Search results for "Antimalarials"
showing 10 items of 50 documents
Prevention of carcinogenesis and metastasis by Artemisinin-type drugs.
2018
Artemisia annua (sweet wormwood, qinhao) is an ancient Chinese herbal remedy for pyrexia. Nowadays, artemisinin (qinghaosu) and its derivatives belong to the standard therapies against malaria worldwide, and its discovery has led to the Nobel Prize in Physiology and Medicine to Youyou Tu in 2015. While most attention has been paid to the treatment of malaria, there is increasing evidence that Artemisinin-type drugs bear a considerable potential to treat and prevent cancer. Rather than reporting on therapy of cancer, this review gives a comprehensive and timely overview on the chemopreventive effects of artemisinin and its derivatives against carcinogenesis and metastasis formation, followin…
Repurposing of artemisinin-type drugs for the treatment of acute leukemia.
2020
Cancer treatment represents an unmet challenge due to the development of drug resistance and severe side effects of chemotherapy. Artemisinin (ARS)-type compounds exhibit excellent antimalarial effects with few side effects and drug-resistance. ARS and its derivatives were also reported to act against various tumor types in vitro and in vivo, including acute leukemia. Therefore, ARS-type compounds may be exquisitely suitable for repurposing in leukemia treatment. To provide comprehensive clues of ARS and its derivatives for acute leukemia treatment, their molecular mechanisms are discussed in this review. Five monomeric molecules and 72 dimers, trimers and hybrids based on the ARS scaffold …
Development of Novel Peptide-Based Michael Acceptors Targeting Rhodesain and Falcipain-2 for the Treatment of Neglected Tropical Diseases (NTDs)
2017
This paper describes the development of a class of peptide-based inhibitors as novel antitrypanosomal and antimalarial agents. The inhibitors are based on a characteristic peptide sequence for the inhibition of the cysteine proteases rhodesain of Trypanosoma brucei rhodesiense and falcipain-2 of Plasmodium falciparum. We exploited the reactivity of novel unsaturated electrophilic functions such as vinyl-sulfones, -ketones, -esters, and -nitriles. The Michael acceptors inhibited both rhodesain and falcipain-2, at nanomolar and micromolar levels, respectively. In particular, the vinyl ketone 3b has emerged as a potent rhodesain inhibitor (k2nd = 67 × 106 M-1 min-1), endowed with a picomolar b…
Biosynthesis of heme O in intraerythrocytic stages of Plasmodium falciparum and potential inhibitors of this pathway
2019
A number of antimalarial drugs interfere with the electron transport chain and heme-related reactions; however, the biosynthesis of heme derivatives in Plasmodium parasites has not been fully elucidated. Here, we characterized the steps that lead to the farnesylation of heme. After the identification of a gene encoding heme O synthase, we identified heme O synthesis in blood stage parasites through the incorporation of radioactive precursors. The presence of heme O synthesis in intraerythrocytic stages of Plasmodium falciparum was confirmed by mass spectrometry. Inabenfide and uniconazole–P appeared to interfere in heme synthesis, accordingly, parasite growth was also affected by the additi…
Access to new highly potent antileukemia, antiviral and antimalarial agents via hybridization of natural products (homo)egonol, thymoquinone and arte…
2018
Hybridization of natural products has high potential to further improve their activities and may produce synergistic effects between linked pharmacophores. Here we report synthesis of nine new hybrids of natural products egonol, homoegonol, thymoquinone and artemisinin and evaluation of their activities against P. falciparum 3D7 parasites, human cytomegalovirus, sensitive and multidrug-resistant human leukemia cells. Most of the new hybrids exceed their parent compounds in antimalarial, antiviral and antileukemia activities and in some cases show higher in vitro efficacy than clinically used reference drugs chloroquine, ganciclovir and doxorubicin. Combined, our findings stress the high pot…
Evaluation of Mucociliary Clearance by Three Dimension Micro-CT-SPECT in Guinea Pig: Role of Bitter Taste Agonists
2016
Different image techniques have been used to analyze mucociliary clearance (MCC) in humans, but current small animal MCC analysis using in vivo imaging has not been well defined. Bitter taste receptor (T2R) agonists increase ciliary beat frequency (CBF) and cause bronchodilation but their effects in vivo are not well understood. This work analyzes in vivo nasal and bronchial MCC in guinea pig animals using three dimension (3D) microCT-SPECT images and evaluates the effect of T2R agonists. Intranasal macroaggreggates of albumin-Technetium 99 metastable (MAA-Tc99m) and lung nebulized Tc99m albumin nanocolloids were used to analyze the effect of T2R agonists on nasal and bronchial MCC respecti…
The activity of Artemisia spp. and their constituents against Trypanosomiasis.
2018
Abstract Background Trypanosomiasis belongs to the neglected tropical diseases. Although standard therapies are available, the safety and efficacy of current synthetic drugs are limited due to the development of drug resistance and adverse side effects. Purpose Artemisia annua and artemisinin are not only active against Plasmodia, but also other protozoa. Therefore, we reviewed the literature on species of the genus Artemisia and their phytochemicals regarding their activity against trypanosomes. Study design A PubMed search for “Artemisia/Artemisinin and Trypanosoma” has been conducted for literature until December 2017. Results Interestingly, not only A. annua L. and its active principle,…
Bistacrine derivatives as new potent antimalarials
2016
Linking two tacrine molecules results in a tremendous increase of activity against Plasmodia in comparison to the monomer. This finding prompted the synthesis of a library of monomeric and dimeric tacrine derivatives in order to derive structure-activity relationships. The most active compounds towards chloroquine sensitive Plasmodium strain 3D7 and chloroquine resistant strain Dd2 show IC50 values in the nanomolar range of concentration, low cytotoxicity and target the cysteine protease falcipain-2, which is essential for parasite growth.
Multi-omics approaches to improve malaria therapy.
2021
Malaria contributes to the most widespread infectious diseases worldwide. Even though current drugs are commercially available, the ever-increasing drug resistance problem by malaria parasites poses new challenges in malaria therapy. Hence, searching for efficient therapeutic strategies is of high priority in malaria control. In recent years, multi-omics technologies have been extensively applied to provide a more holistic view of functional principles and dynamics of biological mechanisms. We briefly review multi-omics technologies and focus on recent malaria progress conducted with the help of various omics methods. Then, we present up-to-date advances for multi-omics approaches in malari…
Development of artemisinin resistance in malaria therapy
2019
Malaria affects 200 million people worldwide. Today, the most successful treatments are artemisinin-based combination therapies (ACT). Resistance has already been described for the elder anti-malarials chloroquine, sulfadoxine-pyrimethamine and mefloquine. Unfortunately, over the last few years there has also been an emerging resistance to the successfully used drug artemisinin, especially in African and Asian countries. A systematic PubMed literature research was conducted for studies published between January 2002 and December 2018. Despite ACTs continue to be first line treatment, the number of studies is rising reporting on artemisinin resistance mutations. Most publications reported on…