A growing body of research is beginning to suggest non-steroidal anti-inflammatory drugs (NSAIDs) may slow wound healing and bone repair, particularly following some surgical procedures. New research now reveals our natural circadian clocks play a major role in wound healing, and as long as anti-inflammatory drugs are taken in the morning they shouldn’t disrupt the primary healing that occurs in a body at night.
Inflammation is not always a bad thing in the human body. In fact, when the immune system is working effectively, inflammation plays a vital role in healing and fighting off infection. When a body is wounded inflammation is fundamental to several stages in the healing process, from clearing out dead cells in the area to making sure pathogens don’t disrupt the tissue repairing.
"There are periods of inflammation that are actually very destructive, and there are periods that are constructive and important for healing," says the new study’s senior co-author Faleh Tamimi, from McGill University. "So many pharmaceutical companies have been trying to develop drugs that will inhibit the destructive processes during inflammation but not interfere with the helpful ones."
The new research began with a hypothesis inspired by what we already know about the relationship between circadian rhythms and immune system activity. Tamimi wondered whether these natural cycles could be used to a patient’s advantage.
“The destructive component of the circadian rhythm as it relates to bone healing occurs during the day, when cells known as osteoclasts break down bones,” explains Tamimi. “The constructive cells, known as osteoblasts that rebuild bones are active at night. By limiting the use of anti-inflammatories to the mornings and giving analgesics at night for the pain, I thought we might get better results in terms of bone healing than if anti-inflammatories are given throughout the day."
The research tested two different groups of mice, modeling a fractured tibia. One group was administered NSAIDs consistently across a 24-hour cycle, while the other group was only administered NSAIDs in the morning, and at night were given analgesics for pain management.
The results were significant, with severe bone healing impairments seen in the group consistently administered the NSAIDs. The group receiving the NSAIDs only in the morning recovered faster, and showed improved expression of over 500 genes known to play a role in bone healing processes. The magnitude of the difference surprised the researchers.
"Its almost as if morning anti-inflammatories and evening anti-inflammatories were two different drugs,” says Tamimi.
The next steps for the researchers will be to explore how broadly these anti-inflammatory drugs influence healing in the human body. This current research only explored healing in relation to bones. A current clinical trial is underway investigating the effect of taking NSAIDs at different times of day after wisdom teeth extraction surgery.
The new study was published in the journal Scientific Reports.
Source: McGill University
