Research news in brief

Energy drink additive shows promise in treatment of first psychosis

New research led by Professor Patrick McGorry from Orygen, the National Centre of Excellence in Youth Mental Health, and colleagues from the Donegal Mental Health Service in Ireland, has found that taurine, an additive present in energy drinks, improves symptoms in young people suffering a first episode of psychosis (FEP). Taurine is a naturally occurring amino acid that has various functions in the body, including in the cardiovascular and central nervous system (CNS). In the CNS, it exhibits an inhibitory neuro-modulatory effect and functions as a neuroprotective agent. It is also involved in the development of the nervous system. A total of 121 patients (aged 18–25 years) with FEP, who were taking low-dose antipsychotic medication, and were attending Orygen’s early intervention services in Melbourne, agreed to take part in the phase 2 study. Of these, 86 (47 taurine, 39 placebo) received the allocated treatment and underwent at least one follow-up and were therefore included in the analysis. Patients received 4 g of taurine or placebo once daily. Symptoms were assessed using the Brief Psychiatric Rating Scale (BPRS), while cognition was assessed using the MATRICS Consensus Cognitive Battery. Taurine was found to be both safe and well tolerated, and significantly improved symptoms on the BPRS, both for overall score and for the psychosis subscore. There were also improvements in depression symptoms (rated by the Calgary Depression Scale for Schizophrenia) and general overall functioning (including social and workplace functioning). However, there was no difference between groups regarding cognition. The study was presented at the International Early Psychosis Association meeting in Milan in October 2016, and the authors concluded that the use of taurine warrants further investigation in larger randomised studies.

Understanding the cannabinoid receptor

Three-dimensional imaging techniques have allowed researchers from China and the United States to determine the structure of human cannabinoid receptor 1 (CB1) which results in the “high” associated with marijuana. The images, published in Cell, reveal how molecules like tetrahydrocannabinol (THC, the psychoactive component of marijuana) and synthetic cannabinoids bind to CB1, which is found in the surface of many nerve cells. This could explain how pain medications meant to mimic cannabis use without the “high” can cause unintended side effects. “Now that we finally have the structure of CB1, we can start to understand how these changes to the drug structure can affect the receptor,” said Professor Ray Stevens, from the iHuman Institute in Shanghai and the University of Southern California. Cannabis-derived therapies have been used as a medication for obesity, but researchers found that the therapeutic molecules could trigger depression, anxiety and even suicidal tendencies, so the drug was taken off the market. Currently, researchers are watching for potential side effects related to synthetic cannabinoids, such as Spice and K2, which aim to replicate the “high” associated with THC, but instead are triggering trips to the emergency room.

Nanoparticles boost dengue virus vaccine

A new dengue fever vaccine uses nanoparticles to amplify immune response, and scientists hope this will lead to a better targeting of all four strains of the tropical disease, according to an article published in PLOS Neglected Tropical Diseases. While more than 350 million people in over 120 countries contract dengue fever every year, researchers have struggled to create effective vaccines against dengue virus, in part because four distinct serotypes, or strains, cause the disease and a vaccine must immunise against all four individually. Attaching DENV2-E protein, a key protein from serotype 2 of the dengue fever virus, to nanoparticles made the vaccine more effective in mice than vaccinating with the DENV2-E protein alone. While this method was very effective for one of the serotypes, a vaccine would need to fight all four serotypes of the virus to be successful in combating the disease. Researchers from the University of Carolina designed nanoparticles using particle replication technology. Each nanoparticle was studded with copies of DENV2-E protein. Then, the researchers immunised 31 mice with a control injection of DENV2-E or one of five different sizes of nanoparticle. Researchers drew blood from the mice to follow their immune responses. Bone marrow and lymph node samples were also taken at various points after immunisation. Mice immunised with the DENV2-E nanoparticles had a specific antibody response to serotype 2 of the dengue virus, but not to the other three serotypes. Compared to mice vaccinated with only the soluble DENV2-E proteins, the nanoparticle formulations led to a stronger immune response. Nanoparticle size and shape did not significantly affect the response. Future studies will be required to test whether the antibody levels prevent dengue infection as well as whether similar nanoparticles can be developed for all dengue serotypes. This method could also be used as a platform to enhance other vaccinations – potentially, for the Zika virus or other flavivirus strains.

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