Aquilaria Crassna Research Articles

Antibacterial activity of Aquilaria crassna leaf extract against Staphylococcus epidermidis by disruption of cell wall.

BackgroundAquilaria crassna Pierre ex Lecomte has been traditionally used in Thailand for treatment of infectious diseases such as diarrhoea and skin diseases for a long time. The main objectives of this study were to examine antibacterial activity of the Aquilaria crassna leaf extract against Staphylococcus epidermidis and its underlying mechanism. The antioxidant activity and acute toxicity were studied as well.MethodsAntioxidant activities were examined by FRAP, ABTS and DPPH scavenging methods. Antibacterial activity was conducted using disc diffusion assay and the minimum inhibitory concentration (MIC) was determined by dilution method. The minimum bactericidal concentration (MBC) was reported as the lowest concentration producing no growth of microbes in the subcultures. Morphological changes of the microbe were observed by scanning electron microscopy, while an inhibitory effect on biofilm formation was evaluated by phase contrast microscopic analysis. Bacterial cell wall integrity was assessed by transmission electron microscopy. Acute toxicity was conducted in accordance with the OECD for Testing of Chemicals (2001) guidelines.ResultsThe extract exhibited considerable antioxidant activity. Staphylococcus epidermidis was susceptible to the extract with the MIC and MBC of 6 and 12 mg/ml, respectively. The extract caused swelling and distortion of bacterial cells and inhibited bacterial biofilm formation. Rupture of bacterial cell wall occurred after treated with the extract for 24 h. Acute toxicity test in mice showed no sign of toxicity or death at the doses of 2,000 and 15,000 mg/kg body weight.ConclusionThe aqueous extract of Aquilaria crassna leaves possesses an in vitro antibacterial activity against Staphylococcus epidermidis, with no sign of acute oral toxicity in mice, probably by interfering with bacterial cell wall synthesis and inhibiting biofilm formation.

Oil Production from De‐shelled Aquilaria crassna Seeds Using Supercritical Carbon Dioxide Extraction

AbstractThis study examined the use of supercritical carbon dioxide (SC‐CO2) in the extraction of triglycerides from de‐shelled Aquilaria crassna seeds. A central composite response surface methodology was employed to evaluate the effects of pressure, temperature and solvent‐to‐solid ratio (SSR) on total yield (TY), concentration of triglycerides (CTG) and recovery of triglycerides (RTG). For this experimental design, pressures that ranged from 250 to 350 bar, temperatures that ranged from 313 to 333 K and SSR that ranged from 80 to 120 were investigated for the SC‐CO2 extractions of 15 g of powdered de‐shelled A. crassna seeds at a CO2 flow rate of 25 mL/min under the supercritical phase. The values of TY, CTG and RTG achieved were 36.89 %, 709.5 mg/g and 95.4 %, respectively, under the conditions of a pressure of 340 bar, a temperature of 333 K and an SSR of 115 obtained from the quadratic fitting models.

TLC-densitometric analysis of beta-sitosterol in agarwood leaf extracts

The leaves of agarwood (Aquilaria spp.) of Thymelaeaceae family, have been used as a herbal tea for health promotion. A quantitative TLC-densitometric method was developed and validated for determining of beta-sitosterol in leaf extracts of the three agarwood species i.e., Aquilaria crassna, A. malaccensis and A. subintegra, cultivated in Thailand. The method was validated for linearity, precision, accuracy, limit of detection (LOD) and limit of quantitation (LOQ). The linearity was found over the range of 125–1750ng/spot with r2=0.9996. The relative standard deviations of intraday and interday precisions studies were less than 2%. The average recovery was 100.78% while LOD and LOQ were 25 and 112.5ng, respectively. The contents of beta-sitosterol in the extracts of A. crassna, A. malaccensis and A. subintegra were 0.14, 0.12 and 0.12% w/w, respectively. The proposed TLC-densitometric method was simple, precise, specific, sensitive and accurate for routine quality control of raw materials of agarwood leaf extracts and their products.

Agarwood (Aquilaria Crassna) Extracts Decrease High-protein High-fat Diet-induced Intestinal Putrefaction Toxins in Mice

Agarwood (Aquilaria spp.) is famous for its aromatic resin, but its leaves are also prized as a healthy tea in South East Asia. Previously, we reported that agarwood extract (Aquilaria sinensis and Aquilaria crassna) shows laxative effect via acetylcholine receptors in constipation model mice and rats. In the present study, we investigated the effects of agarwood (Aquilaria crassna) on intestinal toxins, such as indole derivatives and ammonium to investigate the enteral environment. Male mice received regimens of three types of food, CE-7 (normal diet), CE-2 (high-protein normal diet), and Quick Fat (high-protein high-fat diet). Extracts of agarwood (water extract of agarwood: WEA and ethanol extract of agarwood: EEA) were orally administered once daily for a week. We measured the contents of indole derivatives and ammonium in feces and also examined the Minimum Inhibitory Concentrations (MICs) of agarwood against nine strains of enterobacteria in vitro. As compared with CE-7, Quick Fat increased the contents of indoles and ammonium in fecal beads. Single administration and multiple administrations for 7 days of WEA at 1,000 mg/kg/day decreased the contents of indoles and ammonium in fecal beads; on the other hand, multiple administrations of EEA decreased contents of indoles, but not those of ammonium. Interruption of administration abolished the effects of WEA and EEA. Quick Fat delayed carmine egestion in the digestive tract and administration of WEA and EEA accelerated the carmine egestion. Both WEA and EEA showed significant antimicrobial activity against some urease-positive bacteria, such as Staphylococcus aureus, Clostridium difficile, and Bacteroides spp. In conclusion, feeding with Quick Fat (high-protein high-fat diet) increased fecal-containing toxins and delayed carmine egestion in mice. Administrations of WEA and EEA decreased fecal-containing toxins and accelerated carmine egestion, and the decrement of fecal-containing toxins was abolished in response to interruption of the administration.

Antipyretic, analgesic and anti-oxidative activities of Aquilaria crassna leaves extract in rodents

In Thailand, the leaves of Aquilaria crassna have been used traditionally for the treatments of various disorders, but without any scientific analysis. In this study, the antipyretic, analgesic, anti-inflammatory and anti-oxidative properties of A. crassna leaves extract were investigated at a wide dose range in rodents. Experimental animals were treated orally with an aqueous extract of Aquilaria crassna leaves (ACE). They were tested for antipyretic (Baker's yeast-induced fever in rats), analgesic (hot plate test in mice) and anti-inflammatory (carrageenan-induced paw edema in rats) activities. An anti-oxidative effect of ACE was evaluated by using the DPPH anti-oxidant assay. The results showed that, after 5 hours of yeast injection, 400 and 800 mg/kg ACE significantly reduced the rectal temperature of rats. Mice were found significantly less sensitive to heat at an oral dose of 800 mg/kg ACE, after 60 and 90 min. No anti-inflammatory activity of ACE at an 800 mg/kg dose could be observed in the rat paw assay. An anti-oxidative activity of ACE was observed with an IC 50value of 47.18 μg/ ml. No behavioral or movement change could be observed in mice after oral administration of ACE (800 or 8,000 mg/kg) for seven consecutive days. Interestingly, from the second day of treatment, animals had a significant lower body weight at the 8,000 mg/kg dose of ACE compared to the control. No toxicity was identified and the results of this study state clearly that Aquilaria crassna leaves extracts possess antipyretic, analgesic and anti-oxidative properties without anti-inflammatory activity.

Performance of agarwood ( Aquilaria crassna) seedling transplants improved by shade and fertiliser

While Aquilaria species have had a long history of exploitation and trade, experience with their establishment and management in plantations is only recent. Significant transplant stress during establishment has been a feature of contemporary plantings in Australia. It is therefore important to determine the nature of this stress to mitigate its effect in future plantings. This study examined the influence of antitranspirant and fertiliser applied after planting in open conditions on the relative mean leaf chlorophyll content, survival and growth (height and diameter) of Aquilaria crassna seedlings when compared with a shade control. Additional field-applied fertiliser (without antitranspirant) had a significantly positive effect on mean chlorophyll index and height and diameter growth after transplanting, but a leaf application of antitranspirant had no such effect. Despite the benefit of additional fertiliser (without antitranspirant) this treatment had significantly greater mortality when compared with the shade treatment. The immediate increase in mean chlorophyll index in shade and its initial decline in full-sun exposed seedlings after planting indicates that the transplant stress is influenced, in part, by sun-exposure. Seedlings in the shade treatment were significantly taller than those exposed to full-sun after 60-weeks but no significant differences were found for mean basal diameter. With the exception of one treatment (fertiliser with antitranspirant) it is evident that taller seedlings with thicker stems have a greater survival after transplanting than shorter seedlings with thinner stems. This study reveals that the planting of A. crassna seedlings with mean height and stem diameter of 35 cm and 4.0 mm respectively and providing fertiliser and shade after planting can reduce transplant stress and improve survival and growth of this species. Areas requiring further research including other potential factors influencing transplant stress are explored in this report.

Actinobacterial community and diversity in rhizosphere soils of Aquilaria crassna Pierre ex Lec assessed by RT-PCR and PCR-DGGE

The actinobacterial community in rhizospheres of eaglewood (Aquilaria crassna Pierre ex Lec) was analyzed using culture-independent methods of RT-PCR and PCR DGGE of 16S rRNA gene. We conducted the experiments to investigate the difference in diversity and community structure of actinobacteria with respect to sampling sites and seasons and to determine effect of plant species on selection of rhizosphere community from different sampling sites. Total genomic DNA and RNA were extracted from rhizosphere soils collected from two plantations in Phetchabun province and one plantation in each Nakhonnayok province, Rayong province and Chiang Mai province of Thailand during dry and rainy seasons. The UPGMA dendrogram generated from DGGE fingerprints showed that the actinobacterial community was separated corresponding to sampling sites, suggesting sampling sites effect. The shift in community and diversity between two seasons was detected in all sampling sites. RNA-based analyses showed that several actinobacterial groups appeared to be ubiquitous but different in metabolic activity in different environments. Species diversity (S) and simple indexes (I) indicate the increase in species diversity of actinobacteria from all sampling sites in rainy season. Cloning and sequencing of 16S rRNA gene fragments obtained from DGGE bands revealed that 14 of 40 dominant species of actinobacteria in the rhizospheres of this plant belonged to uncultured actinobacteria. Besides the uncultured actinobacteria, Nocardioides sp., Streptomyces sp., Mycobacterium sp., Rhodococcus sp. and Actinoplanes sp. were indentified and frequently found more than other genera.

Genomic organization of δ-guaiene synthase genes in Aquilaria crassna and its possible use for the identification of Aquilaria species

The resinous portions of Aquilaria plants, called agarwood, have been used as medicines and incenses. Agarwood contains a great variety of sesquiterpenes, and a study using cultured cells of Aquilaria crassna showed that the production of sesquiterpenes (α-guaiene, α-humulene, and δ-guaiene) was induced by treatment with methyl jasmonate, which led to the cloning of δ-guaiene synthases. In the present study, analyses of genomic organization and Southern blotting of δ-guaiene synthase in A. crassna were performed in order to examine the genomic background of δ-guaiene synthases in Aquilaria plants. Genomic cloning and sequencing revealed five types of sequence in putative δ-guaiene synthases sharing more than 96% identity in exon regions, and that these enzymes belonged to the class III TPS subfamily with seven exons and six introns. Furthermore, Southern blotting revealed that at least five copies of δ-guaiene synthase existed in A. crassna. The hybridization of digested DNA of A. crassna and A. sinensis with probes made with a δ-guaiene synthase cDNA fragment resulted in different banding patterns for these two species. It may be possible to identify Aquilaria species by restriction fragment length polymorphism analyses with δ-guaiene synthase cDNA probes.

Anti-inflammatory effects of the ethyl acetate extract of Aquilaria crassna inhibits LPS-induced tumour necrosis factor-alpha production by attenuating P38 MAPK activation

To study the inhibitory effect of the ethyl acetate extract of Aquilaria crassna on lipopolysaccharide (LPS)-induced tumour necrosis factor-alpha (TNF-α) secretion from isolated human peripheral blood mononuclear cells and its mechanisms of antiinflammation so as to provide some evidence for its traditional use. Human peripheral blood mononuclear cells (hPBMCs) were isolated from healthy volunteers. Cells, at a concentration of 1×106 cell/ml, were induced to secrete TNF-α by exposure to 10 ng/ml LPS in the presence and absence of the ethyl acetate extract of Aquilaria crassna. The TNF-α secretion in the collection medium was measured by enzyme-linked immunosorbent assay and the TNF-α gene expression was measured by reverse transcriptase-polymerase chain reaction. Determination of ERK1/2 MAPK and p38 MAPK activation were performedby Western blot analysis using a specific phosphorylated form of ERK1/2, p38 MAPK antibody. LPS at a concentration of 10 ng/ ml significantly increased in TNF-α secretion and was significantly inhibited when treated with 1.5 mg/ml ethyl acetate extract of Aquilaria crassna (P<0.05). Moreover, on treatment with 1.5 mg/ml, the extracts showed TNF-α gene expression inhibition. Co-treatment of the extract with LPS could not block p38 MAPK activation, but pre-treatment of the extracts significantly reduced the p38 MAPK phosphorylation without affecting the ERK1/2 MAPK activation (P<0.05). The ethyl acetate extract of Aquilaria crassna inhibits TNF-α gene expression and secretion in LPS-induced hPBMCs. This inhibitory effect apparently resulted from selectively attenuating the p38 MAPK activation. Key words: Anti-inflammatory, Aquilaria crassna, p38 MAPK, PBMCs, TNF-α

Supercritical carbon dioxide extraction of triglycerides from Aquilaria crassna seeds

This study examines the effects of pressure, temperature and solvent to solid ratio (SSR) on extraction efficiency of triglycerides from powdered Aquilaria crassna seeds by using supercritical carbon dioxide (SC-CO 2) extraction. Supercritical extractions were designed for pressures ranging from 250 to 350 bar, temperatures ranging from 313 to 333 K and SSR values ranging from 60:1 to 120:1. All values were selected using response surface methodology (RSM) in order to determine their effects on the concentration of triglycerides from the SC-CO 2 extracted oil. Using 3000 g of carbon dioxide over 4 h, a supercritical carbon dioxide extraction (at 310 bar, 333 K and an SSR value of 100:1) yielded 33.99% oil having the concentration of triglycerides of 568.3 mg/g. The extraction efficiency (i.e. recovery) of triglycerides reached 96.77%. Changes in pressure presented more effective in increasing the recovery of triglycerides. Both temperature and the SSR value are important in obtaining high concentration of triglycerides from the A. crassna seeds that are potential for biodiesel materials.

Anti Fungal Activity of Wood Extract of Aquilaria crassna Pierre ex Lecomte Against Agarwood-Inducing Fungi, Fusarium solani

This paper provided information regarding artificial agar wood production. Fungi are considered as biological agent for agarwood formation and agarwood is assumed as tree defense mechanism product. This research was aimed at investigating the anti fungal activity (AFA) of Aq ui l ari a crassna , one of the agar wood-producing trees, against F usariu m solani in vi t r o . Aq uilaria crassna wood mill was extracted by 70% ethanol to investigate the anti fungal activity. The result are Aq u i l ari a c r a s s n a exhibited low extractives content, which was only 2.0% (w/w) and a low anti fungal activity i n vitro , especially for ethanol extract. However, further fractionation and bioassay showed that the most active component was likely in the ethyl-acetate soluble fraction that exhibited strong anti fungal activity (52.5%) at 4.0% of concentration.

Endophytic actinomycetes isolated from Aquilaria crassna Pierre ex Lec and screening of plant growth promoters production

A total of 10 endophytic actinomycete strains were successfully isolated from healthy shoots and roots of Aquilaria crassna Pierre ex Lec (eaglewood). Analysis of 16S rDNA sequencing of those isolates showed that they belong to members of the genera Streptomyces (2 isolates), Nonomuraea (1 isolate), Actinomadura (1 isolate), Pseudonocardia (1 isolate) and Nocardia (3 isolates). The remaining 2 isolates were unidentified. All of isolates produced the amount of indole-3-acetic acid (IAA) and ammonia ranging between 9.85 ± 0.31 to 15.14 ± 0.22 μg ml−1 and 2 to 60 mg ml−1, respectively. Among 10 isolates tested, the amount of hydroxamate-type siderophore produced by 2 isolates was undetectable. While the remaining 8 isolates produced the amount of hydroxamate-type ranging between 3.21 ± 0.12 and 39.30 ± 0.40 μg ml−1. Also, catechols-type siderophore produced by 9 isolates was undetectable. Actinomadura glauciflava is only one isolate that produced catechols-type 4.12 ± 0.90 μg ml−1. In addition, 10 endophytic actinomycetes showed protease activity ranging from undetectable to 8.16 ± 0.15 unit ml−1. Genetic relatedness amongst these isolates was determined base on Random amplified polymorphic DNA (RAPD) and Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC PCR). Both methodologies generated specific patterns corresponding to particular genotypes. RAPD fingerprinting proved to be slightly more discriminatory than ERIC PCR. This study is the first published report that actinomycetes can be isolated as endophytes within this plant. It is also the first published report that endophytic actinomycetes are capable of producing IAA and siderophores.

Chemical constituents and antimicrobial activity of essential oil and extracts of heartwood of Aquilaria crassna obtained from water distillation and supercritical fluid carbon dioxide extraction.

Agarwood (Aquilaria crassna) is a high value economic plant.Agarwood oil is widely used among variouscountries as perfumes and ingredient inmedical recipes. In this study, the extraction of driedAgarwood powderbywater distillation (WD), supercritical fluid carbon dioxide extraction (SFE) and SFEwith ethanol as cosolvent(SFE+co) gave 0.2%oil, 0.06%and 0.014%extracts, respectively. The types of chemical constituents of oil andextracts from these 3 extraction methods were quite similar. The major chemical constituents ofWD oil, SFEand SFE+co extracts were g-selinene (13.66%), selina-4,11-dien-14-al (14.25%) and selina-4,11-dien-14-al(13.39%), respectively. The WD oil, SFE and SFE+co extracts had antimicrobial activities against S. auruesand C. albicans, but were not sensitive to E. coli at maximum concentration of the study, 2mg/mL. KeyWords: Agarwood; Aquilaria crassna; Distillation; Supercritical fluid carbon dioxide

Matrix analysis to evaluate sustainability: The tropical tree Aquilaria crassna, a heavily poached source of agarwood

We used size-structured Lefkovitch projection matrix analysis to predict future trends in the survival of Aquilaria crassna (Thymelaeaceae), a tropical evergreen forest tree that has been highly sought after for its valuable aromatic wood (agarwood) for millennia. Data on growth, damage to trees by poachers, fruit production, seed dispersal and seedling recruitment were collected from a 30-ha plot in Khao Yai National Park, central Thailand that had seen moderate poaching. The population asymptotic growth rate, λ a , and transient growth rate, λ tr , found from using the matrix to project the observed population 48 years, were 1.002 and 1.005, respectively, with 95% confidence intervals of [0.985, 1.016] and [0.985, 1.023]. The stable size distribution obtained from the matrix was reasonably similar to the observed size distribution, suggesting that at the time of the study the population was not far from equilibrium. Sensitivity analysis and simulations of poaching on adult trees indicate that both λ’s are very sensitive to the removal of adult trees and the growth of preadult trees. In particular, the increase in tree mortality and decrease in preadult growth rate caused by agarwood collection seen in some areas could cause extirpation of the population. While in such cases the population appears to be poised on the brink of decline, several factors that we could not evaluate could alter its fate. First, adult deaths could stimulate recruitment of young under the parent trees; second, there is marked year-to-year variation in fruiting success and possibly recruitment; third, there is considerable spatial variation in tree density and recruitment, suggesting that attempts to evaluate future success need to encompass larger spatial and time scales.

Does commercialization of a non-timber forest product reduce ecological impact? A case study of the Critically Endangered Aquilaria crassna in Lao PDR

Aquilaria crassna, a tree species on CITES Appendix II and categorized as Critically Endangered on the IUCN Red List, is the main source of the highly valuable, fragrant and resinous agarwood that is extracted in forests in South-east Asia, exported to East Asian and Arab countries, and used for a range of medicinal, aromatic and religious products. Based on interviews with local, non-local and foreign harvesters in Laos we examined the relationships between harvesters' daily net revenue from agarwood extraction, their degree of commercialization (i.e. their differential access to markets) and their ability to target harvesting towards the small fraction of trees that do contain commercial qualities and quantities of agarwood. For comparison we included data on number of trees felled during the most recent harvesting trip. The analysis showed that poor targeting ability and low degree of commercialization were associated with low daily net revenues, whereas good targeting ability and high degree of commercialization were associated with high daily net revenues. In the case of A. crassna in Laos it therefore appears that the activities of highly commercialized harvesters are less harmful to A. crassna populations than those of less specialized, local harvesters.

Choices for tree conservation

Choices for tree conservation

ECOLOGY OF THREE SYMPATRIC FELIDS IN A MIXED EVERGREEN FOREST IN NORTH-CENTRAL THAILAND

Abstract We report on the natural history of 3 rare and mostly unstudied felids, the clouded leopard (Neofelis nebulosa), Asiatic golden cat (Catopuma temminckii), and marbled cat (Pardofelis marmorata), in Phu Khieo Wildlife Sanctuary, Thailand. From February 1999 to February 2003, 4 clouded leopards (2 males and 2 females), 2 Asiatic golden cats (1 male and 1 female), and 1 female marbled cat were captured, radiocollared, and tracked for 1–17 months. Clouded leopards exhibited annual ranges (95% minimum convex polygon) of 22.9–45.1 km2, traveled an average of 1,932 m each day, and were active during 58% of diel activity readings. Asiatic golden cats ranged 32.6–47.7 km2, traveled an average of 1,597 m each day, and exhibited an arrhythmic activity pattern of 58% activity. A marbled cat was tracked for 1 month, ranged 5.3 km2, and was primarily nocturnal in its habits. Examination of limited data indicated diverse prey use by clouded leopards. Illegal hunting and collecting of aloewood (Aquilaria crassna...

MECHANICAL METHODS TO STIMULATE ALOES WOOD FORMATION IN AQUILARIA CRASSNA PIERRE EX H.LEC. (KRITSANA) TREES

MECHANICAL METHODS TO STIMULATE ALOES WOOD FORMATION IN AQUILARIA CRASSNA PIERRE EX H.LEC. (KRITSANA) TREES