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Investment in SARS-CoV-2 sequencing in Africa over the past year has led to a major increase in the number of sequences generated, now exceeding 100,000 genomes, used to track the pandemic on the continent. Our results show an increase in the number of African countries able to sequence domestically, and highlight that local sequencing enables faster turnaround time and more regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and shed light on the distinct dispersal dynamics of Variants of Concern, particularly Alpha, Beta, Delta, and Omicron, on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve, while the continent faces many emerging and re-emerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century.

Three triterpenoidal saponins were isolated from the saponin fraction derived from a Gleditsia caspica Desf. methanolic fruit extract. The isolated saponins were identified as gleditsiosides B, C, and Q based on spectral data. The saponin-containing fraction was evaluated in vivo for genotoxic and antigenotoxic activities. The fraction caused no DNA damage in Swiss albino male mice treated with a dose of 45 mg/kg body weight for 24 h, although it significantly inhibited the number of chromosomal aberrations induced by cyclophosphamide (CP) in bone marrow and germ cells when applied before or after CP administration. The inhibitory indices in chromosomal aberrations were 59% and 41% for bone marrow and 48% and 43% for germ cells, respectively. In addition, the saponin fraction was found to reduce the viability of the human tumor cell line MCF-7 in a dose-dependent manner with an extrapolated IC50 value in the range of 220 μg/mL.

Potential of Casimiroa edulis and Glycosmis pentaphylla leaves extracts were investigated against the effect of two different particle sizes of silver nanoparticles induced toxicity in mice. Mice received silver nanoparticles (AgNPs) (100 mg/kg) with 20 and 100 nm for four weeks followed by daily oral dose of extracts (500 mg/kg) for three weeks. C. edulis leaves identified fourteen phenolic compounds while, G. pentaphylla leaves identified, twelve phenolic compounds. Additionally, biochemical, genotoxicity, mutagenicity, and histopathological investigations were carried out, revealed that liver function activities, lipid profile, hydrogen peroxide, and C-reactive protein were significantly elevate post AgNPs exposure. While, superoxide dismutase, glutathione-S-transferases, and glutathione peroxidase significantly reduce. A marked amelioration in all detected biomarkers, improved histopathological changes and repair DNA damage after treated with C. edulis and G. pentaphylla leaves extracts. These extracts are used for the first time as promising candidate therapeutic agents against toxicity induced by AgNPs. Practical applications The potential applications of AgNPs make it necessary to investigate the possible toxicity associated with release of free silver ions in the biological system. AgNPs of varying particle sizes had toxic effects as evidenced by alterations in some cellular biochemical parameters, genotoxicity, mutagenicity, and histopathological indices on mice. Casimiroa edulis and Glycosmis pentaphylla leaves extracts are used for the first time as promising candidate therapeutic, where they are able to ameliorate the toxicity induced via AgNPs and record vacillate percentage of improvement in the selected biomarkers, as a result of the bioactive secondary metabolites especially flavonoids and other polyphenolic compounds.

SummaryThe genotoxic effects of cobalt chloride (CoCl 2 ) were studied in mice using different mutagenic end points in vivo. The possible protection provided by the antioxidant selenium and vitamins (ACE) against CoCl 2 genotoxicity was also assessed. The results indicate that CoCl 2 has genotoxic effects on mice somatic and germ cells. It induced a significant increase in the frequency of chromosomal aberrations in mouse bone-marrow and spermatocytes after single and repeated oral treatments. The induction of morphological sperm abnormalities was also confirmed in the present study. The supplemental selenium and vitamins (ACE) to reduce the genotoxic effect of CoCl 2 was proved.

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