RIO DE JANEIRO (AFP) - Surrounded by barbed wire and an electric fence, marijuana plants flourish under the bright sun on a farm in a mountainous area outside Rio de Janeiro.

But this farm has nothing to do with drug trafficking. It belongs, in fact, to a pioneering Brazilian non-governmental organisation engaged in the production of medical cannabis to help patients with seizures.

Ms Margarete Brito, a lawyer by training, first started growing cannabis several years ago to relieve the seizures of her daughter Sofia, now 12, who suffers from epilepsy.

After seeing her condition improve, Ms Brito decided to help other patients too. So she founded the Medical Cannabis Research and Patient Support Association, or Apepi, that produces artisanal therapeutic oils made from cannabis to help patients with conditions similar to her daughter's.

That work has required a lot of effort, since growing marijuana remains illegal in Brazil.

"If we follow the letter of the law, nothing authorises us to do that," Ms Brito said.

But she and her husband, Mr Marcos Langenbach, were able to obtain an unprecedented judicial authorisation to cultivate cannabis for medical purposes in 2016.

Today, their farm - about two hours by car from the Brazilian capital - has 2,000 plants growing there to help patients with severe autism, multiple sclerosis and epilepsy.

And, despite initial suspicion and pushback from some, Ms Brito says the endeavour enjoys support in Brazil.

"We have real social legitimacy. That's what protects us," Ms Brito said.

'People have prejudices'

On a recent visit to the farm, which is protected by an electric fence and barbed wire, agricultural engineer Diogo Fonseca made his way among marijuana plants growing in large black pots and marked with the names of their different varieties: Purple Wreck, Schanti, Doctor, Harle Tsu, Solar, CBG.

These plants are used to produce therapeutic oils that meet the individual needs of each patient, depending on whether they require a higher or lower dose of cannabidiol (CBD), a non-psychotropic substance with a relaxing effect.

Using a pocket microscope, the Fonseca examines each plant to assess the ideal time to pick.

In April, armed police with sniffer dogs raided the farm, after a person who had worked on renovating its laboratory reported Apepi to the authorities.

"A lot of people have prejudices," Brito said. "We explain how our project works to everyone, but this person believed that we were drug traffickers and informed against us," said the farm's manager Manoel Caetano.

The police eventually realised the farm was a medical cannabis plantation, apologised and left, according to Ms Brito.

More accessible

Apepi has forged partnerships with respected scientific institutions, such as the Fiocruz Foundation and the University of Campinas. And it has grown has five-fold over the past two years and now counts 1,500 members.

Among them is 19-year-old Gabriel Guerra, who suffers from a severe form of autism and cerebral palsy. When he was eight, he would have 60 seizures a day.

"But when he started to take the custom oil, a few drops three times a day, the attacks stopped. He started to have more independence, looking for ways to communicate," explained his father Ricardo Guerra.

Thanks to Apepi, the products have become much more accessible to patients: 150 reais (S$38) for a 30ml bottle, while imported products can cost anywhere from 600 to 3,000 reais (S$153 to S$763).

Apepi is now awaiting a court decision which they hope would allow the farm to increase its production to 10,000 plants starting next year.

But the group is not very optimistic about the prospect of legalisation of medical cannabis any time soon - President Jair Bolsonaro has already indicated that he would veto a Bill being debated in Congress.