In the never-ending search for the next treatment or cure, many researchers turn towards nature. The study of black pepper is one such result of this. Several studies have revealed that the molecule piperine, a flavor compound in black pepper, actually has anti-cancer effects. It makes you wonder if you should include it in more recipes, huh?
This anti-cancer action still needs significant investigation, as many studies only show surface-level observations such as increased expression in anti-tumor genes or decreases in pro-tumor genes. A group from Universidade Federal do Rio de Janeiro in Brazil wanted to understand how piperine might affect colorectal cancer cells. Previous work had shown it suppressed cancer growth, but no studies have elucidated how it did so.
They began with the hypothesis that piperine might affect the Wnt/β-catenin signaling pathway. This pathway functions as an on/off switch regulating several cellular development pathways. In some cancers, this pathway is stuck in the “on” position and promotes tumor development, while inhibitors designed to turn the pathway off can prevent tumor development.
The study found that in colorectal cell lines, piperine significantly inhibited Wnt/β-catenin signaling. They just needed to narrow down what stage it interacted with. Markers for early events in the pathway saw no change, but β-catenin (the protein responsible for the intracellular signal) was not active in piperine treated cell lines. Piperine had somehow stopped β-catenin’s activation.
Further investigation found that piperine could significantly impair the growth of colorectal cancer cells, but it barely affected healthy colorectal cells. They made the same observations when cell viability (whether a cell dies or not) and cellular migration (a key player in aggressive cancers) were tested. Testing on different Wnt/β-catenin cell lines confirmed that these changes Wnt/β-catenin signaling dependent.
The study could not elucidate the exact mechanism behind piperine’s anti-cancer activities, but it did isolate it to a particular event in the cell. Piperine somehow prevents the activation of β-catenin and stops the expression of pro-tumor genes. It could even do so while not affecting healthy cells.
The team concludes, “Piperine displays anti-cancer effects in different cancer cell lines, probably by interfering with Wnt/β-catenin signaling, among others. Thus, a new path is opened for understanding the molecular mechanisms by which alkaloids suppress tumor progression.” While it doesn’t supply the most conclusive answers, it definitely supports its anti-cancer effects. I know that I, for one, will be adding pepper into more things from now on.