Profiling of phenolic compounds and their antioxidant and anticancer activity in pandan (Pandanus amaryllifolius Roxb.) extracts from different locations of Malaysia.

Background Phytochemicals and antioxidants from plant sources are of increasing interest to consumers because of their roles in the maintenance of human health. Most of the secondary metabolites of herbs are used in a number of pharmaceutical products. Methods Secondary metabolites composition and content of five flavonoids and three phenolic acids were evaluated and determined in Pandanus amaryllifolius extracts from three different locations of Malaysia by RP-HPLC; Total phenolic and total flavonoid content were determined using Folin-Ciocalteau and aluminum chloride colorimetric assay; The antioxidant activity of the extracts was determined by the ferric reducing antioxidant potential (FRAP) assay and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays. MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) Assay was employed to screen anticancer activity of extracts against MCF-7 cancer cell line. Results Highest value of total flavonoids (TF) and total phenolics (TP) was observed in pandan extract from Bachok locattion (1.87 mg/g DW and 6.72 mg/g DW) followed by Klang (1.32 mg/g DW; 5.07 mg/g DW) and Pontian (1.12 mg/g DW; 4.88 mg/g DW). Rutin just detected from Bachok location with value of 0.082 mg/g DW. High content of epicatechin (0.035 mg/g DW) and naringin (0.325 mg/g DW) were observed from Bachok location while, highest content of catechin (0.613 mg/g DW) and kaempferol (0.278 mg/g DW) was observed in pandan extract from Klang location. The extract of pandan from Bachok exhibited highest value of gallic acid (0.423 mg/g DW) and cinnamic acid (0.084 mg/g DW). Ferrulic acid just detected from pandan extract of Bachok location with concentration of 0.281mg/g DW. Between studied locations Bachok exhibited highest value of DPPH (64.27%) and FRAP (517.2 μm of Fe (II)/g) activity followed by Klang (52.16%; 448.6 μm of Fe (II)/g) and Pontian (50.10%; 314.8 μm of Fe (II)/g). The preliminary screening showed pandan extracts from 3 locations possessed anticancer promoting activity against MCF-7 cell line, with 78.3%, 70.5% and 67.4% inhibition rate, respectively. Maximum MCF-7cell line inhibition was observed in pandan extract from Bachok location. Conclusions The samples collected from the North (Bachok) exhibited the highest TP, TF antioxidant and anticancer activity while those from the Southern portion (Pontian) appeared to have the lowest content of TP, TF and antioxidant activity

Identification and concentration of some flavonoid components in Malaysian young ginger (Zingiber officinale Roscoe) varieties by a high performance liquid chromatography method.

Flavonoids make up one of the most pervasive groups of plant phenolics. Due to their importance in plants and human health, it would be useful to have a better understanding of flavonoid concentration and biological activities that could indicate their potentials as therapeutic agents, and also for predicting and controlling the quality of medicinal herbs. Ginger (Zingiber officinale Roscoe) is a famous and widely used herb, especially in Asia, that contains several interesting bioactive constituents and possesses health promoting properties. In this study, total flavonoids and some flavonoid components including quercetin, rutin, catechin, epicatechin, kaempferol and naringenin were extracted from the leaves and rhizomes of two varieties of Zingiber officinale (Halia Bentong and Halia Bara) at three different growth points (8, 12 and 16 weeks after planting), and analyzed by a high performance liquid chromatography (HPLC) method in order to determine the potential of the subterranean part of the young ginger. The results showed that Halia Bara had a higher content of flavonoids in the leaves and rhizomes as compared to Halia Bentong. In both varieties, the concentration of flavonoids in the leaves decreased (Halia Bentong, 42.3%; Halia Bara 36.7%), and in the rhizomes it increased (Halia Bentong 59.6%; Halia Bara 60.1%) as the growth period increased. Quercetin was abundant in both varieties. The antioxidant activity determined by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay showed high activities (65.7%) in the leaves of Halia Bara at 8 weeks after planting. Results suggested a good flavonoid content and antioxidant activity potential in ginger leaves at 8 weeks after planting. The leaves of these ginger varieties could be useful for both food flavourings and in traditional medicine

THE ROLE OF HISTONE ACETYLATION IN THE CONTROL OF IMMUNE CHECKPOINT EXPRESSION IN CD8+ T CELLS

T cell exhaustion is characterized by the expression of multiple immune checkpoint molecules on the surface of T cells and loss of effector functions. Epigenetic programs governing the coordinate expression of immune checkpoints and the implications of different patterns of checkpoint expression on T cell function are currently unknown. In this thesis we identify the environmental cytokine TGF-b1 differentially controls the expression of PD-1 and other immune checkpoints. This differential regulation is driven in part by epigenetic programs involving histone acetylation that alter the promoters of immune checkpoint. Utilizing highly specific small molecule inhibitors of TGF- b1 signaling and class I histone deacetylases allowed for differential programing of immune checkpoint expression on the T cell surface and led to different functional properties of CD8+ T cells. This programming could be altered both in vitro and in vivo. Lastly, we show that treatment with HDAC inhibitors leads to a more profound exhaustion phenotype in both chronic viral infection and tumor models; however, the combination of HDAC inhibitors and checkpoint blockade agents have a synergistic effect on T cell function and anti-tumor immunity

Antioxidant activities, total phenolics and flavonoids content in two varieties of Malaysia young ginger (Zingiber officinale Roscoe.

Ginger (Zingiber officinale Roscoe) is a well known and widely used herb, especially in Asia, which contains several interesting bioactive constituents and possesses health promoting properties. In this study, the antioxidant activities of methanol extracts from the leaves, stems and rhizomes of two Zingiber officinale varieties (Halia Bentong and Halia Bara) were assessed in an effort to compare and validate the medicinal potential of the subterranean part of the young ginger. The antioxidant activity and phenolic contents of the leaves as determined by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay and the total amounts of phenolics and flavonoids were higher than those of the rhizomes and stems. On the other hand, the ferric reducing/antioxidant potential (FRAP) activity of the rhizomes was higher than that of the leaves. At low concentration the values of the leaves' inhibition activity in both varieties were significantly higher than or comparable to those of the young rhizomes. Halia Bara had higher antioxidant activities as well as total contents of phenolic and flavonoid in comparison with Halia Bentong. This study validated the medicinal potential of the leaves and young rhizome of Zingiber officinale (Halia Bara) and the positive relationship between total phenolics content and antioxidant activities in Zingiber officinale

Effects of solvent type on phenolics and flavonoids content and antioxidant activities in two varieties of young ginger (Zingiber officinale Roscoe) extracts

The extractive capability of phenolic components from herb material is considerably depended on the type of solvent. In our research three kinds of solvents (methanol, acetone and chloroform) extracts from different parts (leaves, stems and rhizomes) of two Malaysian young ginger varieties (Halia Bara and Halia Bentong) were used to examine the effects of extraction solvent on total phenolics (TP), total flavonoids (TF), quercetin, catechin and rutin content and antioxidant activity [1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay]. Results showed that extraction solvent had significant effects on TP, TF, quercetin, catechin and rutin content and antioxidant activity. The highest content of TP, TF and DPPH scavenging activities were found in methanol extracts. Additionally, High performance liqouid chromatography results shown that methanol had the highest extraction capacity for quercetin, rutin and catechin. Between varieties Halia Bara had high content of TP, TF and antioxidant activities to compare with Halia Bentong. Accumulation and partitioning of TP and TF in both varieties were: leaves > rhizomes > stems in all the three solvent extracts. However, according to the results extraction yield of phenolic compounds is greatly depending on the solvent polarity. With increased in solvent polarity from chloroform to methanol, amount of phenolic compounds and antioxidant activities increased in both varieties. Thus, for routine screening of young ginger varieties with higher antioxidant activity, methanol was recommended to extract phenolic compounds from young ginger

Elevated carbon dioxide increases contents of flavonoids and phenolic compounds, and antioxidant activities in Malaysian young ginger (Zingiber officinale Roscoe.) varieties.

Zingiber officinale Roscoe. (Family Zingiberaceae) is well known in Asia. The plant is widely cultivated in village gardens in the tropics for its medicinal properties and as a marketable spice in Malaysia. Ginger varieties are rich in physiologically active phenolics and flavonoids with a range of pharmacological activities. Experiments were conducted to determine the feasibility of increasing levels of flavonoids (quercetin, rutin, catechin, epicatechin, kaempferol, naringenin, fisetin and morin) and phenolic acid (gallic acid, vanillic acid, ferulic acid, tannic acid, cinnamic acid and salicylic acid), and antioxidant activities in different parts of Malaysian young ginger varieties (Halia Bentong and Halia Bara) with CO2 enrichment in a controlled environment system. Both varieties showed an increase in phenolic compounds and flavonoids in response to CO2 enrichment from 400 to 800 μmol mol-1 CO2. These increases were greater in rhizomes compared to leaves. High performance liquid chromatography (HPLC) results showed that quercetin and gallic acid were the most abundant flavonoid and phenolic acid in Malaysian young ginger varieties. Under elevated CO2 conditions, kaempferol and fisetin were among the flavonoid compounds, and gallic acid and vanillic acid were among the phenolic compounds whose levels increased in both varieties. As CO2 concentration was increased from 400 to 800 μmol mol-1, free radical scavenging power (DPPH) increased about 30% in Halia Bentong and 21.4% in Halia Bara; and the rhizomes exhibited more enhanced free radical scavenging power, with 44.9% in Halia Bentong and 46.2% in Halia Bara. Leaves of both varieties also displayed good levels of flavonoid compounds and antioxidant activities. These results indicate that the yield and pharmaceutical quality of Malaysian young ginger varieties can be enhanced by controlled environment production and CO2 enrichmen

Effect of intercropping of corn and soybean on dry matter yield and nutritive value of forage corn

Cereal-based forage production could be considered to have potential to supply great deal of energy-rich feed in animal diets. Experiment was conducted to evaluate effect of corn-soybean combinations of 75:25, 50:50 and 25:75 in addition to monocrops of corn and soybean to detremine forage dry matter (DM) yield and quality in corn-soybean intercropping. The crop combination ratio had significant effects on dry matter yield and nutritive quality of forage. The ratio of 75:25 and 50:50 recorded DM yields similar to those of monocropped corn (14.77 t/ha). Forage quality in terms of crude protein (CP) (75:25 ratio 12.75%, 50:50 ratio 13.73% and 25:75 ratio 14.68%) was improved by intercropping due to higher nitrogen availability for corn in intercropping compared with its sole crop (10.83% CP). Increase ratio of corn in corn-soybean mixture, negatively affectd neutral detergent fiber (NDF), acid detergent fiber (ADF) of forage and declined with increasing ratio of soybean plants. Combination ratio of 50:50 gave higher protein yield (1886.45 kg/ha) than other crop combination ratio. Among all the combination ratios, the 50:50 corn-soybean ratio was the optimum giving highest forage yield, protein content as well as protein yield