Effects of 2,4-dichlorophenol on non-specific immunity, histopathological lesions, and redox balance in African Catfish, clarias gariepinus (Burchell, 1822).

The toxic effects of 2, 4-dichlorophenol (2, 4-DCP) on aquatic organisms are well-established; however, the details regarding the mechanisms underlying the toxicity, especially immunotoxicity are poorly understood. Consequently, the aim of this study was to investigate the histopathologic, oxidative stress and immunotoxic effects attributed to exposure to sublethal concentrations of 2,4-DCP in the African catfish, Clarias gariepinus. Juvenile C. gariepinus were exposed to 0.4, 0.8, or 1.6 mg/L 2, 4-DCP for 28 days after which blood and head kidney were extracted for the determination of various nonspecific innate immune parameters while the liver was excised for histopathology examination and measurement of oxidative stress biomarkers. Control fish were maintained in water spiked 10 µL/L ethanol, representing the solvent control. A significant increase was noted in the activities of lactate dehydrogenase and superoxide dismutase as well as in levels of lipid peroxidation and DNA fragmentation in a dose-dependent manner, with higher adverse effects observed at the highest concentration tested (1.6 mg/L). The total white blood cells (WBC) count was significantly elevated in fish exposed to 2,4-DCP compared to control. Myeloperoxidase content was decreased significantly in fish exposed to 2,4-DCP especially at the highest concentration (1.6 mg/L) compared to controls. The respiratory burst activity did not differ markedly amongst groups. Histopathological lesions noted included edema, leucocyte infiltration, and depletion of hemopoietic tissue in the head kidney of exposed fish. There was significant upregulation in the mRNA expression of tumor necrosis factor (TNF-α) and heat shock protein 70 (HSP 70) but downregulation of major histocompatibility complex 2 (MHC 2) in exposed fish. Data demonstrated that exposure to 2,4-DCP resulted in histopathological lesions, oxidative stress, and compromised immune system in C. gariepinus.

Experimental and computational modeling of interaction of kolaviron-kolaflavanone with aldehyde dehydrogenase.

Aldehyde dehydrogenases (ALDHs) are a diverse family of enzymes that catalyze the NAD(P)+-dependent detoxification of toxic aldehyde compounds. ALDHs are also involved in non-enzymatic ligand binding to endobiotics and xenobiotics. Here, the enzyme crucial non-canonical and non-catalytic interaction with kolaflavanone, a component of kolaviron, and a major bioflavonoid isolated from Garcinia kola (Bitter kola) was characterized by various spectroscopic and in silico approaches under simulated physiological condition. Kolaflavanone quenched the intrinsic fluorescence of ALDH in a concentration dependent manner with an effective quenching constant (Ksv) of 1.14 × 103 L.mol-1 at 25 °C. The enzyme has one binding site for kolaflavanone with a binding constant (Ka) of 2.57 × 104 L.mol-1 and effective Forster resonance energy transfer (FRET) of 4.87 nm. The bonding process was enthalpically driven. The reaction was not spontaneous and was predominantly characterized by Van der Waals forces and hydrogen bond. The flavonoid bonding slightly perturbed the secondary and tertiary structures of ALDH that was 'tryptophan-gated'. The interaction was regulated by both diffusion and ionic strength. Molecular docking showed the binding of kolaflavanone was at the active site of ALDH and the participation of some amino acid residues in the complex formation with -9.6 kcal mol-1 binding energy. The profiles of atomic fluctuations indicated the rigidity of the ligand-binding site during the simulation. With these, ALDH as a subtle nano-particle determinant of kolaviron bioavailability and efficacy is hereby proposed.

Hesperetin protects against diesel exhaust particles-induced cardiovascular oxidative stress and inflammation in Wistar rats.

Air particulate matter exposure has been linked to cardiovascular and atherosclerosis as a result of increase oxidative stress and inflammatory response. This study aims to determine the effect of the use of hesperetin (HESP) as a therapeutic agent to mitigate the cardiovascular oxidative and pro-inflammatory effects of diesel exhaust particles in Wistar rats. DEP was collected from an Iveco cargo engine truck, and n-hexane fraction (hDEP) was obtained. Forty Wistar strains of male albino rats (6 weeks) were divided into 8 groups: control group received DMSO and CMC-Na; other groups received either n-hexane extract of DEP (0.064 or 0.640 mg/kg hDEP) or Standard Reference Material 2975 (0.064 mg/kg hSRM) in the presence or absence of 200 mg/kg HESP. Extracts were administered orally. Serum lipids, lipid peroxidation (LPO), conjugated dienes (CDs), and GSH levels were determined. Also, inflammatory cytokines, PCSK-9, LDL-receptor, and antioxidant genes expression were assessed by RT-PCR in both the heart and aorta. The molecular interaction of targeted proteins with HESP was assessed by the in silico approach. Extracts of DEP caused a significant (p < 0.001) increase in serum lipids but significantly decreased HDL-CHOL. It also increased CDs and MDA levels but decreased GSH levels. In addition, the particulate extracts caused a significant (p < 0.001) increase in pro-inflammatory genes expression in the heart and aorta but significantly decreased IL-10 and LDL-R gene expressions. Pre-treatment with hesperetin significantly reversed all these effects. This study shows that hesperetin has the ability to protect against DEP-induced oxidative stress and inflammation in the cardiovascular system.

Identification of Main Protease of Coronavirus SARS-CoV-2 (Mpro) Inhibitors from Melissa officinalis.

BACKGROUND: The recent outbreak of Coronavirus SARS-CoV-2 (Covid-19), which has rapidly spread around the world in about three months with tens of thousands of deaths recorded so far is a global concern. An urgent need for potential therapeutic intervention is of necessity. Mpro is an attractive druggable target for the development of anti-COVID-19 drug development. METHODS: Compounds previously characterized by Melissa officinalis were queried against the main protease of coronavirus SARS-CoV-2 using a computational approach. RESULTS: Melitric acid A and salvanolic acid A had higher affinity than lopinavir and ivermectin using both AutodockVina and XP docking algorithms. The computational approach was employed in the generation of the QSAR model using automated QSAR, and in the docking of ligands from Melissa officinalis with SARS-CoV-2 Mpro inhibitors. The best model obtained was KPLS_Radial_ 28 (R2 = 0.8548 and Q2=0.6474, which was used in predicting the bioactivity of the lead compounds. Molecular mechanics based MM-GBSA confirmed salvanolic acid A as the compound with the highest free energy and predicted bioactivity of 4.777; it interacted with His-41 of the catalytic dyad (Cys145-His41) of SARS-CoV-2 main protease (Mpro), as this may hinder the cutting of inactive viral protein into active ones capable of replication. CONCLUSION: Salvanolic acid A can be further evaluated as a potential Mpro inhibitor.

Kolaflavanone, a biflavonoid derived from medicinal plant Garcinia, is an inhibitor of mitotic kinesin Eg5.

Mitotic kinesin Eg5 remains a validated target in antimitotic therapy because of its essential role in the formation and maintenance of bipolar mitotic spindles. Although numerous Eg5 inhibitors of synthetic origin are known, only a few inhibitors derived from natural products have been reported. In our study, we focused on identifying novel Eg5 inhibitors from medicinal plants, particularly Garcinia species. Herein, we report the inhibitory effect of kolaflavanone (KLF), a Garcinia biflavonoid, on the ATPase and microtubule-gliding activities of mitotic kinesin Eg5. Additionally, we showed the interaction mechanism between Eg5 and KLF via in vitro and in silico analyses. The results revealed that KLF inhibited both the basal and microtubule-activated ATPase activities of Eg5. The inhibitory mechanism is allosteric, without a direct competition with adenosine-5'-diphosphate for the nucleotide-binding site. KLF also suppressed the microtubule gliding of Eg5 in vitro. The Eg5-KLF model obtained from molecular docking showed that the biflavonoid exists within the α2/α3/L5 (α2: Lys111-Glu116 and Ile135-Asp149, α3: Asn206-Thr226; L5: Gly117-Gly134) pocket, with a binding pose comparable to known Eg5 inhibitors. Overall, our data suggest that KLF is a novel allosteric inhibitor of mitotic kinesin Eg5.

Ascorbic Acid and Alpha-Tocopherol Contribute to the Therapy of Polycystic Ovarian Syndrome in Mouse Models.

Polycystic ovary syndrome (PCOS) affects up to 10% of women within reproductive ages and has been a cause of infertility and poor quality of life. Alteration in the oxidant-antioxidant profile occurs in PCOS. This study, therefore, investigates the contribution of ascorbic acid (AA) and alpha-tocopherol(ATE) on different PCOS parameters. The mifepristone and letrozole models were used, and young mature female mice were randomly assigned to groups of six per group. On PCOS induction with either mifepristone or letrozole, mice were administered AA and ATE at doses ranging from 10-1000mg/kg to 0.1-1000 mg/kg in the respective models. Vaginal cytology, body weights, and temperature, as well as blood glucose, testosterone, and insulin levels, were measured. Total antioxidant capacity and malondialdehyde levels were analyzed. Determination of gene expression of some reactive oxygen species and histomorphological analysis on the ovaries and uteri were performed. At the end of the experiments, AA and ATE restored reproductive cycling, with AA being more effective. AA and ATE increased fasting blood glucose but had no significant effect on serum insulin levels. AA decreased testosterone levels, but ATE caused slight increases. AA and ATE both increased total antioxidant capacity and decreased malondialdehyde levels. AA and ATE also slightly upregulated the mRNA expressions of catalase, superoxide dismutase, and heme oxygenase 1 mainly. AA and ATE also decreased ovarian weight and mostly resolved cysts in the ovaries and congestion in the uterus. This study has shown that AA and ATE are beneficial in the therapy of PCOS.

The cardiovascular protective effects of rooibos (Aspalathus linearis) extract on diesel exhaust particles induced inflammation and oxidative stress involve NF-κB- and Nrf2-dependent pathways modulation.

Studies have shown that diesel exhaust particles (DEP) induced oxidative stress and inflammation. This present study examined the molecular effects of aqueous rooibos extract (RE) on the cardiovascular toxic effect of methanol extract of DEP in exposed Wistar rats. The results showed that DEP caused significant (p < 0.001) increase in MDA and CDs levels in the aorta and heart but this increase was significantly (p < 0.001) attenuated by rooibos extract. DEP induced IL-8, TNFα, IL-1ß and decreased IL-10 gene expressions, all of which were reversed in the presence of rooibos extract. The expression of NF-κB, and IκKB genes were also significantly (p < 0.001) induced by DEP in both tissues, but pre-treatment with RE attenuated these effects. In contrast, DEP repressed IκB mRNA level, which was significantly (p < 0.001) reversed by rooibos extract pre-treatment. In addition, pre-treatment with rooibos extract attenuated the increased Nrf2 and HO-1 mRNA levels caused by DEP. This indicates the potential of rooibos extract to protect against DEP-induced cardiovascular toxicity.

Comparative research performance of top universities from the northeastern Brazil on three pharmacological disciplines as seen in scopus database.

OBJECTIVES: Postgraduate programmes around the world are periodically subjected to research performance evaluation through bibliometric indicators. In this research, we characterized and compared the research performance of 15 universities from Northeastern Brazil, in which 13 were among the top Universities of the Latin America. METHODS: Specifically, total documents, citations and the h-index of each university were retrieved from the Elsevier Scopus database and were analysed not only for historical scientific achievement but also across the period of the past 6 years (2010-2015). Using these bibliometric indicators, we also investigated the performance of programmes at these Universities that have their papers indexed in the Scopus database under the category of "Pharmacology, Toxicology and Pharmaceuticals" for the same period. RESULTS: We found that the Federal University of Pernambuco (UFPE) and the Federal University of Ceará (UFC) were the most productive institutions, producing 17847 and 15048 documents, respectively. The number of papers published by each of these universities in the past six years represented more than 50% of their entire productivity. With regards to their scientific output in "Pharmacology, Toxicology and Pharmaceutics", UFC showed the highest number of published documents followed by UFPE and the Federal University of Paraíba (UFPB). UFC received the highest h-index (with and without self-citations) and number of citations and shared their most cited papers with foreign institutions from the USA and Germany. However, papers from UFC were published in journals with lower impact factors (2.322). CONCLUSIONS: The present study shows where each of these universities stands and can be helpful in identifying potential collaborators in these areas of knowledge.