Young and mature leaves of Terminalia catappa of alcoholic and aqueous extracts were evaluated for in vitro antibacterial activity against Vibrio sp. isolated from aquatic animals. Young leaves of T. catappa showed higher antibacterial activity when compared to mature leaves against Vibrio parahemolyticus, with methanolic and aqueous extracts exhibited the largest inhibition zones, 23 and 24 mm, respectively as determined by disc diffusion technique. Ethanolic extract of young leaves showed the lowest MIC and MBC at 3.13 mg/ml and 6.25 mg/ml, respectively. Both alcoholic and aqueous extracts of young and matures leaves exhibit variations in protein, RNA as well as pyrine and pyrimidines leakage of Vibrio sp. Cell membrane disruption is proposed as the mechanism of action of T. catappa leaves extract against Vibrio sp.
The interaction between plants and insects is dynamic, and may favour either the plant or the insect. Plant chemicals are deeply implicated in this relationship and influence insect behaviour. Here, we investigated the oviposition behaviour response of Culex quinquefasciatus mosquitoes based on the colour cues produced by Ipomoea cairica leaves extract. In this study, two sets of oviposition choice experiments were conducted: (1) single solution in a cage; and (2) multiple concentration solutions in a cage. In the single solution experiment, only 1 available oviposition site was offered to 5 gravid females and in the multiple concentration tests, 4 available oviposition sites were offered to 20 gravid females. The tested concentrations were set up at 100 mL of: (1) control (distilled water only); (2) 50 ppm; (3) 150 ppm; and (4) 300 ppm of I. cairica plant extracts. The highest concentration of 300 ppm appeared to show the highest intensity with the darkest colour followed by 150 ppm and 50 ppm concentrations. More gravid females were found drowned in the highest concentration, 300 ppm of acethonilic leaves extract, compared to 150 ppm and 50 ppm of the tested extract. No eggs were found in all tested solutions. The studied extract was found to effectively attract gravid Cx. quinquefasciatus females and subsequently cause mortality and inhibit egg deposition. The interference caused by the acethonilic extract of I. cairica on the oviposition activity of Cx. quinquefasciatus can result in better control of the vector insect.
The evolutionary history and classification of epiphyllous cryptogams are still poorly known. Leptolejeunea is a largely epiphyllous pantropical liverwort genus with about 25 species characterized by deeply bilobed underleaves, elliptic to narrowly obovate leaf lobes, the presence of ocelli, and vegetative reproduction by cladia. Sequences of three chloroplast regions (rbcL, trnL-F, psbA) and the nuclear ribosomal ITS region were obtained for 66 accessions of Leptolejeunea and six outgroup species to explore the phylogeny, divergence times, and ancestral areas of this genus. The phylogeny was estimated using maximum-likelihood and Bayesian inference approaches, and divergence times were estimated with a Bayesian relaxed clock method. Leptolejeunea likely originated in Asia or the Neotropics within a time interval from the Early Eocene to the Late Cretaceous (67.9 Ma, 95% highest posterior density [HPD]: 47.9-93.7). Diversification of the crown group initiated in the Eocene or early Oligocene (38.4 Ma, 95% HPD: 27.2-52.6). Most species clades were established in the Miocene. Leptolejeunea epiphylla and L. schiffneri originated in Asia and colonized African islands during the Plio-Pleistocene. Accessions of supposedly pantropical species are placed in different main clades. Several monophyletic morphospecies exhibit considerable sequence variation related to a geographical pattern. The clear geographic structure of the Leptolejeunea crown group points to evolutionary processes including rare long-distance dispersal and subsequent speciation. Leptolejeunea may have benefitted from the large-scale distribution of humid tropical angiosperm forests in the Eocene.
Experiments were carried out in the laboratory and greenhouse to determine the growth inhibitory effects of Grassohopper’s cyperus (Cyperus iria L.) on the seedlings of 5 Malaysian rice varieties namely MR211, MRQ74, MR220, MR84 and MR232. Three concentrations of the aqueous extract of the weed (12.5, 25.0 and 50.0 g/l) and weed debris (5, 10 and 20 g dry debris/1000 g soil) were used to test the allelopathic effect of
C. iria on the growth of the rice plants. The weed leaf, stem and root extracts reduced the growth of the rice seedlings and showed selective activity in the varieties. The C. iria leaf and stem extracts showed comparatively higher growth inhibitory effects than those from the root. The weed extract caused more reduction in the root length of the rice plant compared to the shoot length. Among the rice varieties tested, MR232 was found to be more susceptible to the weed inhibitory effect. The leaf extract of C. iria at full strength caused root and shoot reduction of MR232 by 88.1% and 73.1% respectively (compared to the control). In most cases the fresh weight of the rice seedlings were more affected than the plant height. Weed debris caused significant reduction of leaf chlorophyll content in all the rice varieties tested with the exception of MR211. The chlorophyll content of MR232 was greatly affected by the weed debris which caused reduction of 36.4% compared to the control. The inhibitory effects of weed extracts and debris on rice growth
parameters were found to be concentration dependent.
Weedy rice (WR) is found in many direct-seeded rice fields. WR possesses morphological characteristics that are similar to cultivated rice varieties in the early stage of growth, making them more difficult to control than other weeds. A comparative morphological study was conducted by collecting WR accessions from four sites within the Pulau Pinang rice growing areas. The objective of the study was to characterise WR accessions of the Pulau Pinang rice granary by comparing their morphological characteristics to those of commercially grown rice in the area. Their morphometric relations were established by comparing 17 morphological characteristics of the WR accessions and the commercial varieties. A total of 36 WR morphotypes were identified from these 4 sites based on 17 characteristics, which included grain shattering habit and germination rate. The Principal Component Analysis (PCA) showed that 45.88% of the variation observed among the WR accessions and commercial varieties were within the first 3 axes. PB6, PP2 and SGA5 WR accessions had a higher number of tillers and longer panicle lengths, culm heights and leaf lengths compared to the commercial rice. The grain
sizes of the commercial varieties were slightly longer, and the chlorophyll contents at 60–70 days after sowing (DAS) were higher than those of the WR accessions. Results from this study are useful for predicting potential WR accession growth, which might improve WR management and agriculture practices that control WR in the future.
The preliminary ichthyotoxic test on all parts of Syzygium malaccense (Myrtaceae) revealed that the leaves fraction was the most ichthyotoxic against tilapia-fish (Tilapia oreochromis). Three compounds, namely ursolic acid (1), β-sitosterol (2) and sitost-4-en-3-one (3), were isolated and their structures were elucidated with the aid of spectroscopic data and comparison with previously reported investigations. However none of these compounds gave any significant ichthyotoxicity. The volatile constituents of the leaves and fruit were determined by Gas Chromatography-Mass Spectrometer (GC-MS), with 180 and 203 compounds being identified in the aroma concentrates, respectively.
This paper studied the thermal behaviour of pineapple leaf fibre (PALF) reinforced high impact polystyrene (HIPS) composite. Thermogravimetric analysis (TGA) and differential scanning calorimetric (DSC) analysis were used to measure the thermal characteristic of HIPS/PALF composites. In particular, the TGA analysis was utilized to measure the degradation and decomposition of materials in neat polystyrene, pineapple fibre, and the composites. The measurements were carried out in the temperature of 25°C – 800°C, at a heating rate of 20°C min-1 and the nitrogen gas flow was 50 mL min-1. The temperature of the DSC analysis was programmed to be between 25°C – 300°C. The results from TGA analysis show that the addition of pineapple fibre has improved the thermal stability of the composites as compared to neat HIPS. In addition, the effects of compatibilising agent and surface modification of PALF with alkali treated were also determined and compared.
This study was done to assess the total phenolic compounds (TPC) and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity in the flowers and leaves of Clitoria ternateaand Vitex negundo Linn. by using methanol and water extraction. TPC were evaluated using Folin-Ciocalteau method. Methanol was more efficient in extracting phenolic compounds compared with water in measuring TPC. Vitex negundo Linn. contained higher amount of TPC compared to Clitoria ternatea. Besides that, leaves for both plants showed higher amount of TPC compared to the flowers. Methanol extracted Vitex negundo Linn. showed higher DPPH scavenging activity compared with Clitoria ternatea. In contrast, DPPH scavenging activity for water extracted Clitoria ternatea showed higher value in compare with water extracted Vitex negundo Linn. The type of solvent used to extract the plant material and concentration of extracts used showed significance difference (P < 0.05) on the amount of DPPH scavenged by the plant extract. The presence of antioxidant activity in both leaves and flowers showed that Clitoria ternatea and Vitex negundo Linn. have the potential to be an alternative source of natural antioxidants. In vivo study is needed for successful commercialization and to benefit both the food and pharmaceutical industries.
The total phenolic contents (TPC) and antioxidant activities of five popular Malay raw salads or Ulam were investigated using DPPH radical scavenging and reducing ferric ion antioxidant power (FRAP) assays. The Ulam studied were the leaves of Cosmos caudatus (Ulam Raja), Oenanthe javanica (Selom), Murraya koenigii (Curry Leaf), Centella asiatica (Pegaga) and the seeds of Parkia speciosa (Petai). Ranking order of TPC (mg gallic acid equivalent per gram of plant on dry basis), TEACDPPH (µmol Trolox equivalent per gram of plant on dry basis) and TEACFRAP (µmol Trolox equivalent per gram of plant on dry basis) values were: Curry Leaf (33.18), Selom (31.8), Ulam Raja (31.3) > Pegaga (11.16) > Petai (6.45); Ulam Raja (212.8) > Selom (185.9) > Curry Leaf (82.1), Petai (67.62) > Pegaga (32.4); Selom (199.96) > Ulam Raja (183.11) > Curry Leaf (108.34) > Pegaga (65.99) > Petai (44.67), respectively. No significant correlation (p>0.05) was observed between antioxidant activities and TPC which could be due to steric hindrance or presence of other reducing agents. Interestingly, Selom showed antioxidant activities that are comparable to Ulam Raja.
This study was undertaken to evaluate the antioxidant and acetylcholinesterase inhibition properties of stems and leaves of hexane and methanolic extracts of Pluchea indica. Methanolic extract of leaves showed the highest antioxidant activity (IC50 = 24.45 ± 0.34 µg/ml) and total phenolic contents (573.52 ± 6.2 mg GAE/100 g crude extract), in DPPH radical scavenging and Folin-Ciocalteu assays respectively, however, it failed to inhibit acetylcholinesterase in TLC bioautographic detection. The rest of plant extracts, including methanolic extract of stems, hexane extract of both leaves and stems, were detected to have acetylcholinesterase inhibitory properties. Hexane extract of both leaves and stems exhibited lower or negligible level of antioxidant activity and phenolic contents. Pluchea indica may provide a potential natural source of bioactive compounds, and maybe beneficial to the human health.
The extraction of phenolics from Citrus hystrix leaf was carried out using supercritical fluid extraction and was optimized using response surface methodology (RSM). The effects of CO2 flow rate, extraction pressure and extraction temperature on yield, total phenolic content and diphenyl-picrylhydrazyl-IC50 were evaluated and compared with ethanol extraction. The extraction pressure was the most significant factor affecting the yield, TPC and DPPH-IC50 of the extracts, followed by CO2 flow rate and the extraction temperature. The optimum conditions of pressure, CO2 flow rate and temperature were at 267 bars, 18 g/min and 50°C, respectively. The yield, TPC and DPPH-IC50 obtained were 5.06%, 116.53 mg GAE/g extract and IC50 of 0.063 mg/ml, respectively. These values were not significantly different (p
Synthetic antioxidants are added to food in the powdered form to preserve it. However these compounds posed serious health concern since they have been associated with causing cancer. Thus using fresh herbs with antioxidant activities would be good alternative. The objectives of this study were to evaluate and compare the total phenolic contents and antioxidant activities of both powdered and fresh forms of turmeric leaf, pandan leaf and torch ginger flower. Total phenolic content (TPC) was assayed based on the redox reaction between Folin-Ciocalteu with phenolics in the sample extracts. Antioxidant activity (AA) was assayed using the ß-carotene linoleate model system and the percentage of antioxidant activity was calculated from the values of degradation rate. Scavenging activity (SA) was assayed using the DPPH radical scavenging model system whereby EC50 value was determined from the plotted graph of scavenging activity against the concentration of sample extracts. Analyses revealed that powdered forms of turmeric leaf, pandan leaf and torch ginger flower had higher TPC (2013.09 ± 5.13, 1784.25 ± 7.59 and 1937.42 ± 6.61 mg GAE/100g, respectively) than their respective fresh forms (348.75 ± 1.26, 356.42 ± 1.32 and 211.59 ± 6.29 mg GAE/100g, respectively). Similarly, powdered forms of turmeric leaf, pandan leaf and torch ginger flower possessed better AA (64.31 ± 0.99, 65.09 ± 0.74 and 11.80 ± 0.40 %, respectively) than their respective fresh forms (24.93 ± 0.71, 16.91 ± 0.70 and 1.45 ± 0.10 %, respectively). Powdered forms of turmeric leaf, pandan leaf and torch ginger flower were also better radical scavenger as compared to their respective fresh forms. In conclusion, all samples in their powdered forms have high total phenolic contents, antioxidant and scavenging activities than their respective fresh forms.
Mineral elemental uptake by Colocasia esculenta growing in swamp agroecosystem was studied following 14, 18 or 28 months of field spraying (MAT, months after treatment) with herbicide Gramoxone ® (paraquat). In overall, Al (68226.67 + 24066.56 μg/g dw) was the major element in riverine alluvial swamp soil, followed by micronutrient Fe (22280.00 + 6328.87 μg/g dw).
Concentration of macronutrient K (20733.33 + 7371.82 μg/g dw) was the highest in swamp taro leaf followed by macronutrient Ca (7050.00 + 3767.26 μg/g dw). In overall, the order of importance of the average mineral concentration in swamp taro leaf was K > Ca > Mn > Al > Na > Fe > Zn > Br > Co. However at 14 MAT, the order of importance of mineral content concentration in swamp taro leaf was K > Ca > Al > Na > Mn > Fe > Zn > Br > Co. At 18 MAT, the order of importance of mineral content concentration in swamp taro leaf was K > Ca > Mn > Al > Fe > Na > Zn > Br > Co. At 28 MAT, the order of importance of mineral content concentration in swamp taro leaf was K > Ca > Mn > Fe > Al > Zn > Na > Br > Co. In overall, the average order of importance of mineral elemental uptake or the soil plant transfer coefficient was Mn > K > Na > Zn > Co > Fe > Al; similar with the order at 28 MAT. However, at 14 MAT the order of importance of the soil plant transfer coefficient was different at Mn > K > Na > Co > Zn > Al > Fe.
Over 114 countries in the world grow rice and more than 50 countries have an annual rice production of 100,000 tonnes or more. Asian farmers produce about 90% of the global total rice production. Generally, there are two most common varieties of rice; cultivated and hill rice. Nowadays a lot of agriculture land is contaminated with toxic elements owing to the use of sludge or municipal compost, pesticides, fertilizers and emissions from municipal waste incinerators, car exhausts, residues from metalliferous mines, and smelting industries. The distribution and concentration of several toxic elements in grains particularly rice has lately become a big concern. A study to determine the concentrations of some elements in a few varieties of rice in our local market using Instrumental Neutron Activation Analysis has been performed by Waste and Environmental Technology Division, Malaysian Nuclear Agency. A total of 15 elements were measured. The method was validated by analysing the Standard Reference Material SRM-1568a (Rice Flour) and SRM-1573a (Tomato Leaves) of NIST. The measured concentrations of major and minor elements were analysed in terms of the average intake of nutrient content and comparison of several toxic elements to other studied values.
Effects of cultural practice under different habitats, of well-managed monoculture plantation and growing wild under rubber trees, were studied in Aquilaria malaccensis (Karas) leaves. This study was carried out on Karas growing in these two habitats each from Lipis, Pahang and Sepang, Selangor areas in Malaysia; under the control and induced treatments. The parameters studied include wet and dry weight of 50 matured leaves, iron and zinc elemental contents in leaf, iron and zinc uptakes from soil, and leaf and soil moisture contents. Iron and zinc were analysed in Karas leaves and soil by using Instrumental Neutron Activation Analysis (INAA) technique.
The inhibitory effect of onion extract on cassava leaf polyphenol oxidase was investigated. The polyphenol oxidase from cassava leaves was strongly inhibited by various anti-browning agents such as L-ascorbic acid and L-cysteine. The percentage of inhibition increased with the increased of anti-browning agents concentrations. The addition of heated onion extract exhibited a stronger inhibitory effect on cassava leaf polyphenol oxidase than the fresh onion extract. The highest percentage of inhibition was exhibited with heated onion extract in the presence of glucose and glycine, which was 87.18%. The onion extract inhibited the cassava leaf polyphenol oxidase non-competitively.
The study was aimed to determine the antioxidant and α-glucosidase inhibition activities of
the stem and leaf of five different traditional medicinal plants. The studied plants exhibited
varied antioxidant and α-glucosidase inhibition activities. The antioxidant activities of the
plants were determined through their free radical scavenging capabilities using DPPH assay.
The most potent antioxidant activity was demonstrated by Neptunia oleracea with an IC50 of
35.45 and 29.72 μg/mL for leaf and stem, respectively. For α-glucosidase inhibition activity,
Neptunia oleracea exhibited potential α-glucosidase inhibition activity with IC50 value of
19.09 and 19.74 μg/mL for leaf and stem, respectively. The highest total phenolic content
(TPC) was also marked in Neptunia oleracea leaf and stem with value of 40.88 and 21.21 mg
GAE/g dry weight, respectively. The results also showed that Strobilanthes crispus collected
from two different locations possessed different levels of phenolic content, antioxidant and
α-glucosidase inhibition activities. The study revealed that phenolic compounds could be the
main contributors to the antioxidant and α-glucosidase inhibition activities with R values of 78.9
and 67.4%, respectively. In addition, antioxidant and α-glucosidase were positively correlated
(R = 81.9%). Neptunia oleracea could be suggested as a potential natural source of antioxidant
and antidiabetic compounds that can be used for the prevention or treatment of diabetes.
Leaves of Thottea dependens have been used as folk medicine in Malaysia for the treatment of
several conditions involving pain and inflammation with accompanying pyrexia. However, there is no scientific
evidence for its effectiveness to treat fever. Hence, the purpose of this study was to evaluate the anti-pyretic
activity of methanol (MeOH) and aqueous (Aq) extracts of T. dependens leaves in albino mice (ICR strain).
The terrestrial Ludisia discolor, also referred to as the jewel orchid is prized for
the quality of its leaves. L. discolor is known as a medicinal herb and is touted for its heatand
pathogen-resisting qualities. L. discolor is valuable in the production of both flavonoids
and anthocyanins, antioxidants that are exalted in the health industry. Plant cell cultures
have emerged as alternative sources of anthocyanin production. Plant protoplast cultures
are used frequently in transient gene expression studies and in the establishment of callus
and cell suspension cultures. Benefits of plant protoplast system include similarity to cells
found in plant tissues, reproduction under controlled conditions, and prevention of masking
of stress responses to previous handling techniques. A study was conducted to assess the
amenability of the stem and leaves of L. discolor to protoplast isolation. The stem and leaf
segments were weighed, sliced into thin layers, immersed in a digestion medium, washed
and then cultured onto a recovery medium. Results indicated that the production of plant
protoplasts from L. discolor may be viewed as an alternative in the generation of cell
cultures and ultimately in the production of anthocyanins from the cell cultures.
Photosynthesis is one of the most fundamental biochemical processes on earth such that it is vital to the existence of most lives on this planet. In fact, unravelling the potentials in enhancing photosynthetic efficiency and electron transfer process, which are thought to improve plant growth is one of the emerging approaches in tackling modern agricultural shortcomings. In light of this, zero-dimensional carbon quantum dots (CQD) have emerged and garnered much interest in recent years which can enhance photosynthesis by modulating the associated electron transfer process. In this work, CQD was extracted from empty fruit bunch (EFB) biochar using a green acid-free microwave method. The resulting CQD was characterized using HRTEM, PL, UV-Vis and XPS. Typical rice (C3) and corn (C4) crops were selected in the present study in order to compare the significant effect of CQD on the two different photosynthetic pathways of crops. CQD was first introduced into crop via foliar spraying application instead of localised placement of CQD before seedling development. The influence of CQD on the photosynthetic efficiency of rice (C3) and corn (C4) leaves was determined by measuring both carbon dioxide conversion and the stomatal conductance of the leaf. As a result, the introduction of CQD greatly enhanced the photosynthesis in CQD-exposed crops. This is the first study focusing on phylogenetically constrained differences in photosynthetic responses between C3 and C4 crops upon CQD exposure, which gives a better insight into the understanding of photosynthesis process and shows considerable promise in nanomaterial research for sustainable agriculture practices.