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Treatment and prevention of malaria
Published in David A Warrell, Herbert M Gilles, Essential Malariology, 2017
David A Warrell, William M Watkins, Peter A Winstanley
On the Thai-Burmese border, parasite resistance to mefloquine 25 mg/kg was 50 per cent in 1994. At this point, treatment was changed to mefloquine 25 mg/kg plus artesunate 4 mg/kg. Over the intervening period to 2000, mefloquine resistance has continued to increase in areas of Thailand where mefloquine monotherapy has been used. Conversely, while the cure rate of the mefloquine plus artesunate regimen has remained over 95 per cent, parasite chemosensitivity to mefloquine has increased rather than decreased. Artesunate is a rapidly acting blood schizontocide, reducing parasite density in vivo faster than any other antimalarial drug. Further, it has a pronounced inhibitory effect on gametocytes, which mefloquine alone does not, and so transmission is reduced. One effect of this double action has been to lower the P. falciparum case load in this area, as well as maintaining or improving therapeutic efficacy. The combination of mefloquine with an artemisinin is now national policy in Thailand, Vietnam and Cambodia. Studies in South-east Asia and Africa have demonstrated that in combinations of drugs with artemisinins (ACT) with mefloquine or sulfadoxine-pyrimethamine, 3 days of artemisinin are needed to improve cure rates of the partner drug alone.
Various Applications of Artemisia annua L. (Qinghao)
Published in Tariq Aftab, M. Naeem, M. Masroor, A. Khan, Artemisia annua, 2017
Himanshu Misra, Mauji Ram, Ashish Bharillya, Darshana Mehta, Bhupendra Kumar Mehta, Dharam Chand Jain
Allergic asthma is a chronic airway disorder characterized by airway inflammation, mucus hypersecretion, and airway hyperresponsiveness (AHR) (Galli et al., 2008). Artesunate is a clinically effective drug for both uncomplicated and severe malaria (Krishna et al., 2008; Rosenthal, 2008; Woodrow et al., 2005). Some recent findings (Cheng et al., 2011) support a novel therapeutic use of artesunate in the treatment of asthma. Cheng et al. (2011), for the first time, investigated the effects of artesunate on various aspects of ovalbumin (OVA)-induced T helper type 2 (TH2)-mediated allergic airway inflammation in an in vivo mouse asthma model to explore the anti-inflammatory mechanism of action of artesunate. Results revealed that artesunate, a semisynthetic derivative of artemisinin, has effectively reduced OVA-induced inflammatory cell recruitment into BAL fluid, IL-4, IL-5, IL-13, eotaxin production, pulmonary eosinophilia, mucus hypersecretion, and AHR in a mouse asthma model potentially via inhibition of the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway.
Artesunate
Published in M. Lindsay Grayson, Sara E. Cosgrove, Suzanne M. Crowe, M. Lindsay Grayson, William Hope, James S. McCarthy, John Mills, Johan W. Mouton, David L. Paterson, Kucers’ The Use of Antibiotics, 2017
Robert J. Commons, Julie A. Simpson, James S. McCarthy, Ric N. Price
Artesunate is available in oral, intravenous, intramuscular and rectal formulations. Similar to other artemisinin derivatives, artesunate acts to rapidly reduce the malaria parasite burden and achieve symptom resolution. It is the only artemisinin that can be delivered intravenously, and as such is a key drug in the treatment of severe malaria. Artesunate has activity against all malaria species, as well as a spectrum of other parasites including trematodes, Leishmania, Trypanosoma, and Taeniidae. Artesunate also has in vitro activity against cytomegalovirus (CMV) and hepatitis B virus.
Lessons learned from the discovery and development of the sesquiterpene lactones in cancer therapy and prevention
Published in Expert Opinion on Drug Discovery, 2022
Israa A. Cheikh, Chirine El-Baba, Ali Youssef, Najat A. Saliba, Akram Ghantous, Nadine Darwiche
The long-term administration of artemisinins was sometimes associated with neurotoxicity and hearing loss. A resected breast cancer patient medicated on 200 mg of artemisinin tablets twice a day, tamoxifen, fluoxetine, and other herbal preparations experienced ataxia, nystagmus and slurred speech, and brainstem encephalopathy that rapidly resolved upon artemisinin withdrawal [197]. Based on the concerns expressed over the possible adverse impact of artemisinin and its derivatives on the brainstem and other neuroauditory structures, a study assessed the tolerability and safety of artesunate for hearing in 23 patients with advanced breast cancer (NCT00764036) [198]. A dose of 200 mg/day of oral artesunate was well tolerated and recommended for further clinical studies [199]. During the first month of the dose escalation therapy with artesunate, four patients experienced subclinical hearing loss and tinnitus. The same adverse effects were experienced by one patient after 11 months of the test phase. One patient experienced severe vertigo side effects which were reversible upon withdrawal of artesunate treatment [198]. Among the participants, 13 patients who had tolerated artesunate without adverse events, continued the treatment for more than one thousand additional days during compassionate use. Grade 3 adverse events were observed, but they were tolerable and with no definite relation to artesunate administration [200]. Therefore, audiological assessment of the extended administration of oral artesunate on a larger patient’s size and in doses up to 200 mg daily is needed in further clinical trials.
Apoferritin: a potential nanocarrier for cancer imaging and drug delivery
Published in Expert Review of Anticancer Therapy, 2021
Hanitrarimalala Veroniaina, Xiuhua Pan, Zhenghong Wu, Xiaole Qi
Their innate tumor-targeting capability without any ligand functionalization or surface modification makes apoferritin ahead of other nanocarriers. Additionally, the high premature efflux of drug molecules from other nanocarriers leads often to an empty vehicle when reached the tumor site [63], this drawback could be effectively solved by apoferritin. Artesunate (AS) is a well-known antimalarial drug and has recently shown significant cytotoxicity in various cancer cells. However, the anti-cancer effect of AS depends on the existence of ferrous ions (Fe(II)). New approaches are therefore needed for effective synchronous delivery of AS and Fe(II) to treat cancers. As apoferritin is the only endogenous protein capable of transporting iron ions, our group has developed a biomineralized apoferritin containing ferriferous oxide to produce auxiliary exogenous Fe(II) when delivering AS to cancer cells [64]**. In this study, AS-loaded Fe(II)-apoferritin significantly improves the tumor-specific targeting and the intracellular uptake of AS in human cervical carcinoma cells. After being captured in the acidic cavity of the endosomes, this protein nanocarrier may simultaneously release Fe(II) and allow AS to activate satisfactory reactive oxygen species (ROS)-mediated apoptosis.
Safety assessment of MEFAS: an innovative hybrid salt of mefloquine and artesunate for malaria treatment
Published in Drug and Chemical Toxicology, 2021
Daniely Alves de Lima, Carlos Eduardo Linhares Andreotti, Fabiane Antiquera Ferreira, Karoline Bach Pauli, Gustavo Ratti da Silva, Rita de Cássia Lima Ribeiro, Paulo Roberto Dalsenter, Nubia Boechat, Arquimedes Gasparotto Junior, Emerson Luiz Botelho Lourenço, Francislaine Aparecida dos Reis Lívero
Toxicological studies assess several physiological parameters (e.g., body weight and food and water consumption), perform histopathological evaluations, and determine the duration and reversibility of toxicological effects (Gonzáles and Silva 2003). In this study, three doses of MEFAS were tested in mice and compared with the same doses of its precursors artesunate and mefloquine. In a preclinical test of the acute toxicity of artesunate, Li et al. (2007) evaluated renal failure in rats that were treated with the drug. Dow et al. (2006) evaluated the neurological effects of mefloquine in rats and observed an increase in spontaneous activity, the impairment of motor function, and the degeneration of specific brainstem nuclei. The clinical toxicological effects of artesunate + mefloquine have been well described in the literature, include neurotoxicity, acute nausea, vomiting, anorexia, gastrointestinal alterations, and dizziness (Ribeiro and Olliaro 1998, Price et al.1999, Park et al.2002, Nevin 2014). In this study, we found that the combination of artesunate + mefloquine caused important clinical and histopathological alterations that were not evident with any of the MEFAS doses tested. Our findings provide evidence of the safety of MEFAS, demonstrating that this compound may be an important therapeutic tool when safety and efficacy are priorities for malaria treatment.