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Conflicting reports on the role of the glycemic effect of Catha edulis (Khat): A systematic review and meta-analysis

Alsalahi A, Alshawsh MA, Mohamed R, Alyousefi NA, Alshagga MA, Shwter AN, et al.

J Ethnopharmacol, 2016 Jun 20;186:30-43.
PMID: 27025406 DOI: 10.1016/j.jep.2016.03.045

ETHNOPHARMACOLOGICAL RELEVANCE: Traditionally, the leaves of Catha edulis Forsskal (Khat) are consumed by the people of Yemen primarily for its recreational effect, and secondarily, for achieving certain tasks. Additionally, Yemeni diabetics chew such leaves in the belief that this can control their elevated blood glucose level.
AIMS: This review focuses on outlining the findings of studies that have been conducted to display the glycemic effect of Catha edulis, while trying to balance it with findings of the association of its chewing with the development of type 2 diabetes mellitus (DM).
MATERIALS AND METHODS: The search strategy adopted was based on a comprehensive research in Medline, PubMed, Web of Science, JSTOR, Scopus and Cochrane for articles, proceeding abstracts and theses to identify complete reports written in the English language about the glycemic effect of Catha edulis in humans and animals from 1976 to 2016. In addition, bibliographies were also reviewed to find additional reports not otherwise published. Thirty seven records were identified of which, 25 eligible studies were included in the meta-analysis using blood glucose as an outcome measurement. Studies were divided into four subgroups according to the experimental model, namely; non-diabetic animals, diabetic animals, non-diabetic humans and diabetic humans. The pooled mean difference (MD) of blood glucose between experimental and control were calculated using random effects model of the weighted mean difference of blood glucose with 95% confidence interval (CI). Heterogeneity between studies was tested using I(2) statistic and a value of P<0.05 was considered to indicate statistical significance.
RESULTS: The scientific reports in the literature prevailed that the glycemic effect of Catha edulis were greatly conflicting with the majority of studies indicating that Catha edulis has a mild hypoglycemic effect. However, the meta-analysis indicted that the overall result showed an insignificant reduction in blood glucose (MD=-9.70, 95% CI: -22.17 to 2.76, P=0.13, with high heterogeneity between subgroups, I(2)=88.2%, P<0.0001). In addition, pooled mean difference of blood glucose of non-diabetic animals, diabetic animals and non-diabetic humans showed an insignificant reduction in blood glucose (MD=-18.55, 95% CI: -39.55 to 2.50, P<0.08, MD=-52.13%, 95% CI: -108.24 to 3.99, P=0.07 and MD=-2.71%, 95% CI: -19.19 to -13.77, P=0.75) respectively. Conversely, a significant elevation in the pooled mean difference of blood glucose in diabetic humans was indicated (MD=67.18, 95% CI: 36.93-97.43, P<0.0001). The conflict shown in the glycemic effect of Catha edulis is thought to be cultivar-related, while demographic and epidemiological reports suggested that chewing Catha edulis might be a predisposing factor contributing to the development of type 2 DM.
CONCLUSION: It was difficult to draw a meaningful conclusion from both the systematic and the meta-analysis with respect to the glycemic effect of Catha edulis since the meta-analysis results were insignificant with high heterogeneity among subgroups and are greatly conflicting. The variation is most likely due to unadjusted experimental factors or is related to Catha edulis itself, such as the differences in the phytochemical composition. Therefore, it is highly recommended that further studies of the glycemic effect of the cultivar of Catha edulis being studied should come with the identification and quantification of phytochemical content so that a meaningful assessment can be made with regard to its hypoglycemic properties. In addition, well-controlled clinical studies should be conducted to confirm whether or not chewing Catha edulis is associated with the development of type 2 DM, since this would be a source of concern seeing that the plant is widely consumed in certain populations.

Matched MeSH terms: Plant Leaves
Temperature and Time of Steeping Affect the Antioxidant Properties of White, Green, and Black Tea Infusions

Hajiaghaalipour F, Sanusi J, Kanthimathi MS

J Food Sci, 2016 Jan;81(1):H246-54.
PMID: 26613545 DOI: 10.1111/1750-3841.13149

Tea (Camellia sinensis) is the most highly consumed beverage in the world next to water. The common way of preparation is steeping in hot water which is varying for different type of tea. We investigated the antioxidant properties of 6 type of tea leaves under different time and temperatures of extraction method used. In general, all samples tested in this study demonstrated high levels of antioxidant capacity and antioxidant activity. The results indicate that the antioxidants activity is significantly affected by time and temperature of steeping and the highest was depending on the variety. White state values, green and black teas showed different levels of antioxidants under different extraction conditions. Overall, the highest activity for white tea was in prolonged hot and in some assays prolonged hot and cold extracts, whereas for green tea the highest activity observed in prolonged cold steeping while, for black tea was in short hot water infusion. The results of this study showed the antioxidant capacity of white and green tea was greater than black tea.

Matched MeSH terms: Plant Leaves
Overexpression of Oil Palm Early Nodulin 93 Protein Gene (EgENOD93) Enhances In Vitro Shoot Regeneration in Arabidopsis thaliana

Nizan IEF, Kamaruddin K, Ong PW, Ramli Z, Singh R, Rose RJ, et al.

Mol Biotechnol, 2022 Jul;64(7):743-757.
PMID: 35107753 DOI: 10.1007/s12033-022-00450-y

EgENOD93 was first identified in a cDNA microarray study of oil palm tissue culture where it was highly expressed in leaf explants with embryogenic potential. Functional characterization via an RNA interference study of its orthologue in Medicago truncatula demonstrated a significant role of this gene in somatic embryo formation. In this study, EgENOD93 was overexpressed in the important model plant Arabidopsis thaliana to investigate the embryogenic potential of EgENOD93 transgenic Arabidopsis explants compared to explants from control plants (pMDC140 and WT). Experiments using leaf explants revealed higher numbers of regenerated shoots at day 27 in all the homozygous transgenic Arabidopsis cultures (Tg01, Tg02 and Tg03) compared to controls. The expression level of EgENOD93 in Arabidopsis cultures was quantified using reverse transcription quantitative real-time PCR (RT-qPCR). The results supported the overexpression of this gene in transgenic Arabidopsis cultures, with 6 and 10 times higher expression of EgENOD93 in callus at Day 9 and Day 20, respectively. Overall, the results support the role of EgENOD93 in the enhancement of shoot regeneration in transgenic Arabidopsis. This together with the previous results observed in oil palm and Medicago truncatula suggests that ENOD93 plays a key role in the induction of somatic embryogenesis. A similarity to early nodulation-like ontogeny is possible.

Matched MeSH terms: Plant Leaves
Distance- and density-dependent leaf dynamics of seedlings of a tropical rainforest tree

Numata S, Kachi N, Okuda T, Manokaran N

Oecologia, 2017 Oct;185(2):213-220.
PMID: 28852866 DOI: 10.1007/s00442-017-3935-z

Parental distance and plant density dependence of seedling leaf turnover and survival was examined to investigate predictions of the Janzen-Connell hypothesis. The focal study species, Shorea macroptera is a canopy tree species in a lowland rain forest in peninsular Malaysia. We found that the peak of the distribution of plants shifted from 3-6 m to 6-9 m during the course of the change from seedling to sapling stage. The leaf demography of the seedlings was influenced by their distance from the adult tree and also by the seedling density. Although significant density- and distance dependence in leaf production was not detected, seedling leaf loss decreased with distance from the parent tree and with seedling density. Similarly, leaf damage was not found to be distance- or density-dependent, but net leaf gain of seedlings increased with distance from the parent tree. Although no significant distance- or density-dependence was evident in terms of leaf damage, significant distance dependence of the net leaf gain was found. Thus, we concluded that positive distance dependence in the leaf turnover of seedlings may gradually contribute to a shift in the distribution pattern of the progeny through reductions in growth and survivorship.

Matched MeSH terms: Plant Leaves/physiology*
Effects of acute salt stress on modulation of gene expression in a Malaysian salt-tolerant indigenous rice variety, Bajong

Yeo BPH, Bhave M, Hwang SS

J Plant Res, 2018 Jan;131(1):191-202.
PMID: 28921169 DOI: 10.1007/s10265-017-0977-6

The small genome size of rice relative to wheat and barley, together with its salt sensitivity, make it an ideal candidate for studies of salt stress response. Transcriptomics has emerged as a powerful technique to study salinity responses in many crop species. By identifying a large number of differentially expressed genes (DEGs) simultaneously after the stress induction, it can provide crucial insight into the immediate responses towards the stressor. In this study, a Malaysian salt-tolerant indigenous rice variety named Bajong and one commercial rice variety named MR219 were investigated for their performance in plant growth and ion accumulation properties after salt stress treatment. Bajong was further investigated for the changes in leaf's transcriptome after 6 h of stress treatment using 100 mM NaCl. Based on the results obtained, Bajong is found to be significantly more salt tolerant than MR219, showing better growth and a lower sodium ion accumulation after the stress treatment. Additionally, Bajong was analysed by transcriptomic sequencing, generating a total of 130 millions reads. The reads were assembled into de novo transcriptome and each transcript was annotated using several pre-existing databases. The transcriptomes of control and salt-stressed samples were then compared, leading to the discovery of 4096 DEGs. Based on the functional annotation results obtained, the enrichment factor of each functional group in DEGs was calculated in relation to the total reads obtained. It was found that the group with the highest gene modulation was involved in the secondary metabolite biosynthesis of plants, with approximately 2.5% increase in relation to the total reads obtained. This suggests an extensive transcriptional reprogramming of the secondary metabolic pathways after stress induction, which could be directly responsible for the salt tolerance capability of Bajong.

Matched MeSH terms: Plant Leaves/physiology
Fulltext Suboptimal Acclimation of Photosynthesis to Light in Wheat Canopies

Townsend AJ, Retkute R, Chinnathambi K, Randall JWP, Foulkes J, Carmo-Silva E, et al.

Plant Physiol, 2018 Feb;176(2):1233-1246.
PMID: 29217593 DOI: 10.1104/pp.17.01213

Photosynthetic acclimation (photoacclimation) is the process whereby leaves alter their morphology and/or biochemistry to optimize photosynthetic efficiency and productivity according to long-term changes in the light environment. The three-dimensional architecture of plant canopies imposes complex light dynamics, but the drivers for photoacclimation in such fluctuating environments are poorly understood. A technique for high-resolution three-dimensional reconstruction was combined with ray tracing to simulate a daily time course of radiation profiles for architecturally contrasting field-grown wheat (Triticum aestivum) canopies. An empirical model of photoacclimation was adapted to predict the optimal distribution of photosynthesis according to the fluctuating light patterns throughout the canopies. While the photoacclimation model output showed good correlation with field-measured gas-exchange data at the top of the canopy, it predicted a lower optimal light-saturated rate of photosynthesis at the base. Leaf Rubisco and protein contents were consistent with the measured optimal light-saturated rate of photosynthesis. We conclude that, although the photosynthetic capacity of leaves is high enough to exploit brief periods of high light within the canopy (particularly toward the base), the frequency and duration of such sunflecks are too small to make acclimation a viable strategy in terms of carbon gain. This suboptimal acclimation renders a large portion of residual photosynthetic capacity unused and reduces photosynthetic nitrogen use efficiency at the canopy level, with further implications for photosynthetic productivity. It is argued that (1) this represents an untapped source of photosynthetic potential and (2) canopy nitrogen could be lowered with no detriment to carbon gain or grain protein content.

Matched MeSH terms: Plant Leaves/physiology
Evaluation of the Persistence and Leaching Behaviour of Thiram Fungicide in Soil, Water and Oil Palm Leaves

Maznah Z, Halimah M, Ismail BS

Bull Environ Contam Toxicol, 2018 May;100(5):677-682.
PMID: 29516138 DOI: 10.1007/s00128-018-2312-x

The residual levels and persistence of thiram in the soil, water and oil palm seedling leaves were investigated under field conditions. The experimental plots were carried out on a clay loam soil and applied with three treatments namely; manufacturer's recommended dosage (25.6 g a.i. plot-1), manufacturer's double recommended dosage (51.2 g a.i. plot-1), and control (water) were applied. Thiram residues were detected in the soil from day 0 to day 3 in the range of 0.22-27.04 mg kg-1. Low concentrations of thiram were observed in the water and leave samples in the range of 0.27-2.52 mg L-1 and 1.34-12.28 mg kg-1, respectively. Results have shown that thiram has a rapid degradation and has less persistence due to climatic factors. These findings suggest that thiram is safe when applied at manufacturer's recommended dosage on oil palm seedlings due to low residual levels observed in soil and water bodies.

Matched MeSH terms: Plant Leaves/chemistry
Leucoxenols A and B, two new phenolics from Bornean medicinal plant Syzygium leucoxylon

Shamsudin KJ, Phan CS, Kulip J, Hatai K, Vairappan CS, Kamada T

J Asian Nat Prod Res, 2019 May;21(5):435-441.
PMID: 29502443 DOI: 10.1080/10286020.2018.1440391

The medicinal plant, Syzygium leucoxylon or commonly known as Obah found in North Borneo was considered as traditional medicine by local committee. Two new phenolics, leucoxenols A (1) and B (2) were isolated and identified as major secondary metabolites from the leaves of S. leucoxylon. Their chemical structures were elucidated based on spectroscopic data such as NMR and HRESIMS. Furthermore, these compounds were active against selected strains of fungi.

Matched MeSH terms: Plant Leaves/chemistry*
Characterization and pathogenicity of Fusarium species associated with leaf spot of mango (Mangifera indica L.)

Omar NH, Mohd M, Mohamed Nor NMI, Zakaria L

Microb Pathog, 2018 Jan;114:362-368.
PMID: 29233777 DOI: 10.1016/j.micpath.2017.12.026

Leaf spot diseases are mainly caused by fungi including Fusarium. In the present study several species of Fusarium were isolated from the leaf spot lesion of mango (Mangifera indica L.) Based on morphological characteristics, TEF-1α sequences and phylogenetic analysis, five species were identified as F. proliferatum, F. semitectum, F. mangiferae, F. solani and F. chlamydosporum. Pathogenicity test indicated that representative isolates of F. proliferatum, F. semitectum and F. chlamydosporum were pathogenic on mango leaves causing leaf spot with low to moderate virulence. Nevertheless, abundance of spots on the leaf can disrupt photosynthesis which in turn reduced growth, and lead to susceptibility to infection by opportunistic pathogens due to weakening of the plant. Fusarium solani and F. mangiferae were non-pathogenic and it is possible that both species are saprophyte which associated with nutrient availability on the surface of the leaf through decaying leave tissues. The occurrence of Fusarium spp. on the leaf spot lesion and the effect from the disease needs to be considered when developing disease management method of mango cultivation as numerous spot on the leaves could effect the photosynthesis process and finally giving low yield and less quality of mango.

Matched MeSH terms: Plant Leaves/microbiology
Recent Advances in Antibacterial, Antiprotozoal and Antifungal Trends of Eurycoma longifolia: A Review of Therapeutic Implications and Future Prospects

Thu HE, Hussain Z, Mohamed IN, Shuid AN

Curr Drug Targets, 2018;19(14):1657-1671.
PMID: 29468964 DOI: 10.2174/1389450119666180219123815

BACKGROUND: Eurycoma longifolia (E. longifolia) has gained widespread recognition due to its versatile pharmacological activities including aphrodisiac, anticancer, antimicrobial, antioxidant, anti-inflammatory, anxiolytic, anti-diabetic, ergogenic, insecticidal, anti-rheumatism, bone protection, and anti-ulcer effects.
OBJECTIVE: This review was aimed to critically overview the literature and summarizes the antibacterial, antiprotozoal, and antifungal trends of E. longifolia and its medicinally active components.
RESULTS: Besides its well-documented safety, efficacy, and tolerability, a plethora of in vitro, in vivo, and human clinical studies has evidenced the antimicrobial efficacy of E. longifolia and its bioactive constituents. Phytochemical screening of various types of extracts (methanolic, ethyl acetate, and nbutanolic) from different parts (roots, stem, and leaves) of E. longifolia displayed a dose-dependent antibacterial, antiprotozoal, and antifungal responses. Comparative analysis revealed that the root extract of E. longifolia exhibited the highest antimicrobial efficacy compared to other parts of the plant. Bioactivity-guided fractionation identified that among all of the medicinal compounds isolated/ extracted from different parts of E. longifolia, eurycomanone displayed the strongest antibacterial, antiprotozoal and antifungal activities.
CONCLUSION: Based on the critical analysis of the literature, we identified that E. longifolia exhibits promising antibacterial, antiprotozoal, and antifungal efficacies against various pathogenic microbes and thus can be considered as a potential complementary and alternative antimicrobial therapy.

Matched MeSH terms: Plant Leaves/chemistry
A new sulphated flavone and other phytoconstituents from the leaves of Tetracera indica Merr. and their alpha-glucosidase inhibitory activity

Alhassan AM, Ahmed QU, Latip J, Shah SAA

Nat Prod Res, 2019 Jan;33(1):1-8.
PMID: 29417849 DOI: 10.1080/14786419.2018.1437427

The bioactivity guided fractionation of Tetracera indica leaves crude ethanolic extract has afforded the isolation and characterization of six compounds including a new natural product viz., 5,7-dihydroxyflavone-O-8-sulphate (1) and five known flavonoids (2-6). The structures of the compounds were elucidated using 1D and 2D NMR and HRESIMS spectroscopic analyses. All the isolated compounds were evaluated for their in vitro inhibitory activity against alpha-glucosidase. Compound 1, 5 and 6 showed strong alpha-glucosidase inhibitory activity, 3 and 4 displayed weak activity while compound 2 was inactive. The interactions of the active compounds with alpha-glucosidase were further investigated using molecular docking to confirm their antidiabetic potential.

Matched MeSH terms: Plant Leaves/chemistry
Fulltext Antibacterial Activity of Ethanolic Extract of Syzygium polyanthum L. (Salam) Leaves against Foodborne Pathogens and Application as Food Sanitizer

Ramli S, Radu S, Shaari K, Rukayadi Y

Biomed Res Int, 2017;2017:9024246.
PMID: 29410966 DOI: 10.1155/2017/9024246

The aim of this study was to determine antibacterial activity of S. polyanthum L. (salam) leaves extract foodborne pathogens. All the foodborne pathogens were inhibited after treating with extract in disk diffusion test with range 6.67 ± 0.58-9.67 ± 0.58 mm of inhibition zone. The range of MIC values was between 0.63 and 1.25 mg/mL whereas MBC values were in the range 0.63 mg/mL to 2.50 mg/mL. In time-kill curve, L. monocytogenes and P. aeruginosa were found completely killed after exposing to extract in 1 h incubation at 4x MIC. Four hours had been taken to completely kill E. coli, S. aureus, V. cholerae, and V. parahaemolyticus at 4x MIC. However, the population of K. pneumoniae, P. mirabilis, and S. typhimurium only reduced to 3 log CFU/mL. The treated cell showed cell rupture and leakage of the cell cytoplasm in SEM observation. The significant reduction of natural microflora in grapes fruit was started at 0.50% of extract at 5 min and this concentration also was parallel to sensory attributes acceptability where application of extract was accepted by the panellists until 5%. In conclusion, S. polyanthum extract exhibits antimicrobial activities and thus might be developed as natural sanitizer for washing raw food materials.

Matched MeSH terms: Plant Leaves/chemistry*
Extraction of nanosilica from oil palm leaves and its application as support for lipase immobilization

Onoja E, Chandren S, Razak FIA, Wahab RA

J Biotechnol, 2018 Oct 10;283:81-96.
PMID: 30063951 DOI: 10.1016/j.jbiotec.2018.07.036

The study reports the preparation of a composite consisting of magnetite coated with nanosilica extracted from oil palm leaves (OPL) ash as nanosupports for immobilization of Candida rugosa lipase (CRL) and its application for the synthesis of butyl butyrate. Results of immobilization parameters showed that ∼ 80% of CRL (84.5 mg) initially offered was immobilized onto the surface of the nanosupports to yield a maximum protein loading and specific activity of 67.5 ± 0.72 mg/g and 320.8 ± 0.42 U/g of support, respectively. Surface topography, morphology as well as information on surface composition obtained by Raman spectroscopy, atomic force microscopy, field emission scanning electron microscopy and transmission electron microscopy showed that CRL was successfully immobilized onto the nanosupports, affirming its biocompatibility. Under optimal conditions (3.5 mg/mL protein loading, at 45 ℃, 3 h and molar ratio 2:1 (1-butanol:n-butyric acid) the CRL/Gl-A-SiO2-MNPs gave a maximum yield of 94 ± 0.24% butyl butyrate as compared to 84 ± 0.32% in the lyophilized CRL. CRL/Gl-A-SiO2-MNPs showed an extended operational stability, retaining 50% of its initial activity after 17 consecutive esterification cycles. The results indicated that OPL derived nanosilica coated on magnetite can potentially be employed as carrier for lipase immobilization in replacement of the non-renewable conventionalsilica sources.

Matched MeSH terms: Plant Leaves/chemistry
Fulltext Logging and soil nutrients independently explain plant trait expression in tropical forests

Both S, Riutta T, Paine CET, Elias DMO, Cruz RS, Jain A, et al.

New Phytol, 2019 03;221(4):1853-1865.
PMID: 30238458 DOI: 10.1111/nph.15444

Plant functional traits regulate ecosystem functions but little is known about how co-occurring gradients of land use and edaphic conditions influence their expression. We test how gradients of logging disturbance and soil properties relate to community-weighted mean traits in logged and old-growth tropical forests in Borneo. We studied 32 physical, chemical and physiological traits from 284 tree species in eight 1 ha plots and measured long-term soil nutrient supplies and plant-available nutrients. Logged plots had greater values for traits that drive carbon capture and growth, whilst old-growth forests had greater values for structural and persistence traits. Although disturbance was the primary driver of trait expression, soil nutrients explained a statistically independent axis of variation linked to leaf size and nutrient concentration. Soil characteristics influenced trait expression via nutrient availability, nutrient pools, and pH. Our finding, that traits have dissimilar responses to land use and soil resource availability, provides robust evidence for the need to consider the abiotic context of logging when predicting plant functional diversity across human-modified tropical forests. The detection of two independent axes was facilitated by the measurement of many more functional traits than have been examined in previous studies.

Matched MeSH terms: Plant Leaves/physiology
Structures and Antimutagenic Effects of Onoceranoid-Type Triterpenoids from the Leaves of Lansium domesticum

Matsumoto T, Kitagawa T, Teo S, Anai Y, Ikeda R, Imahori D, et al.

J Nat Prod, 2018 10 26;81(10):2187-2194.
PMID: 30335380 DOI: 10.1021/acs.jnatprod.8b00341

A methanol extract of the dried leaves of Lansium domesticum showed antimutagenic effects against 3-amino-1,4-dimethyl-5 H-pyrido[4,3- b]indole (Trp-P-1) and 2-amino-1-methyl-6-phenylimidazo[4,5- bI]pyridine (PhIP) using the Ames assay. Nine new onoceranoid-type triterpenoids, lansium acids I-IX (1-9), and nine known compounds (10-16) were isolated from the extract. The structures of the new compounds were elucidated on the basis of chemical and spectroscopic evidence. The absolute stereostructures of the new compounds were determined via their electronic circular dichroism spectra. Several isolated onoceranoid-type triterpeneoids showed antimutagenic effects in an in vitro Ames assay. Moreover, oral intake of a major constituent, lansionic acid (10), showed antimutagenic effects against PhIP in an in vivo micronucleus test.

Matched MeSH terms: Plant Leaves/chemistry*
Estimation of carbon pool in soil, above and below ground vegetation at different types of mangrove forests in Peninsular Malaysia

Rozainah MZ, Nazri MN, Sofawi AB, Hemati Z, Juliana WA

Mar Pollut Bull, 2018 Dec;137:237-245.
PMID: 30503430 DOI: 10.1016/j.marpolbul.2018.10.023

This paper evaluated the total carbon stock of mangrove ecosystems in two contrasting sites: a fishing village in Delta Kelantan (DK) and Ramsar sites in Johor Park (JP). In both sites, aboveground carbon was significantly higher than belowground carbon, and stems contained more carbon than leaf and root partitions. The average carbon concentration of individual mangrove species (44.9-48.1%) was not significantly different but the larger biomass of the DK samples resulted in vegetation carbon stock that was higher than that in JP. Season played an important role in soil carbon stock-a pronounced wet season in DK coincided with the dry season in JP. The total carbon pool was estimated to be 427.88 t ha-1 in JP and 512.51 t ha-1 in DK, where at least 80% was contributed by soil carbon. The carbon dioxide equivalent was 1570.32 t ha-1 CO2e (JP) and 1880.91 t ha-1 CO2e (DK).

Matched MeSH terms: Plant Leaves/chemistry
Bacterial leaf blight resistance in rice: a review of conventional breeding to molecular approach

Chukwu SC, Rafii MY, Ramlee SI, Ismail SI, Hasan MM, Oladosu YA, et al.

Mol Biol Rep, 2019 Feb;46(1):1519-1532.
PMID: 30628024 DOI: 10.1007/s11033-019-04584-2

Breeding for disease resistant varieties remains very effective and economical in controlling the bacterial leaf blight (BLB) of rice. Breeders have played a major role in developing resistant rice varieties against the BLB infection which has been adjudged to be a major disease causing significant yield reduction in rice. It would be difficult to select rice crops with multiple genes of resistance using the conventional approach alone. This is due to masking effect of genes including epistasis. In addition, conventional breeding takes a lot of time before a gene of interest can be introgressed. Linkage drag is also a major challenge in conventional approach. Molecular breeding involving markers has facilitated the characterization and introgression of BLB disease resistance genes. Biotechnology has brought another innovation in form of genetic engineering (transgenesis) of rice. Although, molecular breeding cannot be taken as a substitute for conventional breeding, molecular approach for combating BLB disease in rice is worthwhile given the demand for increased production of rice in a fast growing population of our society. This present article highlights the recent progress from conventional to molecular approach in breeding for BLB disease resistant rice varieties.

Matched MeSH terms: Plant Leaves/microbiology*
The phytochemical and anti-inflammatory studies of Dillenia suffruticosa leaves

Abubakar S, Al-Mansoub MA, Murugaiyah V, Chan KL

Phytother Res, 2019 Mar;33(3):660-675.
PMID: 30653753 DOI: 10.1002/ptr.6255

The Dillenia suffruticosa leaves (Dilleniaceae), a folk medicine recommended in Southeast Asia for treating inflammation, were phytochemically studied for the first time and assessed for suppression of λ-carrageenan-induced paw oedema in rats. The crude methanolic extract orally administered at 5,000 mg/kg, displayed no toxicity and at 250 to 1,000 mg/kg significantly suppressed the paw oedema. Two-isolated triterpenoids, betulinic acid (1) and koetjapic acid (2) orally administered at 50 mg/kg, significantly reduced the paw oedema, (p

Matched MeSH terms: Plant Leaves/chemistry
In Vitro Cytotoxic Activity of Clinacanthus nutans Leaf Extracts Against HeLa Cells

Haron NH, Md Toha Z, Abas R, Hamdan MR, Azman N, Khairuddean M, et al.

Asian Pac J Cancer Prev, 2019 Feb 26;20(2):601-609.
PMID: 30806066

Objective: This study was conducted to investigate the antiproliferative activity of extracts of Clinacanthus nutans
leaves against human cervical cancer (HeLa) cells. Methods: C. nutans leaves were subjected to extraction using 80%
methanol or water. The methanol extract was further extracted to obtain hexane, dichloromethane (DCM), and aqueous
fractions. The antiproliferative activity of the extracts against HeLa cells was determined. The most cytotoxic extract
was furthered analyzed by apoptosis and cell cycle assays, and the phytochemical constituents were screened by gas
chromatography-mass spectrometry (GC-MS). Results: All of the extracts were antiproliferative against HeLa cells, and
the DCM fraction had the lowest IC50 value of 70 μg/mL at 48 h. Microscopic studies showed that HeLa cells exposed
to the DCM fraction exhibited marked morphological features of apoptosis. The flow cytometry study also confirmed
that the DCM fraction induced apoptosis in HeLa cells, with cell cycle arrest at the S phase. GC-MS analysis revealed
the presence of at least 28 compounds in the DCM fraction, most of which were fatty acids. Conclusion: The DCM
fraction obtained using the extraction method described herein had a lower IC50 value than those reported in previous
studies that characterized the anticancer activity of C. nutans against HeLa cells.

Matched MeSH terms: Plant Leaves/chemistry*
Fulltext Inhibition of Human Platelet Aggregation and Low-Density Lipoprotein Oxidation by Premna foetida Extract and Its Major Compounds

Dianita R, Jantan I

Molecules, 2019 Apr 13;24(8).
PMID: 31013947 DOI: 10.3390/molecules24081469

Many Premna species have been used in traditional medicine to treat hypertension and cardiac insufficiency, and as a tonic for cardiac-related problems. Some have been reported to possess cardiovascular protective activity through several possible mechanisms, but not Premna foetida. In the present study, the methanol extract of P. foetida leaves (PFM) and its isolated compounds were evaluated for their ability to inhibit copper-mediated human low-density lipoprotein (LDL) oxidation and arachidonic acid (AA)- and adenosine diphosphate (ADP)-induced platelet aggregation. Six flavonoids, three triterpenoids, vanillic acid and stigmasterol were successfully isolated from PFM. Of the isolated compounds, quercetin was the most active against LDL oxidation (IC50 4.25 µM). The flavonols were more active than the flavones against LDL oxidation, suggesting that hydroxyl group at C-3 and the catechol moiety at B-ring may play important roles in protecting LDL from oxidation. Most tested flavonoids showed stronger inhibition towards AA-induced than the ADP-induced platelet aggregation with apigenin exhibiting the strongest effect (IC50 52.3 and 127.4 µM, respectively) while quercetin and kaempferol showed moderate activity. The results suggested that flavonoids, especially quercetin, apigenin and kaempferol were among the major constituents of P. foetida responsible for anti-LDL oxidation and anti-platelet aggregation.

Matched MeSH terms: Plant Leaves/chemistry*

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