Researchers are looking into the possibility that glycoalkaloids from nightshade plants such as tomatoes and potatoes could be sources for new cancer drugs.
However, experts say there are a number of concerns about the toxic effects of these alkaloids.
They say more research is needed and human clinical trials on these compounds could be years away.
Vegetables such as potatoes could someday help us fight cancer, according to a study completed at Adam Mickiewicz University in Poland and published in the journal Frontiers of Pharmacology.
In their study, researchers examined bioactive compounds called glycoalkaloids and how they can play a role in preventing or treating cancer.
Bioactive compounds are chemicals found in fruits and vegetables that can promote good health. Glycoalkaloids are found in nightshade plants, including tomatoes, eggplant, and potatoes.
Nightshade plants produce alkaloids as a defense against animals that eat plants. Some are toxic. However, the researchers said that if they can find a safe and therapeutic dosage, they could potentially turn a poison into medicine.
“I would be especially cautious when thinking about potato glycoalkaloids, including alpha-solanine and chaconine (which you can find in ‘greened’ potatoes and are the reason why we remove the green parts),” noted Jessica Cooperstone, Ph.D., a researcher with The Ohio State University Comprehensive Cancer Center Carcinogenesis and Chemoprevention Research Program and assistant professor the Ohio State College of Food, Agricultural and Environmental Sciences.
“These can be highly toxic in humans. Something that can be good, or even essential at low or moderate doses, can be toxic when administered at high levels,” she told Healthline.
The scientists in the recent study specifically looked at five alkaloids and how they could be effective in cancer treatment:
•Solanine – could possibly stop carcinogens in the body to inhibit metastasis
•Chaconine – has anti-inflammatory properties and could potentially treat sepsis
•Solasonine – may prevent liver cancer cells from reproducing and may work as a complementary treatment when fighting cancer drug resistance
•Solamargine – is thought to attack cancer stem cells
•Tomatine – supports the body’s regulation of cell cycles and could be used to kill cancer cells
Glycoalkaloids can inhibit cancer cell growth. Some studies have suggested that they aren’t toxic and do not risk damaging DNA or causing future tumors.
However, a 2008 study found the opposite to be true. When a potato begins to sprout, the glycoalkaloid content increases, if you eat small amounts of sprouting potatoes, you could have symptoms such as vomiting, diarrhea, and abdominal pain, typically within a few hours of consumption. Higher consumption levels could cause blood pressure drops, rapid pulse, fever, headaches, confusion, and in extreme cases, death.
Glycoalkaloids could also have some negative effects on the reproductive system.
A study published in 2018 found that sprouted potatoes were associated with anencephaly and cleft lip in newborns.
“We know from last century, scientists derived many of the original chemotherapy and antibiotic drugs from natural bacteria, microorganisms, and plants,” says Dr. Santosh Kesari, a neurooncologist and director of neurooncology at Providence Saint John’s Health Center and chair of the Department of Translational Neurosciences and Neurotherapeutics at Saint John’s Cancer Institute in California and regional medical director for the Research Clinical Institute of Providence Southern California.
“We also know that we currently still have not fully explored the potential of natural products in plants, algae, vegetables, and even marine sources from all the world’s microclimates,” Kesari told Healthline. “There is tremendous potential and more research needed to identify feasible ingredients that benefit human health.”
Magdalena Winkiel, a Ph.D. student at Adam Mickiewicz University and the study’s lead author, suggests that if glycoalkaloids are not able to replace current anticancer drugs, they could possibly be used as a combination therapy that may increase the effectiveness of some treatments.
More Studies Of Glycoalkaloids Needed
A detailed understanding of glycoalkaloid properties would be needed to further evaluate how they can help fight cancer.
“There is an important difference between eating fruits and vegetables for health (often prevention) vs. mining plant materials for potentially bioactive drugs (often treatment),” Cooperstone said.
“There is lots of research that shows the benefits of eating plant foods to lower cancer risk, but little conclusive evidence about the effects of specific compounds or specific foods,” she added.
The next step would be to use in-vitro and model animal studies to determine the safety and effectiveness before moving on to human trials. In-vitro is Latin for “within the glass.”
It refers to studies completed in a laboratory, typically with cells grown in a petri dish or test tube. It can provide a controlled environment for testing.
However, since it occurs away from living organisms, the results must be carefully analysed. The next stage might not come as quickly as hoped.
“Testing of Solanaceous alkaloids for cancer treatment is not yet at the stage of animal testing and human clinical trials are quite far away,” says Cooperstone. “Much of this work is in very early development and needs significant time and financial investment for a full investigation.”
