Data published in Phytotherapy Research indicated that a G. pentaphyllum extract containing gypenoside L was associated with significant increases in maximal oxygen consumption (VO2max) and O2 pulse compared to placebo.
In addition, significant differences were reported between the groups for rating of perceived exertion (RPE) and value of temporal fatigue, reported researchers from Korea.
“Our results demonstrate the potential of plant-derived extracts to mitigate the cognitive aspects of fatigue and improve the performance of the motor system from exercise-induced oxidative stress,” they wrote.
Gynostemma pentaphyllum, also called jiaogulan, is a climbing vine widely distributed across South and East Asia. The study used a G. pentaphyllum extract prepared by BTC Corporation. The ingredient is distributed in the US by Gencor as ActivAMP.
Commenting on the new study, Christopher Bailey, PhD, Gencor's Director of Scientific Affairs, told NutraIngredients-USA that this is the second study using this extract (our coverage of the first can be found HERE). Data from a third study, which measured AMPK in cyclists, is currently being written up for publication in a peer-review journal.
The ingredient is reported to activate the enzyme AMPK (5' adenosine monophosphate-activated protein kinase), a key enzyme for controlling metabolic activity in the body. Activation of AMP Kinase facilitates the transport of glucose into skeletal muscle while promoting an increase in the number of mitochondria - the powerhouses of our cells.
One hundred healthy Koreans aged between 19 and 60 were recruited to participate in the double-blind, placebo-controlled, randomized trial. The people were randomly assigned to one of two groups: Placebo, or the G. pentaphyllum extract (GPE) containing 18.5 mg gypenoside L per gram of GPE and 1.6 mg of ginsenoside Rg3 per gram of the GPE. One capsule was consumed per day, providing a GPE dose of 450 mg.
The participants were subjected to exercise on a treadmill at the start of the study (week 0) and again after 12 weeks of supplementation. Measurements were taken pre-exercise, post-exercise, and during the recovery phase.
On the increases in VO2max in the GPE group, the researchers stated: “Fatigue can generally be evaluated by the analysis of VO2 max to assess the ability of the heart and lungs to transport oxygen to the working muscles. Numerous studies have focused on natural products that increase VO2 max and endurance capacity.”
The researchers also reported significant differences in the rating of perceived exertion (RPE) and value of temporal fatigue between the groups. “Mental fatigue is defined as a psychobiological condition that reduces cognitive activity due to prolonged exercise,” they said. “RPE and MFS are commonly used for measuring an individual's mental fatigue during physical activity in clinical trials along with heart rate, blood pressure, and oxygen consumption.”
Finally, significantly higher levels of endothelial nitric oxide synthase (eNOS) in the blood was recorded in the GPE group, compared to placebo. This is indicative of improved cardiovascular functioning, since this increases the bioavailability of nitric oxide (NO).
“Our randomized controlled trial showed that 12 weeks of administration of GPE resulted in ergogenic properties that may improve both physical and mental performance,” wrote the researchers.
“These results show that GPE induces changes in blood parameters in the recovery period after exercise when comparing baseline and 12 weeks of treatment. In addition, the group that was administrated GPE for 12 weeks showed changes in cardiopulmonary and exercise responses and eNOS levels compared with the control group.”
Source: Phytotherapy Research
Published online ahead of print, doi: 10.1002/ptr.7801
“Effects of gypenoside L-containing Gynostemma pentaphyllum extract on fatigue and physical performance: A double-blind, placebo-controlled, randomized trial”
Authors: Y. Ahn, et al.