Antiproliferative effects of different plant parts of Panax notoginseng on SW480 human colorectal cancer cells

The chemical constituents and antiproliferative effects on SW480 human colorectal cancer cells of different plant parts of P. notoginseng were evaluated. The contents of saponins in extracts from root, rhizome, flower and berry of P. notoginseng were determined using high performance liquid chromatography. The contents and proportions of saponins were different among the four plant parts. Using the cell counting method, the antiproliferative effects were evaluated and the results indicated all four extracts, at 0.05–1.0 mg/mL, showed concentration‐related antiproliferative effects on the cancer cells. The flower extract had stronger effects compared with the other three extracts; at 1.0 mg/mL, it inhibited the cell growth by 93.1% (p < 0.01). The antiproliferative effects of major saponins in notoginseng, notoginsenoside R1, ginsenosides Rb1, Rb3 and Rg1, were also evaluated, and the observed effects of major constituents support the pharmacological activities of extracts. The effects of notoginseng extracts on cell cycle and apoptosis of SW480 cells were determined using flow cytometry. Notoginseng extract can arrest the cells in S and G2/M phases. Remarkably apoptosis induction activities of notoginseng extracts were observed with the flower extract possessing the most potent effect, supporting the antiproliferative effect. Copyright © 2008 John Wiley & Sons, Ltd.     

C‐Glycosyl Flavonoids from Beta vulgaris Cicla and Betalains from Beta vulgaris rubra: Antioxidant,Anticancer and Antiinflammatory Activities—A Review

The green beet (Beta vulgaris var. cicla L.) and red beetroot (B. vulgaris var. rubra L.) contain phytochemicals that have beneficial effects on human health. Specifically, the green beet contains apigenin, vitexin, vitexin‐2‐O‐xyloside and vitexin‐2‐O‐rhamnoside, while the red beetroot is a source of betaxanthins and betacyanins. These phytochemicals show considerable antioxidant activity, as well as antiinflammatory and antiproliferative activities. Vitexin‐2‐O‐xyloside, in combination with betaxanthins and betacyanins, exerts antiproliferative activity in breast, liver, colon and bladder cancer cell lines, through the induction of both intrinsic and extrinsic apoptotic pathways. A significant body of evidence also points to the role of these phytochemicals in the downregulation of the pro‐survival genes, baculoviral inhibitor of apoptosis repeat‐containing 5 and catenin beta‐1, as well as the genes controlling angiogenesis, hypoxia inducible factor 1A and vascular endothelial growth factor A. The multi‐target action of these phytochemicals enhances their anticancer activity. Vitexin‐2‐O‐xyloside, betaxanthins and betacyanins can be used in combination with conventional anticancer drugs to reduce their toxicity and overcome the multidrug resistance of cancer cells. In this review, we describe the molecular mechanisms that enable these dietary phytochemicals to block the proliferation of tumor cells and inhibit their pro‐survival pathways. Copyright © 2017 John Wiley & Sons, Ltd.     

Naphthoquinone Components from Alkanna tinctoria (L.) Tausch Show Significant Antiproliferative Effects on Human Colorectal Cancer Cells

Our research to seek active compounds against human colorectal cancer from the root of Alkanna tinctoria (L.) Tausch led to the isolation of two naphthoquinones, alkannin (1) and angelylalkannin (2). The antiproliferative effects of the two compounds on human colon cancer cells HCT‐116 and SW‐480 were determined by the 3,4‐(5‐dimethylthiazol‐2‐yl)‐5‐(3‐carboxymethoxyphenyl)‐2‐(4‐sulfophenyl)‐2H‐tetrazolium salt (MTS) method. Cell cycle profile and cell apoptosis were determined using flow cytometry. Both of the two compounds showed significant inhibitory effects on the cancer cells. For alkannin (1) and angelylalkannin (2), the median inhibitory concentration (IC₅₀) values were 2.38 and 4.76 µ m for HCT‐116 cells, while for SW‐480 cells they were 4.53 and 7.03 µ m , respectively. The potential antiproliferative mechanisms were also explored. At concentrations between 1–10 µ m , both compounds arrested the cell cycle at the G1 phase and induced cell apoptosis. Copyright © 2012 John Wiley & Sons, Ltd.     

Improving anticancer activities of Oplopanax horridus root bark extract by removing water‐soluble components

O. horridus is used as a folk medicine by natives in the Northern Pacific coast of North America. This experiment studied the antiproliferative effects of the extract of O. horridus root bark and its fractions chromatographed from Dianion HP20 resin column with water, 30, 50, 70 and 100% ethanol on human breast cancer MCF‐7 cells and non‐small cell lung cancer (NSCLC) cells. The role of O. horridus in the cell cycle and apoptosis of MCF‐7 cells was also investigated. The results showed that the 70% and 100% ethanol fractions demonstrated more potent antiproliferative effects than the total extract on both cell lines. The antiproliferative effects may result from the enrichment of active constituents detected by high performance liquid chromatography (HPLC). The IC₅₀ of the total extract, 50, 70, and 100% ethanol fractions for antiproliferation on MCF‐7 cells were 248.4, 123.1, 44.0, and 31.5 μg/mL, respectively, and on NSCLC cells were 125.3, 271.1, 17.6, and 23.2 μg/mL, respectively. On the other hand, the water and 30% ethanol fractions significantly promoted cell proliferation on MCF‐7 cells at concentrations > 100 μg/mL, suggesting that the hydrophilic fractions should be removed from the extract when used for cancer chemoprevention in order to achieve desirable activities. The effects of the total extract on cell cycle and apoptosis were similar to that of the 100% ethanol fraction because of the similarity of their chemical composition. At higher concentrations, the apoptotic effects of the 70% ethanol fraction are more significant. Data from this study suggested that the 70% and 100% ethanol fractions are active antiproliferative fractions and that induction of apoptosis is the mechanism involved in the antiproliferative effect observed. Copyright © 2010 John Wiley & Sons, Ltd.     

Ginger's (Zingiber officinale Roscoe) inhibition of rat colonic adenocarcinoma cells proliferation and angiogenesis in vitro

Ginger's (Zingiber officinale Roscoe) natural bioactives, specifically ginger extract and 6‐gingerol, were measured for their in vitro inhibition of two key aspects of colon cancer biology – cancer cell proliferation and angiogenic potential of endothelial cell tubule formation. Ginger extract was obtained via column distillation, while the 6‐gingerol was purchased from Calbiochem. Antiproliferation activity was assessed through tritiated thymidine ([³H]Tdr) incorporation studies of YYT colon cancer cells; the anti‐angiogenic ability of gingerol was assessed by a Matrigel assays using MS1 endothelial cells. These selected ginger bioactives had: 1) a direct effect on YYT rat cancer cell proliferation (6–1.5% ginger extract; 100–4 µM 6‐gingerol); 2) an indirect effect on MS1 endothelial cell function either at the level of endothelial cell proliferation or through inhibition of MS1 endothelial cell tube formation (100–0.8 µM). Compound 6‐gingerol was most effective at lower doses in inhibiting endothelial cell tube formation. These in vitro studies show that 6‐gingerol has two types of antitumor effects: 1) direct colon cancer cell growth suppression, and 2) inhibition of the blood supply of the tumor via angiogenesis. Further research is warranted to test 6‐gingerol in animal studies as a potential anticancer plant bioactive in the complementary treatment of cancer. Copyright © 2008 John Wiley & Sons, Ltd.     

Superior anticancer activity is demonstrated by total extract of Curcuma longa L. as opposed to individual curcuminoids separated by centrifugal partition chromatography

Three curcuminoids: bisdemethoxycurcumin, demethoxycurcumin, and curcumin from turmeric were successfully separated by a high capacity solvent system composed of heptane: chloroform: methanol: water mixture (5: 6: 3: 2 v/v/v/v) tailored for centrifugal partition chromatographs at K‐values of 0.504, 1.057, 1.644, respectively. These three ferulic acid derivatives obtained at a purity rate exceeding 95% were analysed by an HPLC‐MS spectrometer. Turmeric extract inhibited the proliferation/viability of A549 human lung cancer, HT29 colon cancer, and T98G glioblastoma cell lines in (3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyltetrazolium bromide) tetrazolium reduction assay (MTT). Single curcuminoids significantly decreased the viability/proliferation of lung cancer cells in a dose‐dependent manner. However, total extract displayed the superior anticancer activity in the investigated cell lines. Crude extract in combination with cisplatin augmented the decrease in the viability of cancer cells compared with single compound treatment in A549 lung cancer cells. Total extract of Curcuma longa could be regarded as being more effective against lung cancer cells in vitro than its separated compounds.     

A Novel Triterpene Extract from Mistletoe Induces Rapid Apoptosis in Murine B16.F10 Melanoma Cells

The European mistletoe Viscum album L. is a plant used for remedies in cancer treatment. The benefit of commonly used aqueous extracts is controversial but the plant contains water insoluble triterpene acids providing interesting anticancer properties. Triterpene extracts (TE) from plants and single triterpenoids such as oleanolic acid (OA) or betulinic acid (BA) are known for their cytotoxic effects on cancer cell lines in vitro. We report here cytotoxic effects of a novel OA‐rich triterpene extract from mistletoe (V. album L., Santalaceae) solubilized by 2‐hydroxypropyl‐β‐cyclodextrin (2‐HP‐β‐CD) on B16.F10 mouse melanoma cells. The 2‐HP‐β‐CD solubilized triterpene extract (STE) was highly cytotoxic by causing DNA fragmentation, followed by loss of membrane integrity and intracellular adenosine‐5′‐triphosphate (ATP). Blocking the caspase machinery by inhibitors aborted DNA fragmentation and delayed the cytotoxic effects but did not prevent cell death. The solubilization by 2‐HP‐β‐CD allows a solvent‐free application of triterpene extracts in the in vitro setting. These findings suggest the use of STE from mistletoe as a solvent‐free anticancer drug for preclinical animal experiments and clinical trials. Copyright © 2012 John Wiley & Sons, Ltd.     

The Synergistic Apoptotic Interaction of Panaxadiol and Epigallocatechin Gallate in Human Colorectal Cancer Cells

Panaxadiol (PD) is a purified sapogenin of ginseng saponins, which exhibits anticancer activity. Epigallocatechin gallate (EGCG), a major catechin in green tea, is a strong botanical antioxidant. In this study, we investigated the possible synergistic anticancer effects of PD and EGCG on human colorectal cancer cells and explored the potential role of apoptosis in the synergistic activities. Effects of selected compounds on HCT‐116 and SW‐480 human colorectal cancer cells were evaluated by a modified trichrome stain cell proliferation analysis. Cell cycle distribution and apoptotic effects were analyzed by flow cytometry after staining with PI/RNase or annexin V/PI. Cell growth was suppressed after treatment with PD (10 and 20 µm ) for 48 h. When PD (10 and 20 µm ) was combined with EGCG (10, 20, and 30 µm ), significantly enhanced antiproliferative effects were observed in both cell lines. Combining 20 µm of PD with 20 and 30 µm of EGCG significantly decreased S‐phase fractions of cells. In the apoptotic assay, the combination of PD and EGCG significantly increased the percentage of apoptotic cells compared with PD alone (p < 0.01). The synergistic apoptotic effects were also supported by docking analysis, which demonstrated that PD and EGCG bound in two different sites of the annexin V protein. Data from this study suggested that apoptosis might play an important role in the EGCG‐enhanced antiproliferative effects of PD on human colorectal cancer cells. Copyright © 2012 John Wiley & Sons, Ltd.     

Protective Effects of Turbinaria ornata and Padina pavonia against Azoxymethane‐Induced Colon Carcinogenesis through Modulation of PPAR Gamma,NF‐κB and Oxidative Stress

The aim of this study was to investigate the antiproliferative and protective effects of the brown seaweeds, Turbinaria ornata and Padina pavonia, against azoxymethane (AOM)‐induced colon carcinogenesis in mice. Both algal extracts showed anti‐proliferative effects on the human carcinoma cell line HCT‐116 in vitro, with T. ornata demonstrating a more potent effect. Male albino Swiss mice received intraperitoneal injections of AOM (10 mg/kg) once a week for two consecutive weeks and 100 mg/kg of either T. ornata or P. pavonia extracts. AOM‐induced mice exhibited alterations in the histological structure of the colon, elevated lipid peroxidation and nitric oxide, declined glutathione content and reduced activity of superoxide dismutase and glutathione peroxidase. In addition, AOM induced downregulation of peroxisome proliferator activated receptor gamma (PPARγ) and p53 mRNA expression, with concomitant upregulation of nuclear factor‐kappa B (NF‐κB) in colon tissue. Administration of either algal extract markedly alleviated the recorded alterations. In conclusion, the current study suggests that T. ornata and P. pavonia, through their antioxidant and anti‐inflammatory effects, are able to attenuate colon inflammation by downregulating NF‐κB expression. Furthermore, the protective effects of both algae against AOM‐initiated carcinogenesis were attributed, at least in part, to their ability to upregulate colonic PPARγ and p53 expression. Copyright © 2015 John Wiley & Sons, Ltd.     

Anticancer properties of erucin,an H2S‐releasing isothiocyanate,on human pancreatic adenocarcinoma cells (AsPC‐1)

Plants of the Brassicaceae family are well‐known for containing the glucosinolate myrosinase system, which is able to release isothiocyanates after plant biotic and abiotic lesions. Erucin (ERU; 1‐isothiocyanato‐4‐(methylthio)‐butane), an isothiocyanate particularly abundant in arugula (Eruca sativa Mill., Eruca vesicaria L., etc.), derives from the hydrolysis of the glucosinolate glucoerucin by the enzyme myrosinase. Many other natural isothiocyanates influence cancer cells and, in particular, induce antiproliferative effects at relatively high concentrations. Similar antiproliferative effects have also been shown by the newly emerging gasotransmitter hydrogen sulfide (H₂S) and by H₂S‐releasing compounds. In a previous study, our group demonstrated that isothiocyanates release H₂S in biological environments. In this work, we demonstrated the H₂S‐donor properties of ERU in pancreatic adenocarcinoma cells (AsPC‐1) and delineated its profile as a chemopreventive or anticancer agent. Indeed, ERU showed significant antiproliferative effects: ERU inhibited AsPC‐1 cell viability at relatively high concentrations (30–100 μM). Moreover, ERU inhibited cell migration, altered the AsPC‐1 cell cycle, and exhibited proapoptotic effects. Finally, ERU inhibited ERK1/2 phosphorylation. This mechanism is particularly important in AsPC‐1 cells because they are characterized by a mutation in KRAS that determines KRAS hyperactivation followed by MAP‐kinase hyperphosphorylation, which plays a pivotal role in pancreatic cancer proliferation, growth, and survival.     

Antiproliferative activity and apoptosis induction by trijuganone C isolated from the root of Salvia miltiorrhiza Bunge (Danshen)

In this study, we found that the hexane fraction of Danshen, the dried root of Salvia miltiorrhiza (Lamiaceae), exerted antiproliferative effects on human leukemia cells. Phytochemical investigation of the hexane fraction achieved the isolation of the tanshinone diterpenes: dihydrotanshinone I ( 1 ), trijuganone C ( 2 ), trijuganone B ( 3 ), cryptotanshinone ( 4 ), tanshinone IIA ( 5 ), and tanshinone I ( 6 ). Compound 2 showed significant antiproliferative activities against human leukemia cells HL‐60, Jurkat, and U937. The antiproliferative activities of 2 against human cancer and normal cells indicated that 2 exhibited potent antiproliferative activities with IC₅₀ values less than 10 μM against HL‐60 and Jurkat cells as well as on the colon cancer cells DLD‐1, COLO 205, and Caco‐2. Compound 2 induced chromatin condensation, DNA fragmentation, activation of caspase‐3, ‐8, and ‐9, and the cleavage of poly (ADP‐ribose) polymerase (PARP) in HL‐60 cells. Moreover, 2 activated Bid and Bax, leading to the loss of mitochondrial membrane potential, and 2 induced the cytochrome c release from mitochondria into cytosol. In contrast, Bcl‐2 and Bcl‐xL were unaffected by 2 . These results suggest that 2 exerts antiproliferative effects via apoptosis induction mediated by mitochondrial dysfunction and caspase activation. Compound 2 may serve as a candidate of potential chemotherapeutic agent for human leukemia.     

Inhibition of keratinocyte growth by different Nepalese Zanthoxylum species

A total of 11 methanol extracts obtained from four different Nepalese Zanthoxylum species were screened for their antiproliferative activity against the growth of human keratinocytes (HaCaT cells). The extract obtained from Z. armatum barks was highly active with an IC₅₀ value of 11 µg/mL. Also, the extracts ­obtained from Z. oxyphyllum barks and roots with IC₅₀ values of 53 and 57 µg/mL, respectively, showed potent activity. Their antiproliferative activity was not due to cytotoxic effects on cell membranes, as documented by the activity of lactate dehydrogenase released from the cytoplasm of keratinocytes, which did not exceed that of the control value. Rather, they also protected against radical‐induced ­damage to model membranes stimulated with 2,2′‐azo‐bis(2‐amidinopropane) dihydrochloride. Copyright © 1999 John Wiley & Sons, Ltd.     

Gleditsia sinensis thorn extract inhibits human colon cancer cells: the role of ERK1/2, G2/M‐phase cell cycle arrest and p53 expression

The thorns of Gleditsia sinensis are used as a medicinal herb in China and Korea. However, the mechanisms responsible for the antitumor effects of the water extract of Gleditsia sinensis thorns (WEGS) remain unknown. HCT116 cells treated with the WEGS at a dose of 800 μg/mL (IC₅₀) showed a significant decrease in cell growth and an increase in cell cycle arrest during the G2/M‐phase. G2/M‐phase arrest was correlated with increased p53 levels and down‐regulation of the check‐point proteins, cyclinB1, Cdc2 and Cdc25c. In addition, treatment with WEGS induced phosphorylation of extracellular signal‐regulated kinase (ERK), p38 MAP kinase and JNK (c‐Jun N‐terminal kinases). Moreover, inhibition of ERK by treatment of cells with the ERK‐specific inhibitor PD98059 blocked WEGS‐mediated p53 expression. Similarly, blockage of ERK function in the WEGS‐treated cells reversed cell‐growth inhibition and decreased cell cycle proteins. Finally, in vivo WEGS treatment significantly inhibited the growth of HCT116 tumor cell xenografts in nude mice with no negative side effects, including loss of body weight. These results describe the molecular mechanisms whereby the WEGS might inhibit proliferation of colon cancer both in vitro and in vivo, suggesting that WEGS has potential as an anticancer agent for the treatment of malignancies. Copyright © 2010 John Wiley & Sons, Ltd.     

A Biochemical and Cellular Approach to Explore the Antiproliferative and Prodifferentiative Activity of Aloe Arborescens Leaf Extract

Aloe arborescens Miller, belonging to the Aloe genus (Liliaceae family), is one of the main varieties of Aloe used worldwide. Although less characterized than the commonest Aloe vera, Aloe arborescens is known to be richer in beneficial phytotherapeutic, anticancer, and radio‐protective properties. It is commonly used as a pharmaceutical ingredient for its effect in burn treatment and ability to increase skin wound healing properties. However, very few studies have addressed the biological effects of Aloe at molecular level. The aim of the research is to provide evidences for the antiproliferative properties of Aloe arborescens crude leaf extract using an integrated proteomic and cellular biological approach. We analysed the composition of an Aloe arborescens leaf extract by gas chromatography‐mass spectrometry analysis. We found it rich in Aloe‐emodin, a hydroxylanthraquinone with known antitumoral activity and in several compounds with anti‐oxidant properties. Accordingly, we show that the Aloe extract has antiproliferative effects on several human transformed cell lines and exhibits prodifferentiative effects on both primary and immortalized human keratinocyte. Proteomic analysis of whole cell extracts revealed the presence of proteins with a strong antiproliferative and antimicrobial activity specifically induced in human keratinocytes by Aloe treatment supporting its application as a therapeutical agent. Copyright © 2013 John Wiley & Sons, Ltd.     

Anticancer activity and molecular mechanisms of α‐conidendrin,a polyphenolic compound present in Taxus yunnanensis,on human breast cancer cell lines

α‐Conidendrin is a polyphenolic compound found mainly in Taxus yunnanensis, as the source of chemotherapy drug paclitaxel, which has been used in traditional medicine for treatment of cancer. This study aimed to investigate the anticancer activity and molecular mechanisms of α‐conidendrin on breast cancer cell lines. The results of the present study show that α‐conidendrin possesses potent antiproliferative effects on breast cancer cell lines MCF‐7 and MDA‐MB‐231. α‐Conidendrin significantly induced apoptosis in breast cancer cells via reactive oxygen species generation, upregulation of p53 and Bax, downregulation of Bcl‐2, depolarization of mitochondrial membrane potential (MMP), release of cytochrome c from mitochondria, and activation of caspases‐3 and ‐9. α‐Conidendrin remarkably inhibited the proliferation of breast cancer cells through induction of cell cycle arrest by upregulating p53 and p21 and downregulating cyclin D1 and CDK4. Unlike breast cancer cells, the antiproliferative effect of α‐conidendrin on human foreskin fibroblast cells (normal cells) was very small. In normal cells, reactive oxygen species levels, loss of MMP, release of cytochrome c, mRNA expression of p53, p21, cyclin D1, CDK4, Bax, and Bcl‐2 as well as mRNA expression and activity of caspases‐3 and ‐9 were significantly less affected by α‐conidendrin compared with cancer cells. These results suggest that α‐conidendrin can be a promising agent for treatment of breast cancer with little or no toxicity against normal cells.     

Antitumor and immunomodulating effects of polysaccharides isolated from Solanum nigrum Linne

We have examined the effects of the crude polysaccharides isolated from Solanum nigrum Linne (SNL‐P) in vitro and in vivo against U14 cervical cancer. SNL‐P showed no antiproliferative effects in vitro at a dose up to 1 mg/ml. In vivo administration with SNL‐P (90, 180, 360 mg/kg b.w., p.o.) decreased the number of ascites tumor cells and prolonged the survival time of U14 cervical‐cancer‐bearing mice. FACScan flow cytometer analysis showed that most of the ascites tumor cells were arrested in G2/M phase of cell cycle and the ratio of CD4+/CD8+ peripheral blood T‐lymphocyte subpopulations were restored following treatment of SNL‐P. Furthermore, the treatment with SNL‐P also caused a significant increment in IFN‐γ (p < 0.01, 90, 180 and 360 mg/kg b.w.) and a remarkable decrease in Il‐4 (p < 0.01, 90, 180 mg/kg b.w.; p < 0.05, 360 mg/kg b.w.) by the method of ELISA. These data showed that SNL‐P possess potent antitumor activity and SNL‐P might exert antitumor activity via activation of different immune responses in the host rather than by directly attacking cancer cells on the U14 cervical cancer bearing mice. Thus, SNL‐P could be used as an immunomodulator and an anticancer agent. Copyright © 2009 John Wiley & Sons, Ltd.     

Inhibition of Cancer Cell Proliferation and Antiradical Effects of Decoction,Hydroalcoholic Extract,and Principal Constituents of Hemidesmus indicus R. Br.

Indian Sarsaparilla (Hemidesmus indicus R. Br.) is widely used in Indian traditional medicine. In the present work, we explored the effects of decoction, traditional Ayurvedic preparation, and hydroalcoholic extract, a phytocomplex more traditionally studied and commercialized as food supplement in western medicine, from the roots as possible source of chemicals with new functional potential linked to their nutritional uses. The antiproliferative and antioxidant properties were assayed. To test antiproliferative affects, different cancer cell lines, growing both as monolayers (CaCo2, MCF‐7, A549, K562, MDA‐MB‐231, Jurkat, HepG2, and LoVo) and in suspension (K562 and Jurkat) were used. The decoction showed strong activity on HepG2 cells, while the hydroalcoholic extracts were active on HepG2, LoVo, MCF‐7, K562, and Jurkat cell lines. Weak inhibition of cancer cell proliferation was observed for the principal constituents of the preparations: 2‐hydroxy‐4‐methoxybenzaldehyde, 2‐hydroxy‐4‐methoxybenzoic acid, and 3‐hydroxy‐4‐methoxybenzaldehyde that were tested alone. The antiradical activity was tested with 2,2‐diphenyl‐1‐picrylhydrazyl and 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid)diammonium salt tests and inhibition of nitric oxide production in lipopolysaccharide‐stimulated RAW 264.7 macrophages. Interesting result has also been obtained for hydroalcoholic extract regarding genoprotective potential (58.79% of inhibition at 37.5 µg/mL). Copyright © 2015 John Wiley & Sons, Ltd.     

Aqueous extract of clove inhibits tumor growth by inducing autophagy through AMPK/ULK pathway

Cloves (Syzygium aromaticum), a traditional Chinese medicinal herb, displays broad biological activity. In the present study, the aqueous extract of clove (AEC) was prepared, and its anticancer affects were studied. 3‐(4,5‐Dimethylthiazol‐2‐yl)‐5‐(3‐carboxymethoxyphenyl)‐2‐(4‐sulfophenyl)‐2H‐tetra‐zolium (MTS) analysis revealed that AEC was able to inhibit cancer cell growth in vitro on several cancer cell lines; the IC₅₀ is around 150 μg/ml for human pancreatic ASPC‐1 and human colon HT‐29 cancer cells. Treatment of the cancer cells with AEC also diminished the colony formation significantly in both human pancreatic ASPC‐1 cancer cells and human colon HT‐29 cancer cells. In vivo study revealed that AEC inhibited the tumor growth significantly in HT‐29 xenograft mice model. Transmission electron microscope, flow cytometry assay, and fluorescence microscope analysis confirmed that AEC is capable of inducing cell autophagy. Further study showed that AMPK/ULK pathway plays an important role in AEC‐induced autophagy in cancer cells. Analysis of AEC components was performed by liquid chromatograph mass spectrometer approach, and more than nine constitutes were identified in AEC fraction. The study provides evidence that AEC has potential to be developed as a novel anticancer agent or as an adjuvant in cancer chemotherapy.     

Acalypha wilkesiana extracts induce apoptosis by causing single strand and double strand DNA breaks

Ethnopharmacological relevance

The seeds of Acalypha wilkesiana have been used empirically by traditional healers in Southwest Nigeria together with other plants as a powder mixture to treat patients with breast tumours and inflammation.

Aim of the study

There is an increasing interest among researchers in searching for new anticancer drugs from natural resources, particularly plants. This study aimed to investigate the anticancer properties of Acalypha wilkesiana extracts and the characteristics of DNA damage against brain and lung cancer cells.

Materials and methods

The antiproliferative activity of Acalypha wilkesiana extracts (ethyl acetate, hexane, and ethanol) was examined on human glioma (U87MG), human lung carcinoma (A549), and human lung fibroblast (MRC5) cells.

Results

Cell viability MTT assay revealed that ethyl acetate extract of the plant possessed significant antiproliferative effects against both U87MG (GI₅₀ = 28.03 ± 6.44 μg/ml) and A549 (GI₅₀ = 89.63 ± 2.12 μg/ml) cells (p value < 0.0001). The hexane extract was found to exhibit crucial antiproliferative effects on U87MG (GI₅₀ = 166.30 ± 30.50 μg/ml) (p value < 0.0001) but not on A549 cells. Neither plant extract possessed noticeable antiproliferative effects on the non-cancerous MRC5 cells (GI₅₀ > 300 μg/ml). The ethanol extract showed no antiproliferative effects on any cell line examined. Haematoxylin &; Eosin (H &; E) staining and single cell gel electrophoresis (SCGE) comet assay confirmed that plant extract-treated cells underwent apoptosis and not necrosis. SCGE comet assays confirmed that plant extracts caused both single strand (SSB) and double strand (DSB) DNA breaks that led to the execution of apoptosis.

Conclusion

The extracts (especially ethyl acetate and hexane) of Acalypha wilkesiana possess valuable cytotoxic effects that trigger apoptosis in U87MG and A549 cancer cells through induction of DNA SSBs and DSBs.