Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes), Mycelium Aqueous Extract Modulates High-Altitude–Induced Stress

Environmental adversities such as high altitudes impair human performance and under such environmental threats, adaptogens tend to enhance physical endurance, mental functions, and nonspecific resistance of the body. Herein, adaptogenic activity of the medicinal mushroom Ganoderma lucidum (mycelium aqueous extract; GLMaq) was evaluated by exposing rats to cold (5°C), hypoxia (428 mm Hg), and a restraint state. GLMaq was administered orally at 50, 100, and 150 mg/kg body weight (bw) and rats were fasted overnight before exposure. After exposure, antioxidant and stress markers (catalase, lactate dehydrogenase, lipid peroxidation, reduced glutathione, and superoxide dismutase levels) were investigated in tissue homogenates (liver, heart, and skeletal muscle) along with hematological parameters. Mitochondrial morphology was observed by transmission electron microscopy in skeletal muscles. Biodistribution study for technetium-99m–labeled GLMaq was determined in mice in blood and major organs (heart, intestine, kidney, liver, lungs, muscle, spleen, and stomach). Antioxidants (ascorbic acid, gallic acid, rutin, and quercetin) were quantified by ultra-performance liquid chromatography. In vitro free radical scavenging activities were also determined. A 100 mg/kg bw dose was found to be relatively effective as measured by time taken to reach rectal temperature (Trec) 23°C; however, the 50 mg/kg bw dose showed significant results as observed from biochemical parameters for liver, heart, and skeletal muscle. The current study suggested the potential use of GLMaq as an adaptogenic agent against high-altitude–induced stress; this is further supported by a wide distribution of technetium-99m radiolabeled G. lucidum mycelium aqueous extract to various organs and protective effects of GLMaq against mitochondrial impairment by maintaining mitochondrial number and morphology.