Waterborne pathogens find their way into water bodies through contamination of fecal discharge, stormwater run-offs, agriculture and industrial activities, and poor water infrastructure. These organisms are responsible for causing diarrheal, gastroenteritis, cholera, and typhoid diseases which raise an alarming sense on public human health due to the high mortality rate, especially in children. Several studies have indicated that these waterborne diseases can be managed by monitoring pathogens in water using traditional culture-based and molecular techniques. However, these methods have shown several setbacks such as the longer duration for detection and the inability to detect pathogens at low concentrations. Effective management of these diseases requires rapid, sensitive, highly selective, fast, and efficient economic methods to monitor pathogens in water. Since the creation of biosensors, these tools have been applied and shown the ability to detect pathogens at low concentrations. The highlights of biosensor systems are that they are fast, portable, easy to use, highly sensitive, and specific. The capabilities of biosensors have given these tools exposure to be widely applied in detecting pharmaceutical pollutants, pesticides, toxins, residues of detergents, and cosmetics from household activities in soil and water. With such difficulties faced for detecting waterborne pathogens, this review evaluates the effectiveness of technologies for waterborne pathogens detection and their drawbacks. It further highlights biosensors as the current reliable method available for detecting pathogens in water and its future capabilities in sustaining safe potable water.

Series of the 6-bromo/iodo substituted 2-aryl-4-methyl-1,2-dihydroquinazoline-3-oxides and their mixed 6,8-dihalogenated (Br/I and I/Br) derivatives were evaluated for inhibitory properties against α-glucosidase and/or α-amylase activities and for cytotoxicity against breast (MCF-7) and lung (A549) cancer cell lines. The 6-bromo-2-phenyl substituted 3a and its corresponding 6-bromo-8-iodo-2-phenyl-substituted derivative 3i exhibited dual activity against α-glucosidase (IC₅₀ = 1.08 ± 0.02 μM and 1.01 ± 0.05 μM, respectively) and α-amylase (IC₅₀ = 5.33 ± 0.01 μM and 1.18 ± 0.06 μM, respectively) compared to acarbose (IC₅₀ = 4.40 ± 0.05 μM and 2.92 ± 0.02 μM, respectively). The 6-iodo-2-(4-fluorophenyl)-substituted derivative 3f, on the other hand, exhibited strong activity against α-amylase and significant inhibitory effect against α-glucosidase with IC₅₀ values of 0.64 ± 0.01 μM and 9.27 ± 0.02 μM, respectively. Compounds 3c, 3l and 3p exhibited the highest activity against α-glucosidase with IC₅₀ values of 1.04 ± 0.03, 0.92 ± 0.01 and 0.78 ± 0.05 μM, respectively. Moderate cytotoxicity against the MCF-7 and A549 cell lines was observed for these compounds compared to the anticancer drugs doxorubicin (IC₅₀ = 0.25 ± 0.05 μM and 0.36 ± 0.07 μM, respectively) and gefitinib (IC₅₀ = 0.19 ± 0.04 μM and 0.25 ± 0.03 μM, respectively), and their IC₅₀ values are in the range of 10.38 ± 0.08–25.48 ± 0.08 μM and 11.39 ± 0.12–20.00 ± 0.05 μM, respectively. The test compounds generally exhibited moderate to strong antioxidant capabilities, as demonstrated via robust free radical scavenging activity assays, viz., DPPH and NO. The potential of selected derivatives to inhibit superoxide dismutase (SOD) was also investigated via enzymatic assay in vitro. Molecular docking revealed the N-O moiety as essential to facilitate electrostatic interactions of the test compounds with the protein residues in the active site of α-glucosidase and α-amylase. The presence of bromine and/or iodine atoms resulted in increased hydrophobic (alkyl and/or π-alkyl) interactions and therefore increased inhibitory effect against both enzymes.

Antimicrobial resistance in various microorganisms and opportunistic pathogens associated with HIV/AIDS poses a serious threat to human life and healthcare systems worldwide. Different forms of cancer are likely to arise in immunocompromised patients. The antimicrobial and anticancer effects of methanol extract and fractions from Raphionacme hirsuta have been investigated. The carbon tetrachloride fraction showed a remarkably low minimum inhibitory concentration (MIC) of 0.02 mg/mL against Escherichia coli, Mycoplasma hominis, and Cryptococcus neoformans, while the n-hexane fraction showed a similar MIC against C. neoformans. Furthermore, the carbon tetrachloride fraction exhibited promising IC₅₀ values of 18.21 and 25.22 µg/mL against HeLa and MCF-7 cancerous cell lines, respectively. The fraction was subjected to GC-TOF-MS and yielded four major compounds, including 7,9-Di-tert-butyl-1-oxaspiro (4,5) deca-6,9-diene-2,8-dione (5.322%), Hexanedial (3.691%), 4-(4-tert-Butylphenyl)-1,3-thiazol-2-ylamine (3.329%), and Di-n-decylsulfone (3.201%). These substances could potentially account for the plant species’ initial biological activity, which is why it is necessary to investigate their in vivo actions. The gummy extract had less biological activity than the fractions. To the best of our knowledge, this is the first study to report the antimicrobial and anticancer activities, as well as the phytochemistry, of the plant species.