Hypericum perforatum L.: a medicinal plant with potential as a curative agent against obesity-associated complications

Natural products as novel anti-obesity agents: insights into mechanisms of action and potential for therapeutic management

Obesity affects more than 10% of the adult population globally. Despite the introduction of diverse medications aimed at combating fat accumulation and obesity, a significant number of these pharmaceutical interventions are linked to substantial occurrences of severe adverse events, occasionally leading to their withdrawal from the market. Natural products serve as attractive sources for anti-obesity agents as many of them can alter the host metabolic processes and maintain glucose homeostasis via metabolic and thermogenic stimulation, appetite regulation, pancreatic lipase and amylase inhibition, insulin sensitivity enhancing, adipogenesis inhibition and adipocyte apoptosis induction. In this review, we shed light on the biological processes that control energy balance and thermogenesis as well as metabolic pathways in white adipose tissue browning, we also highlight the anti-obesity potential of natural products with their mechanism of action. Based on previous findings, the crucial proteins and molecular pathways involved in adipose tissue browning and lipolysis induction are uncoupling protein-1, PR domain containing 16, and peroxisome proliferator-activated receptor-γ in addition to Sirtuin-1 and AMP-activated protein kinase pathway. Given that some phytochemicals can also lower proinflammatory substances like TNF-α, IL-6, and IL-1 secreted from adipose tissue and change the production of adipokines like leptin and adiponectin, which are important regulators of body weight, natural products represent a treasure trove for anti-obesity agents. In conclusion, conducting comprehensive research on natural products holds the potential to accelerate the development of an improved obesity management strategy characterized by heightened efficacy and reduced incidence of side effects.

Hypericum perforatum L. and the Underlying Molecular Mechanisms for Its Choleretic, Cholagogue, and Regenerative Properties

Any defects in bile formation, secretion, or flow may give rise to cholestasis, liver fibrosis, cirrhosis, and hepatocellular carcinoma. As the pathogenesis of hepatic disorders is multifactorial, targeting parallel pathways potentially increases the outcome of therapy. Hypericum perforatum has been famed for its anti-depressive effects. However, according to traditional Persian medicine, it helps with jaundice and acts as a choleretic medication. Here, we will discuss the underlying molecular mechanisms of Hypericum for its use in hepatobiliary disorders. Differentially expressed genes retrieved from microarray data analysis upon treatment with safe doses of Hypericum extract and intersection with the genes involved in cholestasis are identified. Target genes are located mainly at the endomembrane system with integrin-binding ability. Activation of α5β1 integrins, as osmo-sensors in the liver, activates a non-receptor tyrosine kinase, c-SRC, which leads to the insertion of bile acid transporters into the canalicular membrane to trigger choleresis. Hypericum upregulates CDK6 that controls cell proliferation, compensating for the bile acid damage to hepatocytes. It induces ICAM1 to stimulate liver regeneration and regulates nischarin, a hepatoprotective receptor. The extract targets the expression of conserved oligomeric Golgi (COG) and facilitates the movement of bile acids toward the canalicular membrane via Golgi-derived vesicles. In addition, Hypericum induces SCP2, an intracellular cholesterol transporter, to maintain cholesterol homeostasis. We have also provided a comprehensive view of the target genes affected by Hypericum's main metabolites, such as hypericin, hyperforin, quercitrin, isoquercitrin, quercetin, kaempferol, rutin, and p-coumaric acid to enlighten a new scope in the management of chronic liver disorders. Altogether, standard trials using Hypericum as a neo-adjuvant or second-line therapy in ursodeoxycholic-acid-non-responder patients define the future trajectories of cholestasis treatment with this product.

The effects of the Rheum ribes plant extract on inflammation, extracellular matrix remodeling, and obesity suggest a therapeutic potential

BACKGROUND

The prevalence of obesity is increasing in the world, and the Type II diabetes associated with obesity led researchers to seek alternative methods to treat these two chronic diseases. In the case of obesity and diabetes, changes occur in the levels of inflammatory mediators. A study was conducted to investigate the molecular mechanism of the Rheum ribes L. plant regarding obesity and inflammation.

METHODS AND RESULTS

Differentiated 3T3-L1 mouse cell lines were used as an experimental model. A dose-response relationship was established to determine at what dose and time of treatment the R. ribes L. plant extract would act effectively. To assess expression on the transcriptional level, q-PCR analyses were performed. The primers to evaluate the expression levels of genes such as Dgat1, Lpl, Fasn, ColV, Il-6, and Mcp1, which are known to be associated with obesity and insulin resistance, inflammation, and cell skeletal restructuring was designed using NCBI sequences. 18S was chosen as the housekeeping gene for normalization.

CONCLUSION

It was found that applying 50 µg/mL and 100 µg/mL of R. ribes root extract to 3T3-L1 adipocyte cells for 24 and 48 h resulted in anti- obesity and anti-inflammatory effects on the genes examined at the transcriptional level. It is an effective study to understand the molecular mechanisms by which R. ribes, which is known to have anti-diabetic, anti-obesity and anti- inflammatory activities, and to establish a link between these activities.

Influence of the Drying Method on the Volatile Component Profile of Hypericum perforatum Herb: A HS-SPME-GC/MS Study

Hypericum perforatum L. (St. John’s wort) is one of the most popular medicinal plants in the world. Due to its documented antimicrobial and antioxidant properties, it is used in the treatment of bacterial and viral infections as well as inflammations. It is also used to treat gastrointestinal diseases and mild to moderate depression. In recent years, there has been an increase in the popularity of herbal medicine. Many people collect their own herbs and dry them at home. A common choice for quick drying of fruits, vegetables and herbs at home are food dehydrator machines. There are not many publications in the scientific literature examining the quality of dried herbal material obtained in such dryers. We characterized St. John’s wort harvested in southern Poland and investigated the effect of specific drying methods on the volatile component profile. The herbal raw material was dried using three methods: indoors at room temperature, in an incubator at 37 °C and in a food dehydrator machine. Volatile components were analysed by HS-SPME GC/MS. The herb dried in a food dehydrator, compared to other drying methods, retained similar or slightly smaller amounts of the compounds from the mono- and sesquiterpenes group, aromatic monoterpenes, aromatic monoterpenoids, sesquiterpenoids, aromatic sesquiterpenes and alkanes. However, monoterpenoids and compounds coming from decomposition reactions, such as alcohols, short-chain fatty acids and esters, were noticed in larger quantities. Usage of a food dehydrator at home can be a convenient alternative to drying herbs. However, due to a different profile of volatile components depending on the drying method, the amount of biologically active substances needs to be considered. By using various methods of drying, the medical effects of herbs can be enhanced or weakened; therefore, further research in this direction should be continued.

St. John's wort (Hypericum perforatum) and depression: what happens to the neurotransmitter systems?

St. John's wort (Hypericum perforatum) is a herbaceous plant containing many bioactive molecules including naphthodianthrones, phloroglucinol derivatives, flavonoids, bioflavonoids, proanthocyanidins, and chlorogenic acid. Evidence has shown the therapeutic effects of St. John's wort and especially its two major active components, hyperforin and hypericin, on different psychiatric and mood disorders such as posttraumatic stress disorder (PTSD), attention-deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), and anxiety disorders. St. John's wort also induces antidepressant effects. In this review study, we aimed to discuss the role of St. John's wort in modulating depression, with respect to the role of different neurotransmitter systems in the brain. We discussed changes in the neurotransmitter levels in depression, and following use of St. John's wort. It was concluded that changes in the function and level of neurotransmitters in depression are complex. Also, St. John's wort can induce inconsistent effects on neurotransmitter levels. We also found that glutamate and acetylcholine may be the most important neurotransmitters to study in future works, because the function of both neurotransmitters in depression is unclear. In addition, St. John's wort induces a dualistic modulation on the activity of cholinergic signaling, which can be an interesting topic for future studies.

3,5-Dicaffeoylquinic Acid Lowers 3T3-L1 Mitotic Clonal Expansion and Adipocyte Differentiation by Enhancing Heme Oxygenase-1 Expression

Adipogenesis is a complex process in which cell commitment and mitotic clonal expansion (MCE) are in-sequence crucial events leading to terminal adipocyte differentiation. The molecules able to block some key signals in this cascade can hamper adipogenesis becoming promising agents to counteract hyperplasia and hypertrophy of adipose tissue. Mono- and di-caffeoylquinic acid isomers are biologically active polyphenols, displaying in vitro and in vivo antioxidant, hepatoprotective, anti-diabetic and anti-obesity properties. Among these isomers, 3,5-dicaffeoylquinic acid (DCQA) has been reported to inhibit lipid accumulation in adipose cells more successfully than others. Thus, we investigated DCQA effects and molecular mechanisms on 3T3-L1 pre-adipocytes induced to differentiate with a hormonal cocktail (MDI). Oil Red O incorporation assessed that DCQA pre-treatment inhibited lipid accumulation in 3T3-L1 cells induced to differentiate for 10 days. At this time, an increased phosphorylation of both AMP-activated kinase and acetyl-CoA carboxylase, as well as a strong decrease in fatty acid synthase protein level, were registered by immunoblotting, thereby suggesting that DCQA treatment can reduce fatty acid anabolism in 3T3-L1 adipocytes. Furthermore, BrdU incorporation assay, performed 48 h after hormonal stimulation, revealed that DCQA treatment was also able to hinder the 3T3-L1 cell proliferation during the MCE, which is an essential step in the adipogenic process. Thus, we focused our attention on early signals triggered by the differentiation stimuli. In the first hours after hormonal cocktail administration, the activation of ERK1/2 and Akt kinases, or CREB and STAT3 transcription factors, was not affected by DCQA pre-treatment. Whereas 24 h after MDI induction, DCQA pre-treated cells showed increased level of the transcription factor Nrf2, that induced the expression of the antioxidant enzyme heme oxygenase 1 (HO-1). In control samples, the expression level of HO-1 was reduced 24 h after MDI induction in comparison with the higher amount of HO-1 protein found at 2 h. The HO-1 decrease was functional by allowing reactive oxygen species to boost and allowing cell proliferation induction at the beginning of MCE phase. Instead, in DCQA-treated cells the HO-1 expression was maintained at high levels for a further 24 h; in fact, its expression decreased only 48 h after MDI stimulation. The longer period in which HO-1 expression remained high led to a delay of the MCE phase, with a subsequent inhibition of both C/EBP-α expression and adipocyte terminal differentiation. In conclusion, DCQA counteracting an excessive adipose tissue expansion may become an attractive option in obesity treatment.

Medical Species Used in Russia for the Management of Diabetes and Related Disorders

Background: Polyherbal mixtures called "medical species" are part of traditional and officinal medicine in Russia. This review aimed to analyze medical species used in Russia for the treatment of diabetes and related disorders. The information relevant to medical species, diabetes, and obesity was collected from local libraries, the online service E-library.ru, and Google Scholar. The prediction of the antidiabetic activity for the principal compounds identified in plants was performed using the free web resource PASS Online. Results: We collected and analyzed information about the compositions, specificities of use, and posology of 227 medical species. The medical species represent mixtures of 2-15 plants, while the most frequently mentioned in the literature are species comprising 3-6 plants. The top 10 plants among the 158 mentioned in the literature include Vaccinium myrtillus L., Phaseolus vulgaris L., Taraxacum campylodes G.E. Haglund., Urtica dioica L., Rosa spp., Hypericum spp., Galega officinalis L., Mentha × piperita L., Arctium spp, and Fragaria vesca L. The leading binary combination found in medical species comprises the leaves of V. myrtillus and pericarp of P. vulgaris; leaves of V. myrtillus and leaves of U. dioica; and leaves of V. myrtillus and aerial parts of G. officinalis. In triple combinations, in addition to the above-mentioned components, the roots of T. campylodes are often used. These combinations can be regarded as basic mixtures. Other plants are added to improve the efficacy, treat associated disorders, improve gastrointestinal function, prevent allergic reactions, etc. Meanwhile, an increase in plants in the mixture necessitates advanced techniques for quality control. A feature of medical species in Russia is the addition of fresh juices, birch sap, seaweeds, and adaptogenic plants. Modern studies of the mechanisms of action and predicted activities of the principal compounds from medicinal plants support the rationality of polyherbal mixtures. Nevertheless, the mechanisms are not well studied and reported due to the limited number of compounds. Further investigations with calculations of synergistic or additive indices are important for strengthening the scientific fundamentals for the wider use of medical species in the therapy of diabetes. Two medical species, "Arfazetin" (7 medicinal plants) and "Myrphasinum" (12 medicinal plants), are approved for use in officinal medicine. The efficacy of these species was confirmed in several in vivo experiments and clinical trials. According to modern regulatory rules, additional experiments and clinical trials are required for more detailed investigations of the mechanisms of action and confirmation of efficacy. Conclusion: We believe that the scientifically based utilization of rich plant resources and knowledge of Russian herbal medicine can significantly contribute to the local economy as well as to the sectors seeking natural healing products.