Ojeok-san ameliorates visceral and somatic nociception in a mouse model of colitis induced colorectal cancer

Authors: Cunningham P, Sumal A, Patton E, Helms H, Noneman MT, Martinez-Muñiz G, Bader JE, Chatzistamou I, Aladhami A, Unger C, Enos RT, Shin HK, Velázquez KT.

PloS One, 2022.

Ojeok-san ameliorates visceral and somatic nociception in a mouse model of colitis induced colorectal cancer

Scientists conduct impedance and MEA testing with Axion’s noninvasive Maestro platform to explore the effects of an alternative pain medicine in a mouse model of colorectal cancer. 

Many people living with cancer use alternative medicines to manage pain and other symptoms. Ojeok-san (OJS)—a complementary medicine made up of seventeen herbs and known to have anti-inflammatory, immunoregulatory, and analgesic properties—is widely used to treat pain in Asian countries, but the underlying mechanisms of action are unclear. In this study, scientists used a multiplatform approach to examine the analgesic properties of OJS in a mouse model of colitis-induced colorectal cancer.  

To help understand the real-time effects of OJS in vitro, the scientists used Axion’s label-free, noninvasive Maestro Edge platform. With impedance testing, the researchers found that OJS reduced referred pain and raised the nociceptive threshold after two weeks in mice, without impacting the actual tumor burden, and confirmed that OJS did not impact tumor growth in a colorectal cancer cell line.  

The authors then conducted multielectrode array (MEA) testing to assess the impact of OJS on sensory neuron hyperactivity in response to inflammatory stimuli using dorsal root ganglion (DRG) neurons dosed with an inflammatory "soup" (IS) to increase DRG activation, or an ERK inhibitor to reduce DRG activation. The MEA recordings demonstrated that DRGs responded as expected to IS and ERK inhibition. Unfortunately, OJS did not significantly reduce the inflammation-induced increase in DRG neuron activity. Instead, the authors suggest that OJS may act by reducing the cytokine and chemokine production by macrophages. Taken together, these findings establish the anti-nociceptive effects of OJS, but additional research is needed to understand its utility in the treatment of chronic pain.