docking was conducted to confirm the nematicidal behavior of CSC based on binding interactions of the above three major compounds with the targeted protein acetylcholine esterase (AChE) of M. incognita. The values of binding free energy are −5.3, −4.5, and −4.9 kcal/mol, observed for 9,12-Octadecadienoic acid, n-Hexadecanoic acid, and Tetradecanoic acid, respectively, suggesting that 9,12-Octadecadienoic acid binds with the receptor AChE more efficiently than the other two ligands. This study indicates that CSC has nematicidal potential that can be used to control M. incognita for sustainable agriculture.

Globally, people are highly affected by Cadmium (Cd), the most hazardous heavy metal. It has been implicated in various pathogeneses. Oxidative stress may be one the main reasons for Cd-induced disorders in the body. This article investigates the protective ability of Catharanthus roseus (CR) extract on oxidative stress in the kidney and liver of rats exposed to Cd. After 21 days, a significant increase in MDA concentration (6.81 ± 0.05), (6.64 ± 0.03) was observed in Cd-treated groups compared to the control (5.54 ± 0.02), (5.39 ± 0.04) for the kidney and liver, respectively, while significant changes were observed in the haematological parameters. Antioxidant enzymes, GPx, CAT, and SOD showed a significant decrease in their activity. We established that increasing the concentration of Cd in the presence of H2O2 was able to cause stand scission in pBR322 plasmid DNA, which may be due to the mediation of ROS generated in the process. The antioxidant ability of CR extract was tested in DPPH and H2O2 scavenging assay, depicted by the increase in the percentage inhibition. Upon treatment of CR extract to rats, MDA concentration was decreased for the kidney and liver compared to the Cd-treated groups. This was again confirmed by comet assay of both tissues, where the degree of cellular DNA breakage caused by Cd toxicity decreased significantly upon treatment with CR extract. Overall, the results suggest that Cd plays a major role as an effector metal ion, causing a decrease in the concentration and activity of AO enzymes and enhanced lipid peroxidation. ROS production resulted in oxidative DNA damage within the cell, whereas CR extract showed potential antioxidant activity against ROS-mediated DNA damage induced by Cd poisoning.

Epidemiological studies have linked dietary consumption of plant polyphenols with lower incidence of various cancers. In particular, flavonoids (present in onion, tomato and other plant sources) induce apoptosis and cytotoxicity in cancer cells. These can therefore be used as lead compounds for the synthesis of novel anticancer drugs with greater bioavailability. In the present study, we examined the chemical basis of cytotoxicity of flavonoids by studying the structure–activity relationship of myricetin (MN), fisetin (FN), quercetin (QN), kaempferol (KL) and galangin (GN). Using single cell alkaline gel electrophoresis (comet assay), we established the relative efficiency of cellular DNA breakage as MN > FN > QN > KL > GN. Also, we determined that the cellular DNA breakage was the result of mobilization of chromatin-bound copper ions and the generation of reactive oxygen species. The relative DNA binding affinity order was further confirmed using molecular docking and thermodynamic studies through the interaction of flavonoids with calf thymus DNA. Our results suggest that novel anti-cancer molecules should have ortho-dihydroxy groups in B-ring and hydroxyl groups at positions 3 and 5 in the A-ring system. Additional hydroxyl groups at other positions further enhance the cellular cytotoxicity of the flavonoids.

Catechins, the dietary phytochemicals present in green tea and other beverages, are considered to be potent inducers of apoptosis and cytotoxicity to cancer cells. While it is believed that the antioxidant properties of catechins and related dietary agents may contribute to lowering the risk of cancer induction by impeding oxidative injury to DNA, these properties cannot account for apoptosis induction and chemotherapeutic observations. Catechin (C), epicatechin (EC), epigallocatechin (EGC) and epigallocatechin-3-gallate (EGCG) are the four major constituents of green tea. In this article, using human peripheral lymphocytes and comet assay, we show that C, EC, EGC and EGCG cause cellular DNA breakage and can alternatively switch to a prooxidant action in the presence of transition metals such as copper. The cellular DNA breakage was found to be significantly enhanced in the presence of copper ions. Catechins were found to be effective in providing protection against oxidative stress induced by tertbutylhydroperoxide, as measured by oxidative DNA breakage in lymphocytes. The prooxidant action of catechins involved production of hydroxyl radicals through redox recycling of copper ions. We also determined that catechins, particularly EGCG, inhibit proliferation of breast cancer cell line MDA-MB-231 leading to a prooxidant cell death. Since it is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies, cancer cells would be more subject to redox cycling between copper ions and catechins to generate reactive oxygen species (ROS) responsible for DNA breakage. Such a copper dependent prooxidant cytotoxic mechanism better explains the anticancer activity and preferential cytotoxicity of dietary phytochemicals against cancer cells.

The emergence of multidrug-resistant (MDR) Escherichia coli ( E. coli ) clonal lineages with high virulence potential is alarming. Lack of sufficient data on molecular epidemiology of such pathogens from countries with high infection burden, such as Bangladesh, hinders management and infection control measures. In this study, we assessed the population structure, virulence potential and antimicrobial susceptibility of clinical E. coli isolates from Dhaka, Bangladesh. A high prevalence of MDR (69%) and extended-spectrum β-lactamase production (ESBL) (51%) was found. Most E. coli isolates were susceptible to amikacin (95%), meropenem (94%) and nitrofurantoin (89%) antibiotics. A high prevalence of ST131 (22%) and ST95 (9%) followed by ST69 (4%) and ST73 (3%) was observed. Phylogroups B2 (46%), B1 (16%), D (10%) and F (9%) were prominent. bla CTX-M-15 (52%) and bla NDM-1 (5%) were the most prevalent ESBL and carbapenem resistance genes, respectively. Moreover, the predominant pathotype identified was extraintestinal pathogenic E. coli (ExPEC) (41%) followed by enteric pathogens (11%). In conclusion, our results suggest the transmission of clonal E. coli groups amidst diverse E. coli population that are associated with high virulence potential and MDR phenotype. This is of high concern and mandates more efforts towards molecular surveillance of antimicrobial resistance (AMR) in clinically significant pathogens.