A parasite found in cat litter can be a probable future cure for neurological disorders like Alzheimer's and Parkinson's, according to a new animal study. Using an engineered form of Toxoplasma gondii - a common parasite found in cat poo, scientists tried to deliver proteins to the brain in mice. Earlier, it was not easy to deliver targeted treatment across the blood-brain barrier and into the correct location inside neurons.

Toxoplasma gondii - an intestinal coccidium that parasitizes members of the cat family as definitive hosts and has a wide range of intermediate hosts, travels from the digestive system to the brain where it can secrete proteins into neurons. Researchers say it has evolved to cross the blood-brain barrier and placenta while posing a risk to pregnant women as it can lead to miscarriages. Usually, doctors advise pregnant women to avoid handling the litter trays of their cats.

However, this study, conducted by Tel Aviv University, Israel is a first of its kind, which the scientists say represents an exciting new field of research. "Evolution already 'invented' organisms that can manipulate our brains. think that instead of re-inventing the wheel, we could learn from them and use their abilities," said Professor Oded Rechavi, of Tel Aviv University.

Most cognitive disorders like Alzheimer's, Parkinson's, and Rett Syndrome are linked to the build-up of two substances in the brain - amyloid, and tau. These substances clump up and form plaques and tangles, which make it harder for the brain to work properly.

The study, conducted in collaboration with international researchers led by the University of Glasgow, has established whether the parasite could act as a medicine delivery vehicle to disease-affected brain cells. For this, they had to find out whether they could effectively make the parasites produce therapeutic proteins, and then test whether the parasites would be able to “spit” the proteins back out into affected brain cells.

Scientists engineered the parasites to deliver the MeCP2 protein - which has already been proposed as a promising therapeutic target for Rett syndrome – a rare genetic disorder that affects the way your brain develops, causing a progressive inability to use muscles for eye and body movements and language. According to experts, this neurological disorder is caused by mutations in the MECP2 gene.

And so, the parasite was able to successfully produce the protein and deliver it to the target cell location in brain organoids and in mice models. However, scientists will conduct further studies to engineer the parasites in a way they die after delivery, to prevent additional cell damage.

According to researchers, in the future after deeper studies are conducted, these parasites could play an important role in the delivery of therapeutic proteins to the brain. “This is a blue-sky project where our collaborative team was thinking out of the box to try to tackle the long-standing medical challenge of finding a way to successfully deliver treatment to the brain for cognitive disorders. The concept is not without challenges, considering the dangers involved with Toxoplasma infection,” said Professor Lilach Sheiner, one of the leading authors of the study from the University of Glasgow's School of Infection and Immunity.

“For our work to become a treatment reality, it will require many more years of careful research and development to enhance efficiency and improve safety,” he added.

The parasite toxoplasma gondii causes toxoplasmosis - an infection that can weaken your immune system to life-threatening complications. You get toxoplasmosis after contact with cat feces or eating contaminated food.

According to doctors, you can accidentally ingest T. gondii after coming in contact with something that’s contaminated, like: