Oleander attenuates hepatic inflammation in a TLR4-independent manner and by favorable modulation of hepatocellular global metabolome that supports cytoprotection.

ETHNOPHARMACOLOGICAL RELEVANCE: Nerium oleander is used to treat liver-associated chronic metabolic diseases in traditional medicinal systems across the globe. The hepatoprotective effects of oleander are mentioned in Indian and Chinese traditional medicinal literature. AIM OF THE STUDY: The present study aimed to investigate the cellular mechanisms behind the hepatoprotective effects of a non-toxic dose of oleander (NO). MATERIALS AND METHODS: The hepatoprotective effects of NO were tested against lipopolysaccharide (LPS)-treated HepG2 cells. Oxidative stress response was studied using cellular enzymatic assays, and gene expression was analyzed using qRT-PCR. HepG2 cells were pretreated with TAK-242 (pharmacological inhibitor of TLR4) to decipher the anti-inflammatory mechanisms of NO. Cell-free metabolites were analyzed using GCMS and were subjected to pathway enrichment analysis. RESULTS: NO reduced systemic inflammation, serum lipid peroxidation byproducts, and glucose without affecting serum transaminase levels and hepatic histopathological features. NO attenuated the inflammation-induced loss of antioxidant enzyme activities and mRNA expressions of toll-like receptor-4 (TLR4)/nuclear factor κß (NFκß)-dependent inflammatory genes. In TAK-242 pretreated cells, LPS was unable to induce inflammatory and oxidative responses. However, NO treatment in TAK-242 pretreated cells with LPS stimulation further reduced the signs of inflammation and improved hepatoprotective activities. A comparative analysis of the intracellular global metabolome from HepG2 cells with and without NO treatment indicated NO-mediated favorable modulation of intracellular metabolic pathways that support cytoprotective activities. CONCLUSION: NO protects HepG2 cells from LPS-induced oxidative and inflammatory injury. The hepatoprotective effects of NO are mediated by a TLR4-independent process and through a favorable modulation of the intracellular global metabolome that supports cytoprotection.

Molecular Modes of Action of an Aqueous Nerium oleander Extract in Cancer Cells In Vitro and In Vivo.

Cancer drug resistance remains a major obstacle in clinical oncology. As most anticancer drugs are of natural origin, we investigated the anticancer potential of a standardized cold-water leaf extract from Nerium oleander L., termed Breastin. The phytochemical characterization by nuclear magnetic resonance spectroscopy (NMR) and low- and high-resolution mass spectrometry revealed several monoglycosidic cardenolides as major constituents (adynerin, neritaloside, odoroside A, odoroside H, oleandrin, and vanderoside). Breastin inhibited the growth of 14 cell lines from hematopoietic tumors and 5 of 6 carcinomas. Remarkably, the cellular responsiveness of odoroside H and neritaloside was not correlated with all other classical drug resistance mechanisms, i.e., ATP-binding cassette transporters (ABCB1, ABCB5, ABCC1, ABCG2), oncogenes (EGFR, RAS), tumor suppressors (TP53, WT1), and others (GSTP1, HSP90, proliferation rate), in 59 tumor cell lines of the National Cancer Institute (NCI, USA), indicating that Breastin may indeed bypass drug resistance. COMPARE analyses with 153 anticancer agents in 74 tumor cell lines of the Oncotest panel revealed frequent correlations of Breastin with mitosis-inhibiting drugs. Using tubulin-GFP-transfected U2OS cells and confocal microscopy, it was found that the microtubule-disturbing effect of Breastin was comparable to that of the tubulin-depolymerizing drug paclitaxel. This result was verified by a tubulin polymerization assay in vitro and molecular docking in silico. Proteome profiling of 3171 proteins in the NCI panel revealed protein subsets whose expression significantly correlated with cellular responsiveness to odoroside H and neritaloside, indicating that protein expression profiles can be identified to predict the sensitivity or resistance of tumor cells to Breastin constituents. Breastin moderately inhibited breast cancer xenograft tumors in vivo. Remarkably, in contrast to what was observed with paclitaxel monotherapy, the combination of paclitaxel and Breastin prevented tumor relapse, indicating Breastin's potential for drug combination regimens.

A toxic shrub turned therapeutic: The dichotomy of Nerium oleander bioactivities.

Nerium oleander L. is a medicinal plant, used for the treatment of cancers and hyperglycemia across the world, especially in Indian sub-continent, Turkey, Morocco, and China. Although clinical studies supporting its pharmacological effects remain critically underexplored, accidental and intentional consumption of any part of the plant causes fatal toxicity in animals and humans. While the polyphenolic fraction of oleander leaves has been attributed to its pre-clinical pharmacological activities, the presence of diverse cardiac glycosides (especially oleandrin) causes apoptosis to cancer cells in vitro and results in clinical signs of oleander poisoning. Thus, the dual pharmacological and toxicological role of oleander is a perplexing dichotomy in phytotherapy. The current investigative review, therefore, intended to analyze the intrinsic and extrinsic factors that likely contribute to this conundrum. Especially by focusing on gut microbial diversity, abundance, and metabolic functions, oleander-associated pharmacological and toxicological studies have been critically analyzed to define the dual effects of oleander. Electronic databases were extensively screened for relevant research articles (including pre-clinical and clinical) related to oleander bioactivities and toxicity. Taxonomic preference was given to the plant N. oleander L. and synonymous plants as per 'The World Flora Online' database (WCSP record #135196). Discussion on yellow oleander (Cascabela thevetia (L.) Lippold) has intentionally been avoided since it is a different plant. The review indicates that the gut microbiota likely plays a key role in differentially modulating the pharmacological and toxicological effects of oleander. Other factors identified influencing the oleander bioactivities include dose and mode of treatment, cardiac glycoside pharmacokinetics, host-endogenous glycosides, plant material processing and phytochemical extraction methods, plant genotypic variations, environmental effects on the phytochemical quality and quantity, gene expression variations, host dietary patterns and co-morbidity, etc. The arguments proposed are also relevant to other medicinal plants containing toxic cardiac glycosides.

Efficacy of oleandrin and PBI-05204 against bovine viruses of importance to commercial cattle health.

BACKGROUND: Bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV). and bovine coronavirus (BCV) threaten the productivity of cattle worldwide. Development of therapeutics that can control the spread of these viruses is an unmet need. The present research was designed to explore the in vitro antiviral activity of the Nerium oleander derived cardiac glycoside oleandrin and a defined N. oleander plant extract (PBI-05204) containing oleandrin. METHODS: Madin Darby Bovine Kidney (MDBK) cells, Bovine Turbinate (BT) cells, and Human Rectal Tumor-18 (HRT-18) cells were used as in vitro culture systems for BVDV, BRSV and BCV, respectively. Cytotoxicity was established using serial dilutions of oleandrin or PBI-05204. Noncytotoxic concentrations of each drug were used either prior to or at 12 h and 24 h following virus exposure to corresponding viruses. Infectious virus titers were determined following each treatment. RESULTS: Both oleandrin as well as PBI-05204 demonstrated strong antiviral activity against BVDV, BRSV, and BCV, in a dose-dependent manner, when added prior to or following infection of host cells. Determination of viral loads by PCR demonstrated a concentration dependent decline in virus replication. Importantly, the relative ability of virus produced from treated cultures to infect new host cells was reduced by as much as 10,000-fold at noncytotoxic concentrations of oleandrin or PBI-05204. CONCLUSIONS: The research demonstrates the potency of oleandrin and PBI-05204 to inhibit infectivity of three important enveloped bovine viruses in vitro. These data showing non-toxic concentrations of oleandrin inhibiting infectivity of three bovine viruses support further investigation of in vivo antiviral efficacy.

Quantitative evaluation of cardiac glycosides and their seasonal variation analysis in Nerium oleander using UHPLC-ESI-MS/MS.

INTRODUCTION: Nerium oleander is an eminent source of structurally diverse cardiac glycosides (CGs), plays a prominent role in the treatment of heart failure, and inhibits the proliferation of cancer cell lines. CGs exert their cardiotonic action by binding to the extracellularly exposed recognition sites on Na+ /K+ -ATPase, an integral membrane protein that establishes the electrochemical gradient of Na+ and K+ ions across the plasma membrane. OBJECTIVE: We aimed to quantitatively determine CGs and their seasonal variation in leaf and stem samples of N. oleander utilizing UHPLC-ESI-MS/MS techniques. METHODS: The UHPLC-ESI-MS/MS analytical method was developed utilizing multiple reaction monitoring (MRM) mode. The Waters BEH C18 (150 mm × 2.1 mm, 1.7 µm) column was used with a 22-min linear gradient consisting of acetonitrile and 5 mM ammonium acetate buffer. RESULTS: In total 21 CGs were quantitatively determined in the seasonal leaf and stem samples of N. oleander along with the absolute quantitation of the three chemical markers odoroside H (244.8 µg/g), odoroside A (231.4 µg/g), and oleandrin (703.9 µg/g). The season-specific accumulation of chemical markers was observed in the order of predominance odoroside A (summer season, stem), odoroside H (winter season, stem), and oleandrin (rainy season, leaf). Besides this, the remaining 18 CGs were relatively quantified in the same samples. CONCLUSION: The developed method is simple and reliable and can be used for the identification and quantification of multiple CGs in N. oleander.

Antitumour effect of odoroside A and its derivative on human leukaemia cells through the ROS/JNK pathway.

Oleandrigenin-3-O-ß-D-diginoside (a derivative of odoroside A), isolated and purified by our group, has seldom been explored for its pharmacological activity. This study aimed at clarifying the mechanisms towards the leukaemia-suppressive role of odoroside A (compound #1) and its derivative, oleandrigenin-3-O-ß-D-diginoside (compound #2) isolated from Nerium oleander. Viability and nuclear morphology change were assessed by CCK-8 assay and fluorescence microscope, respectively. Then, the cell apoptosis and autophagy induced by the compounds were detected by flow cytometry and Western blot. Xenograft model of nude mice was also applied to measure the leukaemia-suppressive effects of compound #2 in vivo. The result displayed that compound #1 and compound #2 inhibited the proliferation of HL60 and K562 cells and stronger effects were found in HL60 than K562 cells. Both of the compounds induced a dose-dependent apoptosis and autophagy in HL60 cells, where compound #2 was more potent than compound #1. Compound #2 also demonstrated a time-dependent apoptosis and autophagy in HL60 cells. Furthermore, ROS generation and JNK phosphorylation occurred in a dose-dependent manner in the cells treated with compound #2. Mitochondria also played critical role, proved by the decrease of Bcl-2, the release of cyto c to cytosol and the activation of caspase-3 and caspase-9. Moreover, the antitumour effects of compound #2 were validated in the nude mouse xenograft model in vivo. Odoroside A and its derivative inhibited the growth of leukaemia by inducing apoptosis and autophagy through the activation of ROS/JNK pathway. These results suggest that the compounds can serve as potential antitumour agents against leukaemia, especially acute myeloid leukaemia (AML).

Biosynthesis of SiO2 nanoparticles using extract of Nerium oleander leaves for the removal of tetracycline antibiotic.

Tetracycline (TC) is one of the antibiotics that is found in wastewaters. TC is toxic, carcinogenic, and teratogenic. In this study, the tetracycline was removed from water by adsorption using dioxide silicon nanoparticles (SiO2 NPs) biosynthesized from the extract of Nerium oleander leaves. These nanoparticles were characterized using SEM-EDX, BET-BJH, FTIR-ATR, TEM, and XRD. The influences of various factors such as pH solution, SiO2 NPs dose, adsorption process time, initial TC concentration, and ionic strength on adsorption behaviour of TC onto SiO2 NPs were investigated. TC adsorption on SiO2 NPs could be well described in the pseudo-second-order kinetic model and followed the Langmuir isotherm model with a maximum adsorption capacity was 552.48 mg/g. At optimal conditions, the experimental adsorption results indicated that the SiO2 NPs adsorbed 98.62% of TC. The removal of TC using SiO2 NPs was 99.56% at conditions (SiO2 NPs dose = 0.25 g/L, C0 = 25 mg/L, and t = 40 min) based on Box-Behnken design (BBD) combined with response surface methodology (RSM) modelling. Electrostatic interaction governs the adsorption mechanism is attributed. The reusability of SiO2 NPs was tested, and the performance adsorption was 85.36% after the five cycles. The synthesized SiO2 NPs as promising adsorbent has a potential application for antibiotics removal from wastewaters.

Protective Effect of Nerium oleander Distillate and Tarantula cubensis Alcoholic Extract on Cancer Biomarkers in Colon and Liver Tissues of Rats with Experimental Colon Cancer.

BACKGROUND: Colon cancers are among the top three causes of cancer-related deaths. This study is a continuation of previous research aiming to identify effective treatments. OBJECTIVE: This study investigated the effects of Tarantula cubensis alcoholic extract (TCAE) and Nerium oleander (NO) distillate on the levels of midkine, transforming growth factor (TGF)-ß, vascular endothelial growth factor (VEGF), alpha-fetoprotein (AFP), cyclooxygenase (COX)-2, insulin-like growth factor (IGF) and caspase-3 in the liver and colon tissues of rats with experimentally induced colon cancer. METHODS: The liver and colon tissues of rats were homogeneously divided into control, colon cancer (azoxymethane, AZM), AZM + TCAE, and AZM + NO distillate groups. The levels of midkine, TGF-ß, VEGF, AFP, COX-2, IGF, and caspase-3 in the colon and liver tissues were measured by ELISA. RESULTS: The levels of all parameters in colon and liver tissues in the AZM group were higher (p<0.05) than those in the control group. TCAE and NO distillate prevented (p < 0.05) increases in midkine, TGF-ß, VEGF, AFP, COX-2, IGF, and caspase-3 levels in the colon. NO distillate prevented the increase in all parameters except IGF, whereas TCAE prevented the increase in all values apart from COX-2 and IGF levels in the liver (p<0.05). CONCLUSION: NO distillate and TCAE may prevent the studied markers from reaching specified levels observed in the colon in AZM-induced colon cancer. The increases in the levels of the parameters in the liver were not as severe as those in the colon; however, an 18-week study period may not be sufficient for liver metastasis formation. Future molecular studies should investigate the mechanisms and pathways of these treatments in greater detail.

Terpestacin, a toxin produced by Phoma exigua var. heteromorpha, the causal agent of a severe foliar disease of oleander (Nerium oleander L.).

Since 1987, several cytochalasins were isolated from Phoma exigua var. heteromorpha, the causal agent of foliar blight disease of oleander (Nerium oleander L.), and chemically and biologically characterised. During the purification process of a large-scale production of cytochalasins A and B, necessary to continue the study on their anticancer activity, a metabolite having a different carbon skeleton compared to that of cytochalasans, was isolated. It was identified as terpestacin, a well-known toxic fungal stestertepenoid, isolated for the first time from P. exigua var. heteromorpha, by spectroscopic investigation (essentially 1D and 2D 1H and 13C-NMR and ESI MS) and optical methods in comparison with the literature data. Terpestacin and some its derivatives (including a natural one, fusaproliferin) were prepared and tested for their biological activity. Terpestacin and fusaproliferin had some inhibitory effects on seed germination of Phelipanche ramosa, whereas none of the compounds caused phytotoxic effects on weed leaves.[Formula: see text].

Antioxidant Activity Derived from Marine Green-Lipped Mussel Perna canaliculus Extracts in Mice.

This study investigates the antioxidant activities of lipid, protein, and carbohydrate extracts from the marine mollusk Perna canaliculus. Lipids were extracted using acetone, which was followed by protein extraction using the broad-spectrum enzyme Alcalase and then carbohydrate extraction using cetylpyridinium chloride. Eighty white BALB/c mice were divided into eight groups according to the administered extracts. Groups 1 and 5 were the control and toxin control groups, respectively. Groups 2, 3, and 4 were administered lipid, protein, and carbohydrate extracts, respectively. The other groups were administered P. canaliculus extracts as well as gentamicin and acetaminophen, known as ethanolic extracts, derived from Nerium oleander to induce oxidation stress. All groups showed significant improvements in body weight (p < 0.05). The lipid extract group showed a significant decrease in low-density lipoprotein cholesterol (p < 0.05) and a significant increase in high-density lipoprotein cholesterol (p < 0.05). After the toxin injection, all groups treated with P. canaliculus extracts showed increased antioxidant effects on hepatocytes (p < 0.05). The lipid extracts induced antioxidant effects to protect the kidney by increasing lipid peroxidation (p < 0.05) and catalase activities (p < 0.05). Also, protein extracts showed antioxidant effects by increasing glutathione and catalase levels significantly (p < 0.005). In conclusion, P. canaliculus extracts, especially lipids and proteins, have potent antioxidant activities that protect vital organs from oxidation stress.

A mechanistic study on the inhibition of bacterial growth and inflammation by Nerium oleander extract with comprehensive in vivo safety profile.

BACKGROUND: Nerium oleander (L.) is well known traditionally used medicinal plant with several pharmacological activities. However, the anti-bacterial, anti-inflammatory activity and in vivo toxicity potential of floral parts of this plant are not reported. Therefore the present study was designed to investigate these activities of Nerium oleander ethanolic flower extract (NOEE) in different animal models. METHODS: Antimicrobial activity of plant extract was compared with five different antibiotics using the disk diffusion method. The time-killing kinetic assay and bacterial killing mechanism of NOEE were also performed. Anti-inflammatory activity was assessed using granuloma induced by cotton-pellet, rat paw edema induced by carrageenan and levels of different inflammatory biomarkers on healthy Wistar rats. The protein and mRNA expressions of nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) were also measured. Acute (14 days) and sub-acute (28 days) oral toxicity studies were also performed on healthy Sprague Dawley rats. RESULTS: NOEE produced highly significant (P < 0.005) and significant (P < 0.05) zones of inhibition at 30 mg/mL and 20 mg/mL respectively against most of the tested bacterial strains. NOEE produced a more drop in viable counts of Gram-negative isolates within 20 min. After 12 h exposure with NOEE, the SEM images of MRSA showed the destruction of cell membrane. NOEE showed highly significant (P < 0.005) anti-inflammatory activity in cotton-pellet and carrageenan inflammatory models. In addition, treatment with NOEE also decreased the production of NO, PGE2, TNF-α and IL-1ß in the rat paw after treated with carrageenan. Similarly, NOEE also suppressed the inducible nitric oxide synthase (iNOS), TNF-α, IL-1ß, and cyclooxygenase-2 (COX-2) mRNA expressions. It is also showed highly significant reduction in total leukocyte count (73.09%) and C-reactive protein levels (54.60%). NOEE also inhibited COX-1, COX-2, 5-LO and 12-LO in a highly significant manner. Moreover, acute and sub-acute toxicity studies of NOEE in rats confirm the toxicity with hepatotoxicity at higher doses (2000 mg/kg) i.e. four times greater than the therapeutic dose. CONCLUSION: It is concluded that crude flower extract of N. oleander is a potent antimicrobial and anti-inflammatory agent with no toxicity potential at therapeutic doses.

LC-DAD-ESI-MS/MS analysis and cytotoxic and antiproliferative effects of chlorogenic acid derivative rich extract from Nerium oleander L. pink flowers.

Nerium oleander L. is a widely used medicinal plant for pharmaceutical purposes. In this work, an extract of the pink flowers of this plant (FE) was characterized in terms of phenolic composition by LC-DAD-ESI-MS/MS and bioactivity, namely, antioxidant and antiproliferative effects. A total of 20 compounds from different classes, including derivatives of phenolic acids and flavonoid glycosylated derivatives, were identified in FE. Chlorogenic acid was the dominant phenolic compound in the extract (62.28 ± 1.74 µg mg-1 of dry extract). The antioxidant activity was assessed by ORAC assay, and FE showed an ability to reduce peroxyl radicals (ORAC value of 791.26 µmol TEAC per g DE). Additionally, the FE inhibited the proliferation of a colorectal cancer cell line (HT29 cells, EC50 = 11.72 ± 0.02 µg mL-1) and showed no cytotoxicity to confluent Caco-2 cells, a model of human intestinal epithelium. These results provide new information about the phenolic composition of Nerium oleander pink flowers and the bioactivity of the extracts.

Leaf Extract of Nerium oleander L. Inhibits Cell Proliferation, Migration and Arrest of Cell Cycle at G2/M Phase in HeLa Cervical Cancer Cell.

BACKGROUND: Cervical cancer is one of the most common gynaecological malignant tumors reported in women. Although a number of early screening and treatment options are available, mortality due to cervical cancer remains high. Nerium oleander L. is a potential medicinal plant that possesses a wide spectrum of pharmacological and physiological activities including anticancer activities. OBJECTIVE: This study aims to evaluate the antiproliferative activity, inhibition of cell migration and cell cycle arrest by the chloroform extract of leaves of Nerium Oleander L. in HeLa cervical cancer cells. The chloroform extract of Catharanthus roseus which contains anti-cancer compounds, Vinblastin and Vincristin, was used as a positive control for this study. METHODS: The chloroform extracts of Nerium oleander L. and Catharanthus roseus were prepared using the standard protocol. The cytotoxic effects were studied by MTT assay. Cell migration was studied by in vitro scratch assay. Analysis of the cell cycle was carried out by Propidium iodide staining and Flow Cytometry. The expression level of various proteins was evaluated by immunocytochemistry. RESULTS: In this study, we showed that the leaf extract of Nerium oleander inhibited the growth of HeLa cervical cancer cells in culture and inhibited cell migration. Besides, it arrested the cell cycle at the G2/M phase. The Epidermal Growth Factor Receptor (EGFR) expression and phosphorylated p-Rb (Ser 780) level were significantly downregulated by leaf extract of Nerium oleander. CONCLUSION: The extract of Nerium oleander L. contains potential bioactive compounds that inhibit HeLa cell proliferation, cell migration and arrest cell cycle at the G2/M phase.

Phenolic compounds from Nerium oleander leaves: microwave assisted extraction, characterization, antiproliferative and cytotoxic activities.

A microwave-assisted extraction (MAE) method was used for the extraction of phenolic compounds from Nerium oleander leaves. The influence of variables such as ethanol concentration, microwave power, irradiation time and liquid/solid ratio on polyphenol extraction was modelled using a second-order regression equation based on response surface methodology (RSM). The optimal conditions for MAE were: extraction solvent 35% ethanol concentration, 500 W microwave power, 60 s irradiation time and a solvent/material ratio of 20 mL g-1. Under optimal MAE conditions, the recovery of TPC was 25.752 mg GAE per g dw. 19 compounds have been identified by HPLC-ESI-MS/MS analysis; the main compounds identified were chlorogenic acid, rutin and quinic acid esters, such as caffeoylquinic acids and dicaffeoylquinic acids. Additionally, the optimized extract demonstrated potential to inhibit HT29 colorectal cancer cell growth (EC50 = 2.432 µg mL-1) without presenting cytotoxicity in confluent Caco-2 cells, a model of human intestinal epithelium. These results supply new information about the phenolic composition of Nerium oleander leaves and their antiproliferative effect.

The pharmaco-toxicological conundrum of oleander: Potential role of gut microbiome.

Nerium oleander L., commonly known as oleander, is a toxic shrub and also a medicinal plant. All parts of oleander are rich in cardiac glycosides that inhibits Na+/K+-ATPase and induce inotropic effect on the cardiomyocytes. Several pre-clinical and clinical reports indicate acute toxicity due to intentional, accidental and suicidal oleander consumption. Contrarily, oleander is used for the treatment of diverse ailments in traditional medicinal practices around the globe and several evidence-based pre-clinical studies indicated metabolic and immunological health benefits of polyphenol-rich oleander extracts. Thus, the current review aims to address this pharmaco-toxicological conundrum of oleander by addressing the possible role of gut microflora in the differential oleander toxicity. Additionally, a comprehensive account of ethnopharmacological usage, metabolic and immunological health benefits has been documented that supplement the conflicting arguments of pharmaco-toxicological properties of oleander. Finally, by addressing the gap of knowledge of ethnomedicinal, pharmacological and toxicological reports of oleander, the current review is expected to pave the way to address the differential pharmaco-toxicological effects of oleander.

Response of young Nerium oleander plants to long-term non-ionizing radiation.

MAIN CONCLUSION: Although exposure to low frequency electromagnetic radiation is harmful to plants, LF-EM irradiated Nerium oleander seedlings exhibited enhanced development and growth, probably taking advantage of defined structural leaf deformations. Currently, evidence supports the undesirable, often destructive impact of low frequency electromagnetic (LF-EM) radiation on plants. The response of plants to LF-EM radiation often entails induction in the biosynthesis of secondary metabolites, a subject matter that is well documented. Nerium oleander is a Mediterranean plant species, which evolved remarkable resistance to various environmental stress conditions. In the current investigation, cultivated N. oleander plants, following their long-term exposure to LF-EM radiation, exhibited major structural modifications as the flattening of crypts, the elimination of trichomes and the reduction of the layers of the epidermal cells. These changes co-existed with an oxidative stress response manifested by a significant increase in reactive oxygen species at both the roots and the above ground parts, a decline in the absorbance of light by photosynthetic pigments and the substantially increased biosynthesis of L-Dopa decarboxylase (DDC), an enzyme catalyzing the production of secondary metabolites that alleviate stress. The exposed plants exhibited greater primary plant productivity, despite a manifested photosynthetic pigment limitation and the severe oxidative stress. This unique response of N. oleander to severe abiotic stress conditions may be owed to the advantage offered by a structural change consistent to an easier diffusion of CO2 within the leaves. A major plant response to an emerging "pollutant" was documented.

Radical scavenging and antiproliferative effect of novel phenolic derivatives isolated from Nerium indicum against human breast cancer cell line (MCF-7)-an in silico and in vitro approach.

Multiple drug resistance and increased side effects due to allopathic drugs has warned scientific community with a global alarm to identify molecules from natural sources to combat diseases with minimum or no side effects. The present investigation was aimed to identify and isolate secondary metabolites from traditionally used Nerium indicum using conventional column chromatography which led to the isolation of two compounds, C-I (fractions NB4f1) and C-II (fractions NC13b1). Further characterized, it is elucidated using spectral data and identified as N-(4-hydroxy-phenyl)-2-methoxy-2-phenyl-acetamide, molecular formula C15H15NO3, and molecular weight 257.3 (C-I) and N-(4-hydroxy-phenyl)-2-phenyl-N-phenylacetyl-acetamide, molecular formula C22H19NO3, and molecular weight 345.4 (C-II). Further, the isolated compounds were investigated using in silico approach by Autodock tool with four different proteins specific for cancer and in vitro assessed cell proliferation, and apoptosis against human breast cancer MCF 7 cell line. The results of the in silico model demonstrated potent binding affinity of both compounds with the proteins representing that the isolated molecules could be a drug of choice for cancer. Further, the isolated compounds revealed significant inhibition of cell proliferation (IC50 values 21 µg/mL for C-I, 19 µg/mL for C-II) with induced apoptosis with nuclear condensation effect on the MCF 7 cells in in vitro condition even at very low concentration. Compound treatment to MCF-7 cell line represented bright fetches indicating condensed chromatins and higher level of nuclear fragmentation with DAPI staining, indicating higher cell death due to induced apoptosis and confirmed using flow cytometry analysis representing inhibition of cell proliferation at S phase. Graphical abstract.

Toxicity effects of Nerium oleander, basic and clinical evidence: A comprehensive review.

INTRODUCTION: Nerium oleander is a plant that is frequently grown in gardens and public areas. N. oleander is distributed originally in subtropical Asia but is now growing in many parts of the world, such as the United States, Australia, China, and Middle East countries. Pharmacological effects of plant including antinociceptive, anti-inflammatory, and anticancer activity were reported, but the potential toxic effects of all parts of the shrub either fresh or dried on animal and human body were documented. METHOD: The data of this review article were obtained from Medline/Pubmed, Scopusand Google Scholar databases in English until September 2019. To include all publications in this field, keywords such as N. oleander and toxicity were used. RESULTS: The poisoning effects of plant or their active alkaloids induced infiltration of cells with hemorrhage and sever negative changes in the lung, induce lesions, and infiltration of inflammatory cells into the portal spaces with scattered necrosis of hepatocytes in the liver, cardiac toxicity of the plant in the heart were included, induced varying degrees of hemorrhage, myocardial degeneration, and necrosis. It also induced arrhythmia, sinus bradycardia, and prolonged P-R interval in electrocardiographic records. CONCLUSIONS: The toxic effects of N. oleander are mostly related to its inhibitory effects on the Na+-K+ ATPase pump in the cellular membrane. However, the exact molecular mechanism involved in the toxicity of N. oleander is not clear.

Synthesis and evaluation of cytotoxic and Na+/K+-ATP-ase inhibitory activity of selected 5α-oleandrigenin derivatives.

Oleandrin, the major biologically active constituent of shrub Nerium oleander preparations of which have been used in traditional Mediterranean and Asian medicine, attracts a great deal of attention due to its pronounced anticancer activity. The synthesis of oleandrigenin model, 16ß-hydroxy-3ß-methoxy-5α-card-20(22)-enolide 16-acetate, from androstenolone acetate through 17ß-(3-furyl)-intermediates has been developed. Several related 17ß-(butenolidyl)- and 17ß-(furyl)-androstane derivatives were synthesized and tested for in vitro cytotoxic and Na+/K+-ATP-ase inhibitory activities. Comparison of Na+/K+-ATP-ase inhibitory and cytotoxic activity underlines complex nature of the relationship.

Nerigoside suppresses colorectal cancer cell growth and metastatic potential through inhibition of ERK/GSK3ß/ß-catenin signaling pathway.

BACKGROUND: Nerigoside (NG), a cardenolide isolated from a commonfolk medicine, Nerium oleander Linn. (Apocynaceae), has not been explored for its biological effects. To date, cardenolides have received considerable attention in pharmacology studies due to their direct effects of apoptosis-induction or growth-inhibitory against tumor in vitro and in vivo. Whether and how NG exerts anticancer effects against colorectal cancer remains to be elucidated. PURPOSE: The aim of this study was to investigate the anticancer effect of NG in human colorectal cancer cells. METHODS: To test anticancer effect, we compared potency of NG in two colorectal cancer cell lines, HT29 and SW620 by WST-1 and colony proliferation assays. And we investigated mechanism of anticancer activities by analyzing players in apoptotic and ERK/GSK3ß/ß-catenin signaling pathways in HT29 and SW620 cells treated with NG. RESULTS: In this study, we showed that NG markedly suppressed the cell viability and colony formation of colorectal cancer cells HT29 and SW620, with no significant toxic effect on non-cancer cells NCM460. Annexin V-FITC/PI and CFSE labeling results revealed that NG suppressed cell proliferation in low concentration, along with reducing expression of PCNA, while NG induced apoptosis in high concentration,. Meanwhile, NG significantly arrested cell migration by reversal of EMT and cell cycle on G2/M. Then, we found that the ERK and GSK3ß/ß-catenin signaling pathway were noticeably blocked in CRC cells after treatment with NG. According to western blot, NG upregulated the expression of p-GSK3ß/GSK3ß and decreased especially the expression of ß-catenin in nuclear. In addition, Wnt signaling and its target genes were suppressed in response to NG. Then, the Ser9 phosphorylation of GSK3ß can be reduced / raised by GÖ 6983 / LiCl, respectively. Thus, we further confirmed that the GSK3ß/ß-catenin axis is involved in NG-prevented cell proliferation. CONCLUSION: NG inhibited the growth of colorectal cancer cells by suppressing ERK/GSK3ß/ß-catenin signaling pathway. And the GSK3ß/ß-catenin axis is involved in preventing cell proliferation and migration by NG-treatment. These results suggest that NG may be used to treat colorectal cancer, with better outcome by combining with GSK3ß inhibitor to block Wnt pathway.