Essential oil composition of diploid and tetraploid clones of ginger (Zingiber officinale roscoe) grown in Australia

Ginger oil, obtained by steam distillation of the rhizome of Zingiber officinale Roscoe, is used in the beverage and fragrance industries. Ginger oil displays considerable compositional diversity, but is typically characterized by a high content of sesquiterpene hydrocarbons, including zingiberene, arcurcumene, beta-bisabolene, and beta-sesquiphellandrene. Australian ginger oil has a reputation for possessing a particular lemony aroma, due to its high content of the isomers neral and geranial, often collectively referred to as citral. Fresh rhizomes of 17 clones of Australian ginger, including commercial cultivars and experimental tetraploid clones, were steam distilled 7 weeks post-harvest, and the resulting oils were analyzed by GC-MS. The essential oils of 16 of the 17 clones, including the tetraploid clones and their parent cultivar, were found to be of substantially similar composition. These oils were characterized by very high citral levels (51-71%) and relatively low levels of the sesquiterpene hydrocarbons typical of ginger oil. The citral levels of most of these oils exceeded those previously reported for ginger oils. The neral-to-geranial ratio was shown to be remarkably constant (0.61 +/- 0.01) across all 17 clones. One clone, the cultivar Jamaican, yielded oil with a substantially different composition, lower citral content and higher levels of sesquiterpene hydrocarbons. Because this cultivar also contains significantly higher concentrations of pungent gingerols, it possesses unique aroma and flavor characteristics, which should be of commercial interest.

Characterization of N-acylhomoserine lactone-degrading bacteria associated with the Zingiber officinale (ginger) rhizosphere: Co-existence of quorum quenching and quorum sensing in Acinetobacter and Burkholderia

Background Cell-to-cell communication (quorum sensing (QS)) co-ordinates bacterial behaviour at a population level. Consequently the behaviour of a natural multi-species community is likely to depend at least in part on co-existing QS and quorum quenching (QQ) activities. Here we sought to discover novelN-acylhomoserine lactone (AHL)-dependent QS and QQ strains by investigating a bacterial community associated with the rhizosphere of ginger (Zingiber officinale) growing in the Malaysian rainforest. Results By using a basal growth medium containing N-(3-oxohexanoyl)homoserine lactone (3-oxo-C6-HSL) as the sole source of carbon and nitrogen, the ginger rhizosphere associated bacteria were enriched for strains with AHL-degrading capabilities. Three isolates belonging to the generaAcinetobacter (GG2), Burkholderia (GG4) and Klebsiella (Se14) were identified and selected for further study. Strains GG2 and Se14 exhibited the broadest spectrum of AHL-degrading activities via lactonolysis while GG4 reduced 3-oxo-AHLs to the corresponding 3-hydroxy compounds. In GG2 and GG4, QQ was found to co-exist with AHL-dependent QS and GG2 was shown to inactivate both self-generated and exogenously supplied AHLs. GG2, GG4 and Se14 were each able to attenuate virulence factor production in both human and plant pathogens. Conclusions Collectively our data show that ginger rhizosphere bacteria which make and degrade a wide range of AHLs are likely to play a collective role in determining the QS-dependent phenotype of a polymicrobial community.

An assessment of Pythium spp. associated with soft rot disease of ginger (Zingiber officinale) in Queensland, Australia

In Australia, Pythium soft rot (PSR) outbreaks caused by P. myriotylum were reported in 2009 and since then this disease has remained as a major concern for the ginger industry. From 2012 to 2015, a number of Pythium spp. were isolated from ginger rhizomes and soil from farms affected by PSR disease and assessed for their pathogenicity on ginger. In this study, 11 distinct Pythium spp. were recovered from ginger farms in Queensland, Australia and species identification and confirmation were based on morphology, growth rate and ITS sequences. These Pythium spp. when tested showed different levels of aggressiveness on excised ginger rhizome. P. aphanidemartum, P. deliense, P. myriotylum, P. splendens, P. spinosum and P. ultimum were the most pathogenic when assessed in vitro on an array of plant species. However, P. myriotylum was the only pathogen, which was capable of inducing PSR symptoms on ginger at a temperature range from 20 to 35 °C. Whereas, P. aphanidermatum only attacked and induced PSR on ginger at 30 to 35 °C in pot trials. This is the first report of P. aphanidermatum inducing PSR of ginger in Australia at high temperatures. Only P. oligandrum and P. perplexum, which had been recovered only from soils and not plant tissue, appeared non-pathogenic in all assays.

Field evaluation of micropropagated and conventionally propagated ginger in subtropical Queensland

The growth and performance of micropropagated ginger (Zingiber officinale Roscoe) was compared with 'seed'-derived plants in field trials conducted in south-eastern Queensland. In the first generation ex vitro, micropropagated plants had significantly (P<0.01) reduced rhizome yield with smaller knobs and more roots. Micropropagated plants had a greater (P<0.01) shoot: root (rhizome) ratio compared with seed-derived plants. Shoots from micropropagated plants were also significantly (P<0.01) smaller with a greater number of shoots per plant. The unusual shoot morphology of the micropropagated plants did not appear to be related to the presence of benzylaminopurine, a plant growth hormone added to the multiplication medium, as plants subcultured for 3 cycles on a hormone-free medium also exhibited similar characteristics. Seed collected from the micropropagated plants and seed-derived plants was harvested and, despite the micropropagated seed being significantly (P<0.01) smaller, by the second generation ex vitro there were no significant differences between the treatments. Factors that can improve rhizome size, while reducing production costs, need to be identified before micropropagated plants can be recommended for routine use in the ginger industry as a source of disease and pest-free planting material.

First report of Pythiogeton ramosum (Pythiales) in Australia

In 2012, a project was initiated to assess if the soft rot disease of ginger in Australian fields was associated with pathogens other than Pythium myriotylum. Together with nine Pythium spp., ten isolates of a Pythium-like organism were also recovered from ginger with soft rot symptoms. These Pythium-like isolates were identified as Pythiogeton (Py.) ramosum based on its morphology and ITS sequences. In-vitro pathogenicity tests allowed confirmation of pathogenicity of Py. ramosum on excised carrot (Daucus carota), sweet potato (Ipomoea batatas) and potato (Solanum tubersum) tubers, although it was not pathogenic on excised ginger (Zingiber officinale) and radish (Raphanus sativus) rhizome/roots. In addition it was found to be pathogenic on bean (Phaseolus vulgaris), capsicum (Capsicum annuum) and cauliflower (Brassica oleracea var. botrytis) seedlings. This is the first record of Py. ramosum and its pathogenicity in Australia.

Botanical insecticides prescription for fish pest control and infestation free protein yield

The dry powders of four local species namely Piper guineense Schum and Thonn, Aframomum melegueta Schum, Zingiber officinale Rose; Capsicum annum Miller at three concentrations of 15g, 20g and 25g.kg were evaluated for their insecticidal effects against the larval of the dried fish weevil Demestes maculates Degeer. All the four species showed some effectiveness with P. guineense given a 100% mortality at the end of 72 hours at the three concentrations. The other species though gave less mortality were able to slow down the rate of development of the larvae to the adult size

Investigation on phytochemical constituents and biological potential of some traditional medicinal plants

Plants and microorganisms provide the pharmaceutical industry with some of the most important sources of components for the research of new medications This thesis involves the study of three medicinal plants belonging to three different important families viz, Cyperus rotundus (Cyperaceae), Stereospermum colais (Bignoniaceae) as well as the well known medicinal plant Zingiber officinale (Zingiberaceae) as the third. The first chapter gives an overview of biologically active natural products with special reference to antioxidant, antidiabetic, anti-inflammatory and antimicrobial molecules from terrestrial sources. Chapter 2 of the thesis deals with the isolation of phytochemical constituents of the medicinal plant Cyperus rotundus and its antioxidant and radical scavenging potential. Chapter 3 of the thesis describes the studies on the roots of Stereospermum colais, A Bignoniaceae plant belonging to the genus Stereospermum which is used extensively. Chapter 3 of the thesis describes the studies on the roots of Stereospermum colais, a Bignoniaceae plant belonging to the genus Stereospermum which is used extensively in Ayurveda. Chapter 4 describes the biological potential of rhizomes of Zingiber officinale. Ethyl acetate extract of ginger (EAG) possessed antioxidant activity as is evident from the results of various in vitro assays compared to other extracts .In conclusion, medicinal plants Cyperus rotundus and Stereospermum colais have been analysed for their phytochemical constituents. Also, the positive results obtained from biological activity studies such as antioxidant, anti-inflammatory and antimicrobial activity on the isolated compounds/extracts add on to the medicinal properties of these plants. Apart from that, ethyl acetate extract of Zingiber officinale (ginger) rhizomes has been shown to have very good biological potential including glucose lowering and adipocyte differentiation inhibitory effect.

Herb-drug interactions and mechanistic and clinical considerations

Herbal medicines are often used in combination with conventional drugs, and this may give rise to the potential of harmful herb-drug interactions. This paper updates our knowledge on clinical herb-drug interactions with an emphasis of the mechanistic and clinical consideration. In silico, in vitro, animal and human studies are often used to predict and/or identify drug interactions with herbal remedies. To date, a number of clinically important herb-drug interactions have been reported, but many of them are from case reports and limited clinical observations. Common herbal medicines that interact with drugs include St John's wort (Hypericum perforatum), ginkgo (Ginkgo biloba), ginger (Zingiber officinale), ginseng (Panax ginseng), and garlic (Allium sativum). For example, St John's wort significantly reduced the area under the plasma concentration-time curve (AUC) and blood concentrations of cyclosporine, midazolam, tacrolimus, amitriptyline, digoxin, indinavir, warfarin, phenprocoumon and theophylline. The common drugs that interact with herbal medicines include warfarin, midazolam, digoxin, amitriptyline, indinavir, cyclosporine, tacrolimus and irinotecan. Herbal medicines may interact with drugs at the intestine, liver, kidneys, and targets of action. Importantly, many of these drugs have very narrow therapeutic indices. Most of them are substrates for cytochrome P450s (CYPs) and/or P-glycoprotein (P-gp). The underlying mechanisms for most reported herb-drug interactions are not fully understood, and pharmacokinetic and/or pharmacodynamic mechanisms are implicated in many of these interactions. In particular, enzyme induction and inhibition may play an important role in the occurrence of some herbdrug interactions. Because herb-drug interactions can significantly affect circulating levels of drug and, hence, alter the clinical outcome, the identification of herb-drug interactions has important implications.

Atividade antifúngica de extratos de plantas a Colletotrichum gloeosporioides

The present work aimed to evaluate the effect fungitoxic of plant extracts on the mycelial growth and on the spores germination of C. gloeosporioides. The plant extracts were obtained starting from dried ground plants, using water and ethilic alcohol as extractor. Twenty-two plant species were used to obtain the extracts. The extracts were tested by means of the incorporation of 20% (v/v) in PDA medium, before or after sterilization. The percentage of inhibition of the mycelial growth (PIM) was determined. Extract in the proportion of 50% was added to a spore suspension used to determine the percentage of inhibition of the spores germination (PIS). The hidroetanolic extracts provided larger PIM of C. gloeosporioides, while larger PIS was obtained with the aqueous extracts. Non autoclaved extracts was the most efficient in mycelial growth of C. gloeosporioides, even more than the autoclaved ones. Aqueous and hidroetanolic extracts of Momordica charantia and hidroetanolic extract of Eucalyptus citriodora provided higher PIM. Aqueous extracts of Luffa acutangula, Eucalyptus citriodora, Chenopodium ambrosioides, and Bauhinia, and hidroetanolic extracts of Ruta graveolens, Eucalyptus citriodora, Zingiber officinale and Chenopodium ambrosioides inhibited more than 90% of spores germination.

Lack of chemopreventive effects of ginger on colon carcinogenesis induced by 1,2-dimethylhydrazine in rats

Ginger (Zingiber officinale Roscoe) has been proposed as a promising candidate for cancer prevention. Its modifying potential on the process of colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) was investigated in male Wistar rats using the aberrant crypt foci (ACF) assay. Five groups were studied: Groups 1-3 were given four s.c. injections of DMH (40 mg/kg b.w.) twice a week, during two weeks, whereas Groups 4 and 5 received similar injections of EDTA solution (DMH vehicle). After DMH-initiation, the animals were fed a ginger extract mixed in the basal diet at 0.5% (Group 2) and 1.0% (Groups 3 and 4) for 10 weeks. All rats were killed after 12 weeks and the colons were analyzed for ACF formation and crypt multiplicity. The rates of cell proliferation and apoptosis were also evaluated in epithelial colonic crypt cells. Dietary consumption of ginger at both dose levels did not induce any toxicity in the rats, but ginger meal at 1% decreased significantly serum cholesterol levels (p < 0.038). Treatment with ginger did not suppress ACF formation or the number of crypts per ACF in the DMH-treated group. Dietary ginger did not significantly change the proliferative or apoptosis indexes of the colonic crypt cells induced by DMH. Thus, the present results did not confirm a chemopreventive activity of ginger on colon carcinogenesis as analyzed by the ACF bioassay and by the growth kinetics of the colonic mucosa. (c) 2005 Elsevier Ltd. All rights reserved.

Concentração de enzimas amilolíticas na hidrólise do amido de gengibre

Uma possibilidade de incremento na cadeia produtiva do gengibre seria o uso de rizomas desclassificados para comercialização in natura, ou mesmo o resíduo da extração de óleos, como matérias-primas para a obtenção de bebidas destiladas. O amido não é diretamente fermentável, necessitando de uma hidrólise prévia de suas cadeias para a obtenção de glicose. Neste trabalho, objetivou-se avaliar o efeito das concentrações de amilases sobre o perfil de açúcares e rendimento no processo de hidrólise-sacarificação de gengibre. O processo seguiu o delineamento central composto rotacional para dois fatores, totalizando 11 tratamentos. Os resultados obtidos mostram o efeito das concentrações da α-amilase (Termamyl 2X) e da amiloglucosidase (AMG 300L) sobre o teor de glicose do hidrolisado e efeito da concentração de amiloglucosidase sobre o teor de dextrina. Os maiores rendimentos de hidrólise da suspensão de gengibre foram obtidos nas condições de elevada concentração de -amilase e amiloglucosidase.

In vitro antibacterial activity of medicinal plant extracts against Escherichia coli strains from human clinical specimens and interactions with antimicrobial drugs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Synergism between plant extract and antimicrobial drugs used on Staphylococcus aureus diseases

Searches for substances with antimicrobial activity are frequent, and medicinal plants have been considered interesting by some researchers since they are frequently used in popular medicine as remedies for many infectious diseases. The aim of this study was to verify the synergism between 13 antimicrobial drugs and 8 plant extracts - guaco (Mikania glomerata), guava (Psidium guajava), clove (Syzygium aromaticum), garlic (Allium sativum), lemongrass (Cymbopogon citratus), ginger (Zingiber officinale), carqueja (Baccharis trimera), and mint (Mentha piperita) - against Staphylococcus aureus strains, and for this purpose, the disk method was the antimicrobial susceptibility test performed. Petri dishes were prepared with or without dilution of plant extracts at sub-inhibitory concentrations in Mueller-Hinton Agar (MHA), and the inhibitory zones were recorded in millimeters. In vitro anti-Staphylococcus aureus activities of the extracts were confirmed, and synergism was verified for all the extracts; clove, guava, and lemongrass presented the highest synergism rate with antimicrobial drugs, while ginger and garlic showed limited synergistic capacity.