Browsing by Author "Nyandoro, Stephen S."

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Antiplasmodial, antimicrobial and cytotoxic activities of extracts from selected medicinal plants growing in Tanzania
    (Taylor & Francis, 2019) Begum, Sartaz; Nyandoro, Stephen S.; Munissi, Joan J. E.; Buriyo, Amelia S.; Makangara, John J.; Lucantoni, Leonardo; Avery, Vicky M.; Erdelyi, Mate
    This paper reports on the evaluation of antiplasmodial, antimicrobial and cytotoxic activities of extracts from eleven plant species traditionally used by some Tanzanian coastal communities for treatment of malaria, microbial infections and related ailments. Crude extracts from selected plant species namely Acacia zanzibarica, Danais xanthorrhoea, Diospyros loureiriana ssp. rufescens, Erythrina sacleuxii, Newtonia paucijuga, Pentas lanceolata, Scorodophloeus fischeri, Stuhlmannia moavi, Tarenna pavettoides, Tessmannia burttii and Toussaintia orientalis growing in Tanzania were investigated using an imaging-based assay (antiplasmodial), well diffusion and microplate dilution methods (antimicrobial) and human embryonic kidney cells (HEK 293) and brine shrimp larvae assays (toxicity). The extracts exhibited activities of varying potencies and cytotoxicity with IC50 values ranging from 0.45 ± 0.09 to 75.70 ± 24.19 μg/mL against Plasmodium falciparum (3D7 strain), MIC ranging from 0.25 to 2.0 mg/mL (against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans and Cryptococcus neoformans), LC50 ranging from 0.75 to 1000 μg/mL against brine shrimp larvae (Artemia salina) and IC50 ranging from 4.02 ± 1.05 to more than 289 μg/mL against HEK 293 cells. The observed bioactivities of some of the investigated plant extracts validate their ethnomedicinal use and are indicative of the presence of bioactive ingredients for further phytochemical investigations.
  • Thumbnail Image
    Item
    Draft genome sequence of Limnospira sp. strain BM01, isolated from a hypersaline lake of the Momela ecosystem in Tanzania
    (American Society for Microbiology, 2021) Maghembe, Reuben; Michael, Angelina; Harish, Ajith; Nyandoro, Stephen S.; Lyantagaye, Sylvester L.; Hati-Kau, Rajni
    The genus Limnospira includes cyanobacterial species used for industrial production of dietary supplements and nutraceutical agents. The metagenome-assembled genome of Limnospira sp. strain BM01 from Big Momela Lake, Tanzania, was 6,228,312 bp long with a GC content of 44.8% and carried 4,921 proteins and 52 RNA genes, including 6 rRNA genes.
  • Thumbnail Image
    Item
    Luteolin: a blocker of SARS-CoV-2 cell entry based on relaxed complex scheme, molecular dynamics simulation, and metadynamics
    (Springer, 2021) Shadrack, Daniel M.; Deogratias, Geradius; Kiruri, Lucy W.; Onoka, Isaac; Vianne, John-Mary; Swai, Hulda; Nyandoro, Stephen S.
    Natural products have served human life as medications for centuries. During the outbreak of COVID-19, a number of naturally derived compounds and extracts have been tested or used as potential remedies against COVID-19. Tetradenia riparia extract is one of the plant extracts that have been deployed and claimed to manage and control COVID-19 by some communities in Tanzania and other African countries. The active compounds isolated from T. riparia are known to possess various biological properties including antimalarial and antiviral. However, the underlying mechanism of the active compounds against SARS-CoV-2 remains unknown. Results in the present work have been interpreted from the view point of computational methods including molecular dynamics, free energy methods, and metadynamics to establish the related mechanism of action. Among the constituents of T. riparia studied, luteolin inhibited viral cell entry and was thermodynamically stable. The title compound exhibit residence time and unbinding kinetics of 68.86 ms and 0.014 /ms, respectively. The findings suggest that luteolin could be potent blocker of SARS-CoV-2 cell entry. The study shades lights towards identification of bioactive constituents from T. riparia against COVID-19, and thus bioassay can be carried out to further validate such observations.