New Delhi, June 19: Biologists have shown that a herbal formulation based on the amla, the Indian gooseberry, can improve memory functions of mice genetically engineered to mimic human Alzheimer's disease, lending a dose of scientific credence to a 2,000-year-old cocktail.

Researchers at the Centre for Cellular and Molecular Biology (CCMB), Hyderabad, said these "humanised mice" appeared to regain their memory capacity when treated with the formulation, Amalaki Rasayana, which has already been shown to deliver similar benefits in laboratory flies.

These chimeric mice possess mutated versions of two human genes that appear to be associated with the accumulation of clumps of beta amyloid protein, the hallmark feature of Alzheimer's.

By the age of seven months, these mice too show the protein accumulation and impaired memory, which is measured by challenging the mice with tests in a laboratory water maze.

The scientists divided the mice into two groups. One group received donepezil, a standard anti-Alzheimer's medication used to improve brain functions, although it does not slow down or cure the disorder. The other group received Amalaki Rasayana. Both therapies were initiated when the mice were 11 months old.

"The mice show improved memory and increased energy production in key regions of the brain within about a month after the start of the therapy with both Amalaki and donepezil," Anant Bahadur Patel, a principal scientist at the CCMB who led the study, told The Telegraph.

"The enhanced energy has long been known to be associated with improved brain functions."

In the water maze test, normal mice were able to find a platform in the water on an average in 47 seconds, while the chimeric mice took more than 90 seconds, an indication of memory dysfunction.

After therapy, the chimeric mice treated with donepezil found the platform on an average in 51 seconds, while the mice that received Amalaki Rasayana did it in about 66 seconds. "The herbal formulation, without side effects, appeared to show changes in neurotransmitter energetics in the brain's hippocampus region just as the donepezil did," Patel said.

The findings of the study, supported by the Union ministry of science and technology, are set to appear in the Journal of Bioscience, published by the Indian Academy of Sciences.

Scientists view the results as fresh evidence in support of a possible use of Amalaki Rasayana in the treatment of Alzheimer's, a neuro-degenerative disease that has no cure.

"The importance lies in the demonstration of this effect in mice, especially humanised mice," said Subhash Lakhotia, a senior zoologist at Banaras Hindu University who had shown over five years ago that Amalaki Rasayana can suppress the accumulation of amyloid beta protein in the brains of fruit flies.

"Flies are flies - they point to something interesting - but experiments on mice takes this a bit closer to humans," said Lakhotia, who along with research scholar Vibha Dwivedi has independently shown that Amalaki Rasayana can also improve fruit flies' tolerance to extreme stress from heat, starvation and overcrowding.

Amalaki Rasayana is among India's oldest traditional herbal formulations, described in a set of ancient texts collectively called the Charak Samhita, which many scholars date to the period between 100 BC and AD 100.

When the Banaras Hindu University team published its findings on fruit flies in 2013, a neuroscientist had cautioned that their relevance to humans was unclear because amyloid beta protein accumulation does not always correlate with symptoms of Alzheimer's. The scientist had said it was still not clear whether the protein plaque is a cause of Alzheimer's.

Patel said he was now hoping to investigate the biological mechanisms that might explain how the ingredients of Amalaki Rasayana had brought about the observed changes in the mice brains.

The advantage with such a formulation, Lakhotia said, is that it has been used for centuries without side effects.

"So, studies on humans should not be such a big challenge," he said. "What is important is quality control of the formulation."