Novel Therapeutic Effects of Pterosin B on Ang II-Induced Cardiomyocyte Hypertrophy.

Pathological cardiac hypertrophy is characterized by an abnormal increase in cardiac muscle mass in the left ventricle, resulting in cardiac dysfunction. Although various therapeutic approaches are being continuously developed for heart failure, several studies have suggested natural compounds as novel potential strategies. Considering relevant compounds, we investigated a new role for Pterosin B for which the potential life-affecting biological and therapeutic effects on cardiomyocyte hypertrophy are not fully known. Thus, we investigated whether Pterosin B can regulate cardiomyocyte hypertrophy induced by angiotensin II (Ang II) using H9c2 cells. The antihypertrophic effect of Pterosin B was evaluated, and the results showed that it reduced hypertrophy-related gene expression, cell size, and protein synthesis. In addition, upon Ang II stimulation, Pterosin B attenuated the activation and expression of major receptors, Ang II type 1 receptor and a receptor for advanced glycation end products, by inhibiting the phosphorylation of PKC-ERK-NF-κB pathway signaling molecules. In addition, Pterosin B showed the ability to reduce excessive intracellular reactive oxygen species, critical mediators for cardiac hypertrophy upon Ang II exposure, by regulating the expression levels of NAD(P)H oxidase 2/4. Our results demonstrate the protective role of Pterosin B in cardiomyocyte hypertrophy, suggesting it is a potential therapeutic candidate.

Screening for Ptaquiloside in Ferns: Using Herbarium Specimens for Qualitative Mapping Purposes.

INTRODUCTION: Ptaquiloside (PTA) is a noxious carcinogen found widespread in Bracken (Pteridium sp.) but with scattered and unresolved distribution outside the genus. The carcinogen causes Bovine Enzootic Haematuria among cattle all-over the World and is under suspicion of causing human cancers. OBJECTIVE: To set-up a methodology for large-scale qualitative studies on the distribution of PTA in ferns using already available herbarium specimens as source. METHODOLOGY: PTA and the main degradation product pterosin B (PtB) were quantified in aqueous frond extracts by HPLC-DAD. PTA was quantified after forced reaction into PtB. Optimal reaction conditions were tested using hydrochloric acid, sulphuric acid, trifluoroacetic acid (TFA), acetic acid and temperature as the experimental variables. A pair-wise test for PTA degradation in plant-press were used to explore the effect of this preservation regime. A selection of up to 50 years old Bracken herbarium specimens were tested for PTA and PtB. The methodology was applied on 21 fern species from Denmark. RESULTS: An optimised TFA-based method results in 30.7% higher conversion and a 1:1 reaction between PTA and PtB. Full three-dimensional resolution of the analyte was obtained. Preservation of fronds in a plant press increase formation of PtB. Hence, the method is only suitable for qualitative studies. Presence of PTA and PtB were found in samples up to 50 years old. Among 21 ferns tested, the compounds were only found in Pteridium aquilinum. CONCLUSION: Herbarium specimens up to 50 years old can be used for explorative risk assessment of ferns using HPLC-DAD for quantification and identification. Copyright © 2017 John Wiley & Sons, Ltd.

Pterosin B improves cognitive dysfunction by promoting microglia M1/M2 polarization through inhibiting Klf5/Parp14 pathway.

BACKGROUND: Pterosin B (PB) exhibits strong neuroprotective effects in vitro, but its therapeutic effect and underlying mechanism on Alzheimer's disease (AD) remain elusive. PURPOSE: This study aimed to investigate the anti-AD effect and mechanism of PB. STUDY DESIGN: The therapeutic effect and mechanism of PB were investigated in APP/PS1 mice and lipopolysaccharide (LPS)-induced BV-2 cells. METHODS: After 8 weeks of oral administration of PB or donepezil, the cognitive function was assessed using behavioral tests. Pathological damage was evaluated using histological analysis and immunohistochemical staining. Flow cytometry was applied to detect M1/M2 polarization. The expression levels of glycolysis- and oxidative phosphorylation-related proteins as well as enzyme activities were determined using Western blot and biochemical kits, respectively. The levels of inflammatory cytokines and Kruppel-like factor 5 (Klf5) were measured using enzyme-linked immunosorbent assay. AD biomarkers in serum were analyzed using single-molecular array. RNA sequencing identified the downstream molecules of Klf5, and interaction was evaluated using dual-luciferase reporter assay. RESULTS: Our findings demonstrated that PB effectively ameliorated cognitive impairment and reduced pathological damage in APP/PS1 mice. Furthermore, PB facilitated the transition of the phenotype of LPS-induced BV-2 cells from M1 to M2 by modulating metabolic reprogramming. Additionally, Klf5 had high expression levels in the serum of patients with AD, which strongly correlated with cognitive performance and AD biomarkers. PB downregulated Klf5 expression both in vitro and in vivo. Subsequently, poly-ADP ribosyl polymerase 14 (Parp14) was identified as a downstream molecule of Klf5 involved in regulating metabolic reprogramming, and PB regulated microglia M1/M2 polarization by inhibiting the Klf5/Parp14 pathway. CONCLUSION: The findings suggested that PB ameliorated cognitive dysfunction in AD by modulating microglia M1/M2 polarization via inhibiting Klf5/Parp14 pathway.

Stability study of ptaquiloside biotoxin from P. esculentum var. Arachnoideum in bovine milk and artisanal dairy-food products.

The potential health risk of consuming dairy products made from milk processed in an artisanal manner was investigated due to possible contamination with Ptaquiloside (PTA), a carcinogenic compound found in the food chain of the bracken fern. The study aimed to assess the occurrence and stability of PTA across various processing stages, including pasteurization, cheese production, and yogurt production. Results indicated that pasteurization effectively converted all PTA to Pterosin (PTB), with PTB levels decreasing during refrigerated storage for up to two weeks. The stability and occurrence of initial PTA contamination remained unchanged in yogurt production. Biotoxin concentrations in soft cheeses decreased over time, independent of ionic strength; cheeses with low salt concentrations showed lower retention of the biotoxin within the cheese protein network. These findings offer valuable insights into the stability and occurrence of PTA, facilitating the monitoring and identification of potential adverse health effects.

Presence of the carcinogen ptaquiloside in fern-based food products and traditional medicine: Four cases of human exposure.

Ptaquiloside (PTA) is a natural carcinogen present in many ferns. Brackens (Pteridium sp.) contain PTA and are classified by WHO/IARC as ' … possibly carcinogenic to humans', however, these ferns are used in food, traditional medicine and as food supplements around the world. This study aimed to outline the presence of PTA in different human exposure routes by using and validating an LC-MS based protocol to test the contents of PTA in commercial products, the degradation product Pterosin B (PtB) and wild specimens from Europe, Asia and North America. The Limit of Detection of the protocol was 0.024 µg g-1 for PTA and 0.028 µg g-1 for PtB. PTA and PtB were present in most wild specimens (PTA: BD - 6300 ± 520 µg g-1; PtB: BD - 449 ± 1 µg g-1) while commercial products made from fronds, as well as fronds prepared as traditional Chinese medicine, were in the range 44 ± 3 to 666 ± 33 µg g-1 for PTA and BD to 1653 ± 184 µg g-1 for PtB. This study did not find PTA/PtB in rhizomes and products made thereof nor in homoeopathic products based on bracken. Boiling or drying bracken showed to reduce PTA some degree but cannot remove it completely. Interestingly, crosiers with no PTA/PtB were found in the USA, indicating a potential for commercial production of PTA-free fronds.

Survey of ferns and clinico-pathological studies on the field cases of Enzootic bovine haematuria in Himachal Pradesh, a north-western Himalayan state of India.

Enzootic bovine haematuria (EBH) in cattle occurs in upland areas of the world. In India, the disease is present in isolated pockets in the Himalayas and in the Nilgiri Hills. The variation in the disease incidence has been attributed to different environmental conditions and animal rearing practices followed in the different regions. The aim of the study was to conduct field surveys in parts of EBH endemic regions of Himachal Pradesh, a north-western Himalayan state of India. Out of the total 103 plant samples collected, a total of 95 samples were identified as ferns. The major ferns identified included, Onychium japonicum (Thunb.) Kunze, Polystichum piceopaleaceum Tagawa, Dryopteris juxtaposita Christ, Pseudocyclosorus canus (Baker) Holttum and J.W. Grimes, Onychium contiguum C. Hope, Dryopteris nigropaleacea (Fraser-Jenk.), Pteridium aquilinum (L.) Kuhn, Diplazium esculentum (Retz.) Sw., Allantodia maxima (D. Don) Ching, Woodwardia unigemmata (Makino) Nakai, Pteris cretica L., Pteris vittata L., Asplenium trichomanes L., Thelypteris phegopteris (L.) Sloss. ex Rydb, Adiantum venustum D. Don and Paraceterach vestita (Hook.) R.M. Tryon. The concentration of ptaquiloside (PTA) and pterosin B (PtB) in some of the ferns collected from Kullu and Chamba regions ranged from 0 to 358.6 ± 70.5 µg/g and 0 to 652.4 ± 50.0 µg/g, respectively. In addition, field cases of the disease in cattle were also studied in the EBH endemic districts. A total of sixteen cattle urine samples and one urinary bladder of EBH affected cattle were collected. On physical, chemical (benzidine test) and microscopic examination of urine sediment, all the sixteen field samples were found to be positive for erythrocytes and the cases were diagnosed as macrohaematuria. The clinico-pathological studies on the field cases and the presence of PTA and PtB in the ferns indicated that EBH is a prevalent disease and there is an association between chronic fern ingestion and EBH in cattle. On the basis of gross pathology, histopathology and immunohistochemistry (p53 and H-ras nuclear expression in the urothelial cells) of the urinary bladder tissue, the field case was diagnosed as transitional cell adenocarcinoma with chronic lymphocytic cystitis.

Determination of ptaquiloside and pterosin B derived from bracken (Pteridium aquilinum) in cattle plasma, urine and milk.

Ptaquiloside (PTA) is a toxin from bracken fern (Pteridium sp.) with genotoxic effects. Hydrolysis of PTA leads to the non-toxic and aromatised indanone, pterosin B (PTB). Here we present a sensitive, fast, simple and direct method, using SPE cartridges to clean and pre-concentrate PTA and PTB in plasma, urine and milk followed by LC-MS quantification. The average recovery of PTA in plasma, urine, and milk was 71, 88 and 77%, respectively, whereas recovery of PTB was 75, 82 and 63%. The method LOQ for PTA and PTB in plasma was 1.2 and 3.7ngmL(-1), 52 and 33ngmL(-1) for undiluted urine and 5.8 and 5.3ngmL(-1) for milk. The method is repeatable within and between days, with RSD values lower than 15% (PTA) and 20% (PTB). When PTA and PTB spiked samples were stored at -18°C for 14 days both compounds remained stable. In contrast, the PTA concentration was reduced by 15% when PTA spiked plasma was left for 5h at room temperature before SPE clean-up, whereas PTB remained stable. The method is the first to allow simultaneous quantification of PTA and PTB in biological fluids in a relevant concentration range. After intravenous administration of 0.092mg PTA per kgbw in a heifer, the plasma concentration was more than 300ngmL(-1) PTA and declined to 9.8ngmL(-1) after 6h, PTB was determined after 10min at 50ngmL(-1.)