Isolation of formononetin-7-O-β-D-glucopyranoside from the grass of Ononis arvensis L. and the assessment of its effect on induced platelet activation

Introduction. Analysis of the clinical and laboratory picture of the SARS-CoV-2 infection suggests the presence of microcirculation and oxygen transport disorders, hemolysis of erythrocytes, intra-alveolar fibrin formation and microthrombus formation in the patient’s pathogenesis. Accordingly, the search for potential anticoagulants, erythrocyte antiplatelet agents, membrane stabilizing drugs and mild thrombolytic drugs can prevent the development of life-threatening complications and reduce the mortality of COVID-19 patients.Aim. Isolation of formononetin-7-O-β-D-glucopyranoside from the grass of Ononis arvensis L. and identification of the molecular mechanisms of its effect on platelet activation in vitro, induced by TRAP-6 (Thrombin receptor activated peptide) and ADP (adenosine diphosphate).Materials and methods. Terrestrial parts of Ononis arvensis L. were collected in the SPCPU nursery of medicinal plants (Leningrad region, Vsevolozhsky district, Priozerskoe highway, 38 km). Isolation of formononetin-7-O-β-D-glucopyranoside was carried out by preparative high performance liquid chromatography on a Smartline device (Knauer, Germany) equipped with a spectrophotometric detector. The structure of formononetin-7-O-β-D-glucopyranoside was confirmed by one-dimensional and two-dimensional NMR spectroscopy (Bruker Avance III, 400 MHz, Germany), as well as high-resolution mass spectrometry (HR-ESI-MS) (Bruker Micromass Q-TOF, Germany). The study of the effect of formononetin- 7-O-β-D-glucopyranoside on induced platelet activation was carried out on human platelets isolated from the blood of healthy volunteers. To research the effect of formononetin-7-О-β-D-glucopyranoside on platelet aggregation flow cytofluorometry with Cyto-FLEX (Beckman-Coulter, USA) was used.Results and discussion. According to the method of fractionation and purification of the total extract of O. arvensis developed in previous studies, formononetin-7-O-β-D-glucopyranoside was isolated in an individual form for subsequent biological studies with a total yield of 30 % in comparison with its content in the original extract. In samples with formononetin-7-O-β-D-glucopyranoside and ADP, there is a pronounced inhibition of platelet activation – the percentage of active platelets ranges from 6.3–6.6 % at doses of formononetin-7-O-β-D-glucopyranoside 1 μM, 3 μM and 30 μM. The inhibitory effect of formononetin-7-O-β-D-glucopyranoside is not dose-dependent (p ≤ 0.05). In samples with formononetin-7-O-β-D-glucopyranoside and TRAP, there is also a pronounced inhibition of platelet activation. The percentage of active platelets is 8 % at 1 μM formononetin-7-O-β-D-glucopyranoside doses, 15 % at 3 μM doses, and 16 % at 30 μM doses.Conclusion. Administration of formononetin-7-O-β-D-glucopyranoside at doses of 1 μM, 3 μM, 30 μM strongly inhibits platelet activation induced by ADP and TRAP-6. For ADP, there is no dose-dependent effect, while for TRAP there is a weak dose-dependent effect, the greatest inhibition efficiency is achieved with the minimum investigated dose of 1 μM. In all cases, the results obtained are statistically significant.

Everolimus and plicamycin specifically target chemoresistant colorectal cancer cells of the CMS4 subtype

Colorectal cancers (CRC) can be classified into four consensus molecular subtypes (CMS), among which CMS1 has the best prognosis, contrasting with CMS4 that has the worst outcome. CMS4 CRC is notoriously resistant against therapeutic interventions, as demonstrated by preclinical studies and retrospective clinical observations. Here, we report the finding that two clinically employed agents, everolimus (EVE) and plicamycin (PLI), efficiently target the prototypic CMS4 cell line MDST8. As compared to the prototypic CMS1 cell line LoVo, MDST8 cells treated with EVE or PLI demonstrated stronger cytostatic and cytotoxic effects, increased signs of apoptosis and autophagy, as well as a more pronounced inhibition of DNA-to-RNA transcription and RNA-to-protein translation. Moreover, nontoxic doses of EVE and PLI induced the shrinkage of MDST8 tumors in mice, yet had only minor tumor growth-reducing effects on LoVo tumors. Altogether, these results suggest that EVE and PLI should be evaluated for their clinical activity against CMS4 CRC.

Multiple pathways of toxicity induced by C9orf72 dipeptide repeat aggregates and G4C2 RNA in a cellular model

The most frequent genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia is a G4C2 repeat expansion in the C9orf72 gene. This expansion gives rise to translation of aggregating dipeptide repeat (DPR) proteins, including poly-GA as the most abundant species. However, gain of toxic function effects have been attributed to either the DPRs or the pathological G4C2 RNA. Here, we analyzed in a cellular model the relative toxicity of DPRs and RNA. Cytoplasmic poly-GA aggregates, generated in the absence of G4C2 RNA, interfered with nucleocytoplasmic protein transport, but had little effect on cell viability. In contrast, nuclear poly-GA was more toxic, impairing nucleolar protein quality control and protein biosynthesis. Production of the G4C2 RNA strongly reduced viability independent of DPR translation and caused pronounced inhibition of nuclear mRNA export and protein biogenesis. Thus, while the toxic effects of G4C2 RNA predominate in the cellular model used, DPRs exert additive effects that may contribute to pathology.

Somatic uniparental disomy mitigates the most damaging EFL1 allele combination in Shwachman-Diamond syndrome

Shwachman-Diamond syndrome (SDS; OMIM: #260400) is caused by variants in SBDS (Shwachman-Bodian-Diamond syndrome gene), which encodes a protein that plays an important role in ribosome assembly. Recent reports suggest that recessive variants in EFL1 are also responsible for SDS. However, the precise genetic mechanism that leads to EFL1-induced SDS remains incompletely understood. Here we present three unrelated Korean SDS patients that carry biallelic pathogenic variants in EFL1 with biased allele frequencies, resulting from a bone marrow-specific somatic uniparental disomy (UPD) in chromosome 15. The recombination events generated cells that were homozygous for the relatively milder variant, allowing for the evasion of catastrophic physiological consequences. Still, the milder EFL1 variant was solely able to impair 80S ribosome assembly and induce SDS features in cell line and animal models. The loss of EFL1 resulted in a pronounced inhibition of terminal oligo-pyrimidine element-containing ribosomal protein transcript 80S assembly. Therefore, we propose a more accurate pathogenesis mechanism of EFL1 dysfunction that eventually leads to aberrant translational control and ribosomopathy.

The essential role of PRAK in tumor metastasis and its therapeutic potential

Metastasis is the leading cause of cancer-related death. Despite the recent advancements in cancer treatment, there is currently no approved therapy for metastasis. The present study reveals a potent and selective activity of PRAK in the regulation of tumor metastasis. While showing no apparent effect on the growth of primary breast cancers or subcutaneously inoculated tumor lines, Prak deficiency abrogates lung metastases in PyMT mice or mice receiving intravenous injection of tumor cells. Consistently, PRAK expression is closely associated with metastatic risk in human cancers. Further analysis indicates that loss of function of PRAK leads to a pronounced inhibition of HIF-1α protein synthesis, possibly due to reduced mTORC1 activities. Notably, pharmacological inactivation of PRAK with a clinically relevant inhibitor recapitulates the anti-metastatic effect of Prak depletion, highlighting the therapeutic potential of targeting PRAK in the control of metastasis.

Antioxidant activity of vitamin E homologues in model systems

The effect of tocopherols, tocotrienols and plastochromanol-8 in the inhibition of lipid peroxidation of liposomes prepared from natural chloroplast lipids, initiated by both water-soluble and lipid soluble azo-compounds, has been studied. In the case of tocopherols, α-tocopherol showed nearly no effect in the inhibition of lipid peroxidation, while β-, γ- and δ-tocopherols inhibited the reaction completely when it was initiated by lipid-soluble AMVN. Similar effects were observed for tocotrienol homologues. In the investigated reaction plastochromanol-8 was as effective as β-, γ- and δ-tocochromanols. When peroxidation was initiated by water-soluble AIPH in liposomes, the order and extent of inhibition was similar to those of AMVN initiator. However, in this case, α-tocopherol and α-tocotrienol showed more pronounced inhibition. When the prenyllipids were investigated in DPPH test, when incorporated into soy lipid liposomes, mixed micelles and micelles, DPPH oxidation was most pronounced in liposomes, followed by mixed micelles and micellar system. When the reaction of α-tocopherol, α-tocotrienol, plastochromanol-8 and α-tocopherol phosphate was examined in niosomes, the oxidation was most pronounced for α-tocopherol and plastochromanol-8, followed by α-tocotrienol. α-tocopherol phosphate showed no activity in this respect. The obtained results were discussed in light of the prenyllipid structures and their localization in the investigated lipid systems.

PECULIARITIES OF MOTOR ACTIVITY OF RATS IN SIMULATION PHARMACOLOGICAL DEPRESSOGENIC STATES

The aim: To analyze and compare the features of changes in the motor activity of rats on the background of pharmacological models of depressive disorders. Materials and methods: Depressive-like state was simulated on 40 mature male Wistar rats using: reserpine (15 mg/kg), clonidine (0.1 mg/kg), haloperidol (0.25 mg/kg). The control group was given as a single dose 0.5 ml of a 0.9% sodium chloride solution intraperitoneally. After 3, 12, 24, 48 and 72 hours from the beginning of the experiment, changes in motor activity in the “open field” test were examined by the number of crossed squares, the calculation was carried out within 5 minutes. Results: Reserpine at a dose of 15 mg/kg caused probable motor activity disorders in rats in the “open field” test during all study periods. The most pronounced inhibition of motor activity was observed within 12-48 hours from the beginning of the experiment. 3 hours after clonidine administration, the number of crossed squares decreased by 310% (p<0.001), after 12 hours – by 180% (p<0.001), after 24 hours – by 140% (p<0.001), after 48 hours – by 50% (p<0.005) in comparison with the control group. On 3rd day, the motor activity of rats was almost completely restored. The use of haloperidol after 3 hours most significantly impaired the motor activity of rats in the “open field” test, and its recovery was observed after 24 hours. Conclusions: Reserpine inhibited the motor activity of rats, most pronounced from 12 to 48 hours of the experiment. Clonidine inhibited mainly in the first hours of the study. Haloperidol impaired motor activity at 3rd and 12th hours of observation.

Multiple pathways of toxicity induced by C9orf72 dipeptide repeat aggregates and G4C2 RNA in a cellular model

The most frequent genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia is a G4C2 repeat expansion in the C9orf72 gene. This expansion gives rise to translation of aggregating dipeptide repeat (DPR) proteins, including poly-GA as the most abundant species. However, gain of toxic function effects have been attributed to either the DPRs or the pathological G4C2 RNA. Here we analyzed in a cellular model the relative toxicity of DPRs and RNA. Cytoplasmic poly-GA aggregates, generated in the absence of G4C2 RNA, interfered with nucleocytoplasmic protein transport, but had little effect on cell viability. In contrast, nuclear poly-GA was more toxic, impairing nucleolar protein quality control and protein biosynthesis. Production of the G4C2 RNA strongly reduced viability independent of DPR translation and caused pronounced inhibition of nuclear mRNA export and protein biogenesis. Thus, while the toxic effects of G4C2 RNA predominate, DPRs exert additive effects that may contribute to pathology.

Fighting the storm: novel anti- TNFα and anti-IL-6 C. sativa lines to tame cytokine storm in COVID-19

The main aspects of severe COVID-19 disease pathogenesis include the increasing hyper-induction of proinflammatory cytokines, also known as ‘cytokine storm’, that precedes acute respiratory distress syndrome (ARDS) and often leads to death. COVID-19 patients often suffer from lung fibrosis, a serious and untreatable condition. There remains no effective treatment for these complications. Out of the cytokines, TNFα and IL-6 play crucial roles in cytokine storm pathogenesis and are likely responsible for the escalation in disease severity. These cytokines also partake in the molecular pathogenesis of fibrosis. Therefore, new approaches are urgently needed that can efficiently and swiftly block TNFα, IL-6, and the inflammatory cytokine cascade in order to curb inflammation and prevent fibrosis, and lead to disease remission.Cannabis sativa has been proposed to modulate gene expression and inflammation and is under investigation for several potential therapeutic applications against autoinflammatory diseases and cancer. Here, we hypothesized that the extracts of our novel C. sativa lines may be used to modulate the expression of pro-inflammatory cytokines and pathways involved in inflammation and fibrosis. To analyze the anti-inflammatory effects of novel C. sativa lines, we used a well-established full thickness human 3D skin artificial EpiDermFTTM tissue model, whereby tissues were exposed to UV to induce inflammation and then treated with extracts of seven new cannabis lines.We noted that out of seven studied extracts of novel C. sativa lines, three (#4, #8 and #14) were the most effective, causing profound and concerted down-regulation of TNFα, IL-6, CCL2, and other cytokines and pathways related to inflammation and fibrosis. Most importantly, one of the tested extracts had no effects at all, and one exerted effects that may be deleterious, signifying that cannabis is not generic and cultivar selection must be based on thorough pre-clinical studies.The observed pronounced inhibition of TNFα and IL-6 is the most important finding, as these molecules are currently considered to be the main actionable targets in COVID-19 cytokine storm and ARDS pathogenesis. Many currently trialed agents, such as anti-TNFα and anti-IL-6 biologics are expensive and cause an arrays of side effects. On the other hand, anti-TNFα and anti-IL-6 cannabis extracts that are generally regarded as safe (GRAS) modalities can be a useful addition to the current anti-inflammatory regimens to treat COVID-19, as well as various rheumatological diseases and conditions, and ‘inflammaging’ - the inflammatory underpinning of aging and frailty.