Phenolic acids from medicinal and edible homologous plants: a potential anti-inflammatory agent for inflammatory diseases

Inflammation has been shown to trigger a wide range of chronic diseases, particularly inflammatory diseases. As a result, the focus of research has been on anti-inflammatory drugs and foods. In recent years, the field of medicinal and edible homology (MEH) has developed rapidly in both medical and food sciences, with 95% of MEH being associated with plants. Phenolic acids are a crucial group of natural bioactive substances found in medicinal and edible homologous plants (MEHPs). Their anti-inflammatory activity is significant as they play a vital role in treating several inflammatory diseases. These compounds possess enormous potential for developing anti-inflammatory drugs and functional foods. However, their development is far from satisfactory due to their diverse structure and intricate anti-inflammatory mechanisms. In this review, we summarize the various types, structures, and distribution of MEHP phenolic acids that have been identified as of 2023. We also analyze their anti-inflammatory activity and molecular mechanisms in inflammatory diseases through NF-κB, MAPK, NLRP3, Nrf2, TLRs, and IL-17 pathways. Additionally, we investigate their impact on regulating the composition of the gut microbiota and immune responses. This analysis lays the groundwork for further exploration of the anti-inflammatory structure-activity relationship of MEHP phenolic acids, aiming to inspire structural optimization and deepen our understanding of their mechanism, and provides valuable insights for future research and development in this field.

Effects of MhMYB1 and MhMYB2 transcription factors on the monoterpenoid biosynthesis pathway in l-menthol chemotype of Mentha haplocalyx Briq

MAIN CONCLUSION

Transcription factors MhMYB1 and MhMYB2 correlate with monoterpenoid biosynthesis pathway in l-menthol chemotype of Mentha haplocalyx Briq, which could affect the contents of ( -)-menthol and ( -)-menthone. Mentha haplocalyx Briq., a plant with traditional medicinal and edible uses, is renowned for its rich essential oil content. The distinct functional activities and aromatic flavors of mint essential oils arise from various chemotypes. While the biosynthetic pathways of the main monoterpenes in mint are well understood, the regulatory mechanisms governing different chemotypes remain inadequately explored. In this investigation, we identified and cloned two transcription factor genes from the M. haplocalyx MYB family, namely MhMYB1 (PP236792) and MhMYB2 (PP236793), previously identified by our research group. Bioinformatics analysis revealed that MhMYB1 possesses two conserved MYB domains, while MhMYB2 contains a conserved SANT domain. Yeast one-hybrid (Y1H) analysis results demonstrated that both MhMYB1 and MhMYB2 interacted with the promoter regions of MhMD and MhPR, critical enzymes in the monoterpenoid biosynthesis pathway of M. haplocalyx. Subsequent virus-induced gene silencing (VIGS) of MhMYB1 and MhMYB2 led to a significant reduction (P < 0.01) in the relative expression levels of MhMD and MhPR genes in the VIGS groups of M. haplocalyx. In addition, there was a noteworthy decrease (P < 0.05) in the contents of ( -)-menthol and ( -)-menthone in the essential oil of M. haplocalyx. These findings suggest that MhMYB1 and MhMYB2 transcription factors play a positive regulatory role in ( -)-menthol biosynthesis, consequently influencing the essential oil composition in the l-menthol chemotype of M. haplocalyx. This study serves as a pivotal foundation for unraveling the regulatory mechanisms governing monoterpenoid biosynthesis in different chemotypes of M. haplocalyx.

Microbial community structure and diversity in fish-flower (mint) symbiosis

The fish-flower symbiosis model is an eco-friendly sustainable farming technology combining plants, fish and microorganisms in a recirculating aquaculture system. However, there are few studies on the structure and diversity of microbial communities in fish intestines, culture water and plant roots during fish-flower symbiosis. Here, we cultured carp (Cyprinus carpio), crucian carp (Carassius auratus) and grass carp (Ctenopharyngodon idella) with mint (Mentha spicala L.) and extracted total genomic DNA from intestinal microorganisms, culture-water microorganisms and root microorganisms for each fish species for high-throughput sequencing of 16S rRNA genes. Analysis of microbial community structure and diversity revealed changes in abundance of microbial genera in the intestines and culture water of each fish species, including changes in the dominant taxa. Pirellula, Truepera, Aquincola, Cetobacterium and Luteolibacter were widespread in the fish intestine, culture water and mint root system. This study revealed the effects of mint feeding on the structure and diversity of microbial communities of fish, water bodies and the mint root system during fish-flower symbiosis, providing a theoretical reference for the promotion and application of fish-flower (mint) symbiosis technology and healthy fish culture technology.

Transcriptome analysis of transcription factors and enzymes involved in monoterpenoid biosynthesis in different chemotypes of Mentha haplocalyx Briq

Background

The main active ingredients of Mentha haplocalyx Briq. essential oils are monoterpenes. According to the component of essential oils, M. haplocalyx can be divided into different chemotypes. Chemotype variation is widespread in Mentha plants but its formation mechanism is unclear.

Methods

We selected the stable chemotype l-menthol, pulegone, and carvone of M. haplocalyx for transcriptome sequencing. To further investigate the variation of chemotypes, we analyzed the correlation between differential transcription factors (TFs) and key enzymes.

Results

Fourteen unigenes related to monoterpenoid biosynthesis were identified, among which (+)-pulegone reductase (PR) and (-)-menthol dehydrogenase (MD) were significantly upregulated in l-menthol chemotype and (-)-limonene 6-hydroxylase was significantly upregulated in carvone chemotype. In addition, 2,599 TFs from 66 families were identified from transcriptome data and the differential TFs included 113 TFs from 34 families. The families of bHLH, bZIP, AP2/ERF, MYB, and WRKY were highly correlated with the key enzymes PR, MD, and (-)-limonene 3-hydroxylase (L3OH) in different M. haplocalyx chemotypes (r > 0.85). The results indicate that these TFs regulate the variation of different chemotypes by regulating the expression patterns of PR, MD, and L3OH. The results of this study provide a basis for revealing the molecular mechanism of the formation of different chemotypes and offer strategies for effective breeding and metabolic engineering of different chemotypes in M. haplocalyx.

Morphology and mass spectrometry-based chemical profiling of peltate glandular trichomes on Mentha haplocalyx Briq leaves

Mentha haplocalyx Briq (M. haplocalyx) is a herbaceous plant that has long been used as a food, medicinal spice, and flavoring agent in traditional Chinese medicine. Its secondary metabolites, having high commercial values, are mainly produced in tiny specialized structures called glandular trichomes (GTs). The primary purpose of this study was to examine the morphology and metabolites of peltate GTs in M. haplocalyx.Peltate GTs possessed globular dome shapes and intense auto-fluorescence on the surfaces of M. haplocalyx leaves. Structure subsidence and cuticle rupture were found throughout the aging stage of peltate GTs. According to histochemical staining results, the secretion of peltate GTs contained anthraquinone, flavonoids, phenolic acid and terpenoids. In M. haplocalyx peltate GTs and leaf tissues without peltate glandular trichomes, ten and two volatile compounds were identified respectively. Peltate GTs contained 42 non-volatile chemicals with a variety of structural types, including 20 flavonoids, 17 phenolic acids,1 diterpene, 3 anthraquinone and 1 alkane. Meanwhile, 15 non-volatile compounds were discovered in leaf tissues without peltate glandular trichomes, and they were all included in the list of peltate GTs' 41 components. Therefore, Peltate GTs were shown to be the primary site of not just volatile compounds but also non-volatile chemicals in M. haplocalyx. This study provides an important theoretical basis and technical approach for clarifying the bio-active metabolite biosynthesis in M. haplocalyx.

Characterization and in vitro simulated gastrointestinal digestion and fermentation of Mentha haplocalyx polysaccharide

An acidic polysaccharide (PMHP-3) obtained from the Mentha haplocalyx was structurally characterized, and in vitro simulated digestion and fermentation were investigated. PMHP-3 was mainly composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose and arabinose with molecular weight of 21.82 kDa. After digestion in saliva and simulated gastric juice, the molecular weight, reducing sugar, total sugar and uronic acid contents of PMHP-3 did not change significantly (p > 0.05). After digestion in simulated intestinal juice, the molecular weight and uronic acid content of PMHP-3 did not change significantly, and there was no free monosaccharide production, but the total sugar and reducing sugar contents slightly decreased. During fermentation, the molecular weight, carbohydrate residue and free monosaccharides of PMHP-3 were decreased, suggesting that PMHP-3 could be degraded by microorganism and metabolized into a variety the short-chain fatty acids (SCFAs) such as acetic, propionic. Meanwhile, PMHP-3 modulated the gut microbiota by reducing the ratio of Firmicutes/Bacteroidetes, promoting the proliferation of beneficial bacteria such as Bacteroidaceae and Bifidobacteriaceae, and inhibiting harmful bacteria such as Lachnospiraceae and Enterobacteriaceae. These results indicate that PMHP-3 is beneficial to the gut health and can be developed as a potential prebiotic to prevent diseases by improving intestinal health.

Potential neuroprotective activity of Mentha longifolia L. in aluminum chloride-induced rat model of Alzheimer's disease

Alzheimer's disease (AD) is an irreversible neurodegenerative disorder manifested by cognitive deterioration where the available treatments failed to delay its progression. The objective of this study was to investigate the neuroprotective activity in an aluminum chloride (AlCl₃ )-induced AD in vivo model and phytochemical profile of the traditional Egyptian herb Mentha longifolia (Ml). Male albino rats were injected with Ml fractions and essential oil for 15 days followed by AlCl₃ for 30 days. Oxidative stress and neuroinflammatory markers were measured namely: malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide (NO), and nuclear factor-κB (NF-κB). Furthermore, cholinesterase activity was tested and analysis of brain neurotransmitters using HPLC was performed. Results showed that methylene chloride and ethyl acetate fractions were able to reverse the AlCl₃ mediated MDA increase, GSH decrease and exhibited anticholinesterase activity. EaFr reversed the increased levels of NF-κB and NO. Ml fractions and oil counteracted the AlCl₃ effect on brain neurotransmitters. Forty metabolites were tentatively characterized in the bioactive fractions using UPLC-PDA-ESI-MS. 5,6,4'-trihydroxy-3',7,8-trimethoxy flavone was isolated from Ml as a first report, in addition to 5,6-dihydroxy-3',4',7,8-tetramethoxy flavone and rosmarinic acid. These findings suggest that Ml is a promising nutraceutical and source of lead compounds halting AD progression. PRACTICAL APPLICATIONS: The results presented in this paper unravels the neuroprotective effect of Mentha longifolia fractions and oil by acting as anti-inflammatory, antioxidant agents, and regulating the levels of neurotransmitters. This provides basic knowledge for the development of Ml as a source of lead compounds and a promising food supplement protective against Alzheimer's disease.

High-Throughput Immunological Analysis of Dictamni Cortex: Implication in the Quality Control of Herbal Medicine

Quality inconsistency of herbal medicine is an obstacle that limits the extensive use and study of traditional Chinese medicine. Differences in environmental conditions and processing methods of herbal medicine often result in varying clinical outcomes in patients. Standard chemical markers used for the quality control (QC) of herbal medicine are usually the most abundant and characteristic components, which may not be therapeutically relevant or cannot comprehensively reflect the biological quality of the herbs. In view of this, a novel QC method for better assessment of herbal medicine has been developed via bioactivities analysis. Immunological activities of Dictamni Cortex, a typical herbal medicine for the treatment of various inflammatory diseases, from different geographical locations in China, were evaluated. Upon in vitro treatment of their water and ethanol extracts, distinct patterns of inflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-10, IL-6, IL-12p70, IL-1β, and chemokine CXCL8 were released from the lipopolysaccharides- and/or phytohaemagglutinin-stimulated human peripheral blood mononuclear cells (PBMC). Thus, in addition to the commonly used morphological, chemical, or DNA markers, the novel high-throughput profiling of inflammatory cytokines and chemokines of PBMC upon treatment with herbal extracts could be an important reference to help for the quality control of herbal medicine in the future.

The Phenolic Fraction of Mentha haplocalyx and Its Constituent Linarin Ameliorate Inflammatory Response through Inactivation of NF-κB and MAPKs in Lipopolysaccharide-Induced RAW264.7 Cells

Mentha haplocalyx has been widely used for its flavoring and medicinal properties and as a traditional Chinese medicine with its anti-inflammation properties. The present study was designed to investigate the anti-inflammatory effects and potential molecular mechanisms of the phenolic fraction of M. haplocalyx (MHP) and its constituent linarin in lipopolysaccharide (LPS)-induced RAW264.7 cells. The high-performance liquid chromatography coupled with linear ion trap-orbitrap mass spectrometry (HPLC-LTQ-Orbitrap MS) was used to analyze the chemical composition of MHP. Using the enzyme-linked immunosorbent assay (ELISA) and quantitative realtime polymerase chain reaction (qRT-PCR), the expression of pro-inflammatory meditators and cytokines was measured at the transcriptional and translational levels. Western blot analysis was used to further investigate changes in the nuclear factor kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and Akt signaling pathways. Fourteen phenolic constituents were identified from MHP based on the data of the mass spectrometry (MS)/MS analysis. MHP and linarin decreased the production of NO, tumor necrosis factor-α (TNF-α), interlenkin-1β (IL-1β), and IL-6. The messenger ribonucleic acid (mRNA) expression levels of inducible NO synthase (iNOS), TNF-α, IL-1β, and IL-6 were also suppressed by MHP and linarin. Further investigation showed that MHP and linarin down-regulated LPS-induced phosphorylation content of NF-κB p65, inhibitor kappa B α (IκBα), extracellular signal-regulated kinase (ERK), c-Jun NH₂-terminal kinase (JNK), and p38. However, MHP and linarin showed no inhibitory effect on the phosphorylated Akt. These results suggested that MHP and linarin exerted a potent inhibitory effect on pro-inflammatory meditator and cytokines production via the inactivation of NF-κB and MAPKs, and they may serve as potential modulatory agents for the prevention and treatment of inflammatory diseases.

Gan-Lu-Siao-Du-yin, a prescription of traditional Chinese medicine, inhibited enterovirus 71 replication, translation, and virus-induced cell apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Gan-Lu-Siao-Du-yin (GLSDY) is a prescription of traditional Chinese medicine. GLSDY contains 11 ingredients and is commonly used for endemic diseases. Enterovirus 71 (EV71) is an endemic disease that can cause meningoencephalitis with mortality and neurologic sequelae without any effective management. It is unknown whether GLSDY is effective against EV71 infection.

AIM OF THE STUDY

To test the hypothesis that GLSDY can protect cell from EV71-induced injury.

MATERIALS AND METHODS

Effects of a hot water extract of GLSDY on EV71 were tested in human foreskin fibroblast cells (CCFS-1/KMC) and human rhabdomyosarcoma cells (RD cells) by plaque reduction assay and flow cytometry respectively. Inhibition of viral replication was further examined by reverse quantitative RT-PCR (qRT-PCR). Its effect on viral protein translation and virus-induced apoptosis were examined by western blot.

RESULTS

GLSDY was dose-dependently effective against EV71 infection (p<0.0001) in both CCFS-1/KMC cells and RD cells. GLSDY was highly effective when supplemented after viral inoculation (P<0.0001) with an IC50 of 8.7μg/mL. GLSDY inhibited viral RNA replication (P<0.0001), formation of viral structural proteins (VP0, VP1, VP2 and VP3) and non-structural proteins (protease 2B and 3AB). Furthermore, 300μg/mL GLSDY is effective to inhibit virus-induced apoptosis possibly through direct inhibition of caspase-8 and indirectly by inhibition of Bax.

CONCLUSIONS

GLSDY is cheap and readily available to manage EV71 infection by inhibiting viral replication, viral protein formations, and EV71-induced apoptosis.

Characterization of Fatty Acid, Amino Acid and Volatile Compound Compositions and Bioactive Components of Seven Coffee (Coffea robusta) Cultivars Grown in Hainan Province, China

Compositions of fatty acid, amino acids, and volatile compound were investigated in green coffee beans of seven cultivars of Coffearobusta grown in Hainan Province, China. The chlorogenic acids, trigonelline, caffeine, total lipid, and total protein contents as well as color parameters were measured. Chemometric techniques, principal component analysis (PCA), hierarchical cluster analysis (HCA), and analysis of one-way variance (ANOVA) were performed on the complete data set to reveal chemical differences among all cultivars and identify markers characteristic of a particular botanical origin of the coffee. The major fatty acids of coffee were linoleic acid, palmitic acid, oleic acid, and arachic acid. Leucine (0.84 g/100 g DW), lysine (0.63 g/100 g DW), and arginine (0.61 g/100 g DW) were the predominant essential amino acids (EAAs) in the coffee samples. Seventy-nine volatile compounds were identified and semi-quantified by HS-SPME/GC-MS. PCA of the complete data matrix demonstrated that there were significant differences among all cultivars, HCA supported the results of PCA and achieved a satisfactory classification performance.

Advanced development in phytochemicals analysis of medicine and food dual purposes plants used in China (2011-2014)

In 2011, we wrote a review for summarizing the phytochemical analysis (2006-2010) of medicine and food dual purposes plants used in China (Zhao et al., J. Chromatogr. A 1218 (2011) 7453-7475). Since then, more than 750 articles related to their phytochemical analysis have been published. Therefore, an updated review for the advanced development (2011-2014) in this topic is necessary for well understanding the quality control and health beneficial phytochemicals in these materials, as well as their research trends.