Effects of plant-derived anti-leukemic drugs on individualized leukemic cell population profiles in Egyptian patients

Phytochemical Investigation of Egyptian Riverhemp: A Potential Source of Antileukemic Metabolites

As part of our research group’s continuous efforts to find alternative treatments for cancer, the aqueous ethanol extract of Sesbania sesban L. Merr. (SS, Egyptian riverhemp) demonstrated an antileukemic activity against K562 cell line. Bioguided fractionation of SS leaves hydroethanolic extract resulted in the isolation of one new compound (33) named as hederatriol 3-O-β-D-glucuronic acid methyl ester as well as 34 known compounds. Seven compounds ((34), (22), (20), (24), (21), (19), and (35)) showed high antiproliferative effects (IC50 = 22.3, 30.8, 31.3, 33.7, 36.6, 37.5, and 41.5 μM, respectively), while four compounds ((32), (5), (29), and (1)) showed milder activities (IC50 = 56.4, 67.6, 83.3, and 112.3 μM, respectively). A mechanistic study was further carried out on a molecular genetics level against several transcription factors signaling pathways that are incorporated in the incidence of cancer. The results showed that compounds (22) and (21) demonstrated a specific inhibition of Wnt pathway (IC50 = 3.8 and 4.6 μM, respectively), while compound (22) showed a specific inhibition of Smad pathway (IC50 = 3.8 μM). Compound (34) strongly altered the signaling of Smad and E2F pathways (IC50 = 5 μM). The bioactive metabolites were further investigated in silico by docking against several targets related to K562 cell line. The results showed that compounds (22) and (34) exhibited a strong binding affinity towards topoisomerase (docking score = −7.81 and −9.30 Kcal/Mole, respectively). Compounds (22) and (34) demonstrated a strong binding affinity towards EGFR-tyrosine kinase (docking score = −7.12 and −7.35 Kcal/Mole, respectively). Moreover, compound (34) showed a strong binding affinity towards Abl kinase (docking score = −7.05 Kcal/Mole).

Antioxidant, Anti-Proliferative Activity and Chemical Fingerprinting of Centaurea calcitrapa against Breast Cancer Cells and Molecular Docking of Caspase-3

Centaurea calcitrapa has been intensively utilized in ethnomedicinal practices as a natural therapeutic recipe to cure various ailments. The current study aimed to chemically characterize ethanolic extract of C. calcitrapa (EECC) aerial parts (leaves and shoots) by use of gas chromatography-mass spectrometry analyses (GC-MS) and investigate its antioxidant and in vitro anticancer activities, elucidating the underlying molecular mechanism by use of flow cytometry-based fluorescence-activated cell sorting (FACS) and conducting in silico assessment of binding inhibitory activities of EECC major compounds docked to caspase-3. CG-MS profiling of EECC identified a total of 26 major flavonoids and polyphenolic compounds. DPPH and ABTS assays revealed that EECC exhibits potent antioxidant activity comparable to standard reducing agents. Results of the proliferation assay revealed that EECC exhibit potent, dose-dependent cytotoxic activities against triple-positive (MCF-7) and triple-negative (MDA-MB-231) breast cancer cell models, with IC50 values of 1.3 × 102 and 8.7 × 101 µg/mL, respectively. The observed cytotoxic effect was specific to studied cancer cells since EECC exhibited minimal (~<10%) cytotoxicity against MCF-12, a normal breast cell line. FACS analysis employing annexin V-FITC/propidium iodide double labeling demonstrated that the observed anti-proliferative activity against MCF-7 and MDA-MB-231 was mediated via apoptotic as well as necrotic signaling transduction processes. The increase in fluorescence intensity associated with DCFH oxidation to DCF, as reported by FACS, indicated that apoptosis is caused by generation of ROS. The use of caspase-3-specific fluorogenic substrate revealed a dose-dependent elevation in caspase-3 substrate-cleavage activity, which further supports EECC-mediated apoptosis in MCF-7 cells. The major EECC compounds were examined for their inhibitory activity against caspase-3 receptor (1HD2) using molecular docking. Three compounds exhibited the highest glide score energy of −5.156, −4.691 and −4.551 kcal/mol, respectively. Phenol, 2,6-dimethoxy established strong binding in caspase-3 receptor of hydrogenic type, with residue ARG 207 and of PI-PI stacking type with residue HIS 121. By contract, hexadecenoic acid showed 3 H-bond with the following residues: ASN 615, ASN 616a and THR 646. Taken together, the current findings reveal that EECC exhibits significant and specific cytotoxicity against breast cancer cells mediated by the generation of ROS and culminating into necrosis and apoptosis. Further investigations of the phytoconstituents-rich C. calcitrapa are therefore warranted against breast as well as other human cancer cell models.

Pediatric acute lymphoblastic leukemia management using multitargeting bioactive natural compounds: A systematic and critical review

Pediatric acute lymphoblastic leukemia (pALL), a malignancy of the lymphoid line of blood cells, accounts for a large percentage of all childhood leukemia cases. Although the 5-year survival rate for children with ALL has greatly improved over years, using chemotherapeutics as its first-line treatment still causes short- and long-term side effects. Furthermore, induction of toxicity and resistance, as well as the high cost, limit their application. Phytochemicals, with remarkable cancer preventive and chemotherapeutic characteristics, may serve as old solutions to new challenges. Bioactive plant secondary metabolites have exhibited promising antileukemic and adjunctive effects by targeting various molecular processes, including autophagy, cell cycle, angiogenesis, and extrinsic/intrinsic apoptotic pathways. Although numerous reports have shown that numerous plant secondary metabolites can interfere with the progression of malignancies, including leukemia, there was no comprehensive review article on the effect of phytochemicals on pALL. This systematic review aims to provide critical and cohesive analysis of the potential of various naturally-occurring metabolites in the management of pALL with the understanding of underlying molecular and cellular mechanisms of action.

Potent antioxidant and anticancer activities of the methanolic extract of Calligonum comosum (L'Her) fruit hairs against human hepatocarcinoma cells

Cancer is a devastating and aggressive disease that is globally ranked as the second-leading cause of deaths despite the relentless efforts being directed towards the discovery of novel chemotherapeutic drugs. Plants naturally produce a plethora of secondary metabolites that play a crucial role as effective therapeutic agents. Cancer treatment rely primarily on chemo- and radio-therapeutic strategies that suffers from known side effects. Recently, the strategy of controlling cancer progression by use of plant-derived natural products have extensively attracted research interests. In this study, the antioxidant and anticancer activities of the methanolic extract of Calligonum comosum (MeCc) fruit hairs were investigated. According to DPPH and ABTS assays, MeCc exhibited potent antioxidant capacity as it displayed significant free-radical scavenging activity. Results of the MTT cytotoxicity assay revealed that the MeCc exhibited potent anti-proliferation activity (IC₅₀ = 10.4 µg/ml) that is specific against human hepatocarcinoma cells (HepG2), as only marginally harmful effect against non-cancerous control BJ-1 cells was detected. Results of the RT-qPCR gene expression analyses indicated that MeCc resulted in significant overexpression of mRNA transcript levels of the pro-apoptotic genes p53, caspase-3 and Bax, while downregulating the level of Bcl-2, an anti-apoptotic marker gene. Immunoblotting of the protein expression levels for the same markers showed similar pattern to that observed in RT-qPCR profiling. While the levels of p53, caspase-3 and Bax proteins exhibited significant increase, the protein level of Bcl-2 was significantly reduced. In conclusion, it is proposed that the observed specific anticancer activity of MeCc against HepG2 cells takes place via the engagement of apoptosis. This highlights the value of C. comosum as a source of potent natural anticancer agents and warrants further investigation to identify the active principals involved.

Combined epigenetic and metabolic treatments overcome differentiation blockade in acute myeloid leukemia

A hallmark of acute myeloid leukemia (AML) is the inability of self-renewing malignant cells to mature into a non-dividing terminally differentiated state. This differentiation block has been linked to dysregulation of multiple cellular processes, including transcriptional, chromatin, and metabolic regulation. The transcription factor HOXA9 and the histone demethylase LSD1 are examples of such regulators that promote differentiation blockade in AML. To identify metabolic targets that interact with LSD1 inhibition to promote myeloid maturation, we screened a small molecule library to identify druggable substrates. We found that differentiation caused by LSD1 inhibition is enhanced by combined perturbation of purine nucleotide salvage and de novo lipogenesis pathways, and identified multiple lines of evidence to support the specificity of these pathways and suggest a potential basis of how perturbation of these pathways may interact synergistically to promote myeloid differentiation. In sum, these findings suggest potential drug combination strategies in the treatment of AML.

Crude Methanol Extract of Rosin Gum Exhibits Specific Cytotoxicity against Human Breast Cancer Cells via Apoptosis Induction

BACKGROUND

Rosin (Colophony) is a natural resin derived from species of the pine family Pinaceae. It has wide industrial applications including printing inks, photocopying paper, adhesives and varnishes, soap and soda. Rosin and its derivatives are employed as ingredients in various pharmaceutical products such as ointments and plasters. Rosin-based products contain allergens that may exert some occupational health problems such as asthma and contact dermatitis.

OBJECTIVE

Our knowledge of the pharmaceutical and medicinal properties of rosin is limited. The current study aims at investigating the cytotoxic potential of Rosin-Derived Crude Methanolic Extract (RD-CME) and elucidation of its mode-of-action against breast cancer cells (MCF-7 and MDA-MB231).

METHODS

Crude methanol extract was prepared from rosin. Its phenolic contents were analyzed by Reversed- Phase High-Performance Liquid Chromatography (RP-HPLC). Antioxidant activity was evaluated by DPPH radical-scavenging assay. Antiproliferation activity against MCF-7 and MDA-MB231 cancerous cells was investigated by MTT assay; its potency compared with doxorubicin as positive control and specificity were assessed compared to two non-cancerous cell lines (BJ-1 and MCF-12F). Selected apoptosis protein markers were assayed by western blotting. Cell cycle analysis was performed by Annexin V-FITC/PI FACS assay.

RESULTS

RD-CME exhibited significant and selective cytotoxicity against the two tested breast cancer cells (MCF-7 and MDA-MB231) compared to normal cells as revealed by MTT assay. ELISA and western blotting indicated that the observed antiproliferative activity of RD-CME is mediated via the engagement of an intrinsic apoptosis signaling pathway, as judged by enhanced expression of key pro-apoptotic protein markers (p53, Bax and Casp 3) relative to vehicle solvent-treated MCF-7 control cells.

CONCLUSION

To our knowledge, this is the first report to investigate the medicinal anticancer and antioxidant potential of crude methanolic extract derived from colophony rosin. We provided evidence that RD-CME exhibits strong antioxidant and anticancer effects. The observed cytotoxic activity against MCF-7 is proposed to take place via G2/M cell cycle arrest and apoptosis. Colophony resin has a great potential to join the arsenal of plantderived natural anticancer drugs. Further thorough investigation of the potential cytotoxicity of RD-CME against various cancerous cell lines is required to assess the spectrum and potency of its novel activity.

Biochemical and Molecular Investigation of In Vitro Antioxidant and Anticancer Activity Spectrum of Crude Extracts of Willow Leaves Salix safsaf

Organic fractions and extracts of willow (Salix safsaf) leaves, produced by sequential solvent extraction as well as infusion and decoction, exhibited anticancer potencies in four cancerous cell lines, including breast (MCF-7), colorectal (HCT-116), cervical (HeLa) and liver (HepG2). Results of the MTT assay revealed that chloroform (CHCl₃) and ethyl acetate (EtOAc)-soluble fractions exhibited specific anticancer activities as marginal toxicities were observed against two non-cancerous control cell lines (BJ-1 and MCF-12). Ultra-high-resolution mass spectrometry Q-Exactive™ HF Hybrid Quadrupole-Orbitrap™ coupled with liquid chromatography (UHPLC) indicated that both extracts are enriched in features belonging to major phenolic and purine derivatives. Fluorescence-activated cell sorter analysis (FACS), employing annexin V-FITC/PI double staining indicated that the observed cytotoxic potency was mediated via apoptosis. FACS analysis, monitoring the increase in fluorescence signal, associated with oxidation of DCFH to DCF, indicated that the mechanism of apoptosis is independent of reactive oxygen species (ROS). Results of immunoblotting and RT-qPCR assays showed that treatment with organic fractions under investigation resulted in significant up-regulation of pro-apoptotic protein and mRNA markers for Caspase-3, p53 and Bax, whereas it resulted in a significant reduction in amounts of both protein and mRNA of the anti-apoptotic marker Bcl-2. FACS analysis also indicated that pre-treatment and co-treatment of human amniotic epithelial (WISH) cells exposed to the ROS H₂O₂ with EtOAc fraction provide a cytoprotective and antioxidant capacity against generated oxidative stress. In conclusion, our findings highlight the importance of natural phenolic and flavonoid compounds with unparalleled and unique antioxidant and anticancer properties.

Antitumor effect of baicalin from the Scutellaria baicalensis radix extract in B-acute lymphoblastic leukemia with different chromosomal rearrangements

Acute B-lymphoblastic leukemia (B-ALL) is the most common hematologic malignancy in children. Many cases of B-ALL harbor chromosomal translocations which are often critical determinants of prognosis. Most of them represent altered transcription factors that impact gene transcription or enhance signaling. B-ALLs harboring the mixed-lineage leukemia 1 (MLL1) gene rearrangements represent aggressive, high-risk type of early childhood leukemias that are usually associated with a very poor prognosis. Therefore, there is an urgent need for novel therapeutic agents as well as new treatment strategies. The objective was to examine the vitro inhibitory effects of Scutellaria baicalensis root extract (SBE) in B-ALL cell lines with different chromosomal rearrangements and in leukemic blasts derived from patients' bone marrow (BMCs). In this study we showed that baicalin which is the main component of the SBE possess antitumor activity against all leukemic cell lines especially those with MLL and PBX1 gene rearrangements. Baicalin inhibited cell proliferation, arrested the cell cycle at the G0/G1 phase, and induced cell death through caspase 3/7 activation. Moreover, baicalin treatment inhibited the glycogen synthase kinase-3β (GSK-3β) by suppressing its phosphorylation at Y216, and upregulated the downstream mediator of the cell cycle arrest - cyclin dependent kinase inhibitor p27Kip1. Bone marrow derived blasts from B-ALL patients also exhibited varied sensitivity towards baicalin with 72% patients sensitive to the SBE and baicalin treatment. Taken together, our findings provide new insights into the anti-cancer properties of baicalin by showing its diverse mode of action which might be related to the different genetic background.

Apoptotic Pathway as the Therapeutic Target for Anticancer Traditional Chinese Medicines

Cancer is a leading cause of morbidity and mortality worldwide. Apoptosis is a process of programmed cell death and it plays a vital role in human development and tissue homeostasis. Mounting evidence indicates that apoptosis is closely related to the survival of cancer and it has emerged as a key target for the discovery and development of novel anticancer drugs. Various studies indicate that targeting the apoptotic signaling pathway by anticancer drugs is an important mechanism in cancer therapy. Therefore, numerous novel anticancer agents have been discovered and developed from traditional Chinese medicines (TCMs) by targeting the cellular apoptotic pathway of cancer cells and shown clinically beneficial effects in cancer therapy. This review aims to provide a comprehensive discussion for the role, pharmacology, related biology, and possible mechanism(s) of a number of important anticancer TCMs and their derivatives mainly targeting the cellular apoptotic pathway. It may have important clinical implications in cancer therapy.