Nurhayati Zainal Abidin

Growth inhibition of human gynecologic and colon cancer cells by Phyllanthus watsonii through apoptosis induction.

Phyllanthus watsonii Airy Shaw is an endemic plant found in Peninsular Malaysia. Although there are numerous reports on the anti cancer properties of other Phyllanthus species, published information on the cytotoxicity of P. watsonii are very limited. The present study was carried out with bioassay-guided fractionation approach to evaluate the cytotoxicity and apoptosis induction capability of the P. watsonii extracts and fractions on human gynecologic (SKOV-3 and Ca Ski) and colon (HT-29) cancer cells. P. watsonii extracts exhibited strong cytotoxicity on all the cancer cells studied with IC50 values of ≤ 20.0 µg/mL. Hexane extract of P. watsonii was further subjected to bioassay-guided fractionation and yielded 10 fractions (PW-1→PW-10). PW-4→PW-8 portrayed stronger cytotoxic activity and was further subjected to bioassay-guided fractionation and resulted with 8 sub-fractions (PPWH-1→PPWH-8). PPWH-7 possessed greatest cytotoxicity (IC50 values ranged from 0.66 – 0.83 µg/mL) and was selective on the cancer cells studied. LC-MS/MS analysis of PPWH-7 revealed the presence of ellagic acid, geranic acid, glochidone, betulin, phyllanthin and sterol glucoside. Marked morphological changes, ladder-like appearance of DNA and increment in caspase-3 activity indicating apoptosis were clearly observed in both human gynecologic and colon cancer cells treated with P. watsonii especially with PPWH-7. The study also indicated that P. watsonii extracts arrested cell cycle at different growth phases in SKOV-3, Ca Ski and HT-29 cells. Cytotoxic and apoptotic potential of the endemic P. watsonii was investigated for the first time by bioassay-guided approach. These results demonstrated that P. watsonii selectively inhibits the growth of SKOV-3, Ca Ski and HT-29 cells through apoptosis induction and cell cycle modulation. Hence, P. watsonii has the potential to be further exploited for the discovery and development of new anti cancer drugs.

Stimulatory effects of polysaccharide fraction from Solanum nigrum on RAW 264.7 murine macrophage cells.

The polysaccharide fraction from Solanum nigrum Linne has been shown to have antitumor activity by enhancing the CD4+/CD8+ ratio of the T-lymphocyte subpopulation. In this study, we analyzed a polysaccharide extract of S. nigrum to determine its modulating effects on RAW 264.7 murine macrophage cells since macrophages play a key role in inducing both innate and adaptive immune responses. Crude polysaccharide was extracted from the stem of S. nigrum and subjected to ion-exchange chromatography to partially purify the extract. Five polysaccharide fractions were then subjected to a cytotoxicity assay and a nitric oxide production assay. To further analyze the ability of the fractionated polysaccharide extract to activate macrophages, the phagocytosis activity and cytokine production were also measured. The polysaccharide fractions were not cytotoxic, but all of the fractions induced nitric oxide in RAW 264.7 cells. Of the five fractions tested, SN-ppF3 was the least toxic and also induced the greatest amount of nitric oxide, which was comparable to the inducible nitric oxide synthase expression detected in the cell lysate. This fraction also significantly induced phagocytosis activity and stimulated the production of tumor necrosis factor-α and interleukin-6. Our study showed that fraction SN-ppF3 could classically activate macrophages. Macrophage induction may be the manner in which polysaccharides from S. nigrum are able to prevent tumor growth.

Effect of extracts from Phyllanthus watsonii Airy Shaw on cell apoptosis in cultured human breast cancer MCF-7 cells.

Species of Phyllanthus have traditionally been used for hundreds of years for treating many ailments including diabetes, anemia, bronchitis and hepatitis. The present study aims to investigate the cytotoxic and apoptotic effects of methanol (PWM), hexane (PWH) and ethyl acetate (PWE) extracts from the leaves of the endemic plant Phyllanthus watsonii Airy Shaw (Phyllanthaceae) on MCF-7 human breast cancer cells. We observed that the PWM, PWH and PWE extracts were cytotoxic and selectively inhibited the growth and proliferation of MCF-7 cells compared to untreated control in a dose dependent manner with an IC(50) of 12.7 ± 4.65, 7.9 ± 0.60 and 7.7 ± 0.29 μg/ml, respectively. However, the extracts were not toxic at these concentrations to normal human lung fibroblast MRC-5 cells. Cell death induced by PWM, PWH and PWE extracts were mainly due to apoptosis which was characterized by apoptotic morphological changes and a nuclear DNA fragmentation. Caspase-3 activation following P. watsonii extracts treatment was also evident for apoptotic cell death which was preceded by an S phase cell cycle perturbation. The results suggested that the cytotoxic activity of P. watsonii extracts was related to an early event of cell cycle perturbation and a later event of apoptosis. Hence, P. watsonii displays potential to be further exploited in the discovery and development of new anticancer agents.

Tumor suppression effect of Solanum nigrum polysaccharide fraction on Breast cancer via immunomodulation

A polysaccharide fraction from Solanum nigrum, SN-ppF3 was shown previously to have an immunomodulatory activity where it could possibly be used to enhance the host immune response in fighting cancer. The non-toxic SN-ppF3 was fed orally to breast tumor bearing-mice with concentrations of 250 and 500mg/kg for 10days. During the treatment period, size of the tumor and weight of the mice were monitored. At the end of the treatment, blood, tumor, spleen and thymus were harvested for physiological and immunological analyses. After the treatment, the tumor volume and tumor weight were significantly inhibited by 65% and 40%, respectively. Based on the histological observation, the treatment of SN-ppF3 resulted in the disruption of tumor cells morphology. The increase in infiltrating T cells, NK cells and macrophages were observed in tumor tissues of the treated mice, which partly explained the higher apoptosis tumor cells observed in the treated mice. Moreover, the level of TNF-α, IFN-γ and IL-4 were elevated, while the level of IL-6 was decreased significantly, in serum of the treated mice. These results suggested that tumor suppression mechanisms observed in SN-ppF3-treated mice were most probably due through enhancing the host immune response.

Protective Effect of Antioxidant Extracts from Grey Oyster Mushroom, Pleurotus pulmonarius (Agaricomycetes), Against Human Low-Density Lipoprotein Oxidation and Aortic Endothelial Cell Damage

This study evaluated the in vitro antioxidant capacities of extracts from Pleurotus pulmonarius via Folin-Ciocalteu, 1,1-diphenyl-2-picrylhydrazyl free radical scavenging, metal chelating, cupric ion reducing antioxidant capacity, and lipid peroxidation inhibition assays. Extract compositions were determined by phenol-sulfuric acid; Coomassie Plus (Bradford) protein; Spectroquant zinc, copper, and manganese test assays; and liquid chromatography-tandem mass spectrometry (LC/MS/MS) and gas chromatography-mass spectrometry (GC/MS). Methanol-dichloromethane extract, water fraction, hot water, aqueous extract and hexane fraction exhibited the most potent extracts in the antioxidant activities. LC/MS/MS and GC/MS showed that the extracts contained ergothioneine, ergosterol, flavonoid, and phenolic compounds. The selected potent extracts were evaluated for their inhibitory effect against oxidation of human low-density lipoproteins and protective effects against hydrogen peroxide-induced cytotoxic injury in human aortic endothelial cells. The crude aqueous extract was deemed most potent for the prevention of human low-density lipoprotein oxidation and endothelial membrane damage. Ergothioneine might be the compound responsible for the activities, as supported by previous reports. Thus, P. pulmonarius may be a valuable antioxidant ingredient in functional foods or nutraceuticals.

First report on a novel Nigrospora sphaerica isolated from Catharanthus roseus plant with anticarcinogenic properties

This paper reports on the vinca alkaloid produced by a novel Nigrospora sphaerica isolated from Catharanthus roseus. Through liquid chromatography–mass spectrometry (LCMS), only the crude mycelia extract of this fungus was positive for determination of vinblastine. This vinca alkaloid was then purified by using high‐performance liquid chromatography (HPLC) and tested for cytotoxicity activity using MTT assays. The breast cell line cancer (MDA‐MB 231) was treated with a purified vinblastine which was intracellulary produced by N. sphaerica. The purified vinblastine from extracted leaf of C. roseus was used as a standard comparison. A positive result with a value of half maximal inhibitory concentration (IC50) of > 32 μg ml−1 was observed compared with standard (IC50) of 350 μg ml−1 only. It showed that a vinblastine produced by N. sphaerica has a high cytotoxicity activity even though the concentration of vinblastine produced by this endophytic fungus was only 0.868 μg ml−1.

Inhibition of nitric oxide production by Solanum melongena and Solanum macrocarpon on RAW 264.7 cells

Nitric oxide (NO) plays an important role in the physiology and pathophysiology of disease. Overproduction of NO is associated with chronic inflammatory diseases and cancers. Several species of Solanaceae have been used traditionally to treat inflammatory-related diseases. To analyse the possible anti-inflammatory properties of these species, the Griess assay was used to evaluate the effects of various Solanum melongena and Solanum macrocarpon extracts on NO production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. The cytotoxicity of the extracts on the cell line was tested using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Extracts that significantly inhibited NO production were further evaluated for inducible nitric oxide synthase (iNOS) expression by Western blot. Thin-layer chromatography was used to determine the major compounds in the extracts. All extracts significantly inhibited NO production in LPS-stimulated RAW 264.7 cells in a dose-dependent manner. At 200 µg/ml, ethyl acetate extract of S. macrocarpon showed the highest NO inhibition of 81%, with a median inhibitory concentration (IC50) value of 44.78 ± 0.04 µg/ml. The viability of cells treated with the extracts was greater than 80%. Ethanol and ethyl acetate extracts of S. melongena, together with ethanol, hexane and ethyl acetate extracts of S. macrocarpon, reduced iNOS expression significantly. At 200 µg/ml, ethyl acetate extract of S. macrocarpon inhibited iNOS protein expression by 79%. Phytochemical analysis of the extracts showed that fluorescent, double-bond compounds, phenols, flavonoids and terpenoids were mainly present in the extracts. Taken together, the results show the potential of ethanol and ethyl acetate extracts of S. melongena, and hexane and ethyl acetate extracts of S. macrocarpon, as agents for the prevention and treatment of inflammatory-related diseases.

Anti-proliferation and anti-migration activities of ten selected Zingiberaceae species against MDA-MB-231 cells

Zingiberaceae plants exhibit various biological activities, but scientific knowledge of the plants in antimetastatic aspects is still very limited. The objective of this study is to examine the anti-metastatic potentials of 30 crude extracts from ten selected local Zingiberaceae species on hormone-independent, highly metastatic human breast cancer cells, MDA-MB-231. The Zingiberaceae rhizomes were extracted with petroleum ether, chloroform, and methanol using Soxhlet extractor system. Effects of the 30 extracts on proliferation and migration of MDA-MB-231 cells were evaluated using 3-(4,5-dimethylthiazol2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and scratch wound assay, respectively. Besides cytotoxicity, it is also vital to determine the potential toxicity of the extract in order to select the most promising extracts for anti-cancer drugs development. Thus, a special parameter–Selectivity Index (SX) was utilized as the selectivity indicator of tested extracts towards tumour cells. The results revealed that petroleum ether extracts of Alpinia galanga, Boesenbergia rotunda, and Zingiber zerumbet; as well as chloroform extracts of Alpinia galanga, Boesenbergia rotunda, and Curcuma domestica were screened to possess the most effective anti-proliferation and anti-migration activities against MDA-MB-231 cells. Three most desirable extracts were selected based on both their anti-metastatic potentials and SX, and were subjected for qualitative analysis using thin-layer chromatography (TLC).

Therapeutic properties of Pleurotus species (oyster mushrooms) for atherosclerosis: A review

ABSTRACT Atherosclerosis is an impairment of the artery walls made up of two membrane layers, intima and media. Oxidative stress, hypertension, and hypercholesterolemia are the three main factors that cause atherosclerosis. These conditions are frequently found together and may cause atherogenesis to rapidly occur. The edible genus Pleurotus is commonly known as oyster mushrooms. Pleurotus spp. has been proven to have valuable medicinal attributes. Hence, they have been listed among “mushroom nutriceuticals” and categorized as both functional foods and medicinal mushrooms. In this review, we report the benefits of Pleurotus spp. for the prevention and treatment of atherosclerosis via reduction of oxidative stress, hypertension, and hypercholesterolemia in terms of the therapeutic compounds responsible. This review revealed that at least ten different types of Pleurotus spp. have been reported to have anti-atherogenic capabilities, with six of them possessing high levels of anti-atherogenic compounds such as ACE inhibitor peptide, ergothioneine, chrysin, and lovastatin. Hence, it has been demonstrated that Pleurotus spp. has great potential for use as food or extracts from fruiting bodies or mycelium in an alternative therapy for atherosclerosis, through prevention and treatment of oxidative stress, hypertension, and hypercholesterolemia.