Studies on the influence of host plants and effect of chemical stimulants on the feeding behavior in the muga silkworm, Antheraea assamensis

The feeding habits of Antheraea assamensis, Helfer (Lepidoptera: Saturniidae) larvae towards the leaves of its four different host plants, Persea bombycina King ex. Hook (Laurales: Lauraceae), Litsea polhantha Jussieu, L. salicifolia Roxburgh ex. Nees and L. citrata Blume, and the chemical basis of feeding preference were investigated. Nutritional superiority of young and medium leaves with respect to soluble protein, total phenol and phenylalanine ammonia lyase activity was observed in the leaves of P. bombycina compared to other host plants. Attraction and feeding tests with detached leaves and artificial diet with different chemical stimulants revealed that a mixture of the flavonoids, myrcetin, and 7, 2’, 4’ trimethoxy dihydroxy flavone with sterol compound β-sitosterol elicited the most biting behavior by A. assamensis larvae. While linalyl acetate alone attracted larvae towards the leaves of the host plants, a mixture of caryophyllene, decyl aldehyde and dodecyl aldehyde was found to both attract them to the host leaves and cause biting behavior. Azaindole was found to deter them from the host plants

In-vitro antioxident and free radical scavenging activity of Alternanthera sessilis

The present study was aimed to evaluate the antioxidant activity of A.sessilis plant extracts in different solvents. The antioxidant activity was studied by phosphomolybdate method and DPPH method. In phosphomolybdate method the highest activity was shown by methanolic extract (12.044 mM of ascorbic acid eqvt/gm of sample). The highest radical scavenging activity by DPPH method was found in methanol extracts (IC 50 587.093µg/ml). Ferrous chelating activity, superoxide radical scavenging activity, nitric oxide radical scavenging activity was found high in acetone, acetone and methanol extracts respectively. Total Flavonoids and crude phenolics were found to be 0.370 mg/gm dry wt. and 1.529 mg/gm dry wt. respectively. The antioxidant activity increases with increase in the concentration. This study indicates that A.sessilis is a potential source of natural antioxidant

Lung function decline: a cohot study in a population exposed to coal dust

Chronic Obstructive Pulmonary Disease (COPD), is characterized by coughing, shortness of breath, sputum production, rapid breathing, wheezing, and weight loss due to the energy required for labored breathing. COPD includes chronic bronchitis and emphysema chronic bronchitis inflammation of the lining of the bronchial tubes emphysema permanent destruction of the alveoli. Chronic respiratory diseases have a preeminent role in the health conditions of people residing near coalmine areas with implications for morbidity and excess mortality from specific causes. Atmospheric pollution from anthropogenic sources such as coal mining, industrial sources is a serious worldwide concern as it is associated with adverse health effects.The aim of this study was to find a correlation between coal dust and reductions in lung function. An environmental health survey was conducted in and around the surrounding areas of opencast coal mine, Tirap to determine the prevalence of various respiratory symptoms and to assess pulmonary function among the villagers. Although cigarette smoking is the main environmental risk factor, only about 15% of smokers develop clinically significant disease suggesting other influences on disease expression. We screened 412 individuals during surveys at the coal mine site, Assam to find out possible occurrences of COPD and associated environmental risk factors, mainly coal dust exposure. Lung function test was done with a portable spirometer. COPD was diagnosed on the basis ATS guidelines. The subjects were categorized into COPD (Smokers and NonSmokers) and NonCOPD (Smokers and NonSmokers). Air quality was monitored using Respirable Dust Sampler and analyzed for Respirable Suspended Particulate Matter (RSPM), SO2 and NO2.Coal dust exposure was a potential factor in development of COP

Studies on secondary metabolites of Som ( Persea bombycina Kost), a primary host plant of muga silkworm (Antheraea assamensis Helfer)

The host plant selection behaviour or feeding preferences of the insects are largely mediated by the presence and distribution of secondary metabolites in plants. Quantitative estimation of few secondary metabolites and HPLC analysis of phenolic compounds were carried out from the leaves of Som plant (Persea bombycina Kost) which is a primary metabolite of the shimmering yellow golden silk yarn producer, the muga silkworm (Antheraea assamensis Helfer). β –sitosterol content in the tender leaves was significantly the highest (1.06%) over semi-mature or mature leaves, whereas Chlorogenic acid content was more in medium leaves (2.06%). Phytic acid content was significantly higher in mature leaves (2310.05 mg/100g), total phenol in tender leaves (1.946%), ADF in mature leaves (26.50%), ADL in mature leaves and tannin in tender leaves (6.71%). Purified phenolic extract when subjected to HPLC analysis, 6 prominent peaks were observed and screening with standard indicates Peaks 1, 2, 3 and 6 correspond to Chlorogenic acid, catechol, Morin and gallic acid, respectively. Keywords: Som, Persea bombycina, Muga silkworm, Antheraea assamensis, secondary metabolites, HPLC analysis