@article{MuthauraKerikoMutaietal.2017,
  author    = {Muthaura, Charles N. and Keriko, Joseph M. and Mutai, Charles and Yenesew, Abiy and Heydenreich, Matthias and Atilaw, Yoseph and Gathirwa, Jeremiah W. and Irungu, Beatrice N. and Derese, Solomon},
  title     = {Antiplasmodial, cytotoxicity and phytochemical constituents of four maytenus species used in traditional medicine in Kenya},
  series = {The natural products journal},
  volume    = {7},
  journal   = {The natural products journal},
  number    = {2},
  publisher = {Bentham Science Publ.},
  address   = {Sharjah},
  issn      = {2210-3155},
  doi       = {10.2174/2210315507666161206144050},
  pages     = {144 -- 152},
  year      = {2017},
  abstract  = {Background: In Kenya, several species of the genus Maytenus are used in traditional medicine to treat many diseases including malaria. In this study, phytochemical constituents and extracts of Maytenus undata, M. putterlickioides, M. senegalensis and M. heterophylla were evaluated to determine compound/s responsible for antimalarial activity. Objective: To isolate antiplasmodial compounds from these plant species which could be used as marker compounds in the standardization of their extracts as a phytomedicine for malaria. Methods: Constituents were isolated through activity-guided fractionation of the MeOH/CHCl3 (1:1) extracts and in vitro inhibition of Plasmodium falciparum. Cytotoxicity was evaluated using Vero cells and the compounds were elucidated on the basis of NMR spectroscopy. Results: Fractionation of the extracts resulted in the isolation of ten known compounds. Compound 1 showed promising antiplasmodial activity with IC50, 3.63 and 3.95 ng/ml against chloroquine sensitive (D6) and resistant (W2) P. falciparum, respectively and moderate cytotoxicity (CC50, 37.5 ng/ml) against Vero E6 cells. The other compounds showed weak antiplasmodial (IC50 > 1.93 mu g/ml) and cytotoxic (CC50 > 39.52 mu g/ml) activities against P. falciparum and Vero E6 cells, respectively. Conclusion: (20 alpha)-3-hydroxy-2-oxo-24-nor-friedela-1(10),3,5,7-tetraen-carboxylic acid-(29)-methyl-ester (pristimerin) (1) was the most active marker and lead compound that warrants further investigation as a template for the development of new antimalarial drugs. Pristimerin is reported for the first time in M. putterlickioides. 3-Hydroxyolean-12-en-28-oic acid (oleanolic acid) (5), stigmast-5-en-3-ol (beta-sitosterol) (6), 3-oxo-28-friedelanoic acid (7), olean-12-en-3-ol (beta-amyrin) (8), lup-20(29)-en-3-ol (lupeol) (9) and lup-20(29)-en-3-one (lupenone) (10) are reported for the first time in M. undata.},
  language  = {en}
}
@article{MuivaMutisyaAtilawHeydenreichetal.2018,
  author    = {Muiva-Mutisya, Lois M. and Atilaw, Yoseph and Heydenreich, Matthias and Koch, Andreas and Akala, Hoseah M. and Cheruiyot, Agnes C. and Brown, Matthew L. and Irungu, Beatrice and Okalebo, Faith A. and Derese, Solomon and Mutai, Charles and Yenesew, Abiy},
  title     = {Antiplasmodial prenylated flavanonols from Tephrosia subtriflora},
  series = {Natural Product Research},
  volume    = {32},
  journal   = {Natural Product Research},
  number    = {12},
  publisher = {Routledge, Taylor \& Francis Group},
  address   = {Abingdon},
  issn      = {1478-6419},
  doi       = {10.1080/14786419.2017.1353510},
  pages     = {1407 -- 1414},
  year      = {2018},
  abstract  = {The CH2Cl2/MeOH (1:1) extract of the aerial parts of Tephrosia subtriflora afforded a new flavanonol, named subtriflavanonol (1), along with the known flavanone spinoflavanone B, and the known flavanonols MS-II (2) and mundulinol. The structures were elucidated by the use of NMR spectroscopy and mass spectrometry. The absolute configuration of the flavanonols was determined based on quantum chemical ECD calculations. In the antiplasmodial assay, compound 2 showed the highest activity against chloroquine-sensitive Plasmodiumfalciparum reference clones (D6 and 3D7), artemisinin-sensitive isolate (F32-TEM) as well as field isolate (KSM 009) with IC50 values 1.4-4.6M without significant cytotoxicity against Vero and HEp2 cell lines (IC50>100M). The new compound (1) showed weak antiplasmodial activity, IC50 12.5-24.2M, but also showed selective anticancer activity against HEp2 cell line (CC50 16.9M). [GRAPHICS] .},
  language  = {en}
}
@article{KumarBasuLemkeetal.2016,
  author    = {Kumar, Reddi K. and Basu, Sayantani and Lemke, Horst-Dieter and Jankowski, Joachim and Kratz, Karl and Lendlein, Andreas and Tetali, Sarada D.},
  title     = {Effect of extracts of poly(ether imide) microparticles on cytotoxicity, ROS generation and proinflammatory effects on human monocytic (THP-1) cells},
  series = {Clinical hemorheology and microcirculation : blood flow and vessels},
  volume    = {61},
  journal   = {Clinical hemorheology and microcirculation : blood flow and vessels},
  publisher = {IOS Press},
  address   = {Amsterdam},
  issn      = {1386-0291},
  doi       = {10.3233/CH-152027},
  pages     = {667 -- 680},
  year      = {2016},
  abstract  = {A high cell viability of around 99 +/- 18\% and 99 +/- 5\% was observed when THP-1 cells were cultured in the presence of aqueous extracts of the PEI microparticles in medium A and medium B respectively. The obtained microscopic data suggested that PEI particle extracts have no significant effect on cell death, oxidative stress or differentiation to macrophages. It was further found that the investigated proinflammatory markers in THP-1 cells were not up-regulated. These results are promising with regard to the biocompatibility of PEI microparticles and in a next step the hemocompatibility of the microparticles will be examined.},
  language  = {en}
}
@article{ChepkiruiOchiengSarkaretal.2020,
  author    = {Chepkirui, Carolyne and Ochieng, Purity J. and Sarkar, Biswajyoti and Hussain, Aabid and Pal, Chiranjib and Yang, Li Jun and Coghi, Paolo and Akala, Hoseah M. and Derese, Solomon and Ndakala, Albert and Heydenreich, Matthias and Wong, Vincent K. W. and Erdelyi, Mate and Yenesew, Abiy},
  title     = {Antiplasmodial and antileishmanial flavonoids from Mundulea sericea},
  series = {Fitoterapia},
  volume    = {149},
  journal   = {Fitoterapia},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0367-326X},
  doi       = {10.1016/j.fitote.2020.104796},
  pages     = {6},
  year      = {2020},
  abstract  = {Five known compounds (1-5) were isolated from the extract of Mundulea sericea leaves. Similar investigation of the roots of this plant afforded an additional three known compounds (6-8). The structures were elucidated using NMR spectroscopic and mass spectrometric analyses. The absolute configuration of 1 was established using ECD spectroscopy. In an antiplasmodial activity assay, compound 1 showed good activity with an IC50 of 2.0 mu M against chloroquine-resistant W2, and 6.6 mu M against the chloroquine-sensitive 3D7 strains of Plasmodium falciparum. Some of the compounds were also tested for antileishmanial activity. Dehydrolupinifolinol (2) and sericetin (5) were active against drug-sensitive Leishmania donovani (MHOM/IN/83/AG83) with IC50 values of 9.0 and 5.0 mu M, respectively. In a cytotoxicity assay, lupinifolin (3) showed significant activity on BEAS-2B (IC50 4.9 mu M) and HePG2 (IC50 10.8 mu M) human cell lines. All the other compounds showed low cytotoxicity (IC50 > 30 mu M) against human lung adenocarcinoma cells (A549), human liver cancer cells (HepG2), lung/bronchus cells (epithelial virus transformed) (BEAS-2B) and immortal human hepatocytes (LO2)},
  language  = {en}
}