Targeting autophagy to counteract neuroinflammation: A novel antidepressant strategy.

Depression is a common disease that affects physical and mental health and imposes a considerable burden on afflicted individuals and their families worldwide. Depression is associated with a high rate of disability and suicide. It causes a severe decline in productivity and quality of life. Unfortunately, the pathophysiological mechanisms underlying depression have not been fully elucidated, and the risk of its treatment is still presented. Studies have shown that the expression of autophagic markers in the brain and peripheral inflammatory mediators are dysregulated in depression. Autophagy-related genes regulate the level of autophagy and change the inflammatory response in depression. Depression is related to several aspects of immunity. The regulation of the immune system and inflammation by autophagy may lead to the development or deterioration of mental disorders. This review highlights the role of autophagy and neuroinflammation in the pathophysiology of depression, sumaries the autophagy-targeting small moleculars, and discusses a novel therapeutic strategy based on anti-inflammatory mechanisms that target autophagy to treat the disease.

Cellular neurobiology of hyperforin.

Hyperforin is a phloroglucinol derivative isolated from the medicinal plant Hypericum perforatum (St John's wort, SJW). This lipophilic biomolecule displays antibacterial, pro-apoptotic, antiproliferative, and anti-inflammatory activities. In addition, in vitro and in vivo data showed that hyperforin is a promising molecule with potential applications in neurology and psychiatry. For instance, hyperforin possesses antidepressant properties, impairs the uptake of neurotransmitters, and stimulates the brain derived neurotrophic factor (BDNF)/TrkB neurotrophic signaling pathway, the adult hippocampal neurogenesis, and the brain homeostasis of zinc. In fact, hyperforin is a multi-target biomolecule with a complex neuropharmacological profile. However, one prominent pharmacological feature of hyperforin is its ability to influence the homeostasis of cations such as Ca2+ , Na+ , Zn2+ , and H+ . So far, the pathophysiological relevance of these actions is currently unknown. The main objective of the present work is to provide an overview of the cellular neurobiology of hyperforin, with a special focus on its effects on neuronal membranes and the movement of cations.

Cytotoxic and Antioxidant Activity of Hypericum perforatum L. Extracts against Human Melanoma Cells from Different Stages of Cancer Progression, Cultured under Normoxia and Hypoxia.

Oxidative stress and the hypoxic microenvironment play a key role in the progression of human melanoma, one of the most aggressive skin cancers. The aim of our study was to evaluate the effect of Hypericum perforatum extracts of different origins (both commercially available (HpEx2) and laboratory-prepared from wild grown (HpEx12) and in vitro cultured (HpEx13) plants) and hyperforin salt on WM115 primary and WM266-4 lymph node metastatic human melanoma cells cultured under normoxic and hypoxic conditions. The polyphenol content, radical scavenging activity, and hyperforin concentration were determined in the extracts, while cell viability, apoptosis, ROS production, and expression of NRF2 and HO-1, important oxidative stress-related factors, were analyzed after 24 h of cell stimulation with HpExs and hyperforin salt. We found that cytotoxic, pro-apoptotic and antioxidant effects depend on the extract composition, the stage of melanoma progression, and the oxygen level. Hyperforin salt showed lower activity than H. perforatum extracts. Our study for the first time showed that the anticancer activity of H. perforatum extracts differs in normoxia and hypoxia. Importantly, the composition of extracts of various origins, including in vitro cultured, resulting in their unique properties, may be important in the selection of plants for therapeutic application.

Convergent gene clusters underpin hyperforin biosynthesis in St John's wort.

The meroterpenoid hyperforin is responsible for the antidepressant activity of St John's wort extracts, but the genes controlling its biosynthesis are unknown. Using genome mining and biochemical work, we characterize two biosynthetic gene clusters (BGCs) that encode the first three steps in the biosynthesis of hyperforin precursors. The findings of syntenic and phylogenetic analyses reveal the parallel assembly of the two BGCs. The syntenous BGC in Mesua ferrea indicates that the first cluster was assembled before the divergence of the Hypericaceae and Calophyllaceae families. The assembly of the second cluster is the result of a coalescence of genomic fragments after a major duplication event. The differences between the two BGCs - in terms of gene expression, response to methyl jasmonate, substrate specificity and subcellular localization of key enzymes - suggest that the presence of the two clusters could serve to generate separate pools of precursors. The parallel assembly of two BGCs with similar compositions in a single plant species is uncommon, and our work provides insights into how and when these gene clusters form. Our discovery helps to advance our understanding of the evolution of plant specialized metabolism and its genomic organization. Additionally, our results offer a foundation from which hyperforin biosynthesis can be more fully understood, and which can be used in future metabolic engineering applications.

Microsomal prostaglandin E2 synthase-1 and its inhibitors: Molecular mechanisms and therapeutic significance.

Inflammation is closely linked to the abnormal phospholipid metabolism chain of cyclooxygenase-2/microsomal prostaglandin E2 synthase-1/prostaglandin E2 (COX-2/mPGES-1/PGE2). In clinical practice, non-steroidal anti-inflammatory drugs (NSAIDs) as upstream COX-2 enzyme activity inhibitors are widely used to block COX-2 cascade to relieve inflammatory response. However, NSAIDs could also cause cardiovascular and gastrointestinal side effects due to its inhibition on other prostaglandins generation. To avoid this, targeting downstream mPGES-1 instead of upstream COX is preferable to selectively block overexpressed PGE2 in inflammatory diseases. Some mPGES-1 inhibitor candidates including synthetic compounds, natural products and existing anti-inflammatory drugs have been proved to be effective in in vitro experiments. After 20 years of in-depth research on mPGES-1 and its inhibitors, ISC 27864 have completed phase II clinical trial. In this review, we intend to summarize mPGES-1 inhibitors focused on their inhibitory specificity with perspectives for future drug development.

Prophylactic effects of hyperforin on anhedonia-like phenotype in chronic restrain stress model: A role of gut microbiota.

Anhedonia is the core symptom of depression, which largely reflects the therapeutic effect of depression. Hypericum perforatum is one of the most important antidepressant herb that has fewer side effects than traditional antidepressants. Considering the antibacterial effect of Hypericum perforatum, we verified whether this antidepressant activity was related to intestinal microbiomics. So we established anhedonia mouse model to explore the underlying treatment mechanism of hyperforin, the key antidepressant ingredient of Hypericum perforatum and to screen new psychobiotics based on hyperforin. It was found that hyperforin prevented anhedonia induced by chronic restraint stress in mice and altered the richness and evenness of bacteria populations compared with stressed mice. Metastat analysis showed that Akkermansia muciniphila and Muribaculum intestinale were the bacterial species obviously affected by hyperforin, and their abundance in hyperforin-treated group significantly increased. The results suggest that the effect of hyperforin on anhedonia may be partly assisted by Akkermansia muciniphila. These also indicate that Muribaculum intestinale may be another important intestinal bacteria involved in the pathogenesis of anhedonia symptom and depression.

Development of new and validated HPTLC methods for the qualitative and quantitative analysis of hyperforin, hypericin and hyperoside contents in Hypericum species.

PURPOSE: Hypericum perforatum L. (St. John's wort) is a medicinally important member of Hypericaceae. Many pharmacological activities have been mostly attributed to its hyperforin, hypericin and/or hyperoside contents. Therefore, qualitative and quantitative determinations of these ingredients are essential to justify the beneficial effects of St. John's wort on health. In the European Pharmacopoeia, the TLC and HPLC methods were given for this purpose. High performance thin layer chromatography (HPTLC) has recently become increasingly used as a suitable technique for analysing herbal drugs. This study aims to develop new and validated HPTLC methods to analyse these active components in different Hypericum spp. to find other suitable species to replace the official plant. METHODS: Three different mobile phases were developed: n-hexane-ethyl acetate (8:2) for hyperforin analysis, toluene-chloroform-ethyl acetate-formic acid (8:5:3.5:0.6) for hypericin analysis and ethyl acetate-formic acid-acetic acid-water (15:2:2:1) for hyperoside analysis. These newly developed and validated HPTLC systems were further applied to determine their concentrations in different Hypericum species. RESULTS: Hyperforin concentration was found between 6.40 to 26.40 mg/g only in H. triquetrifolium, H. scabrum and two H. perforatum samples; hypericin was detected between 0.81 and 1.41 mg/g only in H. bithynicum, H. perfoliatum, H. triquetrifolium and two H. perforatum samples; and hyperoside was identified in all tested specimens ranging from 1.01 to 9.73 mg/g. The new HPTLC methods developed and validated in the present study may ensure reliable results for the qualification and quantification of hyperforin, hypericin and hyperoside contents in Hypericum species.

Hyperforin and Myrtucommulone Derivatives Act as Natural Modulators of Wnt/ß-Catenin Signaling in HCT116 Colon Cancer Cells.

The therapeutic activities of natural plant extracts have been well known for centuries. Many of them, in addition to antiviral and antibiotic effects, turned out to have anti-tumor activities by targeting different signaling pathways. The canonical Wnt pathway represents a major tumorigenic pathway deregulated in numerous tumor entities, including colon cancer. Here, we investigated the acylphloroglucinols hyperforin (HF) from St. John's wort (Hypericum perforatum L.) and myrtucommulone A (MC A) from myrtle (Myrtus communis) and semi-synthetic derivatives thereof (HM 177, HM 297, HM298) for their effects on Wnt/ß-catenin signaling. None of these substances revealed major cytotoxicity on STF293 embryonic kidney and HCT116 colon carcinoma cells at concentrations up to 10 µM. At this concentration, HF and HM 177 showed the strongest effect on cell proliferation, whereas MC A and HM 177 most prominently inhibited anchorage-independent growth of HCT116 cells. Western blot analyses of active ß-catenin and ß-catenin/TCF reporter gene assays in STF293 cells revealed inhibitory activities of HF, MC A and HM 177. In line with this, the expression of endogenous Wnt target genes, Axin and Sp5, in HCT116 cells was significantly reduced. Our data suggest that the acylphloroglucinols hyperforin, myrtucommulone A and its derivative HM 177 represent potential new therapeutic agents to inhibit Wnt/ß-catenin signaling in colon cancer.

Improved Bioactivity of the Natural Product 5-Lipoxygenase Inhibitor Hyperforin by Encapsulation into Polymeric Nanoparticles.

Hyperforin, a highly hydrophobic prenylated acylphloroglucinol from the medical plant St. John's Wort, possesses anti-inflammatory properties and suppresses the formation of proinflammatory leukotrienes by inhibiting the key enzyme 5-lipoxygenase (5-LO). Despite its strong effectiveness and the unique molecular mode of interference with 5-LO, the high lipophilicity of hyperforin hampers its efficacy in vivo and, thus, impairs its therapeutic value, especially because of poor water solubility and strong plasma (albumin) protein binding. To overcome these hurdles that actually apply to many other hydrophobic 5-LO inhibitors, we have encapsulated hyperforin into nanoparticles (NPs) consisting of acetalated dextran (AcDex) to avoid plasma protein binding and thus improve its cellular supply under physiologically relevant conditions. Encapsulated hyperforin potently suppressed 5-LO activity in human neutrophils, but it failed to interfere with 5-LO activity in a cell-free assay, as expected. In the presence of human serum albumin (HSA), hyperforin was unable to inhibit cellular 5-LO activity, seemingly because of strong albumin binding. However, when encapsulated into NPs, hyperforin caused strong inhibition of 5-LO activity in the presence of HSA. Together, encapsulation of the highly hydrophobic hyperforin as a representative of lipophilic 5-LO inhibitors into AcDex-based NPs allows for efficient inhibition of 5-LO activity in neutrophils in the presence of albumin because of effective uptake and circumvention of plasma protein binding.

Therapeutic potential of pharmacological agents targeting TRP channels in CNS disorders.

Central nervous system (CNS) disorders like Alzheimer's disease (AD), Parkinson disease (PD), stroke, epilepsy, depression, and bipolar disorder have a high impact on both medical and social problems due to the surge in their prevalence. All of these neuronal disorders share some common etiologies including disruption of Ca2+ homeostasis and accumulation of misfolded proteins. These misfolded proteins further disrupt the intracellular Ca2+ homeostasis by disrupting the activity of several ion channels including transient receptor potential (TRP) channels. TRP channel families include non-selective Ca2+ permeable channels, which act as cellular sensors activated by various physio-chemical stimuli, exogenous, and endogenous ligands responsible for maintaining the intracellular Ca2+ homeostasis. TRP channels are abundantly expressed in the neuronal cells and disturbance in their activity leads to various neuronal diseases. Under the pathological conditions when the activity of TRP channels is perturbed, there is a disruption of the neuronal homeostasis through increased inflammatory response, generation of reactive oxygen species, and mitochondrial dysfunction. Therefore, there is a potential of pharmacological interventions targeting TRP channels in CNS disorders. This review focuses on the role of TRP channels in neurological diseases; also, we have highlighted the current insights into the pharmacological modulators targeting TRP channels.

Hyperforin induces apoptosis through extrinsic/intrinsic pathways and inhibits EGFR/ERK/NF-κB-mediated anti-apoptotic potential in glioblastoma.

Glioblastoma is the most common primary brain tumor with poor survival rate and without effective treatment strategy. Notably, amplification and active mutation of epidermal growth factor receptor (EGFR) occur frequently in glioblastoma patient that may be a potential treatment target. Several studies indicated that various type of herbal compounds not only regulate anti-depressant effect but also shown capacity to suppress glioblastoma growth via inducing apoptosis and inhibiting oncogene signaling transduction. Hyperforin, an herb compound derived from St. John's wort was used to treat depressive disorder by inhibiting neuronal reuptake of several neurotransmitters. Although hyperforin can reduce matrix metallopeptidases-2 (MMPs) and -9-mediated metastasis of glioblastoma, the detail mechanism of hyperforin on glioblastoma is remaining unclear. Here, we suggested that hyperforin may induce extrinsic/intrinsic apoptosis and suppress anti-apoptotic related proteins expression of glioblastoma. We also indicated that hyperforin-mediated anti-apoptotic potential of glioblastoma was correlated to inactivation of EGFR/extracellular signal-regulated kinases (ERK)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling.

Antiproliferative Effects of St. John's Wort, Its Derivatives, and Other Hypericum Species in Hematologic Malignancies.

Hypericum is a widely present plant, and extracts of its leaves, flowers, and aerial elements have been employed for many years as therapeutic cures for depression, skin wounds, and respiratory and inflammatory disorders. Hypericum also displays an ample variety of other biological actions, such as hypotensive, analgesic, anti-infective, anti-oxidant, and spasmolytic abilities. However, recent investigations highlighted that this species could be advantageous for the cure of other pathological situations, such as trigeminal neuralgia, as well as in the treatment of cancer. This review focuses on the in vitro and in vivo antitumor effects of St. John's Wort (Hypericum perforatum), its derivatives, and other Hypericum species in hematologic malignancies. Hypericum induces apoptosis in both myeloid and lymphoid cells. Other Hypericum targets include matrix metalloproteinase-2, vascular endothelial growth factor, and matrix metalloproteinase-9, which are mediators of cell migration and angiogenesis. Hypericum also downregulates the expression of proteins that are involved in the resistance of leukemia cells to chemotherapeutic agents. Finally, Hypericum and its derivatives appear to have photodynamic effects and are candidates for applications in tumor photodynamic therapy. Although the in vitro studies appear promising, controlled in vivo studies are necessary before we can hypothesize the introduction of Hypericum and its derivatives into clinical practice for the treatment of hematologic malignancies.

Protective Role of St. John's Wort and Its Components Hyperforin and Hypericin against Diabetes through Inhibition of Inflammatory Signaling: Evidence from In Vitro and In Vivo Studies.

Diabetes mellitus is a very common chronic disease with progressively increasing prevalence. Besides the well-known autoimmune and inflammatory pathogenesis of type 1 diabetes, in many people, metabolic changes and inappropriate lifestyle favor a subtle chronic inflammatory state that contributes to development of insulin resistance and progressive loss of ß-cell function and mass, eventually resulting in metabolic syndrome or overt type 2 diabetes. In this paper, we review the anti-inflammatory effects of the extract of Hypericum perforatum L. (St. John's wort, SJW) and its main active ingredients firstly in representative pathological situations on inflammatory basis and then in pancreatic ß cells and in obese or diabetic animal models. The simultaneous and long-lasting inhibition of signal transducer and activator of transcription (STAT)-1, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and mitogen-activated protein kinases (MAPKs)/c-jun N-terminal kinase (JNK) signaling pathways involved in pro-inflammatory cytokine-induced ß-cell dysfunction/death and insulin resistance make SJW particularly suitable for both preventive and therapeutic use in metabolic diseases. Hindrance of inflammatory cytokine signaling is likely dependent on the hyperforin content of SJW extract, but recent data reveal that hypericin can also exert relevant protective effects, mediated by activation of the cyclic adenosine monophosphate (cAMP)/protein kinase cAMP-dependent (PKA)/adenosine monophosphate activated protein kinase (AMPK) pathway, against high-fat-diet-induced metabolic abnormalities. Actually, the mechanisms of action of the two main components of SJW appear complementary, strengthening the efficacy of the plant extract. Careful quantitative analysis of SJW components and suitable dosage, with monitoring of possible drug-drug interaction in a context of remarkable tolerability, are easily achievable pre-requisites for forthcoming clinical applications.

Optimization of Light Intensity, Temperature, and Nutrients to Enhance the Bioactive Content of Hyperforin and Rutin in St. John's Wort.

St. John's wort (Hypericum perforatum L.) is a medicinal plant that alleviates depression and other disorders due to its abundance of active ingredients. Hyperforin, rutin, and melatonin are the main active, and important, ingredients in St. John's wort that alleviate depression. In order to investigate the optimal conditions for accumulating these active ingredients, design of experiments and response surface methodology (RSM) was employed in this study. Two-month-old St John's wort plants were cultivated in growth chambers at varying temperatures, light intensities, and nutrient solution concentrations before analysis by HPLC, for determining differences in hyperforin, rutin, and melatonin content. The results showed that hyperforin and rutin contents were significantly influenced by temperature (18-23 °C) and light intensity (49-147 µmol m-2 s-1 photosynthetic photon flux density (PPFD)), whereas Hoagland's nutrient solution concentration (25-75%) had little effect. The accumulation of melatonin might not be influenced by cultivation conditions. Light intensity and temperature are easily controlled environmental factors in artificial cultivation, both of which are related to secondary metabolite production in the plant. Based on RSM, the optimal conditions for the accumulation of hyperforin and rutin were obtained. The maximum content of hyperforin was 5.6 mg/g, obtained at a temperature of 19 °C, a nutrient solution concentration of 45%, and a light intensity of 49 µmol m-2 s-1 PPFD. The maximum content of rutin was 3.8 mg/g obtained at a temperature of 18 °C, a nutrient solution concentration of 50%, and a light intensity of 147 µmol m-2 s-1 PPFD. This evaluation of suitable conditions for the accumulation of bioactive compounds in St. John's wort can be applied to plant factories on a large scale.

Acid sphingomyelinase - a regulator of canonical transient receptor potential channel 6 (TRPC6) activity.

Recent investigations propose the acid sphingomyelinase (ASM)/ceramide system as a novel target for antidepressant action. ASM catalyzes the breakdown of the abundant membrane lipid sphingomyelin to the lipid messenger ceramide. This ASM-induced lipid modification induces a local shift in membrane properties, which influences receptor clustering and downstream signaling. Canonical transient receptor potential channels 6 (TRPC6) are non-selective cation channels located in the cell membrane that play an important role in dendritic growth, synaptic plasticity and cognition in the brain. They can be activated by hyperforin, an ingredient of the herbal remedy St. John's wort for treatment of depression disorders. Because of their role in the context of major depression, we investigated the crosstalk between the ASM/ceramide system and TRPC6 ion channels in a pheochromocytoma cell line 12 neuronal cell model (PC12 rat pheochromocytoma cell line). Ca2+ imaging experiments indicated that hyperforin-induced Ca2+ influx through TRPC6 channels is modulated by ASM activity. While antidepressants, known as functional inhibitors of ASM activity, reduced TRPC6-mediated Ca2+ influx, extracellular application of bacterial sphingomyelinase rebalanced TRPC6 activity in a concentration-related way. This effect was confirmed in whole-cell patch clamp electrophysiology recordings. Lipidomic analyses revealed a decrease in very long chain ceramide/sphingomyelin molar ratio after ASM inhibition, which was connected with changes in the abundance of TRPC6 channels in flotillin-1-positive lipid rafts as visualized by western blotting. Our data provide evidence that the ASM/ceramide system regulates TRPC6 channels likely by controlling their recruitment to specific lipid subdomains and thereby fine-tuning their physical properties.

Novel Insights into the Effect of Hyperforin and Photodynamic Therapy with Hypericin on Chosen Angiogenic Factors in Colorectal Micro-Tumors Created on Chorioallantoic Membrane.

Photodynamic therapy with hypericin (HY-PDT) and hyperforin (HP) could be treatment modalities for colorectal cancer (CRC), but evidence of their effect on angiogenic factors in CRC is missing. Convenient experimental model utilization is essential for angiogenesis research. Therefore, not only 2D cell models, but also 3D cell models and micro-tumors were used and compared. The micro-tumor extent and interconnection with the chorioallantoic membrane (CAM) was determined by histological analyses. The presence of proliferating cells and HY penetration into the tumor mass were detected by fluorescence microscopy. The metabolic activity status was assessed by an colorimetric assay for assessing cell metabolic activity (MTT assay) and HY accumulation was determined by flow cytometry. Pro-angiogenic factor expression was determined by Western blot and quantitative real-time polymerase chain reaction (RT-qPCR). We confirmed the cytotoxic effect of HY-PDT and HP and showed that their effect is influenced by structural characteristics of the experimental model. We have pioneered a method for analyzing the effect of HP and cellular targeted HY-PDT on pro-angiogenic factor expression in CRC micro-tumors. Despite the inhibitory effect of HY-PDT and HP on CRC, the increased expression of some pro-angiogenic factors was observed. We also showed that CRC experimental micro-tumors created on quail CAM could be utilized for analyses of gene and protein expression.

Hyperforin: To Be or Not to Be an Activator of TRPC(6).

Meantime, it is well accepted that hyperforin, the chemical instable phloroglucinol derivative of Hypericum perforatum, St. John's wort, is the pharmacophore of St. John's wort extracts. With the decline of this scientific discussion, another controversial aspect has been arisen, the question regarding the underlying mechanism leading to the pharmacological profile of the plant extract used in therapy of depression. We will summarize the different concepts described for hyperforin's antidepressive activity. Starting with unspecific protein-independent mechanisms due to changes in pH, we will summarize data of protein-based concepts beginning with concepts based on involvement of a variety of proteins and will finally present concepts based on the modulation of a single protein.

TRPC Channels and Mental Disorders.

Transient receptor potential canonical (TRPC) channels mediate the influx of different types of cations through the cell membrane and are involved in many functions of the organism. Evidences of involvement of TRPC channels in neuronal development suggest that this family of proteins might play a role in certain neurological disorders. As reported, knockout mice for different TRPC channels show alterations in neuronal morphological and functional parameters, with behavioral abnormalities, such as in exploratory and social behaviors. Although mutations in TRPC channels could be related to mental/neurological disorders, there are only a few cases reported in literature, indicating that this correlation should be further explored. Nonetheless, other functional evidences support the implication of these channels in neurological diseases. In this chapter, we summarize the main findings relating TRPC channels to neurological disorders, such as autism spectrum disorders, bipolar disorder, and intellectual disability among others.

Hyperforin Exhibits Antigenotoxic Activity on Human and Bacterial Cells.

Hyperforin (HF), a substance that accumulates in the leaves and flowers of Hypericum perforatum L. (St. John's wort), consists of a phloroglucinol skeleton with lipophilic isoprene chains. HF exhibits several medicinal properties and is mainly used as an antidepressant. So far, the antigenotoxicity of HF has not been investigated at the level of primary genetic damage, gene mutations, and chromosome aberrations, simultaneously. The present work is designed to investigate the potential antigenotoxic effects of HF using three different experimental test systems. The antigenotoxic effect of HF leading to the decrease of primary/transient promutagenic genetic changes was detected by the alkaline comet assay on human lymphocytes. The HF antimutagenic effect leading to the reduction of gene mutations was assessed using the Ames test on the standard Salmonella typhimurium (TA97, TA98, and TA100) bacterial strains, and the anticlastogenic effect of HF leading to the reduction of chromosome aberrations was evaluated by the in vitro mammalian chromosome aberration test on the human tumor cell line HepG2 and the non-carcinogenic cell line VH10. Our findings provided evidence that HF showed antigenotoxic effects towards oxidative mutagen zeocin in the comet assay and diagnostic mutagen (4-nitroquinoline-1-oxide) in the Ames test. Moreover, HF exhibited an anticlastogenic effect towards benzo(a)pyrene and cisplatin in the chromosome aberration test.

Bioactive compounds from Hypericum humifusum and Hypericum perfoliatum: inhibition potential of polyphenols with acetylcholinesterase and key enzymes linked to type-2 diabetes.

CONTEXT: Natural products are reported to have a wide spectrum of pharmacological properties such as antimicrobial, anti-inflammatory and anti-cholinesterase. The genus Hypericum (Hypericaceae) is a source of a variety of molecules with different biological activities, notably hypericin and various phenolics. OBJECTIVES: The goals of the present work were the determination of total phenolic and flavonoid content, hypericin and hyperforin concentration as well as the evaluation of biological of Hypericum humifusum L. (Hhu) and Hypericum perfoliatum L. (Hper). MATERIALS AND METHODS: The various extracts of aerial parts were powdered, and then extracted with methanol. Antibacterial activity was performed according to minimum inhibitory concentration (MIC) and minimum bactericidal (MBC) methods against four Gram-positive bacteria, four Gram-negative bacteria and yeast. RESULTS: The results revealed that H. humifusum, bear the highest total phenolic and flavonoid content (48-113 mg GAE/g and 8-41 mg RE/g, respectively) as well as hypericin (60-90 mg/g) and hyperforin (8-30 mg/g) concentration. Both species showed significant antioxidant activity as revealed by DPPH, FRAP, ABTS, and metal chelating assays. H. humifusum exhibited a strong acetylcholinesterase (3.86-4.57 mg GALAEs/g), α-glucosidase (0.73-2.55 mmol ACEs/g) and α-amylase (3-8 mmol ACEs/g) inhibitory activity. The extract of H. humifusum exhibited strong antibacterial activity mainly against Staphylococcus epidermidis, Staphylococus aureus, and Enterococcus faecium (MIC values ranging from 200 to 250 µg/mL). The highest antifungal activity was showed for H. perfoliatum extract (MIC value = 250 µg/mL). CONCLUSION: The data suggest that H. humifusum could be used as valuable new natural agents with functional properties for pharmacology industries.