[Effects of glycyrrhizic acid on ERK1/2 and p38 MAPK signaling pathway in a murine model of asthma]

Glycyrrhizic Acid against Mycoplasma gallisepticum-Induced Inflammation and Apoptosis Through Suppressing the MAPK Pathway in Chickens

Mycoplasma gallisepticum (MG) is the primary pathogen of chronic respiratory diseases (CRDs) in chickens. In poultry production, antibiotics are mostly used to prevent and control MG infection, but the drug resistance and residue problems caused by them cannot be ignored. Glycyrrhizic acid (GA) is derived from licorice, a herb traditionally used to treat various respiratory diseases. Our study results showed that GA significantly inhibited the mRNA and protein expression of pMGA1.2 and GapA in vitro and in vivo. Furthermore, the network pharmacology study revealed that GA most probably resisted MG infection through the MAPK signaling pathway. Our results demonstrated that GA inhibited MG-induced expression of MMP2/MMP9 and inflammatory factors through the p38 and JUN signaling pathways, but not the ERK pathway in vitro. Besides, histopathological sections showed that GA treatment obviously attenuated tracheal and lung damage caused by MG invasion. In conclusion, GA can inhibit MG-triggered inflammation and apoptosis by suppressing the expression of MMP2/MMP9 through the JNK and p38 pathways and inhibit the expression of virulence genes to resist MG. Our results suggest that GA might serve as one of the antibiotic alternatives to prevent MG infection.

Comparative Efficacy of Haizao Yuhu Decoction Composed of Different Varieties of Glycyrrhiza in Goiter Rats

In traditional Chinese medicine, Glycyrrhiza and Sargassum are one pair of the “18 incompatible medicaments,” which in theory cannot be used together. However, since ancient times, many reports have described using compounds containing both Glycyrrhiza and Sargassum to treat diseases. Haizao Yuhu Decoction (HYD), which contains both ingredients, is mainly used to treat goiter. Chinese Pharmacopoeia officially recorded three varieties of Glycyrrhiza: Glycyrrhiza uralensis, Glycyrrhiza inflata, and Glycyrrhiza glabra. These three varieties have certain differences in chemical composition and pharmacological effects. The purpose of the present study was to investigate whether the HYD containing different varieties of Glycyrrhiza and Sargassum had different therapeutic effects in rats with goiter and to elucidate the underlying mechanism of any difference. In this study, propylthiouracil (PTU) was used to replicate the goiter model, then HYDs containing different varieties of Glycyrrhiza were used for treatment for four weeks, and then the relevant indicators were tested. The results demonstrated that HYD had antigoiter effects, alleviated the pathological changes in the thyroid tissue, and restored the abnormal serum levels of hormones related to thyroid function induced by PTU. HYD containing Glycyrrhiza uralensis had the best therapeutic effect in rats with PTU-induced goiter. The antigoiter effect of HYD may function through the hypothalamic-pituitary-thyroid (HPT) axis, inhibit the expression of the Tg and NIS genes, and regulate the synthesis of thyroid hormones, thereby reducing the excessive stimulation of TSH in thyroid cells. In addition, HYD also prevented goiter by promoting thyroid cell apoptosis and inhibiting the ERK/RSK1 pathway of cell proliferation. In conclusion, three types of HYD had different therapeutic effects in rats with goiter, which might be caused by the compatibility of different varieties of Glycyrrhiza and Sargassum.

Systematic Review: Guideline-Based Approach for the Management of Asthma and Subtypes via Chinese Medicine

Background

Asthma is a chronic condition that results in the inflammation and narrowing of airways, often clinically presenting as wheeze and shortness of breath. Little is known of the mechanisms of action (MOA) of herbs used to treat asthma. The aim of this study is to review existing data regarding known MOA of traditional Chinese medicine which will aid in the understanding of possible interactions between Western drugs and Chinese herbs as well as the standardization of management via a proposed guideline to improve patient safety and possible synergism in the long term.

Methods

We searched through 5 databases for commonly prescribed herbs and formulas for asthma and narrowed down the search to identify the underlying MOA of individual herbs that could specifically target asthma symptoms. We included studies that stated the MOA of individual herbs when used for treating symptoms of asthma, excluding them if they are described as part of a formula.

Results

A total of 26 herbs commonly prescribed for asthma with known mechanism of action were identified. Herbs used for asthma were found to have similar MOA as that for drugs. Based on existing GINA guidelines, a guideline is proposed which includes a total of 5 steps depending on the severity of asthma and the herbs' MOA. 16 formulas were subsequently identified for the management of asthma, which consist of 12 “stand-alone” and 4 “add-on” formulas. “Stand-alone” formulas used independently for asthma generally follow the GINA guidelines but do not proceed beyond step 3. These formulas consist mainly of beta-agonist and steroid-like effects. “Add-on” formulas added as adjunct to “stand-alone” formulas, however, mainly act on T helper cells or have steroid-like effects.

Conclusion

Through the understanding of MOA of herbs and their respective formulas, it will ensue greater patient safety and outcomes.