Effects of Viscum album L. extract and quercetin on methotrexate-induced cyto-genotoxicity in mouse bone-marrow cells

Mechanism of herb pair containing Astragali Radix and Spatholobi Caulis in the treatment of myelosuppression based on network pharmacology and experimental investigation

ETHNOPHARMACOLOGICAL RELEVANCE

The Astragali Radix and Spatholobi Caulis herb pair (ARSC) is one of the most commonly used herbal combinations for bone marrow suppression. According to traditional Chinese medicine, Astragali Radix strengthens the spleen and replenishes qi, while Spatholobi Caulis is a hematinic agent that promotes blood circulation and enrichment. The compatibility of the two helps the body to tonify the spleen and kidneys and compensate for visceral deficiencies. However, the multi-target mechanism of ARSC in bone marrow suppression has remained largely unknown.

AIM OF THE STUDY

The aim of this study is to explore the key targets and signaling pathways of the traditional Chinese herbal pair ARSC for the treatment of bone marrow suppression.

MATERIALS AND METHODS

The active components of ARSC and targets for myelosuppression were screened using network databases. Cytoscape 3.8.0 was used to construct compound-target, compound-disease-target and protein-protein interaction (PPI) networks. Go-function and pathway enrichment analyses were performed to explore the potential mechanism. In vivo animal experiments were conducted to verify the molecular mechanisms.

RESULTS

The 36 active compounds were identified from the ARSC, and a total of 108 genes involved in myelosuppression were screened. VEGFA, IL6, TNF, JUN, STAT3, PTGS2, CASP3 and MMP9 genes were identified as potential drug targets in the PPI network analyzed by CytoHubba. Enrichment analysis indicated that ARSC may treat myelosuppression through various biological processes, such as apoptosis, TNF-α signaling pathway via NF-κB, PI3K/AKT/mTOR signaling pathway, IL6/JAK/STAT3 signaling pathway, P53 signaling pathway and G2/M checkpoint signaling pathway. The results of the experiment showed that the aqueous extract of ARSC significantly alleviated myelosuppression, reduced the apoptosis rate of bone marrow cells, upregulated the mRNA expression levels of TNF-α, IL-6 and VEGF, and promoted NF-κB phosphorylation in myelosuppressed mice.

CONCLUSIONS

This study identified the active components and relevant mechanisms of ARSC in the treatment of myelosuppression. Our findings predicted that ARSC could treat bone marrow suppression through multiple components, multiple targets and multiple pathways. Pharmacological experiments showed that ARSC alleviated fluorouracil-induced myelosuppression by reducing the apoptosis rate of bone marrow cells and regulating the TNF-α/NF-κB signaling pathway.

A Scoping Review of Genus Viscum: Biological and Chemical Aspects of Alcoholic Extracts

The genus Viscum comprises a large number of semi-parasitic shrubs popularly known as Mistletoe. The Viscum species grow in many countries of Europe, Africa and Asia with different popular uses in ornamentation, foods and medicine. Many studies about Viscum have been done over the last years focusing on biological activities and chemical composition of the aqueous extracts, mainly related to anthroposophical medicines. However, it is known that non-aqueous preparations, as alcoholic extracts, have demonstrated different biological activities that are species-and host tree-dependent. Considering the potential of these alcoholic extracts, a scoping review was conducted using data from three online databases: PubMed, Scopus and Embase. Inclusion criteria consisted of the in vitro, in vivo, ex vivo, clinical and chemical studies of alcoholic extracts from Viscum species. The present review summarized 124 original publications about fourteen Viscum species. Viscum album, Viscum articulatum and Viscum coloratum were the main studied species. Alcoholic extracts demonstrated hypotensive, anticancer, antimicrobial, analgesic and anti-inflammatory capabilities, among other biological activities. Flavonoids, phenolic acids and terpenoids represented 48%, 24% and 11% of the total identified compounds, respectively. This review contributes to the knowledge of alcoholic preparations of the Viscum species and points out the lack of clinical studies concerning these different extracts.

A systematic overview of the spermatotoxic and genotoxic effects of methotrexate, ganciclovir and mycophenolate mofetil

INTRODUCTION

Immunosuppressant drugs are increasingly being used in the reproductive years. Theoretically, such medications could affect fetal health either through changes in the sperm DNA or through fetal exposure caused by a presence in the seminal fluid. This systematic overview summarizes existing literature on the spermatotoxic and genotoxic potentials of methotrexate (MTX), a drug widely used to treat rheumatic and dermatologic diseases, and mycophenolate mofetil (MMF), which alone or supplemented with ganciclovir (GCV) may be crucial for the survival of organ transplants.

MATERIAL AND METHODS

The systematic overview was performed in accordance with the PRISMA guidelines: A systematic literature search of the MEDLINE and Embase databases was done using a combination of relevant terms to search for studies on spermatotoxic or genotoxic changes related to treatment with MTX, GCV or MMF. The search was restricted to English language literature, and to in vivo animal studies (mammalian species) and clinical human studies.

RESULTS

A total of 102 studies were identified, hereof 25 human and 77 animal studies. For MTX, human studies of immunosuppressive dosages show transient effect on sperm quality parameters, which return to reference values within 3 months. No human studies have investigated the sperm DNA damaging effect of MTX, but in other organs the genotoxic effects of immunosuppressive doses of MTX are fluctuating. In animals, immunosuppressive and cytotoxic doses of MTX adversely affect sperm quality parameters and show widespread genotoxic damages in various organs. Cytotoxic doses transiently change the DNA material in all cell stages of spermatogenesis in rodents. For GCV and MMF, data are limited and the results are indeterminate, for which reason spermatotoxic and genotoxic potentials cannot be excluded.

CONCLUSIONS

Data from human and animal studies indicate transient spermatotoxic and genotoxic potentials of immunosuppressive and cytotoxic doses of MTX. There are a limited number of studies investigating GCV and MMF.

Micronucleus formation during chromatin condensation and under apoptotic conditions

In early S phase the newly replicated DNA is folded back to increasingly compact structures. The process of chromatin condensation inside the nucleus starts with the formation of a micronucleus observed in five established cell lines (K562, CHO, Indian muntjac, murine preB and SCC). Supercoiling of chromatin generates a polarized end-plate region extruded from the nucleus. The extruded chromatin is turned around itself forming the head portion (micronucleus) visible by fluorescence microscopy until the middle of S phase when chromatin structures are succeeded by distinguishable early forms of chromosomes. The generation of micronuclei upon apoptotic treatment was achieved by the methotrexate (MTX) treatment of cells. A close correlation was found between the frequency of micronucleus and MTX concentration, with low frequency at low (0.1 µM) and increasingly higher frequency between 1 and 100 µM concentrations. Characteristic deformation and shrinkage of nuclei indicated apoptosis. High MTX concentration (100 µM) caused the enlargement and necrotic disruption of nuclei. Inhibition of DNA synthesis during replicative DNA synthesis by biotinylated nucleotide prevented the formation of metaphase chromosomes and elevated the frequency of early intermediates of chromosome condensation including micronucleus formation. Based on these observations the micronucleus is regarded as: (a) a regularly occuring element of early chromatin condensation and (b) a typical sign of nuclear membrane damage under toxic conditions. Explanation is given why the micronucleus is hidden in nuclei under normal chromatin condensation and why chromatin motifs including micronuclei become visible upon cellular damage.

Quercetin-induced changes in femoral bone microstructure of adult male rabbits

Flavonoids are a group of plant metabolites with antioxidant effects. One of the most abundant flavonoids in the human diet is quercetin. It is found widely in fruits, vegetables and has a lot of beneficial effects on human health. Quercetin has a positive pharmacological effect on bone metabolism and it prevents the organism against bone loss. However, its impact on the size of basic structural units of the compact bone is still unknown. Therefore, the aim of present study was to investigate the impact of the quercetin on femoral bone microstructure in 5-month-old male rabbits. Five rabbits of Californian broiler line were randomly divided into two groups. In the experimental group (E group; n=3), animals were intramuscularly injected with quercetin at dose 1000 μg.kg-1 body weight (bw) for 90 days, 3 times per week. Two rabbits without quercetin administration served as a control group (C group). According to our results, intramuscular application of quercetin had an insignificant effect on cortical bone thickness in male rabbits. In these rabbits, changes in qualitative histological characteristics were present in the middle part of the compacta, where primary vascular longitudinal bone tissue was present and expanded there from the periosteum. Also, a lower number of secondary osteons was found in these animals. From the histomorphometrical point of view, significantly decreased sizes of primary osteons' vascular canals and secondary osteons (p <0.05) were found in rabbits administered by quercetin. Our findings indicate that subchronic administration of quercetin at the dose used in our study had considerable impact on both qualitative and quantitative histological characteristics of the compact bone in adult male rabbits.

Quercetin induces hepatic γ-glutamyl hydrolase expression in rats by suppressing hepatic microRNA rno-miR-125b-3p

Exogenous factors such as food components including the flavonoid quercetin are suspected to influence micro RNA (miRNA) concentrations and thus possibly target enzymes involved in xenobiotic metabolism. This study therefore investigates the influence of orally administered quercetin on hepatic miRNA and the identification of enzyme target mRNAs relevant in drug metabolism. Male Wistar rats (n=16) were fed either a diet without (C) or with (Q) the addition of 100-ppm quercetin for 7 weeks and subsequently euthanized at the end of the dark phase. To avoid strong effects of food deprivation on hepatic metabolism, food was not removed until 5 h prior to the procedure. Liver was immediately dissected and snap-frozen in liquid nitrogen. Concentrations of 352 hepatic miRNA were measured in pool samples of each dietary group (n=8) using the RT(2) miRNA PCR Array System. Differential expression of miRNAs was assumed with fold changes ≥3. Target genes of differentially expressed miRNAs were identified using the database TargetScan. Because rno-miR-125b-3p showed the most prominent fold-change (-9) we further analyzed the expression of its top predicted target gene gamma-glutamyl hydrolase (GGH) by quantitative real-time PCR using hypoxanthine phosphoribosyltransferase 1 (hprt1) as endogenous control. Compared to controls, 23 miRNAs were differentially expressed in rats fed quercetin. A ninefold reduction in hepatic miRNA rno-miR-125b-3p was paralleled by significant induction of GGH mRNA in liver of quercetin fed rats. Because increased GGH expressions were repeatedly associated with resistance to methotrexate, concomitant intake with quercetin should be monitored carefully.

Silibinin attenuates methotrexate-induced pulmonary injury by targeting oxidative stress

The aim of the present study was to assess the protective effect of silibinin against methotrexate (MTX)-induced pulmonary toxicity. Rats were divided into four groups (MTX, MTX + silibinin, silibinin and control. MTX was injected intraperitoneally (i.p) into female Wistar rats (10 mg/kg/day for 3 days), which resulted in significant increases in the serum levels of alanine aminotransferase, aspartate aminotransferase and oxidant enzymes, including nitric oxide and myeloperoxidase. Furthermore, significant reductions were detected in the serum activity levels of the antioxidative enzymes, glutathione peroxidase and superoxide dismutase, when compared with the control group. However, administration of silibinin (100 mg/kg/day for 10 days, i.p.) was shown to ameliorate the MTX-induced pulmonary toxicity, as indicated by the normalization of the oxidative stress parameters. Furthermore, silibinin treatment was demonstrated to reduce the histopathological changes associated with MTX. In conclusion, silibinin exhibited protective effects against MTX-induced pulmonary toxicity, which may be attributed to its antioxidant activity.

Brazilin isolated from Caesalpinia sappan L. inhibits rheumatoid arthritis activity in a type-II collagen induced arthritis mouse model

BACKGROUND

Caesalpinia sappan L. extracts exhibit great therapeutic potential, and have been shown to have analgesic and anti-inflammatory properties. This study aimed to understand the anti-rheumatoid activity of brazilin that was isolated from ethyl acetate extract of C. sappan L. The evaluations were conducted in mice with type-II collagen-induced arthritis (CIA).

METHODS

Brazilin was purified via preparative HPLC and identified by mass spectrometry and 1H/13C NMR analysis. DBA/1J mice were divided into four groups (n=10). Three groups of mice received intradermal injections of inducer bovine type-II collagen (BTIIC; 2 mg/ml in 0.05 ml acetic acid) and 0.1 ml of booster complete Freund's adjuvant (CFA). A second injection of BTIIC with booster incomplete Freund's adjuvant (ICFA) was given subsequently after 21 days. On 22nd day, purified brazilin (10 mg/kg body weight) or the disease-modifying anti-rheumatic drug methotrexate (3 mg/kg body weight) was administered intraperitoneally daily or every three days for 21 days, respectively to two groups of mice. At the 42nd day, mice sera were collected, and the levels of pro-inflammatory cytokines and stress enzyme markers in serum were measured using standard immunoassay methods. The microstructure and morphometric analyses of the bones were assessed using high-resolution microfocal computed tomography.

RESULTS

Brazilin isolated from C. sappan reduced the arthritis index score and the extent of acute inflammatory paw edema in CIA-mice. The bone mineral density was significantly (p<0.05) lower in only-CIA mice, and appeared to increase commensurate with methotrexate and brazilin administration. Brazilin prevented joint destruction, surface erosion, and enhanced bone formation as revealed by microstructural examinations. Brazilin markedly attenuated mouse CIA and reduced the serum levels of inflammatory cytokines including TNF-α, IL-1β, and IL-6.

CONCLUSIONS

Brazilin purified from C. sappan L. shows protective efficacy in CIA mouse, and may be useful to treat chronic inflammatory disorders including rheumatoid arthritis.

Genotoxicity of Thermopsis turcica on Allium cepa L. roots revealed by alkaline comet and random amplified polymorphic DNA assays

This study was undertaken to evaluate genotoxic potential of Thermopsis turcica aqueous extracts on the roots of onion bulb (Allium cepa L.) by comet assay and random amplified polymorphic DNA technique. The Allium root growth inhibition test indicated that the EC50 and 2×EC50 values were 8 and 16 mg/ml concentrations of T. turcica aqueous extracts, respectively. The negative control (distilled water), positive control (methyl methane sulfonate, 10 mg/l) and 8 and 16 mg/ml concentrations of T. turcica extracts were introduced to the roots of onion bulbs for 24 and 96 h. The root growth, DNA damage in root cells and randomly amplified polymorphic DNA (RAPD) profiles of root tissue were used as endpoints of the genotoxicity. The comet assay clearly indicated that dose-dependent single strand DNA breaks in the root nuclei of onions were determined for the treatment concentrations of T. turcica extracts. In comparison to RAPD profile of negative control group, RAPD polymorphisms became evident as disappearance and/or appearance of RAPD bands in treated roots. The diagnostic and phenetic numerical analyses of RAPD profiles obviously indicated dose-dependent genotoxicity induced by Thermopsis extracts. In conclusion, the results clearly indicated that water extract of T. turcica has genotoxic potential on the roots of onion bulbs as shown by comet assay and RAPD technique.

A Randomized Study on Postrelapse Disease-Free Survival with Adjuvant Mistletoe versus Oral Etoposide in Osteosarcoma Patients

Background. Osteosarcoma is a highly malignant bone tumour. After the second relapse, the 12-month postrelapse disease-free survival (PRDFS) rate decreases below 20%. Oral Etoposide is often used in clinical practice after surgery as an “adjuvant” outside any protocol and with only limited evidence of improved survival. Viscum album fermentatum Pini (Viscum) is an extract of mistletoe plants grown on pine trees for subcutaneous (sc) injection with immunomodulatory activity. Methods. Encouraged by preliminary findings, we conducted a study where osteosarcoma patients free from disease after second metastatic relapse were randomly assigned to Viscum sc or Oral Etoposide. Our goal was to compare 12-month PRDFS rates with an equivalent historical control group. Results. Twenty patients have been enrolled, with a median age of 34 years (range 11–65) and a median follow-up time of 38.5 months (3–73). The median PRDSF is currently 4 months (1–47) in the Etoposide and 39 months (2–73) in the Viscum group. Patients getting Viscum reported a higher quality of life due to lower toxicity. Conclusion. Viscum shows promise as adjuvant treatment in prolonging PRDFS after second relapse in osteosarcoma patients. A larger study is required to conclusively determine efficacy and immunomodulatory mechanisms of Viscum therapy in osteosarcoma patients.

Emerging roles of mistletoes in malignancy management

Mistletoes are a group of obligate plant semi-parasites in the order Santalales. These clumps of plants growing on a wide range of host plants have been traditionally regarded as medicinal repositories. However, current scientific discoveries have validated their health potentials like never before. Their extracts containing alkaloids, viscotoxins, lectins, and polysaccharides have been evidenced to possess a myriad biological potentials including cancer inhibition. Mistletoes have emerged as promising alternative therapy against colon, oral, lung, and pancreas cancers. The plant extracts bolster immunity, delay tumour initiation and progression, kill malignant tumours, stabilize DNA, alleviate side effects of chemotherapeutics, improve the lifespan, and coping ability of cancer patients and survivors. A range of proprietary formulations viz. Iscador, Eurixor, Helixor, Lektinol, Isorel, Iscucin, Abnoba-viscum and recombinant lectin ML-1 are already being commercialized. This review presents an informative account on the recent developments in mistletoe-mediated cancer management. The underlying mechanisms, possibilities and limitations in cancer therapeutic development are outlined for kindling both researcher and public interest.