Potential of Fermented Stevia in Cancer Treatment

Stevia might be on the verge of stepping up its game beyond being just a sweetener. Recent research indicates that when this natural plant extract is fermented with a specific bacterium found in banana leaves, it demonstrates the ability to target pancreatic cancer cells while sparing healthy kidney cells.

“The rates of pancreatic cancer, both in terms of incidence and mortality, are increasing worldwide, with a five-year survival rate falling below 10%,” pointed out a researcher from Hiroshima University.

“Pancreatic cancer is notably invasive and often metastasizes, showing resistance against standard treatments like surgery and chemotherapy. This highlights a pressing need for new and effective anticancer compounds, especially those derived from medicinal plants.”

Fermented Stevia in Cancer Therapy

The research employed a type of bacterium called Lactobacillus plantarum SN13T, sourced from banana leaves. Stevia leaves were fermented and compared to standard extracts, with the fermented version demonstrating superior results.

“Microbial biotransformation has emerged as a promising strategy to boost the pharmacological effectiveness of natural plant extracts,” remarked one of the study’s authors.

In the study, fermentation conditions were carefully controlled—optimizing time, temperature, and oxygen levels. It was noted that stevia achieved its highest potency when fermented for 72 hours in an oxygen-free environment at 37°C.

Effectiveness Against Cancer Cells

Fermented stevia proved to be more effective at killing pancreatic cancer (PANC-1) cells compared to the non-fermented extract, while having minimal impact on healthy HEK-293 cells. This selectivity is a notable and desirable trait.

Interestingly, at certain concentrations, the fermented extract didn’t kill cancer cells outright. Instead, it seemed to slow their growth. Under microscopic examination, affected cancer cells appeared weakened, lost their shape, and failed to adhere to one another.

This contrasts sharply with healthy kidney cells, which remained predominantly unharmed, hinting at the treatment’s targeted nature.

Antioxidant Properties

Cancer-related challenges extend beyond just rogue cells; oxidative stress is a significant factor as well. The findings indicated that fermented stevia is also a potent antioxidant.

In laboratory assessments, it exhibited a superior ability to neutralize free radicals compared to the regular extract. Scavenging power reached 94% in one test and 75% in another. Moreover, even when healthy cells were exposed to hydrogen peroxide, the fermented extract contributed to their survival.

Researchers suspect that fermentation resulted in the creation of new compounds, notably transforming chlorogenic acid into a more active form known as chlorogenic acid methyl ester (CAME), which was abundant in the fermented stevia but absent in the raw extract.

Power of CAME Against Cancer Cells

CAME demonstrated greater efficacy than chlorogenic acid alone, being capable of halting cancer cell growth and triggering their self-destruction.

The IC50—the concentration that kills half the cancer cells—was strikingly lower for CAME compared to its predecessor. It halted cancer cells by interrupting their cell cycle and inducing apoptosis.

Flow cytometry results revealed that CAME from fermented stevia caused cancer cells to remain in the G0/G1 phase, thus preventing their replication and leading to the release of cytochrome c and activation of caspases responsible for the breakdown of dying cells from within.

Changes in Gene Activity

Delving into gene activity, CAME was found to enhance pro-apoptotic genes like Bax and Caspase-3, while also increasing E-cadherin, associated with less cancer migration. Conversely, it diminished Bcl-2, a gene that typically inhibits cell death.

This gene regulation corroborated the previous findings, illustrating that CAME prompted a targeted self-destruct mechanism in cells rather than indiscriminate death.

Reimagining Stevia’s Role

The fermentation process imparted stevia with a new therapeutic edge—a compound that aims for cancer cells while keeping healthy ones intact. This transformation likely stems from specific bacterial enzymes involved in the fermentation process.

Future research is set to move beyond in vitro studies, as the team aims to explore the effects of fermented stevia in living organisms through upcoming mouse trials.

Overall, this study offers insights into how simple plant extracts, when combined with the right microbes, can evolve into targeted cancer therapies, which is quite impressive for a mere sugar substitute.

This research appears in the International Journal of Molecular Sciences.