In silico molecular modeling and simulations of black tea theaflavins revealed theaflavin-3'-gallate as putative liver X receptor-beta agonist.

The low constitutive activation of Liver X receptor, an endogenous nuclear receptor with two subtypes (α and ß), is a condition lying at the crossroad of cancer and cardiovascular disease. Both natural and synthetic Liver X receptor agonists have reportedly shown remarkable antiproliferative and atheroprotective effects but the repeated doses of its synthetic ones are also paradoxically associated with hyperlipidaemic effects and neurotoxicity, though attributed to the alpha subtype. This highlights the need for novel, safe, and potent LXR-beta-selective agonists. Hypocholesterolaemic effects of black theaflavins have been widely reported, but data on the exact theaflavin compound (s) responsible for these effects is currently lacking. Neither is information on the possible modulatory effects of the compound (s) on LXR-beta nor its possible implications in the context of drug development for cardiovascular diseases and cancers is explored. On this account, we investigated the potential interaction of four main theaflavin monomers (TF1, TF2A, TF2B & TF3) with human LXR-beta through robust computational modelling that entails molecular docking, free energy calculations and molecular dynamics simulations. The ligands were further profiled (in silico) for absorption, distribution, metabolism, excretion, and toxicological properties. Our result revealed theaflavin TF2B as a putative LXR-beta agonist, possibly responsible for the widely observed hypocholesterolaemic effect in black tea. This finding, while encouraging, needs to be experimentally verified in wet studies.Communicated by Ramaswamy H. Sarma.

Mistletoe infested Moringa oleifera and Terminalia catappa leaves supplemented diet enhances antioxidant and insulin-like peptide mRNA levels in Drosophila melanogaster.

Moringa and Almond are common plants of medicinal and economic value which are often infested with mistletoe. Host plants' infestation could result in major differences in their phytoconstituents and biological activities. Thus, effects of mistletoe infestation on Moringa and Almond host plants supplemented diets on mRNA expression levels of Drosophila insulin-like peptide-2 (Dilp2), heat shock protein-70 (Hsp70) and superoxide dismutase (Sod) in diabetic-like flies were evaluated using quantitative real-time PCR system. Mistletoe infestation on host leaves caused significant upregulation of Sod and significant downregulation of Hsp70 and Dilp2 genes. Hence, we opined that infestation of Moringa and Almond trees with mistletoe resulted in improved expression level of antioxidant and insulin-like peptide genes. This may be the mechanism by which host plants caused enhanced regulation of circulating glucose and oxidative stress. Therefore, consumption of mistletoe infested Moringa and Almond host leaves could possibly offer better antioxidant and hypoglycemic effects.

Will Africans take COVID-19 vaccination?

The economic and humanistic impact of COVID-19 pandemic is enormous globally. No definitive treatment exists, hence accelerated development and approval of COVID-19 vaccines, offers a unique opportunity for COVID-19 prevention and control. Vaccine hesitancy may limit the success of vaccine distribution in Africa, therefore we assessed the potentials for coronavirus vaccine hesitancy and its determinants among Africans. An online cross-sectional African-wide survey was administered in Arabic, English, and French languages. Questions on demographics, self-reported health status, vaccine literacy, knowledge and perception on vaccines, past experience, behavior, infection risk, willingness to receive and affordability of the SARS-COV-2 vaccine were asked. Data were subjected to descriptive and inferential statistics. A total of 5,416 individuals completed the survey. Approximately, 94% were residents of 34 African countries while the other Africans live in the Diaspora. Only 63% of all participants surveyed were willing to receive the COVID-19 vaccination as soon as possible and 79% were worried about its side effects. Thirty-nine percent expressed concerns of vaccine-associated infection. The odds of vaccine hesitancy was 0.28 (95% CI: 0.22, 0.30) among those who believed their risk of infection was very high, compared to those who believed otherwise. The odds of vaccine hesitancy was one-fifth (OR = 0.21, 95% CI: 0.16, 0.28) among those who believed their risk of falling sick was very high, compared to those who believed their risk of falling very sick was very low. The OR of vaccine hesitancy was 2.72 (95% CI: 2.24, 3.31) among those who have previously refused a vaccine for themselves or their child compared to counterparts with no self-reported history of vaccine hesitancy. Participants want the vaccines to be mandatory (40%), provided free of charge (78%) and distributed in homes and offices (44%). COVID-19 vaccine hesitancy is substantial among Africans based on perceived risk of coronavirus infection and past experiences.

Molecular docking and pharmacokinetic studies of phytocompounds from Nigerian Medicinal Plants as promising inhibitory agents against SARS-CoV-2 methyltransferase (nsp16).

BACKGROUND: Since the index case was reported in China, COVID-19 has led to the death of at least 4 million people globally. Although there are some vaccine cocktails in circulation, the emergence of more virulent variants of SARS-CoV-2 may make the eradication of COVID-19 more difficult. Nsp16 is an S-adenosyl-L-Methionine-dependent methyltransferase that plays an important role in SARS-CoV-2 viral RNA cap formation-a crucial process that confers viral stability and prevents virus detection by cell innate immunity mechanisms. This unique property makes nsp16 a promising molecular target for COVID-19 drug design. Thus, this study aimed to identify potent phytocompounds that can effectively inhibit SARS-CoV-2 nsp16. We performed in silico pharmacokinetic screening and molecular docking studies using 100 phytocompounds-isolated from fourteen Nigerian plants-as ligands and nsp16 (PDB: 6YZ1) as the target. RESULTS: We found that only 59 phytocompounds passed the drug-likeness analysis test. However, after the docking analysis, only six phytocompounds (oxopowelline, andrographolide, deacetylbowdensine, 11, 12-dimethyl sageone, sageone, and quercetin) isolated from four Nigerian plants (Crinum jagus, Andrographis paniculata, Sage plants (Salvia officinalis L.), and Anacardium occidentale) showed good binding affinity with nsp16 at its active site with docking score ranging from - 7.9 to - 8.4 kcal/mol. CONCLUSIONS: Our findings suggest that the six phytocompounds could serve as therapeutic agents to prevent viral survival and replication in cells. However, further studies on the in vitro and in vivo inhibitory activities of these 6 hit phytocompounds against SARS-CoV-2 nsp16 are needed to confirm their efficacy and dose.

In-silico analysis of the inhibition of the SARS-CoV-2 main protease by some active compounds from selected African plants.

OBJECTIVES: Over the years, Azadirachta indica, Mangifera indica, and Moringa oleifera have been shown to possess some antiviral characteristics. This study applies molecular docking techniques to assess inhibitory effects of some bioactive compounds from the plants mentioned above against the main protease (Mpro), a key protein involved in SARS-CoV-2 replication. Furthermore, adsorption, distribution, metabolism, excretion, and toxicity (ADMET) profiles for screened compounds were predicted in silico. METHODS: The crystal structure of Mpro was retrieved from the Protein Data Bank, while the plant bioactive compounds were retrieved from Pubchem. Drug-likeness of the selected compounds and a control drug (hydroxychloroquine) were assessed, and the compounds that satisfied the drug-likeness rule were docked against Mpro. The docked complexes were analyzed using LigPlot and the protein-ligand profiler server. The top five compound hits were subjected to ADMET screening using the ADMETSar server. RESULTS: A total of 17 out of 22 screened compounds passed Lipinski's assessment. Additionally, the most active compounds from the investigated plants exhibited relative inhibitory potentials against Mpro compared with hydroxychloroquine, which alludes to their possible involvement in inhibiting the SARS-CoV-2 main protease replication process. CONCLUSIONS: In our study, most of the active phytocomponents of the investigated plants exhibited relative inhibitory potentials against Mpro of SARS-CoV-2 and preferred pharmacological features when compared with hydroxychloroquine. These findings indicate these compounds are potentially antiviral candidates against SARS-CoV-2.

Providing TB and HIV outreach services to internally displaced populations in Northeast Nigeria: Results of a controlled intervention study.

BACKGROUND: A decade of Boko Haram insurgency brought conflict, mass displacement, and the destruction of basic infrastructure to Northeast Nigeria. Over 2 million internally displaced persons (IDPs) suffering from lack of basic hygienic conditions, malnutrition, and disease live in camps or are hosted by communities in the region, where the conflict has contributed to a massive destruction of health facilities. Infectious diseases like tuberculosis (TB) and HIV are especially difficult to address under such conditions, and IDPs are vulnerable to both. Although international investment supports some health interventions among IDPs, locally sourced solutions are lacking. METHODS AND FINDINGS: We evaluated the impact of an active case finding (ACF) intervention for TB and testing for HIV in IDP communities and provided linkages to treatment in 3 states in Northeast Nigeria: Adamawa, Gombe, and Yobe. The ACF was a component of a multistakeholder collaboration between government, civil society, and IDP community partners, which also included mapping of IDP populations and health services, supporting existing health facilities, developing a sample transport network, and organizing community outreach to support ACF. Between July 1, 2017, and June 30, 2018, ACF was conducted in 26 IDP camps and 963 host communities in 12 local government areas (LGAs) with another 12 LGAs serving as a control population. Outreach efforts resulted in 283,556 screening encounters. We screened 13,316 children and 270,239 adults including 150,303 (55.6%) adult women and 119,936 (44.4%) men. We tested 17,134 people for TB and 58,976 for HIV. We detected 1,423 people with TB and 874 people living with HIV. We linked 1,419 people to anti-TB treatment and 874 people with HIV to antiretroviral treatment sites. We evaluated additional TB cases notified and conducted comparative interrupted time series (ITS) analyses to assess the impact of ACF on TB case notifications. Through our efforts, bacteriologically confirmed TB notifications increased by 847 (45.1%) during the intervention period, with IDPs accounting for 46% of these notifications. The ITS analyses detected significant positive postintervention trend differences in TB notification rates between the intervention and control areas in all forms TB (incidence rate ratio [IRR] = 1.136 [1.072, 1.204]; p ≤ 0.001) and bacteriologically positive TB (IRR = 1.141 [1.058, 1.229]; p = 0.001). The TB prevalence (502 cases per 100,000 screening encounters) was 10 times the national notification rates and 2.3 times the estimated national incidence. Rates of HIV infection (1.8%) were higher than HIV prevalence estimates in the 3 states. Our study was limited by the nonrandom selection of LGAs. Furthermore, we did not use sensitive screening tools like chest X-ray and likely missed people with TB. CONCLUSIONS: In this study, we observed a burden of TB in IDP populations of Northeast Nigeria many times higher than national rates and HIV rates higher than state level estimates. The impact of the intervention showed that ACF can greatly increase TB case notifications. Engaging IDP communities, local governments, and civil society organizations is essential to ensuring the success of interventions targeting TB and HIV, and such approaches can provide sustained solutions to these and other health crises among vulnerable populations.

Postictal behavioural impairments are due to a severe prolonged hypoperfusion/hypoxia event that is COX-2 dependent.

Seizures are often followed by sensory, cognitive or motor impairments during the postictal phase that show striking similarity to transient hypoxic/ischemic attacks. Here we show that seizures result in a severe hypoxic attack confined to the postictal period. We measured brain oxygenation in localized areas from freely-moving rodents and discovered a severe hypoxic event (pO2 < 10 mmHg) after the termination of seizures. This event lasted over an hour, is mediated by hypoperfusion, generalizes to people with epilepsy, and is attenuated by inhibiting cyclooxygenase-2 or L-type calcium channels. Using inhibitors of these targets we separated the seizure from the resulting severe hypoxia and show that structure specific postictal memory and behavioral impairments are the consequence of this severe hypoperfusion/hypoxic event. Thus, epilepsy is much more than a disease hallmarked by seizures, since the occurrence of postictal hypoperfusion/hypoxia results in a separate set of neurological consequences that are currently not being treated and are preventable.

In vitro replication of bacteriophage GA RNA. Subunit structure and catalytic properties of GA replicase.

An RNA replicase of GA phage, one of the Group II RNA phages, was isolated and purified to a homogeneous state. By SDS polyacrylamide gel analysis, the purified GA replicase was found to contain four different subunits, numbered I, II, III, and IV, the molecular weights of which were 74,000, 60,000, 47,000, and 36,000, respectively. Three of them, I, III, and IV, proved to be host-coded proteins, ribosomal protein S1 (I), and elongation factors Tu (III) and Ts (IV) of protein biosynthesis, respectively. On a phosphocellulose column, the RNA replicase was separated into two components: One composed of subunits I and II, and the other composed of subunits III and IV. Each component alone had no replicase activity. However, when the two components were combined at 0 degree C, 60% of the replicase activity was restored within 10 min. The purified GA replicase catalyzed the GA phage RNA-directed synthesis of template-size RNA. However, the maximum level of product RNA synthesized was less than 20% of the amount of template RNA added. RNA-RNA hybridization experiments indicated that the product RNA included only the RNA strand complementary to the template RNA, and not the viral strand.

Template specificity of Qbeta and SP phage RNA replicases as studied by replication of small variant RNAs.

Template specificity of two RNA-dependent RNA polymerases (Qbeta and SP RNA replicases) was examined using "variant RNAs" as template. Three variant RNAs, one (8S) generated by Qbeta replicase and two (6S and 5.2S) generated by SP replicase, were isolated from the reaction mixtures incubated in the absence of exogenous template RNA. All these RNAs were found to be active as template for both Qbeta and SP replicases, though homologous RNA exhibited activities about three times higher than heterologous RNA with either enzyme, in agreement with the results obtained in phage RNA-dependent reactions. In these reactions, faithful replication of variant RNA was observed, and the amount of RNA synthesized was in a many-fold excess over the template RNA added. We also found that the heterologous RNA-dependent reactions were suppressed by increasing the concentration of salts or decreasing the concentration of substrates. Under such conditions, replication of heterologous variant RNA was almost completely suppressed, while the amount of homologous variant RNA synthesized was only reduced to 50% of that synthesized under the standard conditions. Thus the template specificity of the two RNA replicases seems to be expressed more strictly in these replication systems.

Identification of host-derived subunits of phage SP RNA-dependent RNA polymerase (SP replicase).

Phage SP RNA-dependent RNA polymerase (SP replicase) was purified from Escherichia coli infected with RNA phage SP. The enzyme was found to be composed of four non-identical polypeptides, i.e. subunits I, II, III, and IV and molecular weights of 74,000, 69,000, 47,000, and 36,000 daltons, respectively. As in the case of phage Qbeta replicase, the largest polypeptide is identical with the ribosomal protein S1, and subunits III and IV with polypeptide chain elongation factors EF-Tu and EF-ts, respectively.. This is based on the behaviour of the subunits on SDS-polyacrylamide gel electrophoresis, isoelectric focusing and immunological cross-reaction. Subunits I, III, and IV of SP replicase are derived from the host cell, while subunit II is coded by phage RNA genome. The striking coincidence of the composition and entity of the structural components of SP replicase with those of Qbeta replicase may indicate the structural and functional requirements of host-derived polypeptides in RNA replicase. The binding activity of S1 (in 70S ribosome comples) to poly (U) is retained in SP replicase complex. In contrast, the GDP binding activity of EF-Tu is masked in SP replicase. It is concluded that S1 is required functionally whereas EF-Tu.EF-Ts are required structurally in RNA replicase.

Grouping of RNA phages based on the template specificity of their RNA replicases.

We attempted to apply a new criterion, the template specificity of RNA replicases of Escherichia coli RNA phages, for the grouping of these phages. Based on the template specificity, it was shown that (a) Qbeta, VK, and ST belonged to one group (group III), and SP and FI to another group (group IV), and (b) some similarity existed between groups III and IV. Considering such template specificity in addition to previously reported properties of phage particles, we could separate RNA phages into four major groups (I-IV) with subgroups a, b, and c in group III, and subgroups a and b in group IV.