Drug used to prevent and treat malaria may also be effective for Zika virus

In continuation of my update on chloroquine

A new collaborative study led by researchers at Sanford Burnham Prebys Medical Discovery Institute (SBP) and UC San Diego School of Medicine has found that a medication used to prevent and treat malaria may also be effective for Zika virus. The drug, called chloroquine, has a long history of safe use during pregnancy, and is relatively inexpensive. The research was published today in Scientific Reports.

Zika virus remains a major global health risk. In most adults, Zika causes mild flu-like symptoms. But in pregnant women, the virus can cause serious birth defects in babies--including microcephaly--a neurological condition in which newborns have unusually small heads and fail to develop properly. There is no treatment or way to reverse the condition.

"There is still an urgent need to bolster our preparedness and capacity to respond to the next Zika outbreak," says Alexey Terskikh, Ph.D., associate professor at SBP. "Our latest research suggests the anti-malaria drug chloroquine may be an effective drug to treat and prevent Zika infections."

Terskikh is co-senior author of a new study that examined the effect of chloroquine in human brain organoids and pregnant mice infected with the virus, and found the drug markedly reduced the amount of Zika virus in maternal blood and neural progenitor cells in the fetal brain. Pregnant mice received chloroquine through drinking water in dosages equivalent to acceptable levels used in humans.

"Our research is the first to study Zika infection in a mouse model that transmits the virus in a way similar to humans," explains Alysson R. Muotri, Ph.D., professor and director of the Stem Cell Program at UC San Diego and co-senior author of the study. "Until now, researchers used a mouse strain that is deficient in interferon--a signaling protein that heightens anti-viral defenses. Those mice actually die from Zika infection, making it difficult to study the natural transmission of the virus from father and mother to fetus and to assess the effect of this transmission on the newborns.

"We believe our mouse model more accurately represents the way Zika virus infects men, women, and babies while in the womb," adds Terskikh. "Although chloroquine didn't completely clear Zika from infected mice it did reduce the viral load, suggesting it could limit the neurological damage found in newborns infected by the virus."

"In the 1950's, the Brazilian health agencies added chloroquine into cooking salt and distributed it to the population in endemic areas as an effective way of spreading the inexpensive anti-malarial drug as a prophylactic on a wide scale. This strategy was known as Pinotti's Method, named after its originator Dr. Mario Pinotti. It might be worth considering this medicated salt program one more time in Brazil", suggests Muotri.

"Chloroquine has a long history of successfully treating malaria, and there are no reports of it causing birth defects," says Terskikh. "Additional studies are certainly needed to determine the precise details of how it works. But given its low cost, availability and safety history further study in a clinical trial to test its effectiveness against Zika virus in humans is merited."

Ref : http://www.newswise.com/articles/view/685239/

Drug used to prevent and treat malaria may also be effective for Zika virus

Antimalarial drugs could find another use as cancer treatments, study says

Antimalarial drugs chloroquine and hydroxychloroquine could find another use as cancer treatments, according to a new clinical study published in ecancermedicalscience.

Researchers from the Repurposing Drugs in Oncology (ReDO) project, an international collaboration between the Anticancer Fund, Belgium, and USA-based GlobalCures, say there is evidence to include these drugs in further clinical investigations.

The authors are particularly excited about the potential for chloroquine and hydroxychloroquine as the evidence suggests they make tumor cells more sensitive to cancer treatment.
Chloroquine   Hydroxy chlroquine 

"What makes chloroquine and hydroxychloroquine so interesting is these multiple mechanisms of action", says Ciska Verbaanderd of the Anticancer Fund and the University of Leuven, Belgium, first author of the study."These antimalarial drugs act on both the level of cancer cells and the tumor microenvironment." Studying this has led to interesting scientific insights in tumor biology, such as the importance of autophagy, the tumor vasculature and the immune system."

"The results from the review lead us to believe that these antimalarial drugs could offer significant clinical benefit for certain cancer patients, especially in combination with standard anticancer treatments.This should be confirmed by additional clinical results."

Vikas P. Sukhatme MD ScD, co-founder of GlobalCures and one of the authors of this review, added "We look forward with much anticipation to the results of the 30 or so ongoing clinical studies that use chloroquine or hydroxychloroquine for cancer treatment."

The researchers' hope is that with the publication of this study, increased awareness of the potential applications will bring these medications out of the medicine cabinet - and into cancer care.

Previous papers from the ReDO project have explored how inexpensive, common drugs such as beta-blockers and anti-fungal remedies can be "repurposed" and used as part of cancer treatments.

Ref : http://ecancer.org/news/12864-antimalarial-drugs-could-support-existing-cancer-treatments-in-two-pronged-attack.php

Antimalarial drugs could find another use as cancer treatments, study says

Dual-acting hybrid drug could be a promising new weapon against drug-resistant malaria

A combination of artemisinin and another drug (artemisinin combination therapy, ACT) is currently the best malaria treatment recommended by the World Health Organization. In early 2015, artemisinin-resistant malaria was confirmed in five countries in Southeast Asia: Cambodia, Laos, Myanmar, Thailand, and Vietnam. Even more worrying, malaria cases that are resistant to practically all drugs have begun to emerge along the Thailand-Cambodia border. Such cases do not respond to ACT; thus, new therapies that are effective for resistant malaria are urgently needed.

For a therapy to be effective, it needs to counteract the resistance of malaria to existing drugs. Malaria drugs, such as chloroquine and artemisinin, work within the digestive vacuole of the malaria parasite, which serves as the stomach of the parasite. The killing action of chloroquine is better understood than that for artemisinin. Once chloroquine enters the parasite's "stomach," the stomach membrane traps the drug inside (similar to a window closing and locking) and the high levels of drug can then effectively kill the parasite. However, in a resistant malaria parasite, the stomach membrane is mutated so that it cannot keep the drug inside the stomach, just like a window with a broken lock. Since the drug is no longer concentrated inside the stomach, it can no longer kill the malaria parasite effectively.

Associate Professor Kevin Tan of the Department of Microbiology & Immunology and Associate Professor Brian Dymock of the Drug Development Unit and the Department of Pharmacy have now developed a hybrid drug that combines parts of chloroquine and a chemoreversal agent. This gives the hybrid drug a "dual acting" mechanism: a killing factor (chloroquine-derived) and a second component that acts on that faulty window of the parasite's stomach so it can now close again (the chemoreversal agent). The drug becomes concentrated inside the stomach of the drug-resistant parasite and can kill the parasite.

Dual-acting hybrid drug could be a promising new weapon against drug-resistant malaria: A combination of artemisinin and another drug (artemisinin combination therapy, ACT) is currently the best malaria treatment recommended by the World Health Organization.

Researchers identify 53 existing drugs that may block Ebola virus from entering human cells

Researchers found 53 existing drugs that may keep the Ebola virus from entering human cells, a key step in the process of infection, according to a study led by researchers at the Icahn School of Medicine at Mount Sinai and the National Institutes of Health (NIH), and published today in the Nature Press journal Emerging Microbes and Infections.

Among the better known drug types shown to hinder infection by an Ebola virus model: several cancer drugs, antihistamines and antibiotics. Among the most effective at keeping the virus out of human cells were microtubule inhibitors used to treat cancer.

"In light of the historic and devastating outbreak of Ebola virus disease, there is an urgent need to rapidly develop useful treatments against Ebola infection, and our study results argue that repurposing existing drugs may be among the fastest ways to achieve this," said lead author Adolfo García-Sastre, PhD, Director of the Global Health and Emerging Pathogens Institute within the Icahn School of Medicine at Mount Sinai. "Many of the compounds identified in this study promise to become lead compounds in near-future drug development efforts studies targeting this virus," said Dr. García-Sastre, also the Fishberg Chair and Professor of Medicine (Infectious Diseases) within the School.

A few are listed below...

Ref : http://www.nature.com/emi/journal/v3/n12/full/emi201488a.html

Nocodazole (IC₅₀=0.4 µM), Toremifene (0.55 µM), Tamoxifen (0.76 µM), Raloxifene 1.84 (1.53 µM), Cepharanthine (1.53 µM), Clomiphene (1.72 µM), Dronedarone (2.2 µM), Amodiaquine (4.43 µM), Imipramine (13.7 µM), Chloroquine (15.3 µM), and Nilotinib (15.3 µM).

Researchers identify 53 existing drugs that may block Ebola virus from entering human cells

New low-cost combined therapy shows promise against malaria

Molecular parasitologist Stephen Rich at the University of Massachusetts Amherst has led a research team who report a promising new low-cost combined therapy with a much higher chance of outwitting P. falciparum than current modes. He and plant biochemist Pamela Weathers at the Worcester Polytechnic Institute (WPI), with research physician Doug Golenbock at the UMass Medical School, also in Worcester, have designed an approach for treating malaria based on a new use of Artemisia annua, a plant employed for thousands of years in Asia to treat fever.

"The emergence of resistant parasites has repeatedly curtailed the lifespan of each drug that is developed and deployed," says UMass Amherst graduate student and lead author Mostafa Elfawal. Rich, an expert in the malaria parasite and how it evolves, adds, "We no sooner get the upper hand than the parasite mutates to become drug resistant again. This cycle of resistance to anti-malarial drugs is one of the great health problems facing the world today. We're hoping that our approach may provide an inexpensive, locally grown and processed option for fighting malaria in the developing world."

Currently the most effective malaria treatment uses purified extracts from the Artemisia plant as part of an Artemisinin Combined Therapy (ACT) regime with other drugs such as doxycycline and/or chloroquine, a prescription far too costly for wide use in the developing world. Also, because Artemisia yields low levels of pure artemisinin, there is a persistent worldwide shortage, they add.

The teams's thesis, first proposed by Weathers of WPI, is that locally grown and dried leaves of the whole plant, rich in hundreds of phytochemicals not contained in the purified drug, might be effective against disease at the same time limiting post-production steps, perhaps substantially reducing treatment cost. She says, "Whole-plant Artemisia has hundreds of compounds, some of them not even known yet. These may outsmart the parasites by delivering a more complex drug than the purified form."

Rich adds, "The plant may be its own complex combination therapy. Because of the combination of parasite-killing substances normally present in the plant (artemisinin and flavonoids), a synergism among these constituent compounds might render whole plant consumption as a form of artemisinin-based combination therapy, or what we're calling a 'pACT,' for plant Artemisinin Combination Therapy."

Ref : http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0052746

New low-cost combined therapy shows promise against malaria

Chloroquine as antiviral agent !

We all knew that chloroquine derivatives are better known as antimalarials, but something new chloroquine can be used as antiviral agent? yes says a group of researchers lead by Dr. Moscona and that too against the two lethal viruses Hendra and Nipah.

The research is significant because of the fact that the two henipaviruses that are the subject of the study are Hendra Virus (HeV) and Nipah Virus (NiV) emerged during the 1990s in Australia and Southeast Asia. (Spread via fruit bats, and they did cause potentially fatal encephalitis and respiratory disease in humans, with a devastating 75 percent fatality rate.) More recently, NiV outbreaks in Bangladesh involving human-to-human transmission have focused attention on NiV as a global health concern. One more interesting fact of this research is chloroquine is already an established drug for malaria and its the cheap drug too.

Like the avian flu, SARS, and Ebola viruses Hendra and Nipah are zoonotic pathogens (originating in certain animals but can jump between animal species and between animals and humans). There are currently no vaccines or treatments against the two henipaviruses, which are listed by the U.S. government as possible bioterror agents.

The aproach of this research group is interesting and also of greater importance because the mode of action of chloroquine is (as explained by the authors) it block the action of a key enzyme, called cathepsin L, which is essential to the virus's growth and maturation. Without this enzyme, newly formed Hendra or Nipah viruses cannot process the protein that permits the viruses to fuse with the host cell. Newly formed viruses then cannot spread the infection; in other words, they can invade, but cannot cause disease.

The authors also claim the fact that "several other zoonotic viruses depend on cathepsin L - most notably, Ebola. Our findings, and our methods, could easily be applied to the study of Ebola and other emerging diseases" .

Congrats Dr. Moscona and group for this acheivement. ...