Discarded pine needles could be key to fighting muscle fatigue, study finds

Pine needles from the Korean pine tree — long discarded after the nuts are harvested — may find new life as a functional ingredient that restores muscle energy metabolism and reduces fatigue.

The Korea Institute of Oriental Medicine said Monday that a research team led by Lee Mi-young of its Korean Medicine Convergence Research Division confirmed that an extract from Korean pine needles can improve fatigue by restoring muscle energy metabolism and mitochondrial function.

While the tree's nuts are widely used, its needles have had little commercial application and are mostly discarded. The needles, however, contain a range of beneficial compounds, including polyphenols and terpenoids.

The research team applied the pine needle extract and its key marker compound, lambertianate acid (LA), to muscle cells and to fatigue-induced mice, then analyzed the anti-fatigue effects. The team also examined the underlying mechanisms through computational approaches, including network pharmacology and molecular docking.

When muscle cells subjected to oxidative stress were treated with the pine needle extract, levels of reactive oxygen species fell and damage to the cells and their mitochondria was reduced. Similar effects were observed with lambertianate acid.

The extract also showed results in fatigued mice. After receiving the pine needle extract and lambertianate acid, the animals recovered grip strength that had declined. In a forced swim test, the time the mice spent immobile decreased, and other endurance-related indicators also improved.

Particularly notable was the recovery of muscle energy metabolism. Fatigue-induced mice showed roughly a 70 percent drop in muscle glycogen, along with reduced levels of ATP, the cell's primary energy source. After treatment with the pine needle extract and lambertianate acid, both markers recovered to near-normal levels.

The research team suggested that a PI3K-related signaling pathway may be involved in these effects. PI3K is a key signaling enzyme that regulates cellular metabolism, growth and survival. The pine needle extract appears to reduce oxidative stress and regulate mitochondrial biogenesis through this pathway, the team said.

The research remains at the preclinical stage, based primarily on cell and animal experiments. However, co-research partner Huons N has manufactured a GMP-based standardized extract and completed a human application trial. The institute has since applied to the Ministry of Food and Drug Safety for registration of the extract as an individually recognized functional ingredient for health functional foods.

"We have presented scientific evidence that Korean pine needles — previously of little use — could serve as a functional ingredient for relieving muscle fatigue and be transformed into a high-value anti-fatigue material," Lee Mi-young said. "We will continue follow-up research and commercialization efforts to develop it into a health functional food ingredient that helps alleviate fatigue."

The findings were published in the international journal Applied Biological Chemistry.