Pharmacological Effects of Ginseng: Multiple Constituents and Multiple Actions on Humans

Ginseng is a very commonly used natural product in the world, and its two main species are Asian ginseng and American ginseng. Ginseng is an adaptogenic botanical that reportedly protects the body against stress, stabilizes physiological processes, and restores homeostasis. Previously, different animal models and contemporary research methodologies have been used to reveal ginseng's biomedical activities in different body systems and the linked mechanisms of actions. However, human clinical observation data on ginseng effects have attracted more attention from the general public and medical community. In this paper, after an introduction of the phytochemistry of ginseng species, we review positive ginseng clinical studies, mainly conducted in developed countries, performed over the past 20 years. The reported effects of ginseng are presented in several sections, and conditions impacted by ginseng include diabetes; cardiovascular disorders; cognition, memory, and mood; the common cold and flu; cancer fatigue and well-being; quality of life and social functioning, etc. Administration of ginseng demonstrated a good safety record in humans. Although encouraging beneficial effects obtained from clinical data, using the study treatment regimen, the reported ginseng effects in general only ranged from mild to moderate. Nonetheless, these beneficial effects of ginseng could be a valuable add-on therapy for patients receiving standard drug treatments. Additionally, as a dietary supplement, ginseng possesses an important role in maintaining and promoting human health. We believe that the quality of future ginseng trials should be improved, particularly by providing detailed herbal phytochemistry and quality control information. With solid effectiveness data obtained from a well-designed, carefully executed ginseng clinical trial, this meritoriously herbal medicine will be widely used by consumers and patients.