Academician Zhong Nanshan recently pointed out that “experiments have found that for the prevention of H1N1 and H3N2, Banlangen does have some effective ingredients.” He said that there is no relevant experimental data to support the effectiveness of Banlangen for the prevention of H7N9, and called on the public not to blindly take indiscriminately. So, is it possible to prevent H7N9 virus in the end? Yao Li of the Department of Traditional Chinese Medicine and Cardiovascular Medicine at the Third Affiliated Hospital of Zhejiang University of Traditional Chinese Medicine let us first look at the process of virus invasion into the human body: the virus adsorbs and penetrates into the host cells, the virus sheds its shell and uses the host cell metabolic system to proliferate and replicate, the nucleic acid and protein biosynthesis of the virus is carried out according to the genetic information provided by the viral genome, and then the viral particles are assembled and matured and released from the cells. Currently, the strategies of western drugs against viruses are to compete for receptors on the cell surface and prevent the adsorption of viruses, such as heparin or negatively charged polysaccharides; to impede virus penetration and decapsidation, such as amantadine, which acts by inhibiting the decapsidation of influenza A virus and the transfer of viral nucleic acids to the host cytoplasm; to impede viral biosynthesis; to enhance host resistance to disease, such as interferon, which activates certain enzymes in host cells, degrades viral mRNA and inhibit protein synthesis, translation and assembly. Among these measures, the most effective is to enhance the host’s ability to resist the invasion of the virus. As the saying goes, “If the righteousness exists within, the evil cannot dry up”. Let’s take a look at the pharmacological effects of Panax notoginseng. According to the literature, Panax notoginseng contains alkaloids, amino acids, organic acids, sterols, adenosine, polysaccharides and many other components. From the pharmacological effects, the aqueous infusion of Panax quinquefolium has inhibitory effects on Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Bacillus octococci, Escherichia coli, S. typhi, Streptococcus aureus, S. pneumoniae, S. influenzae, and S. meningitidis (Huang Wenyu et al., 1991). Anti-viral experiments on Panax notoginseng injection showed that it inhibited infection and inhibited proliferation against influenza A virus, encephalitis B virus, mumps virus, and influenza virus (Liu Sheng et al., 2000). Nephrotic hemorrhagic fever virus (HFRSV) and herpes simplex virus (HSV-2) were adsorbed in Vero-6 cells and BGM cells, respectively, and added to different concentrations of Panax notoginseng injection for antiviral experiments, and the results showed significant virucidal effects (Li Wenwen et al., 1994). Panax quinquefolium and the above-ground parts (Da Qing Ye) had the effect of inhibiting HBsAg activity and significantly increased bilirubin excretion per unit time in vivo (Qi Shangbin et al., 1992). Endotoxin is a thermogenic substance produced by bacteria that can cause abnormally high body temperature in thermostatic animals. Panax notoginseng has anti-E. coli endotoxin effect. The chloroform extract of Panax quinquefolium has the effect of anti-E. coli O111B4 endotoxin as confirmed by the rabbit pyrogen examination method and horseshoe crab test method, and some studies suggest that the anti-endotoxin active substances in Panax quinquefolium are organic acids (Liu Yunhai et al., 1994). In fact, for the antiviral effect of Panax notoginseng and other purgative herbs, the biggest difference with western antivirals is their effect on immune function. It is well known that the immune system is a natural barrier against the invasion of pathogenic microorganisms (bacteria, viruses, etc.) inherent in human beings, and its importance to human health can be imagined. It has been proved that Panax notoginseng polysaccharide plays a role in promoting specific and non-specific immunity, humoral immunity and cellular immunity (Xu Yimin et al., 1991). Intraperitoneal injection of Panax quinquefolium polysaccharide can significantly promote immune function in mice, such as significantly increasing spleen weight, total leukocyte count and lymphocyte count in normal mice; significantly counteracting the decrease in spleen index, total leukocyte count and lymphocyte count in immunosuppressed mice caused by hydrocortisone (HC); significantly enhancing the delayed allergic response in normal and cyclophosphamide-induced immunosuppressed mice; and enhancing the percentage of ANAE positive lymphocytes in peripheral blood of normal mice. It also enhanced the percentage of positive lymphocyte ANAE in peripheral blood of normal mice, promoted the function of monocyte macrophage system, and increased the rate of silencing of carbon particles in mice. The process of phagocytosis and killing of bacteria by polymorphonuclear leukocytes (PMN) is an important immune function of the body, and chemiluminescence is the hallmark of PMN respiratory burst, which produces a variety of oxygen reactive groups with strong bactericidal effects. In conclusion, Panax notoginseng plays a holistic and comprehensive effect against viral diseases, i.e., it enhances resistance and inhibits viruses. In the current state of lack of effective drugs against H7N9 virus, the application of Panax notoginseng can better reflect the concept of “prevention before illness” in Chinese medicine. Why not? It is best not to take it orally for more than 3 days because its bitter coldness hurts the stomach and can bring about a series of gastrointestinal reactions such as nausea, vomiting and loss of appetite. Especially for young children, the function of spleen and stomach is not yet sound, more consumption of Banlangen is more likely to cause indigestion and other symptoms. Individual reports have shown that it can cause hemolytic reactions, but its injection can cause urticaria, erythema multiforme, allergic dermatitis, granuloma multiforme and anaphylaxis (Shen Yingjun. Pharmacology of Chinese medicine [M]. Beijing: People’s Health Publishing House, 2006: 247-250), clinical application should be noted. There are few studies on the toxicity of Panax notoginseng, but it has been reported that when the decoction was given to mice, there was no significant change in the chromosome structure aberrations under the conventional chromosome film of their bone marrow cells, but the number of chromosome aberrations increased significantly, suggesting that there may be damage to chromosomes. If used in large doses for a long time, it can cause accumulation of toxicity when the detoxification capacity of the liver is reduced, and damage to the digestive system and hematopoietic system such as upper gastrointestinal bleeding and leukopenia can occur.