Hypericin Content Research Articles

Cytotoxic and Immunomodulatory Effects of Hypericin as a Photosensitizer in Photodynamic Therapy Used on Skin Cell Cultures.

Determination of the hypericin-photodynamic (HY-PDT) effect on the secretion of cytokines secreted by the skin cells, may be the basis for using the immunomodulatory effect of photodynamic action in the treatment of inflammatory skin diseases. The study aimed to evaluate the cytotoxic and immunomodulatory effects of hypericin (HY) in photodynamic therapy (PDT) performed in vitro on cultures of selected skin cell lines. The study used two human cell lines, primary dermal fibroblast (HDFa) and primary epidermal keratinocytes (HEKa). The MTT test was used to define the metabolic activity of treated cells. Cell supernatants subjected to sublethal PDT were assessed to determine the interleukins: IL-2, IL-8, IL-10, IL-11, IL-19, IL-22, and metalloproteinase 1 (MMP-1). The results confirm the destructive effect of HY-PDT and the immunomodulatory effects of sublethal doses on the selected skin cells, depending on the concentration of HY and the light doses. No statistically significant differences were noted in IL-2 and IL-10 concentration after HY-PDT for HEKa and HDFa lines. After using HY-PDT, the concentration of IL-8, MMP-1, IL-22, and IL-11 significantly decreased in the HEKa line. Moreover, the concentration of IL-19 and MMP-1 significantly decreased in the HDFa line. The concentration of IL-11 in the HDFa line after using only the HY, without the light, increased but decreased after HY-PDT. Our experiment confirmed that HY-PDT has not only a cytotoxic effect but, used in sublethal doses, also presents immunomodulatory properties. These may be an advantage of HY-PDT when used in the treatment of persistent skin inflammation, connected with the release of pro-inflammatory cytokines resistant to conventional treatment methods.

Photodynamic antibacterial research on hypericin-loaded PEGylated mesoporous silica delivery system

In this study, a novel drug delivery system (MSN-PEG-Hypericin) was successfully fabricated using tetraethyl orthosilicate and 3-aminopropyltriethoxysilane as raw materials, and the PEGylation of the prepared aminated mesoporous silica and grafting of hypericin onto the carrier were further conducted to obtain MSN-PEG-Hypericin. The successful preparation of MSN-PEG-Hypericin was characterized by several physical-chemical techniques. Furthermore, the MSN-PEG-Hypericin system increased the ability of hypericin to generate reactive oxygen species (ROS) in vitro. The cytotoxicity assay and hemolysis analysis showed that MSN-PEG-Hypericin had good biocompatibility. For antibacterial studies, the irradiation time and incubation time of photodynamic therapy (PDT) for S. aureus and E. coli were respectively 8 min and 8 h, and the concentrations of hypericin were 2.5 and 5 μg/mL. The result of triphenyl tetrazolium chloride assay indicated that MSN-PEG-Hypericin had stronger photodynamic antibacterial activity than free hypericin, and S. aureus was more sensitive to PDT than E. coli, which was related to their cell structural differences. The antibacterial mechanism study indicated that the generated ROS could destroy the bacterial structures and cause bacterial death due to the leakage of the contents. The MSN-PEG-Hypericin system prepared in this study had potential application prospects in the antibacterial field.

Fluorescence-Guided Laparoscopy after Oral Hypericin Administration for Staging of Locally Advanced Gastric Cancer-A Pilot Study.

(1) Background: Laparoscopic staging is essential in gastric cancer (GC) to rule out peritoneal metastasis (PM). Hypericin, a plant-derived fluorescent compound, has been suggested to improve laparoscopic visualization of PM from GC. This prospective, single-arm, open-label clinical trial aimed to assess the feasibility and safety of oral hypericin administration as well as the suitability of fluorescence-guided laparoscopy (FGL) for improving the sensitivity and specificity of staging in GC patients (EudraCT-Number: 2015-005277-21; clinicaltrials.gov identifier: NCT-02840331). (2) Methods: GC patients received Laif® 900, an approved hypericin-containing phytopharmaceutical, once orally two to four hours before white light and ultraviolet light laparoscopy. The peritoneal cancer index was evaluated, biopsies taken and hypericin concentrations in serum and peritoneal tissue were determined by mass spectrometry. (3) Results: Between 2017 and 2021, out of 63 patients screened for eligibility, 50 patients were enrolled and treated per protocol. The study intervention was shown to be feasible and safe in all patients. Standard laparoscopy revealed suspicious lesions in 27 patients (54%), among whom 16 (59%) were diagnosed with PM. FGL identified suspicious areas in 25 patients (50%), among whom PM was confirmed in 13 cases (52%). Although hypericin concentrations in serum reached up to 5.64 ng/mL, no hypericin was detectable in peritoneal tissue biopsies. (4) Conclusions: FGL in patients with GC was shown to be feasible but futile in this study. Sufficient levels of hypericin should be ensured in target tissue prior to reassessing FGL with hypericin.

Exploring the Biochemical Profiles of Medicinal Plants Cultivated Under Stressful Environmental Conditions

The therapeutic potential of medicinal plants, attributed to diverse bioactive chemicals, is impacted by dynamic metabolic changes under environmental stressors such as salt, drought, and heavy metal exposure. This study aimed to elucidate the biochemical alterations in stressed medicinal plants and their implications for therapeutic qualities. Two groups of plants were compared: one cultivated in optimal conditions, serving as a control, and the other exposed to stressors mimicking real-world scenarios. Biochemical parameters, including total phenolic content, flavonoids, antioxidant activity, and specific secondary metabolites, were assessed using established analytical methods. In a case study involving Aloe vera under elevated soil salinity, a significant decrease in total phenolic content and antioxidant activity was observed. Surprisingly, aloin, an anti-inflammatory bioactive compound, exhibited notable upregulation. Stress-induced biochemical variations in medicinal plants differed significantly from those in ideal conditions, demonstrating adaptive responses, including modulation of secondary metabolite synthesis. While certain stresses led to an overall decrease in secondary metabolites, specific instances showed an overexpression of beneficial chemicals. Exploring drought stress in Lavandula angustifolia (lavender), Vitis vinifera, and Artemisia tridentata, revealed a marked reduction in flavonoids and specific secondary metabolites. The study aimed to establish connections between metabolic alterations and stress-adaptive reactions. The findings contribute to understanding how environmental stress influences the therapeutic efficacy of medicinal plants and shed light on the molecular pathways governing stress-induced changes. In the investigation of heavy metal exposure, Hypericum perforatum, and Coriandrum sativum subjected to cadmium-contaminated soil exhibited an overall decline in secondary metabolites, including reduced hypericin content. Contrarily, hyperforin, linked to antidepressant properties, experienced a significant increase. These results have implications for pharmaceutical applications, sustainable farming practices, and the conservation of medicinal plant biodiversity amidst changing environmental dynamics. The study underscores the intricate relationship between environmental stressors and the biochemical makeup of medicinal plants, emphasizing their resilience and capacity to produce valuable bioactive molecules in challenging conditions. The comparative biochemical analysis of stressed medicinal plants involves assessing various parameters to comprehend how stress influences plant metabolism and bioactive compound production.

Apolar Extracts of St. John's Wort Alleviate the Effects of β-Amyloid Toxicity in Early Alzheimer's Disease.

Hypericum perforatum (St. John's wort) has been described to be beneficial for the treatment of Alzheimer's disease (AD). Different extractions have demonstrated efficiency in mice and humans, esp. extracts with a low hypericin and hyperforin content to reduce side effects such as phototoxicity. In order to systematically elucidate the therapeutic effects of H. perforatum extracts with different polarities, APP-transgenic mice were treated with a total ethanol extract (TE), a polar extract obtained from TE, and an apolar supercritical CO2 (scCO2) extract. The scCO2 extract was formulated with silicon dioxide (SiO2) for better oral application. APP-transgenic mice were treated with several extracts (total, polar, apolar) at different concentrations. We established an early treatment paradigm from the age of 40 days until the age of 80 days, starting before the onset of cerebral β-amyloid (Aβ) deposition at 45 days of age. Their effects on intracerebral soluble and insoluble Aβ were analyzed using biochemical analyses. Our study confirms that the scCO2H. perforatum formulation shows better biological activity against Aβ-related pathological effects than the TE or polar extracts. Clinically, the treatment resulted in a dose-dependent improvement in food intake with augmentation of the body weight, and, biochemically, it resulted in a significant reduction in both soluble and insoluble Aβ (-27% and -25%, respectively). We therefore recommend apolar H. perforatum extracts for the early oral treatment of patients with mild cognitive impairment or early AD.

Hypericin and Naringenin Exert no Significant Synergistic Apoptotic Effect on Y79 Retinoblastoma Cell Line.

According to the anti-cancer impact of hypericin and naringenin, we put the main aim of this study to unravel the apoptotic/anti-cancer effect of these compounds on Y79 retinoblastoma cell line. To calculate the 50%inhibitory concentration (IC50) of hypericin for 24 and 48 hours, XTT assay performed. Cytotoxic effect of naringenin investigated by XTT and trypan blue exclusion assay further confirmed the inhibitory impact of these agents on Y79 cells viability. Flow cytometry Annexin V/PI determined the cell death. The mRNAs expression level of Bax and Bcl-2 investigated by real-time PCR in different groups including the control, cells treated with naringenin, hypericin, or concurrent with both compounds. The 24 and 48 hours IC50 of hypericin, calculated to be 2.5 and 1.25 (μg/ml), respectively. 50 (μg/ml) naringenin induced about 20% and 30% apoptosis in Y79 cells after 24 and 48 hours. Trypan blue staining and flow cytometry confirmed this data. Moreover, flowcytometry results, revealed that the kind cell death occurred in these cells post treatment was mostly apoptosis. Simultaneous treatment with both agents didn't show synergistic effect. Bax/Bcl-2 ratio increased in cells treated with hypericin but in cells treated with narigenin didn't show significant increase in the Bax mRNA level. Hypericin had more cytotoxic effect in Y79 cells compared with naringenin. Furthermore, hypericin and naringenin didn't have apoptotic synergistic effect in these cells. According to the real-time PCR results, hypericin induces apoptosis in Y79 cells by disrupt the ratio of Bax/Bcl-2.

Effects of Hypericin on Cultured Primary Normal Human Dermal Fibroblasts Under Increased Oxidative Stress

Introduction Wound healing is a dynamic process that begins with inflammation, proliferation, and cell migration of a variety of fibroblast cells. As a result, identifying possible compounds that may improve fibroblast cell wound healing capacity is crucial. Hypericin is a natural quinine that has been reported to possess a wide range of pharmacological profiles, including antioxidant and anti-inflammatory, activities. Herein we examined for the first time the effect of hypericin on normal human dermal fibroblasts (NHDFs) under oxidative stress. Methods NHDF were exposed to different concentrations of hypericin (0-20 μg/mL) for 24 h. For the oxidative stress evaluation, H2O2 was used as a stressor factor. Cell viability and proliferation levels were evaluated. Immunohistochemistry and flow cytometry were performed to assess cell apoptosis levels and with confocal microscopy we identified the mitochondrial superoxide production under oxidative stress and after the treatment with hypericin. Scratch assay was performed under oxidative stress to evaluate the efficacy of hypericin in wound closure. To gain an insight into the molecular mechanisms of hypericin bioactivity, we analyzed the relative expression levels of genes involved in oxidative response and in wound healing process. Results We found that the exposure of NHDF to hypericin under oxidative stress resulted in an increase in cell viability and ATP levels. We found a decrease in apoptosis and mitochondrial superoxide levels after treatment with hypericin. Moreover, treatment with hypericin reduced wound area and promoted wound closure. The levels of selected genes showed that hypericin upregulated the levels of antioxidants genes. Moreover, treatment with hypericin in wound under oxidative stress downregulated the levels of proinflammatory cytokines, and metalloproteinases; and upregulated transcription factors and extracellular matrix genes. Conclusion These findings indicated that hypericin possesses significant in vitro antioxidant activity on NHDF and provide new insights into its potential beneficial role in the management of diabetic ulcers.

Investigation of essential oil composition, hypericin content, and antioxidant capacity of different extracts from flowers and leaves of Hypericum perforatum L. growing wild in Turkey

In this study, we analyzed the composition of essential oils obtained through hydrodistillation from the leaves and flowers of Hypericum perforatum L., a wild plant species found in Şile, İstanbul, located in the northwest of Turkey. We employed gas chromatography-mass spectrometry (GC-MS) to identify the constituents. Additionally, we investigated the antioxidant capacity and total phenolic composition of the plant using DPPH (2,2-diphenyl-1-picryl-hydrazyl), CUPRAC (CUPric Reducing Antioxidant Capacity), and Folin-Ciocalteu methods. Furthermore, we determined the total amount of hypericin present in the plant. The analysis of essential oils from the leaves revealed the identification of fifty-nine compounds, with 2-methyloctane (34.93%), cyclotetradecane (9.12%), limonene (7.24%), 3-methylnonane (5.58%), α-pinene (5.55%), n-tetradecanol (3.15%), 2-methyldecane (3.03%), nonane (3.0%), and spathulenol (2.07%) as the primary constituents. On the other hand, the essential oil from the flowers contained fifty-seven compounds, with 2-methyloctane (52.81%), α-pinene (4.65%), cyclotetradecane (4.04%), n-tetradecanol (2.99%), D-verbenone (2.28%), 2-methyl-2-octanol (2.17%), and caryophyllene oxide (2.0%) as the major components. When evaluating the antioxidant capacity of H. perforatum L. extracts, our results indicated that both leaves and flowers exhibited significant antioxidant capacity in DPPH assays. However, the Cu2+ ion reduction capacity was comparatively low in the CUPRAC method. The highest hypericin contents of leaves and flowers were determined in extraction with 60% ethanol/water for 120 minutes at 50°C as 0.122 g/g % and with 80% ethanol/water for 120 minutes at 50°C as 0.360 g/g %.

Establishing a simple selection method of high hypericin-producing adventitious root lines from leaf explants of Hypericum perforatum var. Topaz

ABSTRACT Hundreds of adventitious root lines from Hypericum perforatum L. were examined for their hypericin content in order to establish a system for studying the production of hypericin in adventitious root lines. The effects of the medium consistency (solid and liquid) and the effects of three different auxins (Indole-3-butyric acid (IBA), Indole-3-acetic acid (IAA), and 1-Naphthaleneacetic acid (NAA)) on the induction of adventitious roots in leaf explants were studied. In a half-strength MS liquid medium with 2 mg/L IBA concentration, adventitious roots developed from H. perforatum leaves, whereas NAA and IAA caused callus-like and low branch roots. HPLC-UV was used to profile hypericin content variations in 100 H. perforatum adventitious root lines. Hierarchical component analysis (HCA) was used for selecting elite lines. After cluster analysis and selecting high-performance lines in terms of hypericin, five elite lines were chosen and the amount of hypericin production, as well as the phenol and flavonoid content, was analysed.

How Changes in Nitrogen Levels Impact Metabolites and Physiological Features of Hypericum androsaemum

Background: The manipulation of mineral nutrition may affect secondary metabolite production and thus determine the nutritional value of food/medicinal plants. Objectives: The present study investigated the impact of nitrogen supply on the production of secondary metabolites and physiological parameters of Hypericum androsaemum plants grown in sand culture. Methods: Four-week plants were irrigated by full-strength Hoagland solution (control), nitrate was reduced to 1/3, and no nitrate was provided for 14 days. Results: The growth of shoots was inhibited by nitrate limitation, but root growth was stimulated. Soluble proteins and water content were significantly affected by nitrate deficiency. Antioxidative enzyme activities (ascorbate peroxidase (APX) and superoxide dismutase (SOD)) were increased due to nitrate deficiency. Treatment of plants with NO3- deficiency caused an increase in total soluble phenols and phenylalanine ammonia-lyase (PAL) activity, while flavonoid content was mainly elevated by NO3- deficiency. At the level of specific metabolites, NO3- deficiency positively affected hypericin and pseudohypericin content but decreased hyperforin content. The expression of the putative gene for hypericin biosynthesis (hyp-1) was up-regulated in response to nitrate deficiency. Conclusions: The results demonstrated that the nitrogen deficiency in the H. androsaemum plant positively affected the antioxidant system, valuable phenols, and secondary metabolites.

A New UHPLC Analytical Method for St. John’s Wort (Hypericum perforatum) Extracts

Commonly used to treat mood disorders, St. John’s Wort (Hypericum perforatum) is a popular herb in the natural health products industry. The potency of its active ingredients can be determined using a number of different analytical methods, but it is more widely determined using high performance liquid chromatography (HPLC). While monographs in the United States Pharmacopeia (USP) can often be relied upon for suitable analytical methods, the method proposed for determining hypericin content in St. John’s Wort products is inefficient in carrying out this purpose. This paper presents a modified new HPLC method for determining the hypericin content that can also be used for St. John’s Worts capsules and tablets by making use of purified hypericin as a chemical standard instead of oxybenzone, applying a wavelength of 588 nm during analysis and utilizing a binary instead of ternary mobile phase gradient. The resulting method and sample chromatograms provide better resolved, more easily identifiable peaks, shorter run time, and increased sustainability compared to the original USP method. This proposed method was developed using the more refined ultra-high performance liquid chromatography (UHPLC) and serves as a more accurate and reliable method for determining hypericin content in St. John’s Wort.

Effect of Hypericin-Mediated Photodynamic Therapy on the Secretion of Soluble TNF Receptors by Oral Cancer Cells.

Squamous cell carcinoma is the most common cancer of the head and neck region. In addition to the classic surgical treatment method, alternative therapy methods are sought. One such method is photodynamic therapy (PDT). In addition to the direct cytotoxic effect, it is essential to determine the effect of PDT on persistent tumor cells. The study used the SCC-25 oral squamous cell carcinoma (OSCC) cell line and the HGF-1 healthy gingival fibroblast line. A compound of natural origin-hypericin (HY)-was used as a photosensitizer (PS) at concentrations of 0-1 µM. After two hours of incubation with the PS, the cells were irradiated with light doses of 0-20 J/cm2. The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) test was used to determine sublethal doses of PDT. Cell supernatants subjected to sublethal PDT were assessed for soluble tumor necrosis alpha receptors (sTNF-R1, sTNF-R2). The phototoxic effect was observed starting with a light dose of 5 J/cm2 and amplified with the increase in HY concentration and light dose. A statistically significant increase in sTNF-R1 secretion by SCC-25 cells was demonstrated after the PDT with 0.5 µM HY and irradiation with 2 J/cm2 (sTNF-R1 concentration = 189.19 pg/mL ± 2.60) compared to the control without HY and irradiated with the same dose of light (sTNF-R1 concentration = 108.94 pg/mL ± 0.99). The baseline production of sTNF-R1 was lower for HGF-1 than for SCC-25, and secretion was not affected by the PDT. The PDT had no effect on the sTNF-R2 production in the SCC-25 or HGF-1 lines.

Evolutionary Aspects of Hypericin Productivity and Endogenous Phytohormone Pools Evidenced in Hypericum Species In Vitro Culture Model.

Shoot cultures of hypericin non-producing H. calycinum L. (primitive Ascyreia section), hypericin-producing H. perforatum L., H. tetrapterum Fries (section Hypericum) and H. richeri Vill. (the evolutionarily most advanced section Drosocarpium in our study) were developed and investigated for their growth, development, hypericin content and endogenous phytohormone levels. Hypericins in wild-growing H. richeri significantly exceeded those in H. perforatum and H. tetrapterum. H. richeri also had the highest hypericin productivity in vitro in medium supplemented with 0.2 mg/L N6-benzyladenine and 0.1 mg/L indole-3-butyric acid and H. tetrapterum—the lowest one in all media modifications. In shoot culture conditions, the evolutionarily oldest H. calycinum had the highest content of salicylic acid and total jasmonates in some of its treatments, as well as dominance of the storage form of abscisic acid (ABA-glucose ester) and lowest cytokinin ribosides and cytokinin O-glucosides as compared with the other three species. In addition, the evolutionarily youngest H. richeri was characterized by the highest total amount of cytokinin ribosides. Thus, both evolutionary development and the hypericin production capacity seemed to interact closely with the physiological parameters of the plant organism, such as endogenous phytohormones, leading to the possible hypothesis that hypericin productivity may have arisen in the evolution of Hypericum as a means to adapt to environmental changes.

LC-MS/MS profiles, multi-element levels and biological activities of Hypericum heterophyllum Vent

Plants belonging to the genus Hypericum L. are widely used in traditional folk medicine due to their hypericin and pseudohypericin contents. In this study, we investigated the biological activity, phenolic and elemental content of methanol and acetone extracts of sheepskin grass, Hypericum heterophyllum Vent. a species that that lacks both hypericin and pseudohypericin. The total antioxidant status of the extracts was determined by commercial kits. Antibacterial effect of extracts was investigated on seven bacterial strains. Cytotoxic effects of the extracts on lung cancer cell lines were determined by MTT (3-4,5-dimethyl-thiazolyl-2,5-diphenyltetrazolium bromide) method. Phenolic content was determined by LC-ESI-MS/MS. Elements in the plant were determined by ICP-OES. The total phenolic content and antioxidant status of the species’ methanol extract were found to be higher than the acetone extract. Both of the extracts at a concentration of 20% have an antibacterial effect, especially the antibacterial effect of acetone extract. It was determined that acetone extract has an anticarcinogenic impact depending on the dose. Chlorogenic acid, miquelianin and isoquercitrin are the most abundant flavonoids in methanol and acetone extract. The plant contains Ca, K, and Mg elements in high concentrations. The phenolic substances and elements in H. heterophyllum , widely used in our country, have been presented for the first time in the literature. Besides, it can be said that the plant has antioxidant, anticarcinogen, and antimicrobial activities due to the crucial flavonoids and elements it contains

Geleneksel tıp uygulamalarında kullanılan sarı kantaron (Hypericum perforatum l.) yağının standardizasyonunun belirlenmesine yönelik yürütülen bazı kalite analizlerinin incelenmesi

St. John's Wort (Hypericum perforatum L.) plant is among the medicinal plants used as pharmaceutical raw material with traditional methods for more than 2000 years. St. John's Wort plant and its medicinal oil (maserate) obtained from it, usage area is increasing day by day in the food, pharmaceutical and cosmetic industries thanks to the important bioactive components. The pharmacologically important component of the plant is known as hypericin. This study was carried out in Selcuk University, Faculty of Agriculture, Medical and Endemic Plants Training and Research Farm, and examined the effect of different holding environments (sun, shade), harvest periods (25% flowering period, 50% flowering period and full flowering period) and drying methods (wet herb, faded herb and dried herb) on the amount of hypericin in St. John's Wort and its medicinal oil. According to the results of the analysis, the highest amount of hypericin in St. John's Wort herb was determined as 0.32% in full flowering period. The highest amount of hypericin in St. John's Wort oils was determined as 271.92 mg/L in fresh herb during the full flowering period. According to the results of the research, the harvesting periods are effective on the amount of hypericin, and it can be suggested that the wet herb, which is harvested in full bloom and hold, should be macerated with olive oil in the sun to obtain St. John's Wort oil with high hypericin content.

Antioxidant potential and essential oil properties of Hypericumperforatum L. assessed by application of selenite and nano-selenium

It is necessary to develop a simple way to achieve food quality quantitatively. Nanotechnology is a key advanced technology enabling contribution, development, and sustainable impact on food, medicine, and agriculture. In terms of medicinal and therapeutic properties, Hypericumperforatum is an important species. For this study, a randomized complete block design with three replications was used in each experimental unit. The foliar application of selenite and nano-selenium (6, 8, 10, and 12 mg/l), control (distilled water), at the rosette stage and harvesting at 50% flowering stage has been applied as an alleviation strategy subjected to producing essential oils and antioxidant activity. Experimental results revealed that the selenite and nano selenium fertilizers had a significant effect on traits such as total weight of biomass, essential oil percentage, the content of hypericin and hyperforin, the selenium accumulation in the plant, relative leaf water content, chlorophylls, phenolic content, proline, catalase, peroxidase, malondialdehyde, and DPPH. The highest essential oil content was obtained from the control treatment when the accumulation of selenium was achieved with 12 mg/l nano-selenium. The maximum rate of hypericin was seen in the foliar application of 8 mg/l selenite whereas the maximum hyperforin was gained at 10 mg/l selenium. Conceding that the goal is to produce high hypericin/ hyperforin, and also the accumulation of selenium in the plant, treatments of 6 and 8 mg/l of selenite and nano-selenium could be applied. Consequently, an easy detection technique proposed herein can be successfully used in different ranges, including biology, medicine, and the food industry.

The Interaction of Hypericin with SARS-CoV-2 Reveals a Multimodal Antiviral Activity

Hypericin is a photosensitizing drug that is active against membrane-enveloped viruses and therefore constitutes a promising candidate for the treatment of SARS-CoV-2 infections. The antiviral efficacy of hypericin is largely determined by its affinity toward viral components and by the number of active molecules loaded on single viruses. Here we use an experimental approach to follow the interaction of hypericin with SARS-CoV-2, and we evaluate its antiviral efficacy, both in the dark and upon photoactivation. Binding to viral particles is directly visualized with fluorescence microscopy, and a strong affinity for the viral particles, most likely for the viral envelope, is measured spectroscopically. The loading of a maximum of approximately 30 molecules per viral particle is estimated, despite with marked heterogeneity among particles. Because of this interaction, nanomolar concentrations of photoactivated hypericin substantially reduce virus infectivity on Vero E6 cells, but a partial effect is also observed in dark conditions, suggesting multiple mechanisms of action for this drug.

Effects of light intensity and LED spectrum on the medicinal component accumulation of hydroponic Hypericum perforatum L. under controlled environments

Medicinal components of Hypericum perforatum L. plants varies widely due to fluctuations in growth environment and biotic and abiotic contamination during cultivation management. The quality of extracts or preparations is difficult to control because of the unstable raw materials. The aim of this study is to enhance the yield and medicinal component contents of H. perforatum by optimizing lighting factors under controlled environment. H. perforatum plants were hydroponically cultivated for 30 d under 3 levels of photosynthetic photon flux density (PPFD) with 200, 300, and 400 μmol/(m2·s) using white LEDs (R:B ratio is the ratio of red light to blue light, R:B ratio of 0.9 and 1.8) and white plus red LED (R:B ratio of 2.7). The results showed that PPFD and LED spectrum had significant effects on the growth and accumulation of medicinal components of H. perforatum. Biomass accumulation of stem, leaf, and root increased linearly with the increase of PPFD under each LED spectrum. Fresh weights and dry weights of stem, leaf, and root were significantly higher under a PPFD of 400 μmol/(m2·s) with R:B ratio of 0.9 than those of 200 μmol/(m2·s), respectively. The relative growth rate and net photosynthetic rate showed linear relationships with PPFD under the same LED spectrum. Total hypericin content, total hyperforin content, and energy yield of hypericin increased with increasing PPFD. Total hypericin content and energy yield of hypericin of P400-L0.9 were 78% and 89% more than those of P400-L2.7, respectively. Total hyperforin content and energy yield of hyperforin of P400-L0.9 and P400-L2.7 were no significant differences. Based on energy efficiency, an R:B ratio of 0.9 of white LEDs with a PPFD of 400 μmol/(m2·s) was beneficial to improve medicinal component contents of hydroponic H. perforatum in plant factory with LED lighting. Keywords: LED spectrum, light intensity, controlled environments, Hypericum perforatum L. DOI: 10.25165/j.ijabe.20221505.7373 Citation: Gao W, He D X, Zheng J F, Li Y. Effects of light intensity and LED spectrum on the medicinal component accumulation of hydroponic Hypericum perforatum L. under controlled environments. Int J Agric & Biol Eng, 2022; 15(5): 63–69.

Red LED light promotes biomass, flowering and secondary metabolites accumulation in hydroponically grown Hypericum perforatum L. (cv. Topas)

To increase the crop yield and quality, the plant cultivation in equipped growing systems is an alternative to open field production. Artificial light sources are a critical component in the plant factory systems and red and blue wavelengths have a powerful impact on plant growth and photosynthetic capacity. In this study, the effect of different photon flux ratios of red (R) light to blue (B) LED light including 100 R:0B, 80 R:20B, 50 R:50B, 20 R:80B, 0 R:100B and white LEDs (as control) were evaluated on the growth, flowering and secondary metabolite contents of Hypericum perforatum L. cv. Topas at 150 µmol m−2 s−1 irradiation for a 16/8 h.d‐1 photoperiod. Results showed that the plant growth characteristics such as fresh and dry weight, leaf area and number, plant height, flower number and diameter were significantly (P < 0.05) maximum under the enhancement of R/B ratio, especially under 100% red light treatment. Despite the higher transpiration and net photosynthesis rate, photosynthetic pigment concentration, stomatal surface area and RuBisCO activity, the plants under the high fraction of blue light showed the poorest growth and flowering traits. The maximum content of hypericin (14.24 mg g‐1 DW), pseudohypericin (25.98 mg g−1 DW) and hyperforin (163.06 mg g−1 DW) was obtained in flower under 100% red LED. Antioxidant enzymes activities (CAT and POD), total phenolic and flavonoid content were also higher in plants exposed to the mixture of red and blue light. Plants grown under white LED were mediocre in terms of growth parameters and secondary metabolites. These findings showed that the 100% red LED light is suitable for H. perforatum plant growth, flowering, as well as secondary metabolites accumulation in the plant factory system.

Autophagy and Apoptosis Induced in U87 MG Glioblastoma Cells by Hypericin-Mediated Photodynamic Therapy Can Be Photobiomodulated with 808 nm Light

Glioblastoma is one of the most aggressive types of tumors. Although few treatment options are currently available, new modalities are needed to improve prognosis. In this context, photodynamic therapy (PDT) is a promising adjuvant treatment modality. In the present work, hypericin-mediated PDT (hypericin-PDT, 2 J/cm2) of U87 MG cells is combined with (2 min, 15 mW/cm2 at 808 nm) photobiomodulation (PBM). We observed that PBM stimulates autophagy, which, in combination with PDT, increases the treatment efficacy and leads to apoptosis. Confocal fluorescence microscopy, cytotoxicity assays and Western blot were used to monitor apoptotic and autophagic processes in these cells. Destabilization of lysosomes, mitochondria and the Golgi apparatus led to an increase in lactate dehydrogenase activity, oxidative stress levels, LC3-II, and caspase-3, as well as a decrease of the PKCα and STAT3 protein levels in response to hypericin-PDT subcellular concentration in U87 MG cells. Our results indicate that therapeutic hypericin concentrations can be reduced when PDT is combined with PBM. This will likely allow to reduce the damage induced in surrounding healthy tissues when PBM-hypericin-PDT is used for in vivo tumor treatments.