Aframomum melegueta secondary metabolites exhibit polypharmacology against SARS-CoV-2 drug targets: in vitro validation of furin inhibition.

COVID-19 pandemic is currently decimating the world's most advanced technologies and largest economies and making its way to the continent of Africa. Weak medical infrastructure and over-reliance on medical aids may eventually predict worse outcomes in Africa. To reverse this trend, Africa must re-evaluate the only area with strategic advantage; phytotherapy. One of the many plants with previous antiviral potency is against RNA viruses is Aframomum melegueta. In this study, one hundred (100) A. melegueta secondary metabolites have been mined and computational evaluated for inhibition of host furin, and SARS-COV-2 targets including 3C-like proteinase (Mpro /3CLpro ), 2'-O-ribose methyltransferase (nsp16) and surface glycoprotein/ACE2 receptor interface. Silica-gel column partitioning of A. melegueta fruit/seed resulted in 6 fractions tested against furin activity. Diarylheptanoid (Letestuianin A), phenylpropanoid (4-Cinnamoyl-3-hydroxy-spiro[furan-5,2'-(1'H)-indene]-1',2,3'(2'H,5H)-trione), flavonoids (Quercetin, Apigenin and Tectochrysin) have been identified as high-binding compounds to SARS-COV-2 targets in a polypharmacology manner. Di-ethyl-ether (IC50 = 0.03 mg/L), acetone (IC50 = 1.564 mg/L), ethyl-acetate (IC50 = 0.382 mg/L) and methanol (IC50 = 0.438 mg/L) fractions demonstrated the best inhibition in kinetic assay while DEF, ASF and MEF completely inhibited furin-recognition sequence containing Ebola virus-pre-glycoprotein. In conclusion, A. melegueta and its secondary metabolites have potential for addressing the therapeutic needs of African population during the COVID-19 pandemic.

Influence of diffuse and chronic metal pollution in water and sediments on edible seafoods within Ondo oil-polluted coastal region, Nigeria.

The bioconcentration levels of 3 non-essential elements (Pb, Cd and Ni) have been investigated in three different seafoods; Fish (Tilapia zilli), Crab (Callinectes sapidus) and periwinkle (Littorina littorea), to investigate the ecosystem health status in Ondo oil-polluted coastal region, Nigeria. The seafood samples were chosen based on their popularity as a food source and the potential of the species to contain high levels of metals based on past research results. Metal concentrations in the biota showed marked interspecific differences with C. sapidus recording the highest concentrations of all the metals. The bioconcentration factor (BCF) showed that C. sapidus and T. zilli have the greatest potential to concentrate Cd (BCF = 3-10) and Pb (BCF = 11-84) respectively. Lead uptake from both water and sediment (BCF ≈ BSAF: 0.003-0.018) were abysmally low in L. littorea as compared with other organisms. The high concentrations of Pb in fish species, effective bioaccumulation of Cd in species of crab and periwinkles, as well as very high BSAF of Ni found in species of crab indicated a strong influence from anthropogenic pollutant source on the biotic community. Oil pollution appears to be a major source of bioavailable metal contaminants for the selected biota. The study shows that C. sapidus and L. littorea can effectively compartmentalize potentially toxic metals such as Cd, Pb and Ni within their tissues. In terms of toxicity, C. sapidus had Cd concentrations greater than the 3,000 ng/g limit set by the Commission of the European Communities while Pb concentration exceeded their limits in both C. sapidus and T. zilli. All levels of Ni were below the U.S. Food and Drug Administration action levels for these metals in fish, crustaceans and shellfish. The study revealed anthropogenic enrichment of the metals studied which can possibly pose potential threats to the ecology of the area.