Induction of apoptosis in human promyelocytic leukemia cell line HL-60 by C-benzylated dihydrochalcones, uvaretin, isouvaretin and diuvaretin

Study on the Chemical Composition and Multidrug Resistance Reversal Activity of Euphorbia uralensis (Euphorbiaceae)

Euphorbia uralensis belongs to the family Euphorbiaceae and is widely distributed in northern Xinjiang, making it a characteristic plant of the region in Xinjiang, China. The chemical composition and biological activity of Euphorbia uralensis have not yet been reported, although certain compounds isolated from Euphorbia plants in Xinjiang, China, have demonstrated exceptional multidrug resistance (MDR) reversal. This study aims to investigate the chemical components present in Euphorbia uralensis with the potential to reverse MDR. The aerial parts of Euphorbia uralensis were extracted using organic solvents of varying polarities, resulting in dichloromethane (Fr-E) and petroleum ether (Fr-S) fractions, which exhibited greater MDR reversal activity than the other fractions. The chemical constituents of the Fr-S fraction were analyzed using GC-MS. The chemical components of the Fr-E fraction were isolated and purified using column chromatography. The most effective compounds with MDR reversal activity were screened out, and the mechanism was investigated using molecular docking, molecular dynamics simulations, Western blotting, and rhodamine 123 staining. GC-MS analysis showed that the Fr-S fraction was rich in triterpenes, fatty acids, phenols, and long-chain alkanes, all of which were identified for the first time in Euphorbia uralensis. Among these, palmitic acid was present at a content level of 15.86%. This study notably unveils the discovery of a new compound and 16 previously recorded compounds for the first time in this plant, with the main types identified as steroids, sesquiterpenes, and flavonoids. The isolated compounds were tested for cytotoxicity and MDR reversal activity. The new compounds Euphouralosides A, pubinernoid A, naringenin, and punigratine showed good MDR reversal activity against MCF-7 and MCF-7/ADR cell lines. Punigratine was the most active compound. Moreover, punigratine could stably bind to the ABCB1 protein. Western blot analysis revealed that punigratine did not affect the expression of the ABCB1 protein in cells (p > 0.05). However, following treatment with punigratine (0.16 μM), there was a significant increase the intracellular accumulation of Rh123 in MCF-7/ADR cells (p < 0.05). These findings suggest that punigratine can inhibit the efflux of the ABCB1 protein, thereby overcoming MDR in tumors. This study provides a foundation for further research on the biological activity and medicinal potential of Euphorbia uralensis.

The Emerging Role of Natural Products in Cancer Treatment

The exploration of natural products as potential agents for cancer treatment has garnered significant attention in recent years. In this comprehensive review, we delve into the diverse array of natural compounds, including alkaloids, carbohydrates, flavonoids, lignans, polyketides, saponins, tannins, and terpenoids, highlighting their emerging roles in cancer therapy. These compounds, derived from various botanical sources, exhibit a wide range of mechanisms of action, targeting critical pathways involved in cancer progression such as cell proliferation, apoptosis, angiogenesis, and metastasis. Through a meticulous examination of preclinical and clinical studies, we provide insights into the therapeutic potential of these natural products across different cancer types. Furthermore, we discuss the advantages and challenges associated with their use in cancer treatment, emphasizing the need for further research to optimize their efficacy, pharmacokinetics, and delivery methods. Overall, this review underscores the importance of natural products in advancing cancer therapeutics and paves the way for future investigations into their clinical applications.

Novel Mango Ginger Bioactive (2,4,6-Trihydroxy-3,5-diprenyldihydrochalcone) Inhibits Mitochondrial Metabolism in Combination with Avocatin B

Acute myeloid leukemia (AML) is an aggressive blood cancer with limited effective chemotherapy options and negative patient outcomes. Food-derived molecules such as avocatin B (Avo B), a fatty-acid oxidation (FAO) inhibitor, are promising novel therapeutics. The roots of the Curcuma amada plants have been historically used in traditional medicine, but isolated bioactive compounds have seldom been studied. Here, we report that 2,4,6-trihydroxy-3,5-diprenyldihydrochalcone (M1), a bioactive from C. Amada, possesses novel anticancer activity. This in vitro study investigated the antileukemia properties of M1 and its effects on mitochondrial metabolism. In combination with Avo B, M1 synergistically reduced AML cell line viability and patient-derived clonogenic growth with no effect on normal peripheral blood stem cells. Mechanistically, M1 alone inhibited mitochondria complex I, while the M1/Avo B combination inhibited FAO by 60%, a process essential to the synergy. These results identified a novel food-derived bioactive and its potential as a novel chemotherapeutic for AML.

Modulation of inflammatory pathways, medicinal uses and toxicities of Uvaria species: potential role in the prevention and treatment of inflammation

The therapeutic efficacy of the contemporary anti-inflammatory drugs are well established; however, prolonged use of such can often lead to serious and life-threatening side effects. Natural product-based anti-inflammatory compounds with superior efficacy and minimum toxicity can serve as possible therapeutic alternatives in this scenario. Genus Uvaria is a part of Annonaceae family, while the majority of its species are widely distributed in tropical rain forest regions of South East Asia. Uvaria species have been used extensively used as traditional medicine for treating all sorts of inflammatory diseases including catarrhal inflammation, rheumatism, acute allergic reactions, hemorrhoids, inflammatory liver disease and inflamed joints. Phytochemical analysis of Uvaria species has revealed flavones, flavonoids, tannins, saponins, polyoxygenated cyclohexene and phenolic compounds as major phyto-constituents. This review is an attempt to highlight the anti-inflammatory activity of Uvaria species by conducting a critical appraisal of the published literature. The ethnopharmacological relevance of Uvaria species in the light of toxicological studies is also discussed herein. An extensive and relevant literature on anti-inflammatory activity of Uvaria species was collected from available books, journals and electronic databases including PubMed, ScienceDirect, Scopus, Proquest and Ovid. Extracts and isolates of Uvaria species exhibited significant anti-inflammatory activity through various mechanisms of action. 6,7-di-O-Methyl-baicalein, flexuvarol B, chrysin, (-)-zeylenol, 6-hydroxy-5,7-dimethoxy-flavone, and pinocembrin were the most potent anti-inflammatory compounds with comparable IC₅₀ with positive controls. Therefore, it is suggested that further research should be carried out to determine the pharmacokinetics, pharmacodynamics and toxicity of these therapeutically significant compounds, to convert the pre-clinical results into clinical data for drug development and design.

Uvaria rufa Blume attenuates benign prostatic hyperplasia via inhibiting 5α-reductase and enhancing antioxidant status

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional medicine has used Uvaria rufa Blume as an ethnomedicinal plant for treating fever, skin allergies, intestinal ulcers and prostate disorders including BPH. However, no scientific evidence supports the traditional use.

AIM OF THE STUDY

This study aimed to evaluate the therapeutic potential of U. rufa on BPH using in vitro and in vivo models.

MATERIALS AND METHODS

In vitro studies screened the efficacy of a 5α-reductase (5αR) inhibition and antioxidant activity of petroleum ether, ethyl acetate, ethanol and aqueous extracts from the stem of U. rufa. Phytochemical screening was performed to determine the active compound using high-performance liquid chromatography (HPLC). Ethyl acetate extract (UR-EtOAc) of U. rufa was used to evaluate the therapeutic efficacy in vivo models. BPH was induced by subcutaneous injection of testosterone propionate (3mg/kg) to male rats for 30 days. After 30 days of oral administration of UR-EtOAc at doses of 10 and 20mg/kg and finasteride at a dose of 1mg/kg, the prostate weight, prostate index (PI), testosterone and androgen receptor (AR) levels, and histopathological alteration of prostate gland were determined. Also, oxidative status and toxicity indices were assessed.

RESULTS

UR-EtOAc exhibited the highest potency of inhibition of 5αR and possessed potent antioxidants rich in phenolics and flavonoids contents. The active compound analyzed by HPLC was β-sitosterol. In vivo results show a significant reduction in prostate weight, PI, and AR in all treated groups when compared to the BPH model group (P<0.001). Also, the UR-EtOAc and finasteride treated groups had increased prostatic and serum testosterone levels when compared to the BPH model group. A histopathological investigation of the prostate glands supported the above results. UR-EtOAc elevated the antioxidant enzymes and reduced the malondialdehyde level in BPH-induced rats. Moreover, treatment of UR-EtOAc at all doses had no toxic effects on the vital organs and serum biochemical indices.

CONCLUSIONS

UR-EtOAc from the stem of Uvaria rufa Blume appears to have the potential as a phytotherapeutic agent in the management of BPH, which provides the scientific evidence for traditional use.

Biarylmethane and Fused Heterocyclic Arene Synthesis via in Situ Generated o- and/or p-Naphthoquinone Methides

o- and/or p-naphthoquinone methides (NQMs) can be selectively prepared by the ring opening of 1-(siloxymethyl)-1,4-epoxy-1,4-dihydronaphthalene derivatives based on a substituent effect at the 4 position of the substrates. The 4-alkyl- or silyl-substituted 1-(siloxymethyl)-1,4-epoxy-1,4-dihydronaphthalene was transformed to o-NQM (1-naphthoquinone-2-methide), which underwent Friedel-Crafts 1,4-addition of the α,β-unsaturated carbonyl moiety to provide the 2-benzyl-1-naphthol as the biarylmethane and [4 + 2]-cycloaddition with a dienophile to give the fused heterocyclic arene. Meanwhile, the 4-unsubstituted 1-(siloxymethyl)-1,4-epoxy-1,4-dihydronaphthalene could be converted to the corresponding 4-benzyl-1-naphthol by the Friedel-Crafts 1,6-addition of p-NQM (1-naphthoquinone-4-methide) generated by the site-selective ring opening of the 1,4-epoxy moiety. Furthermore, the 4-(siloxymethyl)-(1,4-bis(siloxymethyl))-1,4-epoxy-1,4-dihydronaphthalene was transformed into a 2,4-bisbenzyl-1-naphthol or pentacyclic derivative via both the o- and p-NQM intermediates.

Anti-cancer chalcones: Structural and molecular target perspectives

Chalcone or (E)-1,3-diphenyl-2-propene-1-one scaffold remained a fascination among researchers in the 21st century due to its simple chemistry, ease of synthesis and a wide variety of promising biological activities. Several natural and (semi) synthetic chalcones have shown anti-cancer activity due to their inhibitory potential against various targets namely ABCG2/P-gp/BCRP, 5α-reductase, aromatase, 17-β-hydroxysteroid dehydrogenase, HDAC/Situin-1, proteasome, VEGF, VEGFR-2 kinase, MMP-2/9, JAK/STAT signaling pathways, CDC25B, tubulin, cathepsin-K, topoisomerase-II, Wnt, NF-κB, B-Raf and mTOR etc. In this review, a comprehensive study on molecular targets/pathways involved in carcinogenesis, mechanism of actions (MOAs), structure activity relationships (SARs) and patents granted have been highlighted. With the knowledge of molecular targets, structural insights and SARs, this review may be helpful for (medicinal) chemists to design more potent, safe, selective and cost effective anti-cancer chalcones.

Apoptotic events induced by maleimides on human acute leukemia cell lines

Cyclic imides are known for their antitumor activity, especially the naphthalimide derivatives, such as Mitonafide and Amonafide. Recently, we have demonstrated the cytotoxic effect of a series of naphthalimide derivatives against B16F10 melanoma cells. On the basis of this fact, we have developed a study starting from the synthesis of different cyclic imides and the evaluation of their cytotoxic properties on human acute leukemia cells (K562 and Jurkat). Initially, a screening test was conducted to select the compound with the best cytotoxic effect, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. After this selection, structural modifications were performed in the most active compound to obtain five more derivatives. All compounds presented a good cytotoxic effect. The results of cell cycle analysis, fluorescence microscopy, and Annexin V-FITC assay confirmed that the cells observed in the sub-G0/G1 phase were undergoing apoptosis. From this set of results, cyclic imides 8, 10, and 12 were selected for the evaluation of the mechanisms involved in the apoptotic process. The results demonstrate the involvement of the intrinsic pathway of apoptosis, evidenced by the reduction in mitochondrial potential, an increase in the level of AIF protein expression, a decreased level of expression of anti-apoptotic Bcl-2 protein, and an increased level of expression of pro-apoptotic protein Bax in both K562 and Jurkat cells treated with cyclic imides (8, 10, and 12). Furthermore, cyclic imides 8 and 10 caused an increase in the level of Fas expression in Jurkat cells, indicating the additional involvement of the extrinsic apoptosis pathway. The compounds (8, 10, and 12) also caused a decreased level of expression of anti-apoptotic protein survivin. The biological effects observed with these cyclic imide derivatives in this study suggest promising applications against acute leukemia.

Pyrenes and pyrendiones from Uvaria lucida

A chemical investigation of the chloroform extract of the roots of Uvaria ludida Benth. (Annonaceae), an important African traditional medicine, led to the isolation of six new compounds; three pyrenes, 2-hydroxy-1,8-dimethoxypyrene (1), 8-methoxy-1,2-methylenedioxypyrene (2), and 7-hydroxy-8-methoxy-1,2-methylenedioxypyrene (3), two pyrenediones, 2-hydroxy-1,8-pyrenedione (4) and 2-methoxy-1,8-pyrenedione (5), and a sesquiterpene, (-)-10-oxo-isodauc-3-en-15-oic acid (6), together with eight known compounds (7-14). The structural elucidation by spectroscopic studies of the compounds isolated is described. While pyrenes did not exhibit strong cytotoxicity against human promyelocytic leukemia HL-60 cells, pyrenediones showed strong cytotoxicity. The IC(50) of 4 was 70 ng mL(-1), which was close to that of etoposide (IC(50) = 60 ng mL(-1)).

Induction of apoptosis and cell cycle arrest in L-1210 murine lymphoblastic leukaemia cells by (2E)-3-(2-naphthyl)-1-(3'-methoxy-4'-hydroxy-phenyl)-2-propen-1-one

OBJECTIVES

New compounds with biological targets and less cytotoxicity to normal cells are necessary for cancer therapy. In this work ten synthetic chalcones derived from 2-naphtaldehyde were evaluated for their cytotoxic effect in murine acute lymphoblastic leukemia cells L-1210.

METHODS

A series of ten chalcones derived from 2-naphtaldehyde and corresponding acetophenones were prepared by aldolic condensation, using methanol as solvent under basic conditions, at room temperature for 24 h. The cell viability was determined by MTT colorimeter method. The cell cycle phase analysis was carried out by flow cytometry after propidium iodide staining. The apoptosis induction was assessed by exposure to phosphatidylserine (ANNEXIN V-FITC). Cytometric analysis was performed to evaluate the expression of p53, Bcl-2 and Bax protein. The caspase-3 expression was studied by immunoblotting analysis.

KEY FINDINGS

A preliminary screening of a series of ten chalcones derived from 2-naphtaldehyde showed that chalcone 8, (2E)-3-(2-naphtyl)-1-(3'-methoxy-4'-hydroxy-phenyl)-2-propen-1-one, had the highest cytotoxic effect (IC50 of 54 microM), but not in normal human lymphocytes. To better understand the cytotoxic mechanism of chalcone 8, its effect on cell cycle and apoptosis was assessed. Our results showed that chalcone 8 caused cell cycle arrest in the G2/M phase and a significant increase in the proportion of cells in the subG0/G1 phase. Our results also demonstrated that chalcone 8 promoted a modification in Bax:Bcl-2 ratio and increased p53 expression and caspase-3 activation.

CONCLUSIONS

The studied chalcone 8 has cytotoxic effect against L-1210 lymphoblastic leukaemic cells, and this effect is associated with increase of p-53 and Bax expression.

Dietary chalcones with chemopreventive and chemotherapeutic potential

Chalcones are absorbed in the daily diet and appear to be promising cancer chemopreventive agents. Chalcones represent an important group of the polyphenolic family, which includes a large number of naturally occurring molecules. This family possesses an interesting spectrum of biological activities, including antioxidative, antibacterial, anti-inflammatory, anticancer, cytotoxic, and immunosuppressive potential. Compounds of this family have been shown to interfere with each step of carcinogenesis, including initiation, promotion and progression. Moreover, numerous compounds from the family of dietary chalcones appear to show activity against cancer cells, suggesting that these molecules or their derivatives may be considered as potential anticancer drugs. This review will focus primarily on prominent members of the chalcone family with an 1,3-diphenyl-2-propenon core structure. Specifically, the inhibitory effects of these compounds on the different steps of carcinogenesis that reveal interesting chemopreventive and chemotherapeutic potential will be discussed.

Anticancer Potential of Aqueous Ethanol Seed Extract of Ziziphus mauritiana against Cancer Cell Lines and Ehrlich Ascites Carcinoma

Ziziphus mauritiana (Lamk.) is a fruit tree that has folkloric implications against many ailments and diseases. In the present study, anticancer potential of seed extract of Ziziphus mauritiana in vitro against different cell lines (HL-60, Molt-4, HeLa, and normal cell line HGF) by MTT assay as well as in vivo against Ehrich ascites carcinoma bearing Swiss albino mice was investigated. The extract was found to markedly inhibit the proliferation of HL-60 cells. Annexin and PI binding of treated HL-60 cells indicated apoptosis induction by extract in a dose-dependent manner. The cell cycle analysis revealed a prominent increase in sub Go population at concentration of 20 μg/ml and above. Agarose gel electrophoresis confirmed DNA fragmentation in HL-60 cells after 3 h incubation with extract. The extract also exhibited potent anticancer potential in vivo. Treatment of Ehrlich ascites carcinoma bearing Swiss albino mice with varied doses (100-800 mg/kg b.wt.) of plant extract significantly reduced tumor volume and viable tumor cell count and improved haemoglobin content, RBC count, mean survival time, tumor inhibition, and percentage life span. The enhanced antioxidant status in extract-treated animals was evident from decline in levels of lipid peroxidation and increased levels of glutathione, catalase, and superoxide dismutase.

Cytotoxic Mannich bases of 6-(3-aryl-2-propenoyl)-2(3H)-benzoxazolones

A series of 12 new Mannich bases with chalcone core structure were synthesized as potential antineoplastic agents, via N-aminomethylation of two parent 6-(3-aryl-2-propenoyl)-2(3H)-benzoxazolones. The newly synthesized compounds as well as the chalcone prototypes were evaluated for cytotoxicity in the human pre-B-cell leukemia cell line BV-173 using the MTT-dye reduction assay. The tested compounds exhibited concentration-dependent cytotoxic effects at low micromolar concentrations. Ten of the Mannich bases characterized by significant activity in BV-173 were further evaluated against the chronic myeloid leukemia cell line K-562 and were found to suppress the growth of these cells at relatively higher concentrations as compared to the former tumor model. Selected Mannich bases induced programmed cell death in BV-173 at a concentration of 2.5muM as evidenced by the encountered DNA-laddering. Taken together our data suggest that the presented heterocyclic chalcone derived Mannich bases necessitate detailed pharmacological evaluation in order to define further the structure activity relationships, in a larger spectrum of tumor models and to elucidate the mechanisms implicated in the observed cytotoxic effects.

Monocyte-Mediated Rotenone Neurotoxicity towards Human Neuroblastoma SH-SY5Y: Role of Mitogen-Activated Protein Kinases

Increasing evidence has suggested an important role for rotenone in the pathogenesis of Parkinson's disease (PD). In this report, sequential linking of two culture systems, monocytic THP-1 cell line and SH-SY5Y neuroblastoma, was utilized. The supernatant from rotenone-stimulated THP-1 cells was used as the incubating medium for the second culture which adopted cells of the SH-SY5Y neuroblastoma. At 6.25-50 nM, concentrations that were nontoxic to SH-SY5Y directly, rotenone induced dose-dependent cell death on SH-SY5Y through stimulating monocyte THP-1 within a period of 48 h. Cytotoxicity was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Hoechst 33258 staining revealed that the treatment of SH-SY5Y with rotenone-stimulated THP-1 supernatant resulted in condensed nuclei and a decrease in cell size. Apoptotic rate measured by flow cytometric analysis indicated that at 25 and 50 nM, the percentage of apoptotic SH-SY5Y cells accumulated to 31.5% and 37.0% respectively. We further investigated whether rotenone (50 nM) activated mitogen-activated protein kinase (MAPK) cascades, and found it had effect on p38 MAPK and ERK in THP-1 cells, but not JNK. Pretreatment of THP-1 cells with the MAPK kinase inhibitor, PD98059, inhibited THP-1 cell-mediated rotenone neurotoxicity towards SH-SY5Y, whereas the p38 MEK inhibitor, SB203580, had no effect. These results suggested that activation of microglia intracellular signaling pathway may also involve in microglia-enhanced rotenone neurotoxicity.