Stevia Leaf Extract Shows Cancer-Fighting Promise, Study Reveals

The Potential of Fermented Stevia in Fighting Pancreatic Cancer

Stevia, commonly known as a zero-calorie sugar substitute, may have far more to offer than just sweetening beverages. Recent research suggests that when fermented with specific bacteria, stevia extract could potentially target and kill pancreatic cancer cells without harming healthy kidney cells. This discovery was made by a team of researchers at Hiroshima University and published in the International Journal of Molecular Sciences on April 28.

Pancreatic cancer remains one of the most challenging cancers to treat, with a five-year survival rate of less than 10%. The disease is highly invasive, prone to spreading, and resistant to traditional treatments such as surgery, radiotherapy, and chemotherapy. As a result, there is an urgent need for new and effective anticancer compounds, particularly those derived from natural sources like medicinal plants.

Prior studies have shown that stevia leaf extract has potential as an anticancer agent. However, isolating and applying the specific bioactive components responsible for this effect has been difficult. Researchers have found that fermenting the extract with certain bacteria can alter its structure and produce bioactive metabolites—compounds that can influence living organisms.

Microbial Biotransformation Enhances Anticancer Properties

Masanori Sugiyama, professor in the Department of Probiotic Science for Preventive Medicine, highlighted the importance of microbial biotransformation in improving the pharmacological efficacy of natural plant extracts. His lab has studied over 1,300 lactic acid bacteria (LAB) strains isolated from various sources, including fruits, vegetables, flowers, and medicinal plants.

In their study, the team fermented stevia leaf extract using a plant-derived strain of Lactobacillus plantarum SN13T (FSLE). They then compared its effects on pancreatic cancer (PANC-1) cells and non-cancerous human embryonic kidney cells (HEK-293) to those of non-fermented stevia extract. The results showed that FSLE exhibited significantly greater cytotoxicity against cancer cells while being less toxic to healthy kidney cells.

Identification of Key Anticancer Compounds

Further analysis identified chlorogenic acid methyl ester (CAME) as the active anti-cancer compound in the fermented extract. When fermented, the concentration of chlorogenic acid decreased six-fold, indicating a microbial transformation. According to Narandalai Danshiitsoodol, co-author of the study, this transformation was likely due to specific enzymes present in the bacterial strain used.

The findings suggest that CAME is more effective at inducing cell death in pancreatic cancer cells than chlorogenic acid alone. This pro-apoptotic effect could be a key factor in the extract’s ability to target cancer cells selectively.

Future Research Directions

The researchers plan to conduct further studies in mouse models to better understand the effectiveness of different dosages across the entire body. Their work provides valuable insights into how probiotics might be used as natural anti-tumor agents.

The study also highlights the potential of using microbial fermentation to enhance the therapeutic properties of herbal extracts. By leveraging the power of beneficial bacteria, scientists may unlock new avenues for developing effective cancer treatments.

Collaborative Efforts in Scientific Discovery

The research team included several contributors from Hiroshima University, including Rentao Zhang and Masafumi Noda from the Department of Probiotic Science for Preventive Medicine, as well as Sayaka Yonezawa and Keishi Kanno from the Department of General Internal Medicine at Hiroshima University Hospital.

This study, titled "Stevia Leaf Extract Fermented with Plant-Derived Lactobacillus plantarum SN13T Displays Anticancer Activity to Pancreatic Cancer PANC-1 Cell Line," was published in the International Journal of Molecular Sciences and offers a promising direction for future cancer research.