Translator: Leonardo Silva Reviewer: Cristina Bufi-Pöcksteiner
On the 31st of March, 2016,
a young man returning from the Solomon Islands
presented at an emergency department at one of Brisbane's hospitals.
Soon after, he would be diagnosed
with the first reported case of the Zika virus in Australia.
And in that moment,
the Zika virus, which had both horrified and captivated the world,
was no longer a distant threat oceans, countries and continents away.
It had hit our shores.
As the initial outbreak spread from patient to patient,
village to village, town to town, and country to country,
news stories concerning the phenomenal spread of the virus were prolific.
This was no doubt due, in part,
to the at times devastating side effects of the Zika virus.
At its peak, you could not go a single day without hearing news of it.
Now, although the Zika virus generally only causes mild symptoms,
it is actually becoming a major health issue
due to factors which include its ability to replicate
in those cells which line the vagina wall;
it remains viable in semen six months post infection;
and it's capacity to infect fetal brains in utero,
resulting in numerous devastating birth defects,
including microcephaly, as you can see in the image behind me.
By May, 2017,
the CDC estimated
that there were currently 50 countries with active Zika virus.
Like so many people around the world,
I watched the news coverage
with an overwhelming sense of empathy and concern,
concern for the babies born with microcephaly,
concern for the parents
and concern for the healthcare workers
unable to hold the spread of the virus,
unable to console the parents
because there is no treatment for the Zika virus.
But unlike many of those around the world,
I'm a biochemist, whose research focuses on biodiscovery,
with a particular emphasis on the healing abilities of Australian native plants.
So, as the seemingly endless news coverage continued,
it pushed me to ask:
Could the biodiscovery work
that myself and my team were conducting
provide a solution?
Was it possible
that an Australian native plant had the ability to kill the Zika virus?
The more I thought about it,
the more I was convinced that there was definitely potential there.
My current research to date had already shown
that Australian native plants could definitely produce
scientifically validated medicines.
Now, I was on to something,
something that, if proven correct, could have global implications.
I mentioned the idea of screening a couple of native plants to my husband.
We were standing in the kitchen at home,
and he turned to me and said,
"What?
That's not going to work."
I stood my ground.
(Laughter)
Yeah, I stood my ground and told him
that my gut instinct was telling me otherwise.
Now, being a scientist himself,
who is actually quite experienced
in the rigors of scientific exploration and discovery,
he asked,
"Are there any precedents for plants with antiviral activity?"
Intrigued and captivated,
I was spurred on to find scientific evidence to support this,
but also to support my gut instinct.
I marched straight to my computer.
(Laughter)
I didn't miss a beat, actually.
I did a search using a scientific database
and I had my answer in less than 45 seconds.
Yes, there were indeed precedents for plant-based antiviral activity.
I was excited and I was determined.
So, for me,
my challenge was to not only find a plant
that could totally kill the Zika virus,
but also to find the money so that the work could be conducted.
So,
my next big hurdle was to try and convince my industry partner
that we should go ahead with the project,
even though biodiscovery is extremely costly
and there's no guarantees of success.
But we were talking about the Zika virus.
We were talking about a virus
that was causing microcephaly in unborn and newborn babies.
We were talking about a virus that had the ability to jump continents.
I was very hesitant to ask for more money,
especially since my industry partner had already been so extremely generous
in providing me with funds for my other research.
However,
I spurred on and made my best pitch, of course,
and I included the existing precedents
with regards to plant-based antiviral activity.
Luckily for all concerned, they agreed.
Yes.
So, the next step was, of course, the lab.
Now, for those of you that aren't biochemists,
our goal was actually quite simple,
or simple when you say it really quickly.
(Laughter)
What we were trying to do is to find a plant that could kill the Zika virus
without any damage to the host's cells.
So, to determine whether we could do that,
I selected two Australian native plants.
Methanol was used to extract the bioactive compounds,
or put simply, compounds that have a biological effect.
And now, since a picture paints a thousand words,
what you see here is a plaque assay.
Now, a plaque assay is a way of determining
how many infectious viral particles there are.
Across the plate, we have serial dilutions of the virus,
or rather, different concentrations of the virus,
ranging from highest to lowest.
Here, you can see a virus-only control,
where the virus appears as the white spots.
Next, we have our extract-only control,
and in the middle we have cells
that were treated with either plant species 8472
or species 8473,
18 hours post infection.
So, when we look at those cells that were treated with species 8472,
you can see there was absolutely no effect.
In contrast,
when we look at those cells that were treated with species 8473,
you can see that we have 100% total elimination
of the Zika virus.
(Applause)
Yes, I think this is definitely history in the making.
Our results also showed that there were no toxic effects
or damage to the primate cells that we used in all of these experiments.
Our other work has also shown
that not only can we kill the virus outside the cell,
but we can also totally kill the virus inside the cell.
So, what this means is we have 100% total clearance
of the Zika virus.
Until now,
no antiviral therapies or vaccines have been available
for the treatment of the Zika virus,
anywhere, for anyone in the world.
Hence, the costs associated with the Zika virus,
the spread of the Zika virus,
for example in Latin America and the Caribbean alone,
will total between USD 7 billion to USD 18 billion.
The human costs associated with the spread of the Zika virus
has seen numerous pregnancy losses,
babies born with microcephaly, eye and brain abnormalities
and neural tube deficits.
Now, none of these can be measured in monatary value.
They can, however, be measured in heartache and tears
and the hours that will now be spent providing long-term care.
So, our main goal was to develop a novel therapy
that could not only
kill the virus in those individuals
that are currently infected with the Zika virus,
but also to be used as a preventative treatment
in those areas where the Zika virus is rough.
But this is only the beginning.
Although we have a potential treatment for the Zika virus,
our future work will focus on examining and assessing the plant's ability
to kill other member of the Flaviviridae family,
of which the Zika virus is a part;
for example, the dengue virus.
Like Zika, dengue, there is no treatment,
and estimated costs indicate that 2.5 billion,
that is, 30% of the world's population,
in over 100 countries,
are currently at risk of infection.
Incredibly, each year,
390 million patients are infected with dengue virus.
Of these, 500,000 develop into hemorrhagic fever,
a most severe form of the disease,
which results in up to 24,000 deaths worldwide.
So, if our plant is also shown
to have an effect and to be able to kill the dengue virus,
can you imagine the possibilities?
Today, we have in our lab what by all means appears
to be a cure for the Zika virus.
Tomorrow, who knows what we will achieve.
Thank you.
(Applause) (Cheers)