For centuries, mankind has been on the hunt to find remedies for thousands of diseases and infections. Joining this eternal tradition, Haider Attarwala ’12, human biology, health and society, investigated how the indigenous plants of the Dominican Republic can be used to help treat and even prevent some of those maladies.
Last summer, Attarwala went to the Caribbean nation with the Minority Health International Research Training, an initiative co-sponsored with Cornell and the National Institutes of Health that aims to reduce health disparities.
After learning how locals have used their native plants as medicine, Attarwala chose a few common ingredients from the local cuisine to test for their biological activity. According to Attarwala, his goal was to find plants that could be incorporated into future drugs.
“We were looking at the medicinal chemistry of plants and the potential curative benefits they could have,” Attarwala said.
To determine the plants’ viability as drug candidates, Attarwala ran his chosen samples through three screening tests.
The first screening process investigated the ability of plant extracts to kill tumors using brine shrimp as test subjects. In previous studies, there has been a proven positive correlation between a substance killing brine shrimp and destroying cancerous cells.
The next test involved screening for the ability of the plant extracts to prevent cell mitosis. Attarwala said that mitosis occurs cells divide, grow, or repair themselves. Cancer results from uncontrolled cell mitosis. When the cleaving of a cell is prolific and unregulated, it can result in a tumor.
Attarwala said he wanted to find plants that would stop or even prevent this abnormality from occurring. To do this, he used sea urchin gametes taken from the ocean.
“Right after you fertilize the gametes in a Petri dish, you add the extract from whatever plant you chose,” Attarwala said. “And then you see if it stops mitosis from occurring, which would indicate that the plant could stop a tumor from arising.”
The final test was a general anti-microbial screen. Attarwala said that microbes were taken from common objects to see whether or not microbial growth was inhibited by the plant extracts.
The three tests, the first two of which are cancer-related and the last is fungal-related, were performed using plants Attarwala picked. When choosing his specimens, Attarwala said he wanted ones that would be practical for daily use, namely plants that people would naturally eat and use as medicine. He selected lemongrass, cilantro, culantro and bitter orange.
Attarwala said he found that lemongrass has both anti-tumorigenic and anti-microbial properties, but that the leaves are much more potent for medicinal purposes than the stems.
“I was pretty happy because it allowed me to go beyond just saying, ‘eat lemongrass’ and I was able to narrow down which part of the plant is best medicinally,” he said.
After lemongrass, Attarwala compared cilantro and culantro, two plants that are similar in smell and taste and sometimes used interchangeably in Dominican cuisine. He said he discovered that cilantro was much more potent for the anti-fungal effect than culantro.
Finally, Attarwala tested bitter orange, a plant used to make alcoholic drinks bitter, and poultice, a medicine that is spread on the forehead to alleviate headaches. He said like lemongrass, certain areas of the plant were more useful than others.
“Bitter orange is surprisingly active. I tested the peel and the leaves. The leaves were more anti-microbial and the peel was more anti-tumorigenic,” he said. “To that was interesting because different parts of the same plant could have totally different chemistries and different effects.”
Attarwala said the plants he tested are ingredients people have consumed in the local cuisine for generations and each plant showed biological activity of some kind in all three of the tests.
“This shows that people have been choosing food out of the environment for medicinal reasons throughout history,” he said. “Our cuisine has an effect on our health. What you eat really affects how you feel and even the potential diseases you could contract.”
Attarwalasaid he met his goal of finding biologically active plants that could be harnessed medicinally. Although he acknowledges that he did not find any breakthrough cure for cancer, he said he believes his research adds to the collective body of knowledge of pharmacology and ethnobotany, or the study of the relationships between people and plants.
According to Attarwala, this particular research project was important for his own growth as well.
“Having a living and working experience in a condensed abroad experience was a crucible for my mindset about how I want to work,” he said. “Intensive research projects change how you think about and interact with the world.”