Inula Japonica Thunb. Flower Ethanol Extract Improves Obesity and Exercise Endurance in Mice Fed A High-Fat Diet

Characterization of Sesquiterpene Dimers from the Flowers of Inula japonica and the Structural Revisions of Related Compounds

Sesquiterpene dimers are mainly found in the Asteraceae family. However, conflicting reports on the structures of these compounds can be found in the literature. Herein, we describe ten sesquiterpene dimers isolated from the flowers of Inula japonica, including configurational revisions of japonicone H (1-1), japonicone D (2-1), inulanolide A (4-1), japonicone X (5-1), and inulanolide F (5-2) to compounds 1, 2, 4, and 5, respectively. Five new related metabolites (3 and 6-9) are also described. Application of GIAO NMR/DP4+ analyses and ECD/OR calculations enabled us to revise the absolute configurations of an additional 13 sesquiterpene dimers isolated from plants of the genus Inula. Compounds 1, 2, 4, and 6 exhibited inhibition of nitric oxide production in lipopolysaccharide activated RAW264.7 macrophages with IC50 values of 4.07-10.00 μM.

Polyphenols of the Inuleae-Inulinae and Their Biological Activities: A Review

Polyphenols are ubiquitous plant metabolites that demonstrate biological activities essential to plant-environment interactions. They are of interest to plant food consumers, as well as to the food, pharmaceutical and cosmetic industry. The class of the plant metabolites comprises both widespread (chlorogenic acids, luteolin, quercetin) and unique compounds of diverse chemical structures but of the common biosynthetic origin. Polyphenols next to sesquiterpenoids are regarded as the major class of the Inuleae-Inulinae metabolites responsible for the pharmacological activity of medicinal plants from the subtribe (Blumea spp., Dittrichia spp., Inula spp., Pulicaria spp. and others). Recent decades have brought a rapid development of molecular and analytical techniques which resulted in better understanding of the taxonomic relationships within the Inuleae tribe and in a plethora of data concerning the chemical constituents of the Inuleae-Inulinae. The current taxonomical classification has introduced changes in the well-established botanical names and rearranged the genera based on molecular plant genetic studies. The newly created chemical data together with the earlier phytochemical studies may provide some complementary information on biochemical relationships within the subtribe. Moreover, they may at least partly explain pharmacological activities of the plant preparations traditionally used in therapy. The current review aimed to systematize the knowledge on the polyphenols of the Inulae-Inulinae.

Anti-Fibrosis Effect of Panax ginseng and Inula japonica Formula in Human Pulmonary Fibroblasts

Panax ginseng Meyer and Inula japonica Thunb. are well established in traditional medicine and are known for their therapeutic properties in managing a range of ailments such as diabetes, asthma, and cancer. Although P. ginseng and I. japonica can alleviate pulmonary fibrosis (PF), the anti-fibrosis effect on PF by the combination of two herbal medicines remains unexplored. Therefore, this study explores this combined effect. In conditions that were not cytotoxic, MRC-5 cells underwent treatment using the formula combining P. ginseng and I. japonica (ISE081), followed by stimulation with transforming growth factor (TGF)-β1, to explore the fibroblast-to-myofibroblast transition (FMT). After harvesting the cells, mRNA levels and protein expressions associated with inflammation and FMT-related markers were determined to evaluate the antiinflammation activities and antifibrosis effect of ISE081. Additionally, the anti-migratory effects of ISE081 were validated through a wound-healing assay. ISE081 remarkably reduced the mRNA levels of interleukin (IL)-6, IL-8, α-smooth muscle actin (SMA), and TGF-β1 in MRC-5 cells and suppressed the α-SMA and fibronectin expressions, respectively. Furthermore, ISE081 inhibited Smad2/3 phosphorylation and wound migration of MRC-5 cells. Under the same conditions, comparing those of ISE081, P. ginseng did not affect the expression of α-SMA, fibronectin, and Smad2/3 phosphorylation, whereas I. japonica significantly inhibited them but with cytotoxicity. The results indicate that the synergistic application of P. ginseng and I. japonica enhances the anti-fibrotic properties in pulmonary fibroblasts and concurrently diminishes toxicity. Therefore, ISE081 has the potential as a prevention and treatment herbal medicine for PF.

Inula japonica ameliorated the inflammation and oxidative stress in LPS-induced acute lung injury through the MAPK/NF-κB and Keap1/Nrf2 signalling pathways

OBJECTIVES

To investigate the protective effect and underlying mechanism of Inula japonica (TEIJ) in the treatment of acute lung injury (ALI).

METHODS

Protective effects of TEIJ in the inflammation and oxidative stress were studied in lipopolysaccharide (LPS)-induced ALI mice. Meanwhile, Western blot and real-time qPCR were carried out to investigate the underlying mechanism of TEIJ for ALI as well as immunohistochemistry.

KEY FINDINGS

TEIJ significantly alleviated the course of ALI via suppressing the interstitial infiltrated inflammatory cells, the increase of inflammatory factors and the decrease of anti-oxidative factors. TEIJ inactivated the MAPK/NF-κB signalling pathway to suppress the transcription of its downstream target genes, such as TNF-α, IL-6, etc. Meanwhile, TEIJ activated the Keap1/Nrf2 signalling pathway to regulate expression levels of Nrf2 and its target proteins. The results of LC-QTOF-MS/MS indicated potential active constituents of I. japonica, terpenoids and flavonoids. Additionally, terpenoids and flavonoids synergistically alleviated LPS-induced ALI depending on MAPK/NF-κB and Keap1/Nrf2 signalling pathways.

CONCLUSION

I. japonica could be considered a potential agent to treat ALI via regulating the MAPK/NF-κB and Keap1/Nrf2 signalling pathways.

A Botanical Mixture Consisting of Inula japonica and Potentilla chinensis Relieves Obesity via the AMPK Signaling Pathway in 3T3-L1 Adipocytes and HFD-Fed Obese Mice

Excessive lipid accumulation in white adipose tissue (WAT) is the major cause of obesity. Herein, we investigated the anti-obesity effect and molecular mechanism of a botanical mixture of 30% EtOH extract from the leaves of Inula japonica and Potentilla chinensis (EEIP) in 3T3-L1 preadipocytes and high-fat diet (HFD)-fed obese mice. In vitro, EEIP prevented lipid accumulation by downregulating the expression of lipogenesis-related transcription factors such as CCAAT/enhancer binding protein (C/EBP)α, peroxisome proliferator-activated receptor (PPAR)γ, and sterol regulatory element binding protein (SREBP)-1 via AMP-activated protein kinase (AMPK) activation and G0/G1 cell cycle arrest by regulating the Akt-mTOR pathways without inducing cytotoxicity. In vivo, EEIP significantly reduced body weight gain and body fat mass in the group administered concurrently with HFD (pre-) or administered during the maintenance of HFD (post-) including subcutaneous, gonadal, renal, and mesenteric fats, and improved blood lipid profiles and metabolic hormones. EEIP pre-administration also alleviated WAT hypertrophy and liver lipid accumulation by reducing C/EBPα, PPARγ, and SREBP-1 expression via AMPK activation. In the brown adipose tissue, EEIP pre-administration upregulated the expression of thermogenic factors. Furthermore, EEIP improved the HFD-induced altered gut microbiota in mice. Taken together, our data indicated that EEIP improves HFD-induced obesity through adipogenesis inhibition in the WAT and liver and is a promising dietary natural material for improving obesity.

Anti-inflammatory sesquiterpene dimers and diterpenes from the aerial part of Inula japonica

Phytochemical investigation on the 95% alcohol extract of the aerial part of Inula japonica led to the isolation of three new compounds, inulanolides F-G (1-2) and 17α-carboxaldehyde-ent-kaur-18-oic acid (3), together with four known compounds (4-7). The structures of new compounds were elucidated by using spectroscopic data. Most of the isolated compounds showed significant anti-inflammatory activities.

A Comprehensive Review on Anti-obesity Potential of Medicinal Plants and their Bioactive Compounds

Background:

Obesity is a complex health and global epidemic issue. It is an increasing global health challenge covering significant social and economic costs. Abnormal accumulation of fat in the body may increase the health risks including diabetes, hypertension, osteoarthritis, sleep apnea, cardiovascular diseases, stroke and cancer. Synthetic drugs available on the market reported to have several side effects. Therefore, the management of obesity got to involve the traditional use of medicinal plants which helps to search the new therapeutic targets and supports the research and development of anti-obesity drugs.

Objective:

This review aim to update the data and provide a comprehensive report of currently available knowledge of medicinal plants and phyto-chemical constituents reported for their anti-obesity activity.

Methodology:

An electronic search of the periodical databases like Web of Science, Scopus, PubMed, Scielo, Niscair, ScienceDirect, Springerlink, Wiley, SciFinder and Google Scholar with information reported the period 1991-2019, was used to retrieve published data.

Results:

A comprehensive report of the present review manuscript is an attempt to list the medicinal plants with anti-obesity activity. The review focused on plant extracts, isolated chemical compounds with their mechanism of action and their preclinical experimental model, clinical studies for further scientific research.

Conclusion:

This review is the compilation of the medicinal plants and their constituents reported for the managements of obesity. The data will fascinate the researcher to initiate further research that may lead to the drug for the management of obesity and their associated secondary complications. Several herbal plants and their respective lead constituents were also screened by preclinical In-vitro and In-vivo, clinical trials and are effective in the treatment of obesity. Therefore, there is a need to develop and screen large number of plant extracts and this approach can surely be a driving force for the discovery of anti-obesity drugs from medicinal plants.

Japonicone A and related dimeric sesquiterpene lactones: molecular targets and mechanisms of anticancer activity

OBJECTIVE AND DESIGN

Japonicone A (Jap-A) is a sesquiterpene lactone (SL) dimer isolated from the plant Inula japonica Thunb. and the leading compound in the japonicone series of SL dimers which comprises 25 members (Jap-A to Jap-Y). We have analyzed the anticancer properties of Jap-A and the associated molecular targets.

METHODS

All literature data on japonicones and related SL dimers, including inulanolide A (Inu-A) and lineariifolianoid A (Lin-A) have been analyzed. Molecular models of the compound/target interactions were constructed to support our analysis.

RESULTS

Inulae Flos (Xuan Fu Hua) is used in traditional medicine in China and Korea to treat inflammatory diseases. The plant contains diverse japonicones and structurally related SL dimers. The interactions of Jap-A with the two main proteins, the pro-inflammatory cytokine TNF-α and the ubiquitin ligase MDM2, are at the origin of the anti-inflammatory and anticancer effects. Molecular docking analyses suggest that Inu-A is better adapted than Lin-A and Jap-A to form stable complexes with both TNF-α and MDM2. Jap-A exhibits marked capacities to inhibit cancer cell proliferation and dissemination and to trigger apoptosis, both in vitro and in vivo in several tumor models in mice. Its analogue Inu-A is more potent, functioning as a dual inhibitor of the MDM2-NFAT1 pathway.

CONCLUSION

This review shed some new light on the molecular targets and potential therapeutic benefits of these SL dimers and should help the design of novel anticancer agents derived from these compounds.

A review of the botany, traditional uses, phytochemistry, and pharmacology of the Flos Inulae

ETHNOPHARMACOLOGICAL RELEVANCE

Plants of the genus Inula have long been used as an ethnomedicine in Asia, Europe, and North America for its high medicinal value and health benefits. Inula japonica Thunb. (I. japonica) and Inula britanica L. (I. britanica) are included in Chinese Pharmacopoeia (2020 edition) as the traditional Chinese medicine Flos inulae (FI). In TCM, FI tastes bitter, pungent, and salt, with warm nature and has the functions of water removal, reduction in nausea, and prevention of vomiting and is often used for cold-related coughs, sputum, wheezing coughs, vomiting, belching and other related diseases. In addition, Inula japonica Thunb is used as a botanical medicine in Korea and Inula britannica L. is also used as a traditional plant medicine in Iran.

AIM OF THE STUDY

This paper collects the relevant research literature (1970-2021) and provides a systematic summary of the botany, ethnopharmacology, processing, phytochemistry, pharmacology, toxicity, analytical methods and quality control of FI to explore its potential and expand its scope for better clinical application.

MATERIALS AND METHODS

Information on Inula japonica Thunb. and Inula britanica L. was collected from scientific databases (1970-2021), including Google Scholar, Baidu Scholar, Springer, PubMed, CNKI and Wan Fang DATA. Information was also collected from classic books of Chinese herbal medicine and Ph.D. and M.Sc. theses.

RESULTS

More than 200 chemical compounds have been isolated from Inula japonica Thunb. and Inula britanica L., including sesquiterpenes, flavonoids, volatile oils, triterpenoids, diterpenoid glycosides, monoterpenoids, polysaccharides, steroid and small molecule acids. Based on a wide variety of chemically active ingredients, FI has a wide range of pharmacological effects. Modern pharmacological research has proven that the pharmacological effects of FI include anti-inflammatory, antitumor, antioxidant, antiallergy, antidiabetic, blood lipid reduction, skin whitening, liver protection, anticonstipation, and antinociceptive effects.

CONCLUSIONS

FI is a very important traditional Chinese herbal medicine with anti-inflammatory antitumor, antioxidant, antiallergy, antidiabetic and other pharmacological effects that can treat a variety of related diseases. This paper summarizes the botany, ethnopharmacology, processing, phytochemistry, pharmacology, toxicity, analytical methods, and quality control of FI. However, the research on the processing, toxicity and quality control of FI is currently too shallow, especially concerning the relationship between the changes in active components before and after processing and the changes in its pharmacological action, which remains unclear. There are few toxicity experiments conducted with FI, so it is impossible to evaluate the safety of FI objectively and impartially. There are also few studies on the material basis and doses of FI causing toxicity and side effects, and more in-depth and concrete researches should be carried out in the future regarding these aspects. Furthermore, to ensure effective and safe clinical medication, we should also pay attention to the mixed use of FI in various regions of China to control the quality of the FI plant.

Medicinal Inula Species: Phytochemistry, Biosynthesis, and Bioactivities

As a genus of the Asteraceae, Inula is widely distributed all over the world, and several of them are being used in traditional medicines. A number of metabolites were isolated from Inula species, and some of these have shown to possess ranges of pharmacological activities. The genus Inula contains abundant sesquiterpenoids, such as eudesmanes, xanthanes, and sesquiterpenoid dimers and trimers. In addition, other types of terpenoids, flavonoids, and lignins also exist in the genus Inula. Since 2010, more than 300 new secondary metabolites, including several known natural products that were isolated for the first time from the genus Inula. Most of them exhibited potential bioactivities in various diseases. The review aimed to summarize the advance of recent researches (2010-2020) on phytochemical constituents, biosynthesis, and pharmacological properties of the genus Inula for providing a scientific basis and supporting its application and exploitation for new drug development.

Inula britannica Inhibits Adipogenesis of 3T3-L1 Preadipocytes via Modulation of Mitotic Clonal Expansion Involving ERK 1/2 and Akt Signaling Pathways

The flower of Inula britannica contains various phenolic compounds with prophylactic properties. This study aimed to determine the anti-adipogenic effect of an I. britannica flower aqueous extract (IAE) and its underlying mechanisms in the 3T3-L1 preadipocytes and to identify the phenolic compounds in the extract. Treatment with IAE inhibited the adipogenesis by showing a dose-dependent suppressed intracellular lipid accumulation and mitigated expression levels of lipogenesis- and adipogenesis-associated biomarkers including transcription factors. IAE exerted an anti-adipogenic effect through the modulation of the early phases of adipogenesis including mitotic clonal expansion (MCE). Treatment with IAE inhibited MCE by arresting the cell cycle at the G0/G1 phase and suppressing the activation of MCE-related transcription factors. Furthermore, IAE inhibited adipogenesis by regulating the extracellular signal-regulated kinase 1/2 and Akt signaling pathways. Protocatechuic acid, chlorogenic acid, kaempferol-3-O-glucoside, and 6-methoxyluteolin, which are reported to exhibit anti-adipogenic properties, were detected in IAE. Therefore, modulation of early phases of adipogenesis, especially MCE, is a key mechanism underlying the anti-adipogenic activity of IAE. In summary, the anti-obesity effects of IAE can be attributed to its phenolic compounds, and hence, IAE can be used for the development of anti-obesity products.

Synergistic lipid-lowering effects of Zingiber mioga and Hippophae rhamnoides extracts

The effects of a mixture of Hippophae rhamnoides (HR) and Zingiber mioga (ZM) extract (ZH) on intracellular lipid accumulation were investigated in vitro and the anti-obesity effects of ZH evaluated in mice with high-fat diet-induced obesity. The results revealed that ZH inhibited lipid accumulation in 3T3-L1 adipocytes and Huh-7 cells by suppressing adipogenic and lipogenic gene and protein expression. To evaluate the anti-obesity effects of ZH, mice fed a high-fat diet were orally administered low and high doses of ZH (low, ZM 400 mg/kg + HR 100 mg/kg; high, ZM 800 mg/kg + HR 200 mg/kg) for 9 weeks. ZH significantly reduced body weight gain and adipose tissue accumulation with no reduction in food intake when compared to control treatment. Furthermore, ZH reduced hepatic triglyceride and total cholesterol levels, as well as adipose cell size, in the liver and epididymal fat pads, respectively, through inhibition of adipogenesis and lipogenesis-related gene expression. These results suggested that ZH inhibits lipid accumulation, thereby indicating its potential for use as a new therapeutic strategy for obesity.

Inula L. Secondary Metabolites against Oxidative Stress-Related Human Diseases

An imbalance in the production of reactive oxygen species in the body can cause an increase of oxidative stress that leads to oxidative damage to cells and tissues, which culminates in the development or aggravation of some chronic diseases, such as inflammation, diabetes mellitus, cancer, cardiovascular disease, and obesity. Secondary metabolites from Inula species can play an important role in the prevention and treatment of the oxidative stress-related diseases mentioned above. The databases Scopus, PubMed, and Web of Science and the combining terms Inula, antioxidant and secondary metabolites were used in the research for this review. More than 120 articles are reviewed, highlighting the most active compounds with special emphasis on the elucidation of their antioxidative-stress mechanism of action, which increases the knowledge about their potential in the fight against inflammation, cancer, neurodegeneration, and diabetes. Alantolactone is the most polyvalent compound, reporting interesting EC50 values for several bioactivities, while 1-O-acetylbritannilactone can be pointed out as a promising lead compound for the development of analogues with interesting properties. The Inula genus is a good bet as source of structurally diverse compounds with antioxidant activity that can act via different mechanisms to fight several oxidative stress-related human diseases, being useful for development of new drugs.