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

The relationship of nitrogen and C/N ratio with secondary metabolites levels and antioxidant activities in three varieties of Malaysian Kacip Fatimah (Labisia pumila Blume).

Kacip Fatimah (Labisia pumila Blume), one of the most famous and widely used herbs, especially in Southeast Asia, is found to have interesting bioactive compounds and displays health promoting properties. In this study, the antioxidant activities of the methanol extracts of leaves, stems and roots of three varieties of L. pumila (var. alata, pumila and lanceolata) were evaluated in an effort to compare and validate the medicinal potential of this indigenous Malaysian herb species. The antioxidant activity determined by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, as well as the total amount of phenolics and flavonoids were the highest in the leaves, followed by the stems and roots in all the varieties. A similar trend was displayed by the ferric reducing antioxidant potential (FRAP) activity, suggesting that the L. pumila varieties possess high foliar antioxidant properties. At low FRAP activity concentrations, the values of the leaves' inhibition activity in the three varieties were significantly higher than those of the stems and roots, with var. alata exhibiting higher antioxidant activities and total contents of phenolics and flavonoids compared to the varieties pumila and lanceolata. The high production of secondary metabolites and antioxidant activities in var. alata were firmly related to low nitrogen content and high C/N ratio in plant parts. The study also demonstrated a positive correlation between secondary metabolite content and antioxidant activities, and revealed that the consumption of L. pumila could exert several beneficial effects by virtue of its antioxidant activity

Relationship between extractable chlorophyll content and SPAD values in three varieties of Kacip Fatimah under greenhouse conditions

Relationship between extractable chlorophyll and relative chlorophyll values obtained using Soil Plant Analytical Development (SPAD)-502 meter were determined in three varieties of Labisia pumila (alata, pumila, lanceolata) under greenhouse conditions using fresh weight basis. The experiment was arranged as a complete randomized design replicated three times with each experimental unit containing five plants. There were no significant differences (P ≥ 0.05) for all the three varieties in their chlorophyll a, b and total. Best fit relationship was found to be linear in chlorophyll a, b and total (P ≤ 0.01) with ascending slope as SPAD values intensified. Chlorophyll b was higher than chlorophyll a in all the varieties indicating species as shade-loving plants. The chlorophyll content of L. pumila leaves can be conveniently determined using SPAD-502 chlorophyll meter, a technique providing simple, rapid, and nondestructive method to estimate leaf chlorophyll content which could also be an indicator of leaf nitrogen (N) status

Photosynthetic capacity, photochemical efficiency and chlorophyll content of three varieties of Labisia pumila Benth. Exposed to open field and greenhouse growing conditions.

Three varieties (Alata, Pumila and Lanceolata) of Malaysian indigenous medicinal herb Labisia pumila Benth. grown in greenhouse and open field were tested to evaluate and compare their photosynthetic and maximal quantum efficiency of photosystem II (F v/F m) reactions. Every variety grown in greenhouse demonstrated higher light-saturated photosynthetic capacity than in the open field. The diurnal net photosynthesis (A) curve in the open field also displayed dual peaks with lower daily average A compared to the greenhouse. Varieties Alata and Pumila were found to acclimatize better under both growing conditions. The diurnal patterns of F v/F m indicated that plants grown under greenhouse encountered less photoinhibition than in open field condition. A decrease in chlorophyll (chl) a/b ratio in leaves of greenhouse plants with significant increase in chl b was observed. This study indicates that var. Alata and var. Pumila have the capacity to acclimatize to greenhouse growth condition

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

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

Antioxidant potential and anticancer activity of young ginger (Zingiber officinale Roscoe) grown under different CO2 concentration.

In the present study, leaves and rhizomes extract from two Malaysian young ginger (Zingiber officinale Roscoe) varieties namely: Halia Bentong and Halia Bara grown under ambient (400µ mol/mol) andelevated (800µ mol/mol) CO2 concentrations were studied for their antioxidant and in vitro anticanceractivities against two human cancer cell lines (MCF–7 and MDA–MB–231). Antioxidant activities in bothvarieties determined using thiobarbituric acid (TBA) assays increased significantly with increasing CO2 concentration from 400 to 800µ mol/mol. High antioxidant activity was observed in the rhizomes of HaliaBara grown under elevated CO2 concentration. The results showed that CO 2 enriched Halia Baraexhibited the highest anticancer activity on MCF–7 cancer cells with IC 50 values of 25.3 and 27.31 µg/mlrespectively for rhizomes and leaves extract. IC 50 values for MDA–MB–231 exhibition were 30 and 32.81µg/ml, respectively for rhizomes extract of Halia Bara and Halia Bentong. Results showed that HaliaBentong and Halia Bara possessed anticancer and antiradical properties especially when grown underelevated CO2 concentration. Antioxidant activities of ginger leaves and rhizomes could be increased orimproved by using CO2 enrichment in a controlled environment condition. Results also implied thatthese ginger varieties could be employed in ethno-medicine for the management of cancerousdiseases

Microclimate inside a tropical greenhouse equipped with evaporative cooling pads

Tropical greenhouses require active evaporative cooling system such as pad-and-fan to ensure a suitable microclimate for crop production. Excess heat causes indoor temperature to become hotter than desired resulting in detrimental effects to crop growth and production. Solar radiation intensity and outside temperature affect temperature and relative humidity level inside a greenhouse, while wide gradients in temperature and relative humidity can cause problems related to crop growth and production uniformity. A 300 m2 greenhouse, equipped with evaporative pad and four exhaust fans at each end walls, was used in the study. Horizontal and vertical profiles of the temperature and relative humidity inside the greenhouse were investigated. Results showed that temperature increased from evaporative pad area to exhaust fans area in a horizontal plane, while relative humidity showed an inverse pattern from temperature. In the vertical plane, temperature increased, while relative humidity decreased from lower level to the upper level. ANOVA results showed that in overall, temperature and relative humidity inside the greenhouse were uniform as there was no significant difference at 95% confidence interval. Thus, it was concluded that greenhouse cooling system by evaporative pad and exhaust fans are suitable for application in a tropical country such as Malaysia

Simultaneous effects of water and nitrogen stress on the vegetative and yield parameters of choy sum (Brassica chinensis var. parachinensis)

Hypothetically, leafy vegetables need water and nitrogen (N) simultaneously in their applications for good growth. Therefore, this study was conducted to determine the effects of four watering frequencies (watering once a day, once a week and once in every two weeks and no watering) and five levels of nitrogen (0, 34, 68, 136 and 272 kg N ha-1) on the vegetative and yield parameters of choy sum over a period of four weeks. The choy sum was grown in polyethylene bags under a rain shelter. The experimental design was a split-split plot with four replications. Plant vegetative and yield parameters measured weekly were plant height, leaf number, total leaf area, maximum root length, the various plant part weights and total tissue nitrogen. Water stress detrimentally affected choy sumfs leaf growth more than root growth and the effect of water stress was more than nitrogen stress. Higher nitrogen rates in water-stressed condition increasingly reduced the number of leaves and height of the choy sum. Choy sum grown under once-a-day watering and once-a-week treatments did not experience water stress. The optimal soil water content and nitrogen application rate were 0.4 m3 m-3 and 30 to 40 kg N ha-1, respectively. The rate of 34 kg N ha-1 and once-a-week watering treatment generally gave the highest values for all the measured vegetative and yield parameters. Under lower and point of sufficient nitrogen rates, nitrogen was used for leaf thickness and weight rather than for intercepting light via leaf area expansion

The relationship between phenolics and flavonoids production with total non structural carbohydrate and photosynthetic rate in labisia pumila benth. under high CO2 and nitrogen fertilization.

A factorial split plot 4 × 3 experiment was designed to examine and characterize the relationship among production of secondary metabolites (total phenolics, TP; total flavonoids, TF), carbohydrate content and photosynthesis of three varieties of the Malaysian medicinal herb Labisia pumila Benth. namely the varieties alata, pumila and lanceolata under CO2 enrichment (1,200 μmol mol-1) combined with four levels of nitrogen fertilization (0, 90, 180 and 270 kg N ha-1). No varietal differences were observed, however, as the levels of nitrogen increased from 0 to 270 kg N ha-1, the production of TP and TF decreased in the order leaves>roots>stems. The production of TP and TF was related to increased total non structural carbohydrate (TNC), where the increase in starch content was larger than that in sugar concentration. Nevertheless, the regression analysis exhibited a higher influence of soluble sugar concentration (r² = 0.88) than starch on TP and TF biosynthesis. Photosynthesis, on the other hand, displayed a significant negative relationship with TP and TF production (r² = -0.87). A decrease in photosynthetic rate with increasing secondary metabolites might be due to an increase in the shikimic acid pathway that results in enhanced production of TP and TF. Chlorophyll content exhibited very significant negative relationships with total soluble sugar, starch and total non structural carbohydrate