Researchers Create Synthetic Cancer Treatments from Guavas

Chemists have developed a synthetic method to produce powerful compounds from guavas, which may lead to new liver cancer treatments.

The molecules found naturally in these fruits, which originate from regions like Mexico and Central America, have been shown to kill liver cancer cells. However, it would be unfeasible to extract enough of these molecules to meet global demand.

Scientists at the University of Delaware have now invented a laboratory technique that allows them to synthesize these cancer-fighting compounds using common chemicals.

In the United States, liver cancer affects around 42,000 people annually, leading to about 30,000 deaths. The incidence rates have significantly increased since 1980, with mortality rates more than doubling during that time.

William Chain, an associate professor in the university’s chemistry department, noted, “Most clinically approved medications are derived from natural products or inspired by them.” He added that the natural resources available don’t suffice to manufacture enough treatments, making their new method potentially revolutionary.

Many medicines, both prescription and over-the-counter, originate from natural sources. For example, willow bark is known as nature’s aspirin, while the antibiotic penicillin comes from a mold. Additionally, metformin, a common diabetes drug, was initially sourced from the French Lilac plant.

This new approach offers scientists a straightforward and cost-effective strategy for generating large quantities of guava’s naturally occurring cancer-fighting molecules in the lab, potentially leading to better and more accessible liver cancer treatments.

Women saw a drop in liver cancer deaths throughout the 20th century, but rates have begun to increase, now reaching 5.3 deaths per 100,000 cases. In men, the situation is more severe, with rates at 10.1 deaths per 100,000.

The molecule synthesized by the Delaware team, known as (-)-psiguadial A, shows significant promise in inhibiting the growth of liver cancer cells.

Dr. Chain led a team that initially focused on building a critical component of this molecule found in guavas. Achieving the correct 3D shape was essential since the molecule needs to fit perfectly for it to be effective.

Once this was done, they connected it to another key part of the molecule—a challenging task, as the bonding sites were obscured by other atoms.

Finally, they triggered a chemical reaction that caused the molecule to loop back and bond with itself, forming a distinctive ring structure, which is vital for its cancer-fighting properties.

While this is a significant first step, researchers emphasize that there’s still a long way to go. The precise mechanism by which (-)-psiguadial A targets and kills cancer cells requires further investigation.

Initial potency measurements were made from experiments on human liver cancer cells in petri dishes, alongside previous studies involving animal cells. Extracts containing these compounds have been evaluated against various human cancer types, like breast and lung cancers. However, the compound has not yet been trialed on human patients, although this synthesis marks an important milestone.

While it’s still years before it could see human use, this breakthrough lays the groundwork for possible new targeted therapies. The aim is to develop treatments that are more precise and come with fewer side effects than traditional chemotherapy.

Liam O’Grady, a doctoral student in Chain’s lab, stated, “We’ve begun to illuminate this unknown pathway, and it’s exciting to think where it could lead.”

The research team is now looking to collaborate with experts in various fields to explore, refine, and assess whether this compound could become a viable treatment option.

Past studies have highlighted the anti-cancer properties of the guava plant, which recently took center stage as an international team reported that concentrated extracts from guava leaves could significantly hinder the growth of liver cancer cells. Higher doses led to a more pronounced effect, with the most potent extracts stopping over two-thirds of the cancer cells from proliferating.

This extract doesn’t just poison the cells; it activates their self-destruct mechanism, known as apoptosis, causing a toxic buildup and energy shutdown that leads to cell death.

Liver cancer, notorious for its rapid progression, offers limited treatment options, imposing a substantial financial burden on the U.S. healthcare system. With a grim prognosis for advanced cases—where fewer than 15% of patients survive beyond five years—the research team has teamed up with the National Cancer Institute to further investigate the guava-derived molecule against different cancer types and push towards developing a treatment.