Traditional cultivation and management practices of agarwood (Aquilaria malaccensis) in Golaghat district of Assam

A few plant species of the Thymelaeceae family are highly valuable and demanding because it contains resinous oil in their stem, branches, and roots. Agarwood (Aquilaria malaccensis) is one of them, which is found primarily in Assam and adjoining region of North Eastern parts of India as well as in other countries of South and South East India. In Assam, the plant is profusely cultivated in Golaghat, Jorhat and Sivasagar districts. Naturally, stem of the older plant is infected by fungal consortia via the holes made by stem borer. The blackish infection appears inside the stem along the line of the borer tunnel and valuable resinous oil can be extracted through water distillation from the black, infected wood. The agar oil has great demand in international market and is used in manufacturing perfume, incense stick, fragrant smoke, and pharmaceuticals industry. Since ancient time, people of this region have been cultivating Aquilaria with the methods adopted from traditional knowledge and found better success of infection and oil yield. Documentation of this traditional knowledge of Aquilaria malaccensis is of significant importance for promoting its cultivation among the people of this region before the knowledge is lost forever. The knowledge will also be useful for developing scientific method of commercial cultivation of this perennial tree. In this paper, we are discussing the traditional method of cultivation of Aquilaria malaccensis including seedling preparation, cultivation, intercropping and management practices. Agar is propagated through seeds for growing healthy seedlings; and cultivation practices of the plant are of utmost concern for harvesting valuable oil. Extensive field survey has been conducted at Golaghat district of Assam, India to document the method of cultivation and management practices of the plant. The results obtained from the field study were analyzed and interpreted for understanding the importance of this traditional cultivation practice.

Nectar host plant selection and floral probing by the Indian butterfly Danaus genutia (Nympahlidae [Nymphalidae])

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A high performance thin layer chromatography (HPTLC) method for the quality assessment of citronella oil: application in commercial sample analysis

Citronella oil, extracted from Cymbopogon species (winterianus and nardus) is a commercially valuable essential oil used in personal-care products and insect repellents. Routine analysis in gas chromatography is incapable of detecting high-boiling adulterants therein. In this study, an HPTLC technique was developed for the absolute quantification of citronellal (characteristic chemical marker) and triglyceride (main constituent of vegetable oil adulterant) in citronella oil for its quality assessment. It was validated in terms of specificity, linearity, sensitivity, accuracy and precision. Further, the developed method was employed to quantify citronellal and triglyceride in twenty commercial samples. The results showed a wide variation in citronellal content (trace to 30.65% w/w) and could differentiate its two chemotypes. Also, it revealed the possibility of vegetable oil adulteration through the detection and quantification of triglyceride in selected samples. It can be a simple and rapid technique for the quality control of citronella oil.</p

Vapor of Volatile Oils from <em>Litsea cubeba</em> Seed Induces Apoptosis and Causes Cell Cycle Arrest in Lung Cancer Cells

<div><p>Non-small cell lung carcinoma (NSCLC) is a major killer in cancer related human death. Its therapeutic intervention requires superior efficient molecule(s) as it often becomes resistant to present chemotherapy options. Here we report that vapor of volatile oil compounds obtained from <em>Litsea cubeba</em> seeds killed human NSCLC cells, A549, through the induction of apoptosis and cell cycle arrest. Vapor generated from the combined oils (VCO) deactivated Akt, a key player in cancer cell survival and proliferation. Interestingly VCO dephosphorylated Akt at both Ser⁴⁷³ and Thr³⁰⁸; through the suppression of mTOR and pPDK1 respectively. As a consequence of this, diminished phosphorylation of Bad occurred along with the decreased Bcl-xL expression. This subsequently enhanced Bax levels permitting the release of mitochondrial cytochrome c into the cytosol which concomitantly activated caspase 9 and caspase 3 resulting apoptotic cell death. Impairment of Akt activation by VCO also deactivated Mdm2 that effected overexpression of p53 which in turn upregulated p21 expression. This causes enhanced p21 binding to cyclin D1 that halted G1 to S phase progression. Taken together, VCO produces two prong effects on lung cancer cells, it induces apoptosis and blocked cancer cell proliferation, both occurred due to the deactivation of Akt. In addition, it has another crucial advantage: VCO could be directly delivered to lung cancer tissue through inhalation.</p> </div

VCO induces apoptosis in A549 lung cancer cells.

<p>(<b>A</b>) Annexin-Cy3 (red) and 6-CFDA (green) double staining of apoptotic cells was examined by fluorescence microscopy where VCO treated A549 cells showed both green and red stains and control (untreated) cells stained green only. (<b>B</b>) Percentage of apoptotic A549 cells was measured at different time points (0 h, 12 h, 24 h, 36 h) with VCO treatments. (<b>C</b>) Mitochondrial membrane potential was observed in control and VCO exposed (36 h) A549 lung cancer cells by JC-1 staining assay. (<b>D</b>) Apoptotic DNA fragmentation was observed by VCO treated A-549 cells on 1.5% agarose gel electrophoresis. Data are presented as means ± SEM of three independent experiments. *p<0.05, **p<0.01 versus control (0 h). Bar represents 20 µm.</p

Deactivation of Bad with altered Bcl-xL/Bax ratio on mitochondrial membrane by VCO exposure.

<p>(<b>A</b>) Immunoblot analysis was performed to evaluate the level of pBad Ser¹³⁶ and Bad in A549 cells exposed with VCO for different time periods (0 h, 12 h, 24 h, 36 h). β-actin served as internal control. Bands were quantified by densitometric analysis where pBad level was compared with Bad level. (<b>B</b>) Protein level of Bcl-xL and Bax of these cells were also evaluated by immunoblot analysis. Densitometric analysis showed Bcl-xL was negatively correlated with Bax level when A549 cells were exposed with VCO. Values are means ± SEM of three independent experiments, *p<0.05, **p<0.01 versus control (0 h).</p

VCO induces apoptotic cell death by activating caspase cascade.

<p>(<b>A</b>) A549 cells were exposed with VCO for 36 h followed by staining of mitochondria with Mitotracker (red) and cytochrome c with FITC conjugated anti-cytochrome c antibody (green). (<b>B</b>) Immunoblot analysis was done by using anti-cleaved caspase-9 or caspase-3 antibodies in A-549 cells incubated in the presence of VCO at 0 h, 24 h, 36 h time intervals. β-actin used as internal control. (<b>C</b>) A549 cells were exposed with VCO for indicated time periods and on termination of exposure, cells were lysed and caspase 3 activity was measured in DTX multimode detector by using proluminescent caspase 3 as the substrate. (<b>D</b>) PARP cleavage was observed in VCO exposed cells by immunoblot analysis using anti-PARP antibody. β-actin used as loading control. Values are means ± SEM of three independent experiments, *p<0.01, **p<0.001 versus control (0 h). Bar represents 20 µm.</p

Time dependent inhibition of Akt phosphorylation by VCO.

<p>(<b>A</b>, <b>B</b>) Immunoblot analysis of Akt phosphorylation at Thr³⁰⁸ (A) and Ser⁴⁷³ (B) in A549 treated cells with VCO for the indicated time period (upper panel). Fold change represents the protein level of the VCO treated cells relative to the control cells. Bands were quantified by densitometric analysis where pAkt level was then normalized to the total Akt level (lower panel). β-actin served as loading control. (<b>C</b>, <b>D</b>) Immunoblot analysis of pPDK1 Ser ²⁴¹ (C) and mTOR (D) was done at different time hour (0 h, 12 h, 24 h, 36 h) exposure of VCO to A549 cells (upper panel). Bands were quantified by densitometric analysis where pPDK1 or mTOR level was then normalized with β-actin which is represented by folds change (lower panel). Figures are representative of three independent experiments, *p<0.01, **p<0.001 versus control (0 h).</p