Herbal Cure for Dengue?

Atty. Alan F. Siu of Cebu had an interesting comment on my dengue post yesterday:

Doc, I'm glad you're blogging on dengue. One of our staff just lost a child to dengue last November. A lot of people here in Cebu are claiming that if the victim is given a drink from an herb called "mangagao" (I think it is "gatas-gatas" in Luzon) this would boost the immune system and fight off the virus. The child who died wasnt able to drink it. I suppose you might be aware of this, and I look forward to your comment. Thanks.

The herb being referred to is scientifically known as Euphorbia hirta. Locally, it is known by many names: gatas-gatas and mangagao, as Atty. Siu mentioned; it is also known as botobotonis, golandrina, saikan, bambanilag, pansi-pansi, patik-patik, and tawa-tawa. Internationally, it is known as the Australian asthma weed, snake weed, and cat's hair.

Claims of its curative effects against dengue include boosting the immune system, increasing platelet counts, and being able to stop hemorrhage and bleeding.

But that's just it. All of its supposed curative effects are purely anecdotal. There has been no serious scientific study locally that has tested its effectivity against the dengue virus. At this point, I can already guess why. No funds. And no one wants to even try and test if it really works. Of course, there are students who give it a try to meet their requirements in some high school or college science project, but the efforts still fall short. What we need is some credible institution to undertake the project, like a government agency or a university-hospital with proven and peer-reviewed clinical and laboratory studies done previously.

There's some irony in it, I tell you. Being one of the Asian countries with the highest dengue cases annually, you would assume that those concerned will be working overtime to find a cure to this disease, right? Well, sadly, that's not happening.

A quick research on peer-reviewed scientific journals about Euphorbia hirta shows the following fascinating results:

1. It has weak larvicidal properties against Aedes aegypti and Culex quinquefasciatus - yes, it can kill baby mosquitoes which might carry dengue later on. The Culex mosquito is a filariasis vector. [Parasitology Research, Dec 2007]



2. It has anti-allergy effects - studies in mice have shown that when the ethanolic extract of Euphorbia hirta was given at an oral dose 100 to 1000 mg/kg, it was able to prevent and inhibit both systemic and cutaneous allergies. [Fitoterapia, July 2007]



3. It can be a potential anxiolytic drug - studies in mice have shown that its hydroalcoholic extract had significantly reduced the anxiety levels of chronically-stressed mice. [Journal of Neural Transmission, Jan 2008]



4. It has antibiotic properties - particularly effective against E.coli (enteropathogen), Proteus vulgaris, Pseudomonas aeruginosa and Staphylococcus aureus. [Fitoterapia, July 2006]



5. It can decrease gastrointestinal motility - this means it can be a potential anti-diarrheal medication. [Fitoterapia, Jan 2006]



6. It has anti-malarial properties - in malarial-infected mice, oral administration of E.hirta extracts were shown to supress the malaria parasite. [Journal of Ethnopharmacology, Dec 1999]



7. It has diuretic effects - in rats, the water extract of E. hirta leaf had similar diuretic spectrum to that of acetazolamide. This simply means it can increase urine output. [Journal of Ethnopharmacology, April 1999]

In 2005, a SunStar Cebu editorial mentioned a UP Visayas Biology student having observed increased platelet counts in mice orally administered with Euphorbia hirta extracts but it was "not significantly different from the platelet count of control specimens that had no intake of the decoction."

With all the medicinal benefits I enumerated above, we can speculate that Euphorbia hirta may indeed be a potential useful medicine someday. I also learned that in Africa and some parts of Australia, Euphorbia hirta is considered to be an all-purpose herbal medicine. But take heed also that ALL of the studies mentioned above were done in rats or mice. Euphorbia hirta has NEVER been tested on humans.

Because of this, you probably know what my advice is regarding its use. Dengue is a viral illness. The reason why you can still get it after surviving an infection is because there are four (4) dengue viral strains. You might get immuned with one strain, but you're still susceptible to the other three. The dengue vaccine and drug are still under development. Until such time, we only have our own immune systems to defend us. In spite of its hype and anecdotal popularity, I still think drinking Euphorbia hirta extracts and concoctions is not safe.