Life sciences

This study investigated the antioxidant, antityrosinase and antigenotoxic ability of pupae of the muga silkworm Antheraea assamensis. DPPH radical scavenging activity of methanolic pupae extract (MPE) with IC 50 value of 25.83 mg/mL was highly correlated with MPE of in vitro lipid peroxidation activity (r ¼0.985, p40.05) and antityrosinase activity (r ¼0.894, po0.05). The MPE had significant higher phenolic (11.2 mg catechin/g) and flavanoid content (5.12 mg quercetin/g) (po0.05). The major fatty acid compounds found in the pupae of the muga silkworm were palmitic acid (23.36%), oleic acid (15.31%), stearic acid (5.83%), linoleic acid (2.76%) and palmitoleic acid (0.73%). At concentration of 1 mg/mL, the pupae extract exhibit the protective effect on H 2 O 2 induced DNA damage by Comet assay. The mineral contents of pupae were Al (9.67 mg/g), Ca (0.809 mg/g), K (0.59 mg/g), Mg (0.55 mg/g), and Zn (0.54 mg/g). Therefore, pupae could be used as natural antioxidants on food products.

Cocoons of Antheraea assamensis (muga) silkworm were treated with different classes of natural-acidic (Citrus limon and Dillenia indica) and alkaline (Musa balbisiana) materials with the aim to elucidate their effectiveness as degumming agents. The tensile strength of silk fibers increased significantly after bio-degumming compared to industrial degumming using sodium carbonate. Scanning electron microscopy of bio-degummed fibers appeared clean and even with clear individual fibroin filaments. FTIR studies confirmed that bio-degumming resulted in holding the innate nature of muga silk. Under the implemented experimental conditions, M. balbisiana and C. limon functioned as most efficient degumming agents, followed by D. indica. The findings of this study propose the use of such eco-friendly degumming practices over the usual harsh industrial treatments for obtaining applaudable quality of silk with robust strength necessary for both textile and biomaterial purpose, besides reducing the impact of chemical toxicity on the environment.

This study evaluated the antioxidant effect of crude sericin extract (CSE) from Antheraea assamensis in high cholesterol fed rats. Investigation was conducted by administering graded oral dose of 0.25 and 0.5 gm/kg body weight (b.w.)/day of CSE for a period of 28 days. Experiments were conducted in 30 rats and were divided into five groups: normal control, high cholesterol fed (HCF), HCF + 0.065 gm/kg b.w./day fenofibrate (FF), HCF + sericin 0.25 gm/kg b.w./day (LSD), and HCF + sericin 0.5 gm/kg b.w./day (HSD). In brain, heart, liver, serum, and kidney homogenates nitric oxide (NO), thiobarbituric acid reactive substances (TBARS), protein carbonyl content (PCC), superoxide dismutase, reduced glutathione (GSH) was measured. LSD treatment prevented the alterations in GSH and PCC levels in hypercholesterolemic (HyC) brain tissue homogenates of rats. CSE lowers the serum total cholesterol level in HyC rats by promoting fecal cholesterol (FC) excretion. CSE increases FC level by promoting inhibition of cholesterol absorption in intestine. The endogenous antioxidant reduced significantly and the oxidative stress marker TBARS level increases significantly in the peripheral tissue of HCF rats. However, the administration of LSD and HSD exhibited a good antioxidant activity by reducing the TBARS level and increasing the endogenous antioxidant in peripheral tissue. In addition, a histological examination revealed loss of normal liver and kidney architecture in cholesterol fed rats which were retained in sericin treated groups. The findings of this study suggested that CSE improves hypercholesterolemia in rats fed a HyC diet. Clinical relevance of this effect of CSE seems worthy of further studies.

Chlorpyrifos is a most widely used organophosphate insecticide because of its cost effectiveness and degradable nature. However, this pesticide enters and contaminates the environment either by direct application, spray drifts or crop run off and shows adverse effect on the non-targeted organisms. Philosamia ricini (eri silkworm), one of the most exploited, domesticated and commercialized non mulberry silkworm is known for mass production of eri silk. The silkworm larvae get exposed to pesticide residues on the leaves of food plants. The present study investigates the effect of commercial formulation of chlorpyrifos (Pyrifos-20 EC) on eri silkworm. Initially the LC 50 value of chlorpyrifos was determined at 24-96 h and further experiments were carried out with sub lethal concentrations of the chlorpyrifos after 24 h of exposure period. The potential toxicity of chlorpyrifos was evaluated as a fuction of metabolism and nutritional physiology in 3rd, 4th, and 5th instar larvae. Alteration in histoarchitecture of 5th instar eri silkworm gut exposed to sub lethal concentration of chlorpyrifos formulation was also studied. Chlorpyrifos induced genotoxicity in silkworm hemocytes was also investigated by single cell gel electrophoresis, micronuclei assay, and apoptosis assay. Herein, LC 50 values of chlorpyrifos were calculated as 3.83, 3.35, 2.68, and 2.35 mg/L at 24, 48, 72, and 96h respectively. A significant decrease in trehalose activity along with digestive enzyme activity was observed in chlorpyrifos affected groups (P < 0.05). Further, genotoxicity study revealed higher tail percentage, tail length and tail moment of the damage DNA in chlorpyrifos exposed groups (P < 0.001). Moreover, at 2.0 mg/L concentration, ∼10 fold increases in tail length was observed as compared to the control. Results showed activation of caspase activity following 24 h chlorpyrifos exposure (1.5 and 2.0 mg/L) in a dose-dependent manner. Moreover, in control group less number of apoptotic cells was detected, however in both chlorpyrifos exposed groups' numbers of apoptotic cells were statistically higher (P < 0.001). Taken together, this study provides evidence that chlorpyrifos pollution might have adverse effect on overall nutritional physiology and genotoxicity of eri silkworm that could lead to reduced survivability of this economically beneficial insect.

The Indian Eri silkworm, Philosamia ricini Hutt, a commercial silk producing insect, is believed to have originated in the Brahmaputra valley of Assam. In this study, the genetic diversity and phylogenetic relationships of six morphs of Eri silkworm viz. white plain, white zebra, white spotted, blue plain, blue zebra and blue spotted collected from different geographical locations of NorthEast India were investigated by using random amplified polymorphic DNA (RAPD) and the first internal transcribed spacer region (ITS1). This study revealed a low genetic diversity among the morphs of Eri silkworm. Twenty-eight random primers generated 199 bands. Out of these, 112 were polymorphic (56.28%) with an average of 7.1 bands per primer. The genetic similarity matrix ranged from 0.56 to 0.99. The morphs collected from same geographical area shared the same cluster in the dendrogram. The genetic diversity in case of ITS1 sequences (2.19%) was found to be less as compared to RAPD. The ITS1 sequences of the morphs collected from same geographical area were found to be identical. The information generated in this study will help in conservation and effective breeding program to improve its productivity.

The natural spinning process in silkworms involves the conformation transition of the liquid silk protein present in the silk gland to make fiber. This conformation transition is influenced by different factors, and some studies suggested that changes in the metallic ion concentrations is one of them (Zhou et al. 2005). This study investigated the changes in the metallic ion compositions in the silk glands (before and during spinning) and cocoons of non-mulberry silkworm Antheraea assamensis helfer. Intact silk glands were dissected from mature 5th instar A. assamensis larvae. The glands were rinsed with deionized water and divided into five divisions: posterior silk gland (PSG), middle silk gland (MSG), anterior silk gland (ASG), posterior middle (PM) and anterior middle (AM) division of silk gland. Cocoon pieces and the gland parts were dried and digested in acid mixture to quantify the metallic contents in an atomic absorption spectrophotometer (Shimadzu, AA7000). We determined seven metals (Na, K, Mg, Ca, Cu, Zn, Fe) present in the different parts of the secretory pathway as well as in the fibers of A.assamensis. Our results suggested that the concentrations of Mg, Ca, Na, and K were more abundant in the gland than the Cu and Zn. Fe concentration was found comparatively less in amount in the gland. Amount of Ca found to be higher in the cocoons. The differences in the metallic ion concentrations in the gland parts before and during spinning suggested the possibility of their role in the formation of silk thread from luminal silk.

Antheraea assamensis Helfer, popularly known as Muga silkworm, the golden silk producer of Northeast India, is economically important and unique among the Saturniid silkworms. Muga silkworm is said to exhibit three semi-domesticated morphs i.e. green, blue, orange and one wild morph. In this study, the genetic diversity and phylogeny among the morphs of Muga silkworm collected from various geographical locations of Northeast India were investigated using RAPD and internal transcribed spacer DNA1 (ITS1) sequences. Thirty random primers generated 192 discrete bands; 123 of them were polymorphic (64.062%). The average amplicon per primer was found to be 6.4. In RAPD analysis, a wide range of genetic distance i.e. 0.0544-0.6228 was observed among the morphs. In the ITS1 sequence analysis, 35.35% of polymorphism and a range of genetic distance from 0.0024 to 0.2349 were observed. The phylogenetic trees based on RAPD and ITS1 sequences comprised of two major clades. The first clade comprised of the semi-domesticated morphs while the second clade included the wild morphs of different geographical origin. The information generated in this study can be used for conservation of the Muga silkworm through effective breeding programs.

Silk cocoons from Antheraea assamensis silkworms have been degummed under high temperature and pressure (autoclave) conditions and the efficiency of degumming is assessed in terms of weight loss, reeling length and fibre quality. The silk cocoon sericin removal percentage by autoclave degumming is found to be maximum (23.67%) as compared to conventional alkali degumming (22.28%). The autoclaved fibre is found easily reelable and produce 280 m of length with 10 numbers of fibre breaks. The morphology of fibres shows smooth surface throughout the length and improved mechanical behavior in terms of tensile properties. The molecular conformation estimated by FTIR and thermal behavior analysis shows unchanged nature of the core fibroin fibre degummed under autoclave conditions. Taken together, these results show the utilization of ecofriendly and less hazardous method of autoclave degumming for production of mechanically strong fibres with uniform surface smoothness.

Assam is a treasure house of flora and fauna having tremendous economical value. Antheraea assamensis (Muga silkworm) and their host plants are good example of this wealth. Muga silkworm which produces golden silk of high economic value available in Assam especially in Brahmaputra valley. Antheraea assamensis (Helfer) is a polyphagous insect, hence it thrives on various types of food plants. Lack of scientific knowledge about plants, degradation of environment for various reasons and nonimplementation of proper policy for restoration of the same make most of the food plants vulnerable. In this paper systematic study of some of the food plants of Muga silkworm has been reported. The problems associated with these plants have been discussed and few strategical points have been suggested for conservation of the biodiversity of both flora and fauna.

Organic extraction of pigmentation constituents of the cocoons of Antheraea assamensis (muga) was investigated in this study. Chemical extraction of muga cocoon fibers and their host plant som (Machilus bombycina) leaves were carried out using two benign solvents: hexane and ethyl acetate. Thin-layer chromatography (TLC) revealed the presence of methyl isoeugenol and isoeugenyl acetate from extracts of cocoon fiber and som leaves, respectively. The compounds were further confirmed by gas chromatography-mass spectroscopy (GC-MS) and nuclear magnetic resonance (NMR) analysis. Methyl isoeugenol is a yellow colored compound, which resembles the color of the muga fiber and may be responsible for coloration of the same. It is anticipated that isoeugenyl acetate (also known as isoeugenol acetate), a phenylpropanoid compound present in the host plant might be converted to methyl isoeugenol during the course of metabolism in the silkworm larva, which in turn may be responsible for production of golden yellow colored silk fiber for building the cocoons. The present investigation might help to utilize methyl isoeugenol as a potential dyeing material for other fabrics in the industry thus providing a new dimension into the textile field. 摘要 研究了有机萃取法提取柞蚕茧色素的工艺. 采用正己烷和乙酸乙酯两种温 和溶剂对木瓜茧纤维及其寄主植物木瓜叶进行了化学提取. 薄层色谱法 (TLC)分别检测了蚕茧纤维和SOM叶提取物中的甲基异丁烯醇和乙酸异 丁烯酯. 通过气相色谱-质谱(GC-MS)和核磁共振(NMR)分析进一步证 实了化合物. 甲基异丁烯醇是一种黄色化合物，它类似于木瓜纤维的颜 色，可能与木瓜纤维的颜色有关. 在家蚕幼虫的代谢过程中，寄主植物中 的一种苯丙烷类化合物乙酸异丁烯(也称为乙酸异丁烯)可能被转化为 甲基异丁烯醇，而甲基异丁烯醇又可能负责生产金黄色的蚕丝纤维，用 于结茧. 本研究可能有助于利用甲基异丁烯醇作为工业上其他织物的潜在 染色材料，从而为纺织领域提供一个新的视角.

In present study immunotoxic effect of organophosphate pesticide, chlorpyrifos formulation (Pyrifos-20 EC) on Philosamia ricini (eri silkworm) was evaluated. Herein, two sub lethal concentrations of chlorpyrifos (1.5 mg/L and 2.0 mg/L) were administered to eri silkworm and the effect on Phenoloxidase (PO), lysozyme enzyme activity and hemocyte immunity were investigated at 24-96 h time interval. Results showed at 72-96 h 2.0 mg/L concentration showed significant inhibition in enzyme activity. Likewise, after 24 h of exposure a significant increase in lysozyme activity was recorded in both pesticide exposed groups, however at 72-96 h significant decrease in lysozyme activity was measured. Moreover, after 48-96 h significant reduction in hemocyte abundance was observed (p<0.05). Changes in proportional counts of hemocytes showed that sub lethal chlorpyrifos exposure caused an increase of granulocytes and plasmatocytes in a concentration-dependant manner. However, prohematocytes, spehrulocytes and oenocytes abundance was decreased significantly (p<0.05) in chlorpyrifos exposed groups.

The present study seeks to investigate the comparative estimation and electrophoretic profile of haemolymph proteins among the different semi domesticated morphs (green, blue, orange) and the wild (bivoltine) morph of Antheraea assamensis Helfer in order to investigate their differential gene expression. The proteomic approach was utilized to investigate the proteome of the haemolymph of early, mid and late stages of 5th instar (larval stage) and to improve the understanding of their important bioprocess and gene expression situation. The results suggest that the quantitative approach is useful to arrive at a conclusion of genetic variation among the morphs. SDS-PAGE electrophoresis of protein associated with haemolymph revealed separation of 16 distinct protein bands among which some of them represent the storage and immunity related proteins.

The North Eastern India of the country is very rich in medicinal plants resources. The natural environment favours to grow ample species of valuable plants. On the other hand folk practices of this region are also highly countable and the flora of this area is among the richest of the country. Majority of valuable medicinal plants are gradually facing danger for its survival and many of which have already been destroyed even without having the scientific uses. World Health Organization estimates that 80% of the people in developing countries of the world rely on traditional medicine for their primary health care needs. About 3.5 to 4 billion people in the world rely on plants as sources of drugs. In countries like India medicinal plants has specific role in the rural health care. The common diseases are often treated by effective herbal remedies. The authors have collected the knowledge of such uncommon folk practises from different parts of Assam and the work is being continued further by Authors. This article mainly highlighted such 32 Folk Practices of some herbal Medicines used in rural health care system for the common diseases particularly by the rural peoples of Assam along with their local name, botanical name, disease conditions, part used and method of use. These medicinal use of the herbs when compared with Ayurvedic text it is seen that some herbs are described for similar use or properties and on the other hand some herbs are found to use in traditional medicine in other parts of India and abroad. It is also seen that some herbs are used as preventive measure for diseases and taken as food substances by these rural peoples.

The present invention relates to the use of radiofrequency oxygen plasma treatment for surface modification of muga (Antheraea
assama) silk fibroin (AASF) followed by antibiotic drug loading and subsequent development as antibiotic-loaded suture biomaterial.
This invention provides an efficient, dry and environmentally-friendly method of modifying surface properties of AASF for
developing it as antibiotic-loaded suture biomaterial. The method i.e. radiofrequency oxygen plasma treatment described in this
invention involves low consumption of energy, chemical and time as compared to wet chemical/radiation treatment and more
importantly can effectively modify the surface properties of polymeric materials without influencing their bulk properties which is
difficult to achieve through wet chemical/radiation treatment processes. This invention provides an effective solution on eliminating
post surgical bacterial infection of wound and significant improvement in rapid wound healing activity though development of
antibiotic-loaded AASF suture by radiofrequency oxygen plasma treatment.

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) infection has increased precipitously over the past several decades, with far-reaching health care and societal costs. MRSA infections in the context of burn wounds lead to invasive disease that could potentially cause mortality. Chloramphenicol is a well-known broad-spectrum bacteriostatic antibiotic that has been used since 1949, but due to its hydrophobicity, poor penetration in skin, fast degradation, and toxicity, its application has been hindered. Furthermore, it has been demonstrated that old antibiotics such as chloramphenicol remained active against a large number of currently prevalent resistant bacterial isolates due to their low-level use in the past. Recently, the novel nanoparticulate drug-delivery system has been used and reported to be exceptionally useful for topical therapeutics, due to its distinctive physical characteristics such as a high surface-to-volume ratio and minuscule size. It helps to achieve better hydrophilicity, bioavailability, and controlled delivery with enhanced therapeutic index, which has resulted in decreased toxicity levels compared to the crude drug. Here, we report a novel chloramphenicol loaded with poly(ε-caprolactone) (PCL)-pluronic composite nanoparticles (CAM-PCL-P NPs), physicochemical characterizations, and its bioactivity evaluation in a MRSA-infected burn-wound animal model. CAM-PCL-P NPs could encapsulate 98.3% of the drug in the nanoparticles and release 81% of the encapsulated drug over 36 days with a time to 50% drug release of
72 hours (51%). Nanoparticle suspensions maintained the initial properties with respect to size and encapsulation efficiency, even after 6 months of storage at 4°C and 25°C, respectively (P0.05). Significant reduction in the level of toxicity was observed for CAM-PCL-P NPs compared with that of free drug as confirmed from hemolytic activity against human blood erythrocytes and cytotoxicity assay against an MCF-7 breast cancer cell line. In vitro antibacterial activities were performed by zone of inhibition, minimum inhibitory concentrations, minimum bacterial concentration, and time-kill assays, which showed that CAM-PCL-P NPs exhibited significantly enhanced anti-MRSA activity against ten clinical isolates of MRSA strains. The augmented activity of CAM-PCL-P NPs was further tested on a MRSA-infected burn-wound animal model and achieved quicker efficacy in MRSA clearance and improved the survival rate compared with free-chloramphenicol treatment. Thus, we propose CAM-PCL-P NPs as a promising novel antimicrobial candidate that may have a good potential for preclinical applications.
Keywords: chloramphenicol, PCL-pluronic, nanoparticle, methicillin-resistant Staphylococcus aureus, anti-MRSA activity, burn-wound animal model