Lentinan is a polysaccharide extracted from Shiitake mushrooms and used as an adjuvant therapeutic drug in treating patients with lung cancer in China. Lentinan is mainly composed of β-glucan with anti-tumor, anti-inflammatory, anti-diabetes properties, and other therapeutic properties. Lentinan was approved as an adjuvant for stomach cancer therapy in Japan in 1985. It is approved for treating multiple types of cancer, hepatitis, and other diseases in China. Lentinan is available as capsules, tablets, and injections. The capsules and tablets of lentinan is taken orally as a traditional medicine. Intravenous injection of lentinan is clinically approved and used in hospital with a dose of 1–1.5 mg/day. Low blood pressure, allergy, urgent appeal, and dizziness were the major side effects.

Histamine is a depressor amine derived by enzymatic decarboxylation of histidine. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and a centrally acting neurotransmitter. Phosphate salt of jistamine was used as a diagnostic aid for evaluation of gastric acid secretory function. In addition, this compound is used as a positive control in evaluation of allergenic (immediate hypersensitivity or "Type I") skin testing. In addition, histamine is being studied for treatment of multiple sclerosis. It was approved, that histamine physiological functions are mediated by four 7-transmembrane G protein-coupled receptors (H1R, H2R, H3R, H4R) that are all targets of pharmacological intervention. The receptors display molecular heterogeneity and constitutive activity. H1R antagonists are long known antiallergic and sedating drugs, whereas the H2R led to the development of H2R-antagonists that revolutionized stomach ulcer treatment. The H3R is an auto receptor and heteroreceptor providing negative feedback on histaminergic and inhibition on other neurons. The H4R occurs on immuncompetent cells and the development of anti-inflammatory drugs is anticipated.