Research on the Chemical Components and Anti inflammatory Activities of Huaijiang
Huai Jiang is a fresh rhizome of Zingiber officinale Roscoe, a plant in the ginger family. It is produced in ancient Huaiqing Prefecture and is a specialty of Bo’ai County, Jiaozuo City, Henan Province. It is also a provincial-level intangible cultural heritage and a national geographical indication product of China. It is mainly produced in the towns of Qinghua, Yueshan (Shangzhuang), Baishan, Xuliang in the northern part of Bo’ai County and Shanwangzhuang Town in Qinyang City. It has been cultivated for more than 1600 years. Boai County has loose and fertile land, abundant rainfall, ample sunshine, mild climate, and a unique natural environment that is very suitable for the growth of Huai Jiang. The ginger produced in Huaiqing Prefecture is among the best of its kind, with compact chunks, fine yellow threads, fresh and spicy taste, and dense texture. It has the effects of cold resistance, stomach health, sweating, and disease elimination. Used for the treatment of cold, wind and cold, vomiting, phlegm and other diseases.
At present, research on Huaijiang focuses on planting, cultivation, and nutritional composition, and there are no reports on systematic chemical composition studies. To elucidate the pharmacological substance basis of Huaijiang and provide a theoretical basis for its development and utilization, our research group systematically isolated the chemical components of Huaijiang for the first time, and used 1D (1H NMR, 13C NMR, DEPT) and 2D (1H-1H COSY, HSQC, HMBC, NOESY) nuclear magnetic resonance techniques to identify the structures of the compounds. A total of 12 compounds were identified (see Figure 1). Plant ginger belongs to the category of medicinal and edible plants, and oral toxicity experiments have shown that ginger is a non-toxic substance. Gingerol is the main chemical component of plant ginger, which has a 3-methoxy-4-hydroxyphenyl structural unit and strong anti-inflammatory activity. Research has shown that compounds 6-gingerol, 8-gingerol, 10 gingerol, and 6-gingerol have anti-inflammatory activity and have been extensively studied. Therefore, the selected compounds were isolated and identified for anti-inflammatory activity screening. Provide reference for the development and utilization of Huaijiang and the research and development of anti-inflammatory drugs.

The plant ginger mainly contains volatile oils, gingerols, and diphenylheptanes. This study systematically isolated the chemical components of Huaijiang for the first time. Twelve compounds were isolated from the ethyl acetate fraction of Huaijiang, including one sesquiterpene compound, two carboxylic acid ester compounds, eight gingerol compounds, and one other compound. Among them, the eight gingerol components were two gingerols, three gingerols, one gingerol ketone, and two gingerol diols. Except for compound 5, the remaining 11 compounds were isolated from ginger for the first time, and 4 compounds were isolated from ginger plants for the first time.

In LPS induced inflammatory cells, the expression of nitric oxide synthase (iNOS) increases, catalyzing NO production and promoting the secretion of inflammatory marker factor tumor necrosis factor alpha (TNF – α). TNF – α induces the expression and release of interleukin-1 (IL-1) and interleukin-6 (IL-6), amplifying the cascade effect of inflammatory damage and further exacerbating the inflammatory response. Ginger extract can inhibit the increased release of NO and prostaglandin E2 (PGE2) in LPS induced inflammatory cells by reducing the mRNA expression of iNOS and cyclooxygenase-2 (COX-2), further downregulating the expression of inflammatory factors, reducing their release, and exerting anti-inflammatory effects. Gingerol compounds have a significant inhibitory effect on the production of inflammatory mediators (NO and PGE2), and show a clear dose-dependent pattern; At a concentration of 6 μ M, the anti-inflammatory inhibitory effect of 6-gingerol on the production of NO and PGE2 is superior to that of 10 gingerol, and the anti-inflammatory inhibitory effect of 10 gingerol on the production of NO and PGE2 is superior to that of 6-gingerol and 8-gingerol; The carbon chain length of gingerol affects its anti-inflammatory activity, and the unsaturated ketone structure makes gingerol more effective than gingerol in anti-inflammatory activity. Van Breemen et al. used purified human recombinant proteins cyclooxygenase-1 (COX1) and cyclooxygenase-2 (COX-2) instead of cell experiments and found that 8-gingerol, 10 gingerol, and 10 gingerol exert anti-inflammatory effects by inhibiting COX-2 rather than COX-1 production; At a concentration of 1.3 μ M, 10 gingerol has a stronger inhibitory effect on COX-2 than 8-gingerol. This study selected compounds (-) – muurola-4,11-diene, (2Z) – linear acetal gingerdiol, 8-gingerol, 10 gingerol, 6-paradol, (3R, 5S) -3,5-diacetoy-1- (4-hydroxy3-methoxy-phenyl) decane, and used lipopolysaccharide (LPS) – induced RAW 264.7 cell inflammation as a model, with NO content as the evaluation index and indomethacin as the positive control, to evaluate the anti-inflammatory activity of the compounds; The results showed that compounds (2Z) – linear acetal gingerdiol, 8-gingerol, 6-paradol, and (3R, 5S) -3,5-diametoxy-1- (4-hydroxy-3-methoxy-phenyl) decane had stronger anti-inflammatory activity compared to indomethacin, with 8-gingerol showing better anti-inflammatory activity than compounds (2Z) – linear acetal gingerdiol, 6-paradol, and (3R, 5S) -3,5-diametoxy-1- (4-hydroxy-3-methoxy-phenyl) decane. This article investigates the anti-inflammatory activity of 8-gingerol by inhibiting the expression of iNOS, reducing the release of NO from LPS induced inflammatory cells, and thus achieving anti-inflammatory effects. It confirms that 8-gingerol has good anti-inflammatory activity and may be a good candidate drug for the development and treatment of inflammatory diseases. This study not only enriches the chemical structure information of Huaijiang, providing a basis for its anti-inflammatory activity research, but also provides a foundation for the development and utilization of Huaijiang.