Interaction between water and wind as a driver of passive dispersal in mangroves.[Pubmed: 25811191]

Although knowledge on dispersal patterns is essential for predicting long-term population dynamics, critical information on the modalities of passive dispersal and potential interactions between vectors is often missing. Here, we use mangrove propagules with a wide variety of morphologies to investigate the interaction between water and wind as a driver of passive dispersal. We imposed 16 combinations of wind and hydrodynamic conditions in a flume tank, using propagules of six important mangrove species (and genera), resulting in a set of dispersal morphologies that covers most variation present in mangrove propagules worldwide. Additionally, we discussed the broader implications of the outcome of this flume study on the potential of long distance dispersal for mangrove propagules in nature, applying a conceptual model to a natural mangrove system in Gazi Bay (Kenya). Overall, the effect of wind on dispersal depended on propagule density (g l(-1)). The low-density Heritiera littoralis propagules were most affected by wind, while the high-density vertically floating propagules of Ceriops tagal and Bruguiera gymnorrhiza were least affected. Avicennia marina, and horizontally floating Rhizophora mucronata and C. tagal propagules behaved similarly. Morphological propagule traits, such as the dorsal sail of H. littoralis, explained another part of the interspecific differences. Within species, differences in dispersal velocities can be explained by differences in density and for H. littoralis also by variations in the shape of the dorsal sail. Our conceptual model illustrates that different propagule types have a different likelihood of reaching the open ocean depending on prevailing water and wind currents. Results suggest that in open water, propagule traits (density, morphology, and floating orientation) appear to determine the effect of water and wind currents on dispersal dynamics. This has important implications for inter- and intraspecific variation in dispersal patterns and the likelihood of reaching suitable habitat patches within a propagule's viable period.

A new cinnamoylglycoflavonoid, antimycobacterial and antioxidant constituents from Heritiera littoralis leaf extracts.[Pubmed: 24443810]

A new cinnamolyglycoflavonoid 3-cinnamoyltribuloside (1), its precursor tribuloside and two known flavonoid glycosides afzelin and astilbin were isolated from Heritiera littoralis Dryand (Sterculiaceae) ethanolic leaf extract. The dichloromethane leaf extract afforded two known pentacyclic triterpenoids, 3β-taraxerol and friedelin. Extracts and compounds isolated therefrom, with the exception of 3β-taraxerol, exhibited antimycobacterial activity against the non-pathogenic Mycobacterium species Mycobacterium madagascariense and Mycobacterium indicus pranii, with a minimum inhibitory concentration (MIC) 5.0 mg/mL for the crude extracts and MICs in the range of 1.6-0.8 mg/mL for the pure compounds. The extracts together with 3-cinnamoyltribuloside (1), tribuloside and astilbin exhibited 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. The compounds that showed dual activities could be further evaluated under clinical settings for co-administration with standard anti-tuberculosis drugs.

Can scientific evidence support using Bangladeshi traditional medicinal plants in the treatment of diarrhoea? A review on seven plants.[Pubmed: 23698166]

Diarrhoea is a common disease which causes pain and may be deadly, especially in developing countries. In Bangladesh, diarrhoeal diseases affect thousands of people every year, and children are especially vulnerable. Bacterial toxins or viral infections are the most common cause of the disease. The diarrhoea outbreaks are often associated with flood affected areas with contaminated drinking water and an increased risk of spreading the water-borne disease. Not surprisingly, plants found in the near surroundings have been taken into use by the local community as medicine to treat diarrhoeal symptoms. These plants are cheaper and more easily available than conventional medicine. Our question is: What is the level of documentation supporting the use of these plants against diarrhoea and is their consumption safe? Do any of these plants have potential for further exploration? In this review, we have choosen seven plant species that are used in the treatment of diarrhoea; Diospyros peregrina, Heritiera littoralis, Ixora coccinea, Pongamia pinnata, Rhizophora mucronata, Xylocarpus granatum, and Xylocarpus moluccensis. Appearance and geographical distribution, traditional uses, chemical composition, and biological studies related to antidiarrhoeal activity will be presented. This review reveals that there is limited scientific evidence supporting the traditional use of these plants. Most promising are the barks from D. peregrina, X. granatum and X. moluccensis which contain tannins and have shown promising results in antidiarrhoeal mice models. The leaves of P. pinnata also show potential. We suggest these plants should be exploited further as possible traditional herbal remedies against diarrhoea including studies on efficacy, optimal dosage and safety.

[Optimization of extraction on flavonoids from leaves of Heritiera littoralis].[Pubmed: 23019912]

To optimize the preparation procedure for extraction of flavonoids from leaves of Heritiera littoralis.

Anti-inflammatory principles from Heritiera littoralis bark.[Pubmed: 20363114]

Compounds from the hexane, dichloromethane and acetone extracts of Heritiera littoralis bark were investigated for their nitric oxide (NO) inhibitory effects using RAW264.7 macrophage cells. The result indicated that ergosterol peroxide (13) exhibited the highest activity against NO release with an IC(50) value of 2.5 microM, followed by 6-alpha-hydroxystigmast-4-en-3-one (11, IC(50)=9.5 microM) and stigmast-4-en-3-one (9, IC(50)=15.9 microM), whereas other compounds showed moderate and mild effects (25.4- > 100 microM). Ergosterol peroxide (13) and 6-alpha-hydroxystigmast-4-en-3-one (11) were also tested against prostaglandin E(2) (PGE(2)) and tumor necrosis factor alpha (TNF-alpha) releases. It was found that ergosterol peroxide (13) possessed marked activity against PGE(2) release with an IC(50) value of 28.7 microM, while 6-alpha-hydroxystigmast-4-en-3-one (11) was 86.7 microM. However, these two compounds were inactive towards TNF-alpha release (IC(50) > 100 microM). The mechanism in transcriptional level of ergosterol peroxide (13) was found to down regulate mRNA expressions of iNOS and COX-2 in dose-dependent manners.

Shedding light on an extremophile lifestyle through transcriptomics.[Pubmed: 19549131]

The tropical intertidal ecosystem is defined by trees - mangroves - which are adapted to an extreme and extremely variable environment. The genetic basis underlying these adaptations is, however, virtually unknown. Based on advances in pyrosequencing, we present here the first transcriptome analysis for plants for which no prior genomic information was available. We selected the mangroves Rhizophora mangle (Rhizophoraceae) and Heritiera littoralis (Malvaceae) as ecologically important extremophiles employing markedly different physiological and life-history strategies for survival and dominance in this extreme environment. For maximal representation of conditional transcripts, mRNA was obtained from a variety of developmental stages, tissues types, and habitats. For each species, a normalized cDNA library of pooled mRNAs was analysed using GSFLX pyrosequencing. A total of 537,635 sequences were assembled de novo and annotated as > 13,000 distinct gene models for each species. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) orthology annotations highlighted remarkable similarities in the mangrove transcriptome profiles, which differed substantially from the model plants Arabidopsis and Populus. Similarities in the two species suggest a unique mangrove lifestyle overarching the effects of transcriptome size, habitat, tissue type, developmental stage, and biogeographic and phylogenetic differences between them.

Natural products from semi-mangrove flora: source, chemistry and bioactivities.[Pubmed: 19177225]

This review covers the source, chemistry and bioactivities of natural products from semi-mangrove species worldwide. The chemotaxonomy of semi-mangrove plants and total synthesis of heritol analogues, which are potential biocompatible pesticides, are discussed.1 Introduction, 2 Acanthaceae, 2.1 Acanthus, 2.1.1 Aliphatic glycosides, 2.1.2 Alkaloids, 2.1.3 Flavonoids, 2.1.4 Lignan glycosides, 2.1.5 Megastigmane and phenolic glycosides, 2.1.6 Phenylethanol glycosides, 2.1.7 Triterpenoids, 2.1.8 Miscellaneous, 2.1.9 Bioactivities, 3 Euphorbiaceae, 3.1 Excoecaria, 3.1.1 Diterpenoids, 3.1.2 Miscellaneous, 3.1.3 Bioactivities, 4 Lythraceae, 4.1 Pemphis acidula, 5 Sterculiaceae, 5.1 Heritiera littoralis, 5.1.1 Flavones, 5.1.2 Triterpenoids, 5.1.3 Benzene derivatives, 5.1.4 Sesquiterpenes, 5.1.5 Steroids, 6 Total syntheses of heritol and its analogues, 7 Chemotaxonomy and concluding remarks, 8 Acknowledgements 9 References.

[Screening of cytotoxic activity against B16 tumor cell of mangrove fungi isolate from Qinglan harbor in Hainan].[Pubmed: 18807979]

Six hundred and eight fungi strains were isolated from seventy-eight samples of mangrove plants and soil that collected from Qinglan harbor. Cyctotoxic activity was detected by observing the growth inhibition or killing of the tumor cells under microscope. The result showed that 81 strains (about 13.32% of the total strains isolated) displayed cytotoxic activity against B16 tumor cell. The most fungi strains were isolated from mangrove plant Sonneratia alba, and most of cytotoxic active fungi strains were isolated from mangrove plant Heritiera littoralis.

Seed predation by insects in tropical mangrove forests: extent and effects on seed viability and the growth of seedlings.[Pubmed: 22160114]

Although insects are known to be important seed predators in most terrestrial forests, their role in marine tidal (mangrove) forests has not been examined. Surveys at 12 sites in tropical Australia showed that between 3.1 and 92.7 percent of the seeds or propagules of 12 mangrove tree species had been attacked by insects. Seeds/propagules of six species (Avicennia marina, Bruguiera gymnorrhiza, B. parviflora, Heritiera littoralis, Xylocarpus australasicus and X. granatum) showed consistently high (>40%) levels of insect damage. Greater than 99% of H. littoralis seeds were attacked by insect predators. The survival and subsequent growth in height and biomass of insect-damaged and non-damaged control seeds/propagules of eight mangrove species were compared in shadehouse experiments. Mangrove species fell into 4 groups with regard to the effect of insect predators on their seeds and seedlings. Xylocarpus australasicus and X. granatum had significantly decreased survival (X 48 and 70%) and growth in height (X 61 and 96%) and biomass (X 66 and 85%). Bruguiera parviflora showed decreased survival (X 59%), but there was no effect of insects on the growth of surviving propagules. In contrast, there was no effect of insect damage on the survival of seedlings of Avicennia marina and Bruguiera exaristata, but decreased growth in height (X 22 and 25%) and biomass (X 22 and 26%). Survival and growth of seedlings of Rhizophora stylosa and Bruguiera gymnorrhiza were not affected. The influence of insect seed predators on the survival and growth of seeds of mangrove species in forests will depend on the relative abundance of seed-eating crabs and intertidal position in mangrove forests.