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

Phytochemical analysis and antimicrobial activities of methanolic extracts of leaf, stem and root from different varieties of Labisa pumila Benth.

A local herb, Kacip Fatimah, is famous amongst Malay women for its uses in parturition; however, its phytochemical contents have not been fully documented. Therefore, a study was performed to evaluate the phenolics, flavonoids, and total saponin contents, and antibacterial and antifungal properties of the leaf, stem and root of three varieties of Labisia pumila Benth. Total saponins were found to be higher in the leaves of all three varieties, compared to the roots and stems. Leaves of var. pumila exhibited significantly higher total saponin content than var. alata and lanceolata, with values of 56.4, 43.6 and 42.3 mg diosgenin equivalent/g dry weight, respectively. HPLC analyses of phenolics and flavonoids in all three varieties revealed the presence of gallic acid, caffeic acid, rutin, and myricetin in all plant parts. Higher levels of flavonoids (rutin, quercitin, kaempferol) were observed in var. pumila compared with alata and lanceolata, whereas higher accumulation of phenolics (gallic acid, pyrogallol) was recorded in var. alata, followed by pumila and lanceolata. Antibacterial activities of leaf, stem and root extracts of all varieties determined against both Gram positive (Micrococcus luteus, Bacillus subtilis B145, Bacillus cereus B43, Staphylococcus aureus S1431) and Gram negative (Enterobacter aerogenes, Klebsiella pneumonia K36, Escherichia coli E256, Pseudomonas aeruginosa PI96) pathogens showed that crude methanolic extracts are active against these bacteria at low concentrations, albeit with lower antibacterial activity compared to kanamycin used as the control. Antifungal activity of methanolic extracts of all plant parts against Fusarium sp., Candida sp. and Mucor using the agar diffusion disc exhibited moderate to appreciable antifungal activities compared to streptomycin used as positive control

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

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

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

Solid state fermentation effects on pistachio hulls antioxidant activities

Pistachio (Pistacia vera L.) is a small tree native to mountainous regions of Iran. The seed has a mauvish skin and light green flesh, with a distinctive flavor. The hulls contain high amount of phenolic and flavonoid compounds, which are known as source of antioxidant. Recently, the use of natural additives found in plant material as preservative in food and cosmetic products received considerable attention. On the other hand was know processing method to improve the antioxidant activity of agriculture byproducts and reduce the anti-nutritional metabolites. Therefore, this experiment was carried out to determine the effect of solid state fermentation on pistachio hulls antioxidant activities using five types of fungi namely White rot fungi (ATCC 64897), White rot fungi (ATCC 90467), Aspergillus terreus (ATCC 74135), Rhizopus oligosporus and Aspergillus oryzae. Pistachio hulls were subjected to fermentation process for the period of 10 days. Freeze-dried samples were extracted with 80% methanol. The result showed that the samples contained varied concentration of phenolic compounds from 0.721 to 2.277 mg gallic acid equivalent/g DM, and total flavonoids varied from 0.249 to 1.204 mg rutin equivalents/g DM. The highest antioxidant activity of 50.39% at a concentration of 300 μg/ml of crude extract was found in crude methanolic extract of control while the lowest antioxidant activity of 31.19% was found in crude methanolic extract of hulls fermented by white rot fungi (ATCC 90467). The result indicated a reduction in the antioxidant activities of pistachio hulls when undergoing solid state fermentation. Therefore, it is not a recommended method to improve the antioxidant activities of pistachio hulls

Impact of environmental stress on reproductive development in sweet pepper (Capsicum annuum L.)

This investigation was aimed at determining the impact of environmental stresses such as high temperature, low irradiance and drought on reproductive development in sweet pepper, particularly var. Blue Star. Special attention was given to abscission of the primary and secondary flowers. The role of assimilate accumulation and partitioning and the endogenous growth regulator ethylene in mediating stress effects on flower abscission were investigated. The hypothesis that flower abscission is promoted by these stress factors and that abscission is mediated by increased ethylene production and reduced assimilate partitioning to the flowers was tested. Imposition of a mean daily temperature (26 °C) from the third true leaf stage accelerated the development of the first primary flowers to anthesis when combined with high irradiance (4.9 MJ m-² d-¹). However, abscission was increased by 17 % as compared to lower temperature treatments at the same irradiance. The combination of high temperature and low irradiance (2.4 MJ m-² d-¹) induced complete abscission of the primary flowers. Although flower abscission was reduced at the lowest temperature examined (14 °C), development of the primary flowers to anthesis was slower than at higher temperatures. Both varieties, Blue Star and Bell Boy, were able to grow over a wide range of temperatures, as indicated by the large difference (c. 35 °C) between the base and maximum temperatures for growth indicated by a germination trial. In Blue Star, the base (Tb), optimum (To) and maximum (Tm) temperatures were 6.0, 27.5 and 41.5 °C respectively, whereas in Bell Boy, the corresponding values were 8.5, 23.0 and 44.0 °C. Severe water stress imposed progressively after the appearance of the first flower bud promoted the initial development of the primary, but not the secondary flowers to anthesis, but induced early and increased abscission of both primary and secondary flowers shortly afterwards. The high percentage abscission of the primary flowers was partially offset by the lower abscission of secondary flowers. Percentage abscission increased as the severity and duration of water stress increased. However, short exposures to stress did not reduce abscission, or advance anthesis. A more advanced stage of flower development (4.0 mm diameter) proved more susceptible to early abscission than younger flower buds (1.0 mm) when exposed to severe stress. Temporary osmotic adjustment occurred soon after the imposition of water stress, during which osmotic potential decreased sharply from -1.15 to -1.80 MPa, and noticeable reductions in turgor were observed in all treatments between 11 - 22 d after the imposition of stress. Although water stress reduced vegetative growth under low irradiance, complete flower abscission occurred after anthesis. The advancement of anthesis in stressed plants was associated with a decrease in dry matter accumulation in the leaves and stems. However, at the onset of flower abscission, assimilate accumulation and partitioning were not significantly affected by water stress, and flower abscission was not directly related to any reduction in assimilate production or its distribution within the shoot. Instead, prior to flower abscission in severely stressed plants, ethylene evolution in the flowers increased by 8-fold as compared to unstressed plants, and by 40-fold relative to severely stressed plants measured just before anthesis. The application of the ethylene releasing substance, 2 chloroethylphosphonic acid (CEPA), mimicked the effects of severe water stress, as reflected by a surge in ethylene evolution prior to abscission, followed by increased bud abscission. Sweet pepper flowers were also capable of forming abscission zones at the base of their pedicels in response to elevated ethylene production, whilst mature leaves were apparently incapable of this response. Foliar application of silver thiosulphate (STS) to water stressed plants and STS pre-treatment of plants subsequently sprayed with CEPA blocked the action of elevated ethylene resulting from severe stress or CEPA application in inducing flower abscission

Accumulation and partitioning of total phenols in two varieties of Labisia pumila Benth. under manipulation of greenhouse irradiance

Two varieties of Labisia pumila (var. pumila and alata) were exposed to four levels of greenhouse irradiance (100, 70, 50, 30% of the incoming radiation (IR); equivalent to respective 670, 630, 470, 240 μmol m-2 s -1) in a 2-factorial Randomized Complete Block Design trial with the aim to determine the existence of varietal preferences in total phenols (TP) accumulation and their distribution to different organs (leaf, stem, root) due to manipulation in irradiance levels. TP were determined according to Folin-Ciocalteu method and results expressed in mg Gallic acid g-1 dry weight (DW). Total phenolic content in red var. alata consistently recorded lower values (p≤0.0001) than green var. pumila when exposed to high irradiance (100-70% IR) by 4.5-6.6%. Reducing irradiance to 50% IR; however, increased TP in red higher than green var. by 39.2% (10.96 vs. 7.87 mg GAE g-1 DW) due to marked increase (p≤0.0001) in phenols partitioning to the leaf of red var. compared to green var. (4.6 vs. 3.0 mg g"). Partitioning of phenols to the leaf in red var. alata, although kept increasing (6.5% over green var.), did not continue to enhance plant TP with further decrease in irradiance to 30% IR. Instead TP partitioning to the stem and root in green var. pumila exceeded substantially over red var. alata by 11.8-18.4%, respectively, implying there are varietal preferences between var. pumila and alata in terms of TP accumulation and partitioning related to varying levels of irradiance. Although both varieties are shade loving, var. alata was more sensitive to high irradiance than var. pumila in accumulation of TP in the plants and that manipulation of irradiance in controlled environment agriculture was able to enhance partitioning of phenols to different parts or organs of Labisia pumila for potential niche production of plant parts