Gynostemma pentaphyllum or Jiaogulan (Chinese name) is climbing vine of the family Cucurbitaceae and distributes naturally in shaded and humid places. It is an oriental medicinal herb for heat clearing, detoxification and relieving cough in southern China, Japan, India, and Korea . Gypenosides are saponins isolated from Gynostemma pentaphyllum and are reported to be effective in the treatment of cardiovascular diseases .
Benefits of Gypenosides for sport performance
Well, gypenosides are most often promoted to increase nitric oxide production. This belief originates from in vitro study by Tanner and others  which demonstrated that extracts of Jiaogulan directly stimulates nitric oxide release. However, more recent in vitro study by Fugen and associates  showed a suppression of nitric oxide synthesis.
Some studies  are also showing that saponins isolated from Gynostemma pentaphyllum can lower blood sugar (hypoglycemic effect). Although several types of compounds have hypoglycemic properties, the mechanisms responsible for achieving this effect are different. It is noted in the literature that these saponins may affect glucose disposal and insulin release . A study by Norberg and colleagues  demonstrated that gypenoside (which they named phanoside) extracted from Gynostemma pentaphyllum has a potent insulin-releasing activity.
One animal study  has found an increased tolerance to fatigue in forced swimming.
Isolated gypenosides have also been reported to exert a variety of effects, such as anti-inflammatory, antioxidant, lipid-lowering, anti-carcinogen  and adaptogenic properties .
There is no clinical data regarding the use of Gynostemma pentaphyllum as an adaptogen.
Side effects of gypenoside ingestion
Side effects reported in clinical studies included severe nausea and increased bowel movements .
Ding, Y. J., et al. “Effects of Gypenosides from Gynostemma pentaphyllum supplementation on exercise-induced fatigue in mice.” Afr. J. Agri. Res 5.8 (2010): 707-711.
Tanner, Miles A., et al. “The Direct Release of Nitric Oxide by Gypenosides Derived from the Herb Gynostemma pentaphyllum.” Nitric oxide 3.5 (1999): 359-365.
Aktan, Fugen, et al. “Gypenosides derived from Gynostemma pentaphyllum suppress NO synthesis in murine macrophages by inhibiting iNOS enzymatic activity and attenuating NF-κB-mediated iNOS protein expression.” Nitric Oxide 8.4 (2003): 235-242.
Norberg, Åke, et al. “A novel insulin-releasing substance, phanoside, from the plant Gynostemma pentaphyllum.” Journal of Biological Chemistry 279.40 (2004): 41361-41367.
Chen, J. “Antistress action of Gynostemma pentaphyllum.” Chinese Tradit Patent Med 11.1 (1989): 31-32.
- Wolters Kluwer. Drugs.com Retrieved from Drugs.com at 5. June 2013