Vitex negundo L. Essential Oil: Odorant Binding Protein Efficiency Using Molecular Docking Approach and Studies of the Mosquito Repellent.

(1) Background: Malaria fever affects millions of people yearly in Africa and Asia's tropical and subtropical areas. Because there is no effective vaccine, malaria prevention is solely dependent on avoiding human-vector interaction. (2) Aim: This study examines the interaction between the constituents of Vitex negundo essential oil and Anopheles gambiae Odorant Binding Proteins (OBP) as well as the compositional variation, repellent efficacy, and toxicity profile. (3) Methods: The oils were subjected to GC-MS and mosquito behavioral analysis. OBP-ligand interactions, Anopheles species authentication, and the toxicity profile were determined by molecular docking, PCR assay and in silico ADME/tox tool. Docking protocol validation was achieved by redocking the co-crystallized ligands into the protein binding pocket and root mean square deviation (RMSD) calculation. (4) Results: The oil yields and compositions are climate-soil dependent with ≈71.39% monoterpenes and ≈16.32% sesquiterpene. Optimal repellency is achieved at 15 min at ED50 0.08-0.48% v/v while the RMSD was estimated to be within 0.24-1.35 Å. Strong affinities were demonstrated by α-pinene (-6.4 kcal/mol), citronellal (-5.5 kcal/mol), linalool (-5.4 kcal/mol), and myrcene (-5.8 kcal/mol) for OBP1, OBP7, OBP4, and OBP; respectively. The hydrophobic interactions involve Leu17 (α-helix 1), Cys35 (α-helix 2), ALA52 (α-helix 3), Leu73, Leu76 (α-helix 4), Ala88, Met91, Lys93, Trp114 (α-helix 5), Phe123 (α-helix 6), and Leu124 (α-helix 7) receptors within the binding cavities, and may cause blocking of the olfactory receptors resulting in disorientation. (5) Conclusion: The ligand efficiency metrics, ADME/tox and repellency screening are within the threshold values; hence, α-pinene, linalool, and myrcene are safe and fit-to-use in the development of a green and novel repellent.

Rejection Capacity of Nanofiltration Membranes for Nickel, Copper, Silver and Palladium at Various Oxidation States.

Electroplating and metalworking industries produce enormous amounts of waste containing heavy metals in their effluents, leading to potential threats to biotic and abiotic life. According to regulation, heavy metal contamination must be kept within the regulated standard of a few parts per million, which has led to a recent pique in interest in the utilization of nanofiltration technology for metal recovery. The effect of feed pH, pressure, metal concentration, and oxidation of metal on the rejection of heavy metal ions using three commercial nanofiltration membranes (NF, NF90, and NF270) were explored. To begin, studies of electrolyte salts, contact angle, and water permeability were employed to characterize the nanofiltration membranes. A dead-end module was used to test the permeation and retention capacities of the nanofiltration membranes. The results showed an increase in salt rejection for all metals examined irrespective of the membrane, at a pH below the isoelectric point. For divalent cations, the NF90 membrane achieved recovery capacities of 97% and 85% at 200 ppm and 20 ppm respectively, as compared to the recovery observed for Ni2+, Cu2+, and Pd2+ ions by NF and NF270. At a pH 2, 20 ppm and 5 bar, the NF90 membrane had the highest percent recovery, but at a pH 3, the recovery was at 95%. Mono and divalent stable Ag+ and Ni2+ ions showed a comparatively high percent recovery as compared to Pd2+ and Cu2+, which have high molecular weight and charge effect. In the presence of chelating agents, the membrane surface area is increased, resulting in high divalent ion recovery capacities due to favourable interaction with the polyamide functional group of the membranes. This study establishes the significance of oxidation in high removal efficiency cation in varying experimental conditions.

Increase in SARS-CoV-2 infected biomedical waste among low middle-income countries: environmental sustainability and impact with health implications.

Studies have shown that severe acute respiratory syndrome corona virus-2 (SARS-CoV-2) is a highly infectious disease, with global deaths rising to about 360,438 as of 28 May 2020. Different countries have used various approaches such as lockdown, social distancing, maintenance of personal hygiene, and increased establishment of testing and isolation centers to manage the pandemic. Poor biomedical waste (BMW) management, treatment, and disposal techniques, especially SARS-CoV-2 infected BMW, may threaten the environmental and public health in most developing countries and, by extension, impact the economic status of individuals and the nation at large. This may increase the potential for the transmission of air/blood body fluid-borne pathogens, increase the growth of microorganisms, risk of mutagenesis, and upsurge of more virulent strain. In contrast, uncontrolled substandard burning could increase the potential spread of nosocomial infection and environmental exposure to toxic organic compounds, heavy metals, radioactive, and genotoxic bio-aerosols which might be present in the gaseous, liquid, and solid by-products. The paucity of understanding of pathophysiology and management of the SARS-CoV-2 pandemic has also necessitated the need to put in place appropriate disposal techniques to cater for the sudden increase in the global demand for personal protective equipment (PPE) and pharmaceutical drugs to manage the pandemic and to reduce the risk of preventable infection by the waste. Therefore, there is a need for adequate sensitization, awareness, and environmental monitoring of the impacts of improper handling of SARS-CoV-2 infected BMWs. Hence, this review aimed to address the issues relating to the improper management of increased SARS-CoV-2 infected BMW in low middle-income countries (LMICs).

Cocos nucifera L. oil alleviates lead acetate-induced reproductive toxicity in sexually-matured male Wistar rats.

OBJECTIVES: Lead primarily affects male reproductive functions via hormonal imbalance and morphological damage to the testicular tissue with significant alteration in sperm profile and oxidative markers. Though, different studies have reported that Cocos nucifera L. oil has a wide range of biological effects, this study aimed at investigating the effect of Cocos nucifera L. oil on lead acetate-induced reproductive toxicity in male Wistar rats. METHODS: Twenty (20) sexually matured male Wistar rats (55-65 days) were randomly distributed into four groups (n=5). Group I (negative control)-distilled water orally for 56 days, Group II (positive control)-5 mg/kg bwt lead acetate intraperitoneally (i.p.) for 14 days, Group III-6.7 mL/kg bwt Cocos nucifera L. oil orally for 56 days and Group IV-lead acetate intraperitoneally (i.p.) for 14 days and Cocos nucifera L. oil for orally for 56 days. Rats were sacrificed by diethyl ether, after which the serum, testis and epididymis were collected and used for semen analysis, biochemical and histological analysis. RESULTS: The lead acetate significantly increases (p<0.05) testicular and epididymal malondialdehyde (MDA) levels, while a significant reduction (p<0.05) in sperm parameters, organ weight, testosterone and luteinizing hormone was observed when compared with the negative control. The coadministration of Cocos nucifera oil with lead acetate significantly increases (p<0.05) testosterone, luteinizing hormone, sperm parameters and organ weight, with a significant decrease (p<0.05) in MDA levels compared with positive control. Histological analysis showed that lead acetate distorts testicular cytoarchitecture and germ cell integrity while this was normalized in the cotreated group. CONCLUSIONS: Cocos nucifera oil attenuates the deleterious effects of lead acetate in male Wistar rats, which could be attributed to its polyphenol content and antioxidant properties.

Proxeed plus salvage rat testis from ischemia- reperfused injury by enhancing antioxidant's activities and inhibition of iNOS expression.

Testicular torsion is an acute urological emergency condition that occurs due to obstruction of blood flow to the testicles which may result in ischemia and loss of testicular functions. This study examined the protective effects of Proxeed Plus (PP), a dietary supplement on testicular ischemia/reperfusion (I/R) injured rats using oxidative stress markers, hormonal levels, apoptotic parameters, histological and immunohistochemistry analysis at 4 h and after 7 days of reperfusion. The protective treatment of the I/R injured rats with PP at 1000 and 5000 mg/kg body weight (bw) resulted in significant increases in the serum and tissue antioxidative defense capacities (superoxide dismutase, reduced glutathione, catalase, glutathione-s-transferase, and glutathione peroxidase), sex hormones (luteinizing hormone, follicle-stimulating hormone, and testosterone), also reduce pro-oxidative markers (malondialdehyde and hydrogen peroxide), serum iNOS and apoptotic parameters (Caspase -3 and Caspase -9) in comparison to the results detected in the I/R untreated rats. It was also observed that PP ameliorated histological changes of I/R injured rats; increased spermatogenetic activity, seminiferous tubular diameter, Leydig cell mass, and reduced expressions of testicular inducible nitric oxide synthase (iNOS). Therefore, the therapeutic use of Proxeed Plus could be considered a promising approach in averting testicular damage against I/R injury.

Characterization of Selected Polymeric Membranes Used in the Separation and Recovery of Palladium-Based Catalyst Systems.

Membrane separation processes tender a capable option for energy-demanding separation processes. Nanofiltration (NF) and reverse osmosis (RO) membranes are among the most explored, with a latent use in the chemical industry. In this study, four commercial membranes (NF90, NF270, BW30, and XLE) were investigated for their applicability based on the key structural performance characteristics in the recycling of Pd-based catalysts from Heck coupling post-reaction mixture. Pure water and organic solvent permeabilities, uncharged solute permeability, swelling, and catalyst rejection studies of the membranes were conducted as well as the morphological characterization using Fourier transform infrared, field emission gun scanning electron microscopy, and atomic force microscopy. Characterization results showed trends consistent with the manufactures' specifications. Pure water and organic solvent fluxes generally followed the trend NF270 > NF90 > BW30 > XLE, with the solvent choice playing a major role in the separation process. Pd(PPh3)2Cl2 was well rejected by almost all membranes in 2-propanol; however, XLE rejects Pd(OAc)2 better at high pressure in acetonitrile. Our study, therefore, revealed that the separation and reuse of the two catalysts by NF90 at 10 bar resulted in 97% and 49% product yields with 52% and 10% catalyst retention for Pd(OAc)2 while Pd(PPh3)2Cl2. gave 87% and 6% yields with 58% and 36% catalyst retention in the first and second cycles, respectively. Considering, the influence of membrane-solute interactions in Pd-catalyst rejection, a careful selection of the polymeric membrane and solvent, a satisfactory separation, and recovery can be achieved.

Silver Nanoparticles Stimulates Spermatogenesis Impairments and Hematological Alterations in Testis and Epididymis of Male Rats.

The potential pharmaceutical application of nanoparticles has led to the toxicity within the male reproductive system. In the present study, the effects of silver nanoparticles (Ag-NPs) on hematological parameters, free radical generation, antioxidant system, sperm parameters, and organ histo-morphometry in male rats were investigated. Ag-NPs were produced by the reduction of silver ions, while the formation of which was monitored by UV-visible spectrophotometry. Zeta potential, transmission, and scanning electron microscopies were applied for the characterization of AgNPs. A total of 30 rats were divided into 6 groups and were sub-dermally exposed to Ag-NPs at the dosage of 0 (control), 10, and 50 mg/kg bodyweight (bw) doses for either 7 or 28 days. Ag-NP administration altered hematological indices and caused dose-dependent decreases in sperm motility, velocity, kinematic parameters, concentrations of luteinizing hormone, follicle-stimulating hormone, and testosterone. In the epididymis and testis, the concentrations of malondialdehyde and peroxide increases while superoxide dismutase, catalase, reduced glutathione, and total thiol group decreases. These findings suggest that Ag-NP triggered hormonal imbalance and induce oxidative stress in testis and epididymis; which negatively affect sperm parameters of male rats.

Investigation into the Thermal Response and Pharmacological Activity of Substituted Schiff Bases on α-Amylase and α-Glucosidase.

The emphasis of previous studies has targeted the development of insulin mimic with little attention given to the development of metabolic enzyme inhibitors. Our focus is to synthesise nine o-hydroxy and p-nitro-azomethine analogues, investigate their digestive enzyme inhibitory capacity, as well as the antioxidant and antimicrobial activities. The substituted Schiff bases were analysed using thermal gravimetric analyser (TGA), X-ray diffractometer (XRD), nuclear magnetic resonance spectroscopy (NMR), elemental analyser, and Fourier-transform infrared spectroscopy (FT-IR). Determination of synthetic yield revealed that the o-hydroxy analogues produced the highest yield of ≥77.1% compared to p-nitro and unsubstituted analogues. Spectra study showed the presence of azomethine stretching vibration at 1698⁻1613 cm-1, proton signals at δ 8.46⁻9.81, and carbon signals at δ 145.95⁻159.53 ppm. Investigation into the thermal property indicated an elevated melting point for the o-hydroxy analogue, compared to the p-nitro derivative which showed high stability to heat. There are similarities in crystalline structure with few unique patterns suggesting different substituent group. The antioxidant activities of the substituted analogues registered low half maximal inhibitory concentration (IC50), with exception to the ferric reducing power; indicating that the Schiff bases are weak siderophores. All nine Schiff bases were bacteriostatic or fungistatic at the screened concentrations; however, the nitro-substituted analogues have an enhanced activity with Minimum Inhibitory Concentration (MIC) values of 0.03⁻2.54 µM. Both o-hydroxy and p-nitro-substitution does not improve the antifungal activity of the compounds against A. niger. The o-hydroxyl and p-nitro Schiff base derivatives showed enhanced activity towards the inhibition of α -amylase and α-glucosidase by hydroxylation and glycosylation, respectively. Although, hydroxy derivatives of sulphonic acid derived Schiff base slightly decreased the activities on α-glucosidase and α-amylase. Our findings suggest that p-nitro substitution enhances the in vitro nonenzymatic activity while the o-hydroxy derivatives are good hydrolase inhibitors. Therefore, substituent modification can be used as an enhancement technique in designing novel pharmacophore.