Coltsfoot — an old herb for coughs that raises concerns?

Aim of the study: This study reviews the current advances in the research on the botany, ethnopharmacology, phytochemistry, pharmacology, and toxicology of Farfarae Flos. Prospects for future investigation and application of this herb are also discussed.

Results: Approximately 175 chemical compounds, including terpenoids, organic acids, flavonoids, alkaloids, chromones, volatile oils, and other compounds, have been isolated from FF. This TCM has been reported to produce pharmacological effects on the respiratory, cardiovascular, and digestive systems, and exert antioxidant, anti-inflammatory, and neuroprotective activities. FF is safe in the traditional dose range, but the potential toxicity due to the emergence of pyrrolidine alkaloids needs to be paid more attention. FF is a commonly used TCM with pharmacological activities mainly on the respiratory system. This study suggests that the further expansion of the pharmacological effect of FF and in-depth study of its prescription need to be concerned about. The investigations of the role of more active substances and the pharmacokinetics of the hepatotoxic components of FF will help to maximize the therapeutic potential and promote its popularization and application.

Aim of the study: The flower bud of Tussilago farfara L. (Compositae) (FTF) is one of the traditional Chinese medicinal herbs used to treat cough, phlegm, bronchitic, and asthmatic conditions. The objective of this study is to isolate four caffeoylquinic acids from the ethyl acetate extract (EtE) of FTF and to evaluate their antitussive, expectorant, and anti-inflammatory activities.

Results: The four compounds were identified as chlorogenic acid (1), 3,5-dicaffeoylquinic acid (2), 3,4-dicaffeoylquinic acid (3), and 4,5-dicaffeoylquinic acid (4). All compounds, especially compound 4 (58.0% inhibition in cough frequency), showed a significant antitussive effect. However, the mixture was the most effective to inhibit the cough frequency by 61.7%. All compounds also showed a significant expectorant effect, while compound 2 was the most potent to enhance the phenol red secretion by 35.7%. All compounds significantly alleviated inflammation, but compound 4 showed the strongest effect to inhibit the leukocytosis by 49.7%. The caffeoylquinic acids and their mixture, exhibiting significant antitussive, expectorant, and anti-inflammatory effects, could be considered as the main effective ingredients of FTF, and they may act in a collective and synergistic way.

Results: Flower bud significantly lengthened the latent period of cough, decreased cough frequency caused by ammonia and enhanced tracheal phenol red output in expectorant evaluation. Principal component analysis (PCA) yielded good separation between flower bud and rachis, and corresponding loading plot showed that the phenolic compounds, organic acid, sugar, amino acid, terpene and sterol contributed to the discrimination. These findings provide pharmacological and chemical evidence that only flower bud can be used as the antitussive and expectorant herbal drug. The high concentration of chlorogenic acid, 3,5-dicaffeoylquinic acid, rutin in flower buds may be related with the antitussive and expectorant effects of Flos Farfara. To guarantee the clinical effect, rachis should be picked out before use.

Aim of the study: The aim of study is to explore the efficiency of FTF in vitro and in vivo for the treatment of lung inflammation, and to illustrate the possible mechanisms of FTF in treating inflammation-related respiratory diseases targeting NOD-like receptor 3 (NLRP3) inflammasome, nuclear factor erythroid 2-related factor 2 (Nrf2), and nuclear transcription factor-κB (NF-κB).

Results: FTF-EtOH suppressed CS-induced overproduction of inflammatory factors [e.g., tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β)], and upregulation of the content of intracellular MDA in the lung homogenate of mice. In cell-based models, FTF-EtOH reduced the lipopolysaccharide (LPS)-induced overproduction of inflammatory factors, and attenuated the CS extract-induced overgeneration of reactive oxygen species (ROS). Furthermore, FTF-EtOH up-regulated Nrf2 and its downstream genes through enhancing the stability of Nrf2 protein, and inhibited the activation of NF-κB and NLRP3 inflammasome, which have been confirmed by detecting the protein levels in the mouse model. FTF-EtOH effectively attenuated lung inflammation in vitro and in vivo. The protection of FTF-EtOH against inflammation was produced by activation of Nrf2 and inhibitions of NF-κB and NLRP3 inflammasome.

Aim of the study: An increased risk of developing respiratory diseases has been linked to exposure to cigarette smoking (CS). The flower buds of Tussilago farfara L., also known as Farfarae Flos (FF), can be used for the treatment of cough, bronchitis, and asthmatic disorders in China.

Results: The results showed that FF administration could relieve the lung inflammation as demonstrated by lung index, interleukin-6 (IL-6), and interleukin-1β (IL-1β) levels, as well as the pulmonary pathological change. The lung metabolomics coupled with molecular docking showed that FF could alleviate lung inflammation by regulating lysophosphatidylcholine biosynthesis through the caffeoyl quinic acids distributed in the lung tissue. In addition, fecal metabolome coupled with 16S rRNA gene sequencing showed that FF could regulate the tryptophan metabolism by regulating the intestinal flora disorders. This study provided new insights of FF to relieve CS-induced pulmonary inflammation with the multimechanism.

Aim of the study: Chronic bronchitis (CB) is a complex respiratory disease characterized by a persistent cough, dyspnea, and excessive sputum production. Flos Farfarae (FF), derived from the dried flower buds of Tussilago farfara L.

Results: Similarly, interactions between lung microbiota and serum metabolites, as well as between gut microbiota and serum metabolites, were significantly enhanced. However, FF treatment significantly reduced these interactions. FF treatment not only alleviates the inflammatory state of rats with chronic bronchitis by modulating specific lung and gut microbiota and serum metabolites, but also may restore gut and lung microbial homeostasis by decreasing serum metabolite-mediated interactions between the lung and gut microbiota, thereby resulting in therapeutic effects in rats with CB. We systematically evaluated the efficacy of the traditional Chinese medicine FF in CB from the innovative perspective of serum metabolite-mediated interactions between lung and gut microbiota for the first time.

Aim of the study: The normal transport velocity of the isolated ciliated epithelium of the frog oesophagus was proved to be 228 +/- 15 micron . s-1.

Results: The following ingredients increased the transport rate with falling rank order: Folia farfarae (coltsfoot), fructus foeniculi (fennel), and fructus anisi (anise). Herba plantaginis (plantain), flores verbasci (torch weed), and radix liquiritiae (liquorice) were ineffective whereas semen foenigraeci (foenugrec), radix althaeae (marsh mallow), and herba thymi (mother of thyme) had an inhibiting effect in raising rank order. The latter two groups of ingredients are constituents of the tea because of their attributed additional effects, e.g. protective effects due to mucous layers in the hypopharynx and spasmolytic, secretolytic and bactericide effects.

Aim of the study: This review aims to provide a critical evaluation of the current knowledge on the ethnobotanical value, phytochemistry, pharmacology, toxicity and quality control of coltsfoot, thus provide a basis for further investigations.

Results: Coltsfoot has diverse uses in local and traditional medicine, but similarities have been noticed, specifically for relieving inflammatory conditions, respiratory and infectious diseases in humans. Regarding its pharmacological activities, many traditional uses of coltsfoot are supported by modern in vitro or in vivo pharmacological studies such as anti-inflammatory activities, neuro-protective activity, anti-diabetic, anti-oxidant activity. Quantitative analysis (e.g. GC-MS, UHPLC-MRMHR) indicated the presence of a rich (>150) pool of chemicals, including sesquiterpenes, phenolic acids, flavonoids, chromones, pyrrolizidine alkaloids (PAs) and others from its leaves and buds. In addition, adverse events have resulted from a collection of the wrong plant which contains PAs that became the subject of public concern attributed to their highly toxic. So far, remarkable progress has been witnessed in phytochemistry and pharmacology of coltsfoot.