Multisolvent Similarity Measure of Chinese Herbal Medicine Ingredients for Cold–Hot Nature Identification

Unveiling gut microbiota's role: Bidirectional regulation of drug transport for improved safety

Drug safety is a paramount concern in the field of drug development, with researchers increasingly focusing on the bidirectional regulation of gut microbiota in this context. The gut microbiota plays a crucial role in maintaining drug safety. It can influence drug transport processes in the body through various mechanisms, thereby modulating their efficacy and toxicity. The main mechanisms include: (1) The gut microbiota directly interacts with drugs, altering their chemical structure to reduce toxicity and enhance efficacy, thereby impacting drug transport mechanisms, drugs can also change the structure and abundance of gut bacteria; (2) bidirectional regulation of intestinal barrier permeability by gut microbiota, promoting the absorption of nontoxic drugs and inhibiting the absorption of toxic components; (3) bidirectional regulation of the expression and activity of transport proteins by gut microbiota, selectively promoting the absorption of effective components or inhibiting the absorption of toxic components. This bidirectional regulatory role enables the gut microbiota to play a key role in maintaining drug balance in the body and reducing adverse reactions. Understanding these regulatory mechanisms sheds light on novel approaches to minimize toxic side effects, enhance drug efficacy, and ultimately improve drug safety. This review systematically examines the bidirectional regulation of gut microbiota in drug transportation from the aforementioned aspects, emphasizing their significance in ensuring drug safety. Furthermore, it offers a prospective outlook from the standpoint of enhancing therapeutic efficacy and reducing drug toxicity, underscoring the importance of further exploration in this research domain. It aims to provide more effective strategies for drug development and treatment.

Bitter-Pungent Flavor Identification Based on Ingredient Information Similarity of Chinese Herbal Medicines

BACKGROUND

The flavor theory of Chinese herbal medicines (CHMs) is one of the core theories of traditional Chinese medicine (TCM). Accurate flavor identification of CHMs is essential to guide the clinical application of CHMs.

OBJECTIVE

To develop a new method for flavor identification of CHMs according to the ingredient information for CHMs.

METHODS

It was found that the chemical basis of medicinal flavors was CHM ingredients. We developed a bitter-pungent flavor identification scheme to build a relationship between medicinal flavors and CHM ingredients. We firstly proposed a scientific hypothesis that "CHMs with similar flavors should have a similar chemical basis". To test this scientific hypothesis, we then explored an intelligent algorithm for bitter-pungent flavor identification of CHMs based on the information similarity of CHM ingredients. GC was used to separate the chemical ingredients of CHMs and analyze the ingredient information of CHMs. A distance metric learning algorithm was built to measure the similarity of GC chemical fingerprints. A bitter-pungent flavor identification scheme (BPFI) was proposed to predict the bitter-pungent flavor of CHMs. Finally, a number of experiments were performed to evaluate the identification performance of our scheme.

RESULTS

Compared to classical algorithms, our proposed BPFI scheme has better flavor prediction performance. The total identification accuracy of our BPFI scheme reached 0.843. The area under ROC (receiver operating characteristic curve) curve (AUC) was 0.899.

CONCLUSION

The experimental results confirmed our inference that the chemical basis of CHM flavors was CHM ingredients, and implied that CHMs with similar flavors had similar composition. The BPFI model proved to be effective and feasible.

HIGHLIGHTS

Verification hypothesis: CHMs with similar flavors should have similar chemical basis.

Mechanism difference of ginseng medicines with different natures on hyperthyroidism

ETHNOPHARMACOLOGICAL RELEVANCE

Medicinal nature is a unique index in traditional Chinese medicine (TCM) to measure the efficacy of Chinese medicines. Hyperthyroidism, qi-Yin deficiency syndrome in TCM was regarded as the classic heat syndrome category in Chinese medicine. Moreover, it is extensively employed to evaluate the medicinal nature of herbs within the framework of the 'hot/cold' nature theory. Ginseng, red and black ginseng (GS, RG, and BG, respectively), and ginseng leaves (GL) are qi-tonifying herbs with different medicinal natures and were just right used to examine the underlying mechanisms between the nature of ginseng medicines and their tonifying effect.

AIM OF THE STUDY

To examine the different mechanisms between different natures of ginseng medicines and their qi-tonifying action by comparison of their effects on hyperthyroidism and elucidate the nature of BG.

MATERIALS AND METHODS

The hyperthyroidism model was induced through the oral administration of Euthyrox. Steroids belonging to hypothalamus pituitary adrenal (HPA) and hypothalamic pituitary gonadal (HPG) axes were determined with an ultra-performance liquid chromatography-triple quadrupole tandem mass spectrometry (UPLC-QqQ-MS/MS) method. Furthermore, the biochemical indexes associated with energy metabolism, including the serum cyclic nucleotide system and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) signaling pathways were examined. Additionally, the gut microbiota was subjected to 16 S rDNA sequencing, followed by gas chromatography-mass spectrometry (GC-MS) analysis of short-chain fatty acids (SCFAs).

RESULTS

GS, RG, and BG could treat hyperthyroidism rats by regulating the hypothalamus pituitary thyroid (HPT) axis. The RG also had a strong regulatory effect on the HPA and HPG axis. The BG has a regulatory effect on the HPG axis. GL had a strong regulatory effect on HPA, HPG, and HPT axes. GS had the ability to regulate Firmicutes/Bacteroides of the intestinal flora, and GS, RG, and BG ameliorated the decrease of SCFAs induced by hyperthyroidism. According to PCA, BG is similar to GS, indicating a mild-warm nature.

CONCLUSION

The nature of BG was attributable to mild-warm and the GL with cold nature is best for the treatment of hyperthyroidism based on PCA analysis with all the bio-indices. In addition, the mechanism study indicated that the qi-tonifying effects of ginseng medicines are involved in HPT, HPA, and HPG axes to alleviate hyperthyroidism. In addition, the primary indexes reflected different natures of ginseng medicines are cyclic adenosine monophosphate (cAMP)/cyclic guanosine monophosphate (cGMP), AchE, and substance metabolism associated with Na+-K+-ATPase and PI3K/AKT signaling pathways, which are potential biomarkers for evaluation on the natures of qi-tonifying medicines.

Rhubarb charcoal-crosslinked chitosan/silk fibroin sponge scaffold with efficient hemostasis, inflammation, and angiogenesis for promoting diabetic wound healing

Diabetic patients often experience long-term risks due to chronic inflammation and delayed re-epithelialization during impaired wound healing. Although the severity of this condition is well known, the treatment options for diabetic wounds are limited. Rhubarb charcoal, a well-known traditional Chinese medicine, has been used to treat skin wounds for thousands of years. We produced a chitosan/silk fibroin sponge scaffold loaded with natural carbonized rhubarb and crosslinked it by freeze-drying to create a highly efficient RCS/SF scaffold. Rhubarb carbon and carboxymethyl chitosan exhibit antibacterial activity and promote wound healing. Owing to its 3D porous structure, this scaffold is antibacterial and pro-angiogenic. It also possesses remarkable properties, such as excellent swelling and biocompatibility. The supportive effect of carbonized rhubarb on mouse fibroblast migration is mediated at the cellular/tissue level by increased skin neovascularization and re-epithelization. Compared to the control group, RCS/SF scaffolds promoted faster healing, increased neovascularization, enhanced collagen deposition, and re-epithelialization within two weeks. The scaffold's pro-healing properties and efficient release of carbonized rhubarb, with rapid hemostatic and good sterilization effects, make it an outstanding candidate for treating diabetic wounds and novel therapeutic interventions for diabetic ulcers.

A comparative metabolomics study on dried and processed Rehmannia Radix

The efficacy of Rehmannia Radix changes after processing. However, the precise effect of processing on the properties of Rehmannia Radix is an intricate topic, as this effect cannot be explained by traditional methods. The purpose of this study was to investigate how processing methods influence the properties of Rehmannia Radix, as well as the changes in body function after administering dried Rehmannia Radix (RR) and processed Rehmannia Radix (PR) using a metabolomics approach. In addition, principal component analysis and orthogonal partial least-squares discriminant analysis models were generated using SIMCA-P 14.0 to evaluate the properties of RR and PR. Potential biomarkers were identified, and associated metabolic networks were established to clarify differences in the properties and efficacies of RR and PR. The results showed that RR and PR have cold and hot properties, respectively. RR can exert a hypolipidaemic effect by regulating nicotinate and nicotinamide metabolism. PR exerts a tonic effect and regulates the body's reproductive function through the regulation of alanine, aspartate and glutamate metabolism, arachidonic acid, pentose and glucuronate metabolism, respectively. Ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry-based metabolomics is a promising approach to determine the cold/hot properties of traditional Chinese medicine formulations.

Compatibility between cold-natured medicine CP and hot-natured medicine AZ synergistically mitigates colitis mice through attenuating inflammation and restoring gut barrier

ETHNOPHARMACOLOGICAL RELEVANCE

Ulcerative colitis (UC) is a nonspecific intestinal inflammation with complex pathogenesis. Traditional Chinese Medicine (TCM) formula consists of several TCM herbs following the principle of herbal property and compatibility. Our previous studies found that Huanglian Ganjiang decoction (HGD) exhibited anti-colitis capacity and the compatibility between hot-natured medicine and cold-natured medicine was main compatibility. However, the association between compatibility mechanism of HGD and its anti-colitis effect has not been fully illustrated yet.

AIM OF STUDY

Here, we would explore whether cold-natured medicine Coptis chinensis Franch. plus Phellodendron chinense C.K.Schneid. (CP) and hot-natured medicine Angelica sinensis (Oliv.) Diels plus Zingiber officinale Roscoe (AZ) in HGD respectively produce different impacts on UC, and exert synergistic effect on UC together.

MATERIALS AND METHODS

UPLC/MS-MS was used to qualitatively analyze chemical profiles of CP, AZ and CPAZ extracts. CPAZ-UC target network was constructed using network pharmacology. Colitis mice was induced by 3% DSS for 7 days and treated with CP, AZ and CPAZ for another 7 days. The levels of multiple cytokines and proportions of innate and adaptive immune cells were determined to assess inflammatory profiles. The leakage of FITC-dextran, expressions of tight junction proteins were detected for evaluation of gut barrier function.

RESULTS

CP, AZ and CPAZ could improve symptoms of colitis mice. CP showed superiority in reducing proportions of pro-inflammatory immune cells M1 cells, neutrophils, Th1 and Th17 cells, and levels of pro-inflammatory cytokines IFN-γ, IL-6, IL-10, TNF-α. In the contrast, AZ had advantage of elevating ratios of anti-inflammatory immune cells M2 and Treg cells as well as the production of anti-inflammatory cytokines IL-10 and TGF-β. In addition, CP and AZ synergistically regulated M1/M2 macrophage polarization and the following IL-6, IL-10, TNF-α, IFN-γ production, thereby restoring intestinal mucosal barrier.

CONCLUSION

Taken together, our study first demonstrated that cold-natured medicine CP and hot-natured medicine AZ took on different functions in treatment of colitis mice. Meanwhile, they exhibited synergistic effect on the alleviation of intestinal inflammation and reinforcement of gut barrier function and integrity.

Integrated Metabonomic Study on the Relationship between Medicinal Properties and Efficacy of Rehmanniae Radix

Each Chinese medicine has its own properties and effects. However, the close connection between the medicinal properties and the effects of the medicine remains unclear. To export the scientific connection between the medicinal properties and efficacy of Rehmanniae Radix (RR), this study established a model and evaluated the therapeutic effects of RR on cold-heat syndrome to access the properties of RR, and then established a blood-heat syndrome model through the injection of rats with dry yeast combined with anhydrous ethanol. Related biochemical indicators (coagulation factors and central pyrogenic factor) were measured to assess the efficacy of RR. Finally, metabonomic technology was used to study the blood-cooling mechanism of RR from two aspects: medicinal properties and efficacy. The comprehensive results suggest that RR can significantly reduce the rectal temperature of blood-heat syndrome model rats and increase both the expression levels of coagulation factors (TNF-[Formula: see text], IL-1[Formula: see text], and IL-6) and the central pyrogenic factors (c-AMP, PGE-2). RR also cools the blood through regulating arginine, proline, phenylalanine, taurine, hypotaurine, sulfur, glycerophospholipid, primary bile acid metabolic pathways, and the tricarboxylic acid cycle. Therefore, RR plays the role of cooling blood by virtue of its cold property. The medicinal property of RR has a guiding effect on the clinical application. Moreover, the integrated metabolomic approach is a powerful tool for studying the properties and efficacy of Chinese medicine.

Cold-hot nature identification of Chinese herbal medicines based on the similarity of HPLC fingerprints

The nature theory of Chinese herbal medicines (CHMs) is the core theory of traditional Chinese medicine (TCM). Cold-hot nature is an important part of CHM nature. It is found that the material basis of cold-hot nature is CHM ingredients. To test the scientific hypothesis that “CHMs with similar cold-hot nature should have similar material basis,” we explored an intelligent method for cold-hot nature identification of CHMs based on the feature similarity of CHM ingredients in this work. Sixty one CHMs were selected for cold-hot nature identification. High performance liquid chromatography (HPLC) was used to separate the chemical ingredients of CHMs and extract the feature information of CHM ingredients. A distance metric learning algorithm was then learned to measure the similarity of HPLC fingerprints. With the learned distance metric, cold-hot nature identification scheme (CHNIS) was proposed to build an identification model to evaluate the cold-hot nature of CHMs. A number of experiments were designed to verify the effectiveness and feasibility of the proposed CHNIS model. The total identification accuracy rate of 61 CHMs is 80.3%. The performance of the proposed CHNIS algorithm outperformed that of the compared classical algorithms. The experimental results confirmed our inference that CHMs with similar cold-hot nature had similar composition of substances. The CHNIS model was proved to be effective and feasible.

Phytochemical, Antimicrobial and Cytotoxic Activities of Gaultheria Trichophylla Royle

Gaultheria trichophylla fruit is used by the indigenous people to treat asthma, headache, and as an appetizer in the alpine and sub-alpine regions of Western Himalaya. No studies exist on the antimicrobial significance of this species. The current study describes the phytochemical composition, in vitro cytotoxic, and antimicrobial effects of different extracts of Gaultheria trichophylla. In antimicrobial assay, four different bacterial strains (Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, and Staphylococcus aureus) as well as four fungal strains (Helminthosporium solani, Fusarium solani, Aspergillus flavus, and Aspergillus fumigates) were used. Qualitative phytochemical screening showed the existence of different active compounds. Quantitative phytochemical screening showed the existence of phenolic contents in the range from 3.27 ± 0.44 mg GE/g to 14.17 ± 088 mg GE/g, whereas flavonoids were from 8.08 ± 0.48 mg QE/g to 26.9 ± 0.23 mg QE/g. The elemental analysis quantified essential minerals of life importance such as Na (3.24 ± 0.05 µgg−1), Mg (1.93 ± 0.08 µgg−1), and Ca (1.83 ± 0.056 µgg−1), while none of the heavy metal levels were high from the permissible limit of WHO. Cytotoxic assay showed moderate activity in terms of LC50 of (50 μg/mL) for methanolic extracts. Antifungal assay of methanolic and other extracts against different tested fungal strains showed a zone of inhibitions from 29 ± 1.154% to 86.66 ± 0.09%. As an antibacterial, the MIC values were from 7.5 mg/mL to 15 mg/mL for the tested extracts. The observed biological potentials were at the expense of its phytochemical composition, however, further confirmation in animal models and responsible phytochemical isolations in pure form is needed.

Quantification of “Cold-Hot” Medicinal Properties of Chinese Medicines Based on Primary Metabolites and Fisher’s Analysis

Background

Chinese medicinal properties (CMP) are an important part of the basic theory of traditional Chinese medicines (TCMs). Quantitative research on the properties of TCMs is of great significance to deepen the understanding and application of the theory of drug properties and promoting the modernization of TCMs. However, these studies are limited to strong subjectivity or distinguish different drug properties based on certain indicators since CMP studies are diverse.

Objective

To realize quantitative comparison of same medicinal properties of different Chinese medicines.

Method

To solve the above problem, we proposed and explored quantification of Chinese medicinal properties (QMP) and the quantification value of medicinal properties “R”. The correlation between primary metabolites and “cold-hot” medicinal properties was explored on the premise of material basis of Chinese herbal medicines and Fisher's analysis. Based on indicators related to “cold-hot” medicinal properties, we utilized quantitative values “R” to characterize the strength or weakness of “cold-hot” medicinal properties.

Results

According to QMP, the same medicinal properties were quantified and compared by quantification value of medicinal properties that expressed by alphabet “R”. The general theoretical formula of “R” deduced is R = (‖l‖ × cos θ)/‖L‖ = ∑_i=1ⁿj_ip_i/∑_i=1ⁿp_i², in which n ≥ 1. In the light of formula of “R” and indicators related to “cold-hot” medicinal properties, we got “R” value of “cold-cool” and “warm-hot” medicinal properties. “R” values of “cold-cool” medicinal properties of Phellodendri chinensis cortex, Coptidis rhizoma, and Menthae haplocalycis herba were 0.63, 1.00, and 0.49, respectively. The result showed that Coptidis rhizoma is the most “cold-cool”, followed by Phellodendri chinensis cortex, with Menthae haplocalycis herba is the weakest in the three Chinese medicines, consistent with cognition of TCM theory.

Conclusion

QMP has certain guiding significance for the quantification of “cold and hot” drug properties. “R” is feasible to realize the quantitative comparison of the same drug properties of different traditional Chinese medicine, which is helpful to promote process of modern Chinese medicine construction.

Prediction of the taxonomical classification of the Ranunculaceae family using a machine learning method

A machine learning method is successfully applied to determine lineage-specific features among various genera within the Ranunculaceae family.

"Efficacy-Nature-Structure" Relationship of Traditional Chinese Medicine Based on Chemical Structural Data and Bioinformatics Analysis

Traditional Chinese medicines (TCMs) have wide pharmacological activities, and the ingredients in individual TCMs determine their efficacies. To understand the "efficacy-nature-structure" relationship of TCM, compounds from 2444 kinds of herbs were collected, and the associations between family, structure, nature, and biological activities were mined and analyzed. Bernoulli Naïve Bayes profiling and a data analysis method were used to predict the targets of compounds. The results show that genetic material determined the representation of ingredients from herbs and the nature of TCMs and that the superior scaffolds of compounds of cold nature were 2-phenylochrotinone, anthraquinone, and coumarin, while the compounds of hot nature were cyclohexene. The results of the similarity analysis and distribution for molecular descriptors of compounds show that compounds associated with the same nature were similar and compounds associated with different natures occurred as a transition in part. As for integral compounds from 2-phenylochrotinone, anthraquinone, coumarin, and cyclohexene, the value of the shape index increased, indicating the transition of scaffolds from a spherical structure to a linear structure, with various molecular descriptors decreasing. Three medicines and three recipes prescribed based on "efficacy-nature-structure" had a higher survival rate in the clinic and provided powerful evidence for TCM principles. The research improves the understanding of the "efficacy-nature-structure" relationship and extends TCM applications.

Nature Identification of Chinese Herbal Medicine Compounds Based on Molecular Descriptors

BACKGROUND

The nature of Chinese herbal medicines (CHMs) is a bridge between traditional Chinese medicine and clinical application. Accurate nature identification of CHMs is essential for guiding the clinical application of CHMs.

OBJECTIVE

To develop a new method for nature identification of CHMs according to compounds in CHMs.

METHODS

The nature of a CHM is a comprehensive manifestation of the properties of various compounds in the CHM. In this study, 2012 CHM compounds were extracted to construct a compound data set. Molecular descriptors were utilized to build an identification model for classification of the cold-hot-neutral nature of CHM compounds.

RESULTS

The predictive accuracy and confusion matrix were validated using the assembled data set. The best model produced accuracies of 96.5 ± 0.5% and 86.5 ± 1.5% on training set and test set, respectively. Furthermore, the identification model is robust in predicting the cold-hot-neutral nature of CHM compounds.

CONCLUSION

This work shows how a classification model for medical nature identification can be developed. The derived model can be utilized for the application of CHMs.

HIGHLIGHTS

To construct a nature identification model for analysis of the cold-hot-neutral nature of CHMs according to the compounds in CHMs.

Mass spectrometry-based multi-omics analysis reveals the thermogenetic regulation of herbal medicine in rat model of yeast-induced fever

ETHNOPHARMACOLOGICAL RELEVANCE

In the principle of traditional Chinese medicine (TCM), clinical usage is based on drug attributes of the herbal medicine. The cold and hot properties of TCM are classified accordingly to their pharmacological effects, such as temperature change. Herbal medicine has been used as food supplements in our daily life, and the thermogenetic regulation is one of their primary applications. However, the underlying mechanism of "cold" or "hot" stimulating effect of herbal medicine has not been fully identified.

AIM OF THE STUDY

Thermogenetic regulation and classification of herbal medicine of hot/cold herbs were determined by rat model of yeast-induced fever.

MATERIALS AND METHODS

Here, a novel method in classifying and characterizing cold- and hot-herbal medicines was established by analyses of mass spectrometry (MS)-based metabolomics and lipidomics from the serum of herbal extract-treated rats. The yeast-induced inflammatory rats were used as the model system, which were subjected to the treatments of cold- or hot-herbal medicine.

RESULTS

The multi-omics approach identified the clustering of metabolites from cold and hot herb-treated rat serum by using partial least squares discriminant analysis (PLS-DA), and which subsequently identified that the 8-h treatment was the metabolic perturbation point of herb-mediated thermogenesis. Meanwhile, the levels of identified metabolites in the serum, i.e. lysoPE, lysoPC and carnitine, showed a positive relationship with the regulation of body temperature; while the levels of amino acid, fatty acid and bile acid were contrary correlated with the temperature change. In addition, the differential expressed metabolites were subjected to pathway enrichment and network analyses in revealing the possible action mechanism of herbal medicines in relating to thermogenetic regulation.

CONCLUSION

The developed MS-based omics provides a new insight in characterizing the properties of cold/hot herbal medicine.

Cold-hot nature identification based on GC similarity analysis of Chinese herbal medicine ingredients

The theory of cold-hot nature of Chinese herbal medicines (CHMs) is the core theory of CHM. It has been found that the volatile oil ingredients in CHMs are closely related to their cold-hot nature. Guided by the scientific hypothesis that "CHMs with similar component substances should have similar medicinal natures", exploration of the intelligent identification of the cold-hot nature of CHMs based on the similarity of their volatile oil ingredients has become a research focus. Gas chromatography (GC) chemical fingerprints have been widely used in the separation of volatile oil ingredients to analyze the cold-hot nature of CHMs. To verify the above hypothesis, in this work, we study the quantification of the similarity of the volatile oil ingredients of CHMs to their fingerprint similarity and explore the relationship between the volatile oil ingredients of CHMs and their cold-hot nature. In this study, we utilize GC technology to analyze the chemical ingredients of 61 CHMs that have a clear cold-hot nature (including 30 'cold' CHMs and 31 'hot' CHMs). Using the constructed fingerprint dataset of CHMs, a distance metric learning algorithm is applied to measure the similarity of the GC fingerprints. Furthermore, an improved k-nearest neighbor (kNN) algorithm is proposed to build a predictive identification model to identify the cold-hot nature of CHMs. The experimental results prove our inference that CHMs with similar component substances should have similar medicinal natures. Compared with existing classical models, the proposed identification scheme has better predictive performance. The proposed prediction model is proved to be effective and feasible.

Traditional Chinese medicines differentially modulate the gut microbiota based on their nature (Yao-Xing)

BACKGROUND

Property theory is a unique principle guiding traditional Chinese medicine (TCM) that classifies various TCMs into four natures (hot, warm, cool, and cold) to reflect their medical actions on the human body. Despite successful application for thousands of years, characterizing the nature of medical TCMs by modern physiological indicators remains a challenge.

PURPOSE

In this study, we investigated the potential relationship between the nature of TCMs and their modulation of the gut microbiota.

STUDY DESIGN

We selected twelve TCMs with hot, warm, cool, or cold natures that possess antidiarrheal effects. Their aqueous extracts were orally administered to C57BL/6 mice at a clinical dose for 4 weeks. The gut microbiota was measured by 16S rRNA-based metagenomics, and the correlation between microbial composition/function and TCM nature was analyzed.

RESULTS

Antidiarrheal TCMs with different natures showed distinct impacts on the gut microbiota. Hot-natured TCMs had no influence on the gut microbiota, warm-natured TCMs had a moderate influence, cool-natured TCMs had a strong influence, and cold-natured TCMs substantially changed the structure of the gut microbial community. The abundance of Anaerotruncus, Tyzzerella and Ruminiclostridium steadily increased, while that of Ruminococcaceae_UCG-010, Parasutterella and Bifidobacterium continuously decreased as the herbal nature turned from cold to hot. Microbiome functional prediction for Cluster of Orthologous Groups (COG) of proteins and Kyoto Encyclopedia of Genes and Genomes (KEGG) categories showed that colder TCMs imposed a stronger influence on microbial functional repertoires. Specifically, the abundance of ABC transporters, key bacterial proteins involved in nutrient absorption and drug resistance, was gradually decreased by colder TCMs.

CONCLUSION

Our results demonstrated that the nature of TCMs could be reflected by their modulation of gut microbes. Cold TCMs may exert their antidiarrheal effects, at least partially, by modulating the gut microbiota, while hot TCMs may alleviate dysentery in other ways.

A Song of Ice and Fire: Cold and Hot Properties of Traditional Chinese Medicines

The theory of cold and hot properties is the basic theory of traditional Chinese medicines (TCMs) and has been successfully applied to combat human diseases for thousands of years. Although the theory of cold and hot is very important to guide the clinical application of TCMs, this ancient theory remains an enigma for a long time. In recent years, more and more researchers have tried to uncover this ancient theory with the help of modern techniques, and the cold and hot properties of a myriad of TCMs have been studied. However, there is no review of cold and hot properties. In this review, we first briefly introduced the basic theories about cold and hot properties, including how to distinguish between the cold and hot properties of TCMs and the classification and treatment of cold and hot syndromes. Then, focusing on the application of cold and hot properties, we take several important TCMs with cold or hot property as examples to summarize their traditional usage, phytochemistry, and pharmacology. In addition, the mechanisms of thermogenesis and antipyretic effect of these important TCMs, which are related to the cold and hot properties, were summarized. At the end of this review, the perspectives on research strategies and research directions of hot and cold properties were also offered.