Essential oils extracted from Citrus macroptera and Homalomena aromatica (Spreng.) Schott. exhibit repellent activities against Aedes aegypti (Diptera: Culicidae).

BACKGROUND OBJECTIVES: Mosquitoes alone transmit diseases to around 700 million individuals annually, killing approximately 0.7 million people every year worldwide. Considering the potential health risks linked with synthetic repellents, it has become vital to identify eco-friendly, natural repellents for mosquito control as well as to understand the underlying mechanism for mosquito repellent activity. To address this, objectives were set to extract essential oils from Citrus macroptera peel and Homalomena aromatica (Spreng.) Schott. rhizomes, evaluate their mosquito repellent activity against Aedes aegypti, and further explore their mosquito odorant receptor inhibition potential. METHODS: The oils were extracted using Clevenger's apparatus, and properties like specific gravity, refractive index, and boiling point were evaluated and characterised using Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectroscopy (GC-MS). Aedes aegypti mosquito eggs collected from the Indian Council of Medical Research (ICMR), Dibrugarh, were reared in the Department of Pharmaceutical Sciences, Research Laboratory, to obtain adult Aedes aegypti mosquitoes for the mosquito repellent activity evaluation of the essential oils using the Human Bait technique'. Molecular docking studies were performed for the oil components against mosquito odorant binding proteins. Further, toxicity studies of these two oils were evaluated against human dermal fibroblast adult (HDFa) cells. RESULTS: The results revealed the presence of limonene (86.76%) and linalool (52.35%), respectively, in Citrus macroptera and Homalomena aromatica oils. It was found that the combination of the oils in a ratio of 1:1 showed mosquito repellent activity for up to 6.33 ± 0.23 h. Molecular docking studies showed the presence of major oil components having mosquito odorant receptor blocking potential comparable to N, N-diethyl-meta-toluamide (DEET), indicating a rationale for extended mosquito repellent action. Further, both of these oils were found to be non-cytotoxic against HDFa cells after 24 h. INTERPRETATION CONCLUSION: The encouraging mosquito repellent activity of these two oils as compared to synthetic mosquito repellent DEET might pave the way for the development of novel herbal mosquito repellent formulations containing these essential oils.

Synthesis and characterization of citrate soft rice starch: A new strategy of producing disintegrating agent for design drug and resistant starch.

Assam soft rice starch (ASRS) and Citric acid-esterified Assam soft rice starch (c-ASRS) were studied extensively. FTIR, CHN, DSC, XRD, SEM, TEM and optical microscope studies were performed for native and modified starches. Powder rearrangements, cohesiveness and flowability were studied by the Kawakita plot. Moisture and ash content was around 9 % and 0.5 %. In vitro digestibility of ASRS and c-ASRS produced functional RS. Paracetamol tablets were prepared using ASRS and c-ASRS as granulating-disintegrating agents through wet granulation methods. The prepared tablets' physical properties, disintegrant properties, in vitro dissolution and dissolution efficiency (DE) were performed. The average particle size was obtained at 6.59 ± 0.355 µm and 8.15 ± 0.168 µm for ASRS and c-ASRS, respectively. All the results were statistically significant at p < 0.05, p < 0.01 and p < 0.001. The amylose content was 6.78 %, classifying it as a low amylose type of starch. The disintegration time was reduced with the increasing concentration of ASRS and c-ASRS and facilitated the immediate release of the model drug from the tablet compact to improve its bioavailability. Therefore, the current investigation concludes that ASRS and c-ASRS can be used as novel and functional materials in pharmaceutical industries due to their unique physicochemical attributes. HYPOTHESIS: The central hypothesis of the current work was to develop citrated starch through a one-step reactive extrusion method and investigate its disintegrants property for pharmaceutical tablets. Extrusion is a continuous, simple, high-speed, low-cost, producing very limited wastewater and gas. Characterization was done through different instrumental techniques to confirm successful esterification. The flow properties were evaluated, and tablets were prepared at a different level of ASRS and c-ASRS (disintegrating agent), followed by the evaluation of tablets to confirm the model drug's dissolution and disintegration efficiency. Finally, in vitro digestibility of both ASRS and c-ASRS was analyzed to establish their potential nutritional benefits.

Recent Developments in Shape-Controlled Synthesis of Cellulose Nanocrystals.

Cellulose Nanocrystals (CNCs) have been touted to be among the materials of the 21st century. It is an emerging biocompatible and biodegradable nanomaterial with unique physicochemical properties adaptable to various surface modifications. The characteristics and properties of CNCs are now understood to depend upon the source of the cellulose and the conditions of its isolation. Over the past decade, CNCs with various morphologies, including rod, ribbon, needle shapes, spherical, square, block and rectangular shapes with unique surface properties, have been synthesized. Studies have shown that surface and morphological properties of CNCs have substantial control over the rheology, cytotoxicity and cellular uptake, which ultimately influence its purposive biomedical applications. The objective of the current survey is to analyze the advances made in the shape-controlled synthesis and fabrication of CNCs morphology and review the influence such morphological variations have on its functionality in biomedical fields.

High-Value Compounds and Bioactivity of Rice Bran, Rice Bran Protein: A review.

BACKGROUND: Rice bran and rice bran protein are important sources of minerals, energy, and vitamins. Other bioactive compounds are abundantly available to exert therapeutical activity. Health-promoting activities of high-value compounds of rice bran were significant, as observed in recent studies. INTRODUCTION: A variety of bioactive components present in rice bran and rice bran extract are responsible to exhibit therapeutical potential like chemopreventive, cardioprotective, hepatoprotective, immunomodulatory, neuroprotective, and lipid-lowering activity. Several bioactivity representative compounds like γ-oryzanol, ferulic acid, caffeic acid, tricin, protocatechuic acid, vanillic acid, coumaric acid, phytic acid, isoferulic acid, gallic acid, γ-amino butyric acid, sinapic acid, saturated and unsaturated fatty acids, vitamin E complexes, ß-sitosterol, stigmasterol, campesterol, cyanidin-3-glucoside, peonidin-3-glucoside, quercetin, rutin, kaemferol, ß-carotene, lutein, vitamin B and lycopene are known to display significant health benefits. The bioactive components produced therapeutical effects by regulation of different mechanisms like increasing faecal excretion, reducing oxidative stress, reducing the level of malondialdehyde (MDA), regulation of NF-kb activation, reduction of proinflammatory cytokines production, suppression of SREBP-1, reduction in the expression of anti-apoptotic protein Bcl-2, elevated the expression of pro-apoptotic protein Bax, up-regulating P53 expression and suppressing COX-2. METHODOLOGY: Several research engines like PubMed, google scholar, science direct, etc. were used to collect the data on the mentioned keywords. Recent scientific works were included in this article. CONCLUSION: In this review paper, we profiled the high-value compounds and focused on their antioxidant, anti-hyperlipidemic, antidiabetic, and anticancer activity with their possible mechanism of action.

Evaluation of novel microcrystalline cellulose from Ensete glaucum (Roxb.) Cheesman biomass as sustainable drug delivery biomaterial.

Microcrystalline cellulose (MCC) is one of the most important functional excipient in Pharmaceutical industries. A renewable biomass from Ensete glaucum (Roxb.) was investigated as a potential source of a novel functional MCC. MCC was prepared by a simple, dilute acid hydrolysis and characterized through FTIR, DSC, XRD, along with micromeritic studies. Functional properties such as packing, rearrangement, consolidation and compactibility of the prepared MCC were also evaluated in view of its application as drug delivery biomaterial. Results suggest that the prepared MCC exhibit properties comparable to commercially available standard MCC. From Kawakita and Heckel plots, it was observed that the new MCC consolidates better than the standard MCC. Disintegration efficiency test also indicates that the novel MCC functions as a better tablet disintegrant to the standard MCC indicating the potential of Ensete glaucum (Roxb.) as a green resource for preparation of the low cost, functional and sustainable carbohydrate polymer.

Taro starch (Colocasia esculenta) and citric acid modified taro starch as tablet disintegrating agents.

The objective of the present work is to study the physicochemical and functional properties of taro starch (Colocasia esculenta) and to further modify the starch by treating with citric acid to obtain a novel functional material. DSC, FTIR and SEM studies were performed along with physicochemical analysis. The disintegrant efficiency ratio and dissolution efficiency were determined on paracetamol tablets prepared by wet granulation taking the starch as a binder-disintegrant. The moisture content and ash values of taro and citrate taro starches were about 13% and 0.5% respectively. The average particle size of taro starch was found to be 1.53 µm and citration was not found to cause significant changes in the particle size. Results from disintegration efficiency study showed that both the taro and citrate modified taro starch showed tablet disintegrant property and even performed better than the standard corn starch. The reduced disintegration time was also found to enhance dissolution of the model drug from the tablet.

Physicochemical and disintegrant properties of glutinous rice starch of Mizoram, India.

The objective of the current work is to characterize the physicochemical and disintegrant properties of a starch obtained from a novel glutinous rice variety from Mizoram, India. Different properties such as total starch, apparent amylose content, protein and moisture content, along with micromeritic properties were evaluated. Viscosity was determined by Brookfield viscometer, DSC and FTIR spectroscopic analyses were also performed. The disintegrant efficiency was evaluated after dicalcium phosphate tablets were prepared using the starch as binder-disintegrant at different concentrations. The total starch content was found to be 83.48% with 2.83% crude protein and 10.22% moisture content. The average particle size of the starch was also found to be 11.39µm. DSC and FTIR analysis shows the starch possesses typical characteristics of starches. Results from disintegration efficiency study also showed that the starch possesses significant disintegration property and the disintegration efficiency increases with increase in concentration of the starch.

Exploitation of novel gum Prunus cerasoides as mucoadhesive beads for a controlled-release drug delivery.

The present study deals with the formulation of pH-sensitive mucoadhesive beads using natural gum isolated from Prunus cerasoides (PC) in combination with sodium alginate (SA) for the controlled release of diclofenac sodium (DS). PC and SA composite (PC-SA), DS loaded SA (DS-SA) and DS loaded PC-SA (DS-PC-SA) beads were prepared by ionotropic gelation method. The absence of interaction between DS and PC-SA was shown by FTIR, DSC and TGA analyses. The optimized DS-PC-SA formulation exhibited mucoadhesive property and the controlled release of DS was achieved 68% in 12h. The in vitro release kinetics follows zero order with anomalous diffusion mechanism. Therefore, the formulated mucoadhesive beads with the novel gum are preferable for the controlled release of DS by prolonging the residence time of the drug in the gastrointestinal tract, overcoming the problems associated with the immediate release dosage forms of DS.

Recent developments in novel drug delivery systems for wound healing.

INTRODUCTION: Complete regeneration and restoration of the skin's structure and function with no or minimal scarring remains the goal of wound healing research. Novel pharmaceutical carriers have the potential to deliver wound healing drugs such as antibiotics, antimicrobials, human EGFs, and so on. Thus, offering a potential platform to overcome the limitations of conventional wound dressings. AREAS COVERED: This review will describe various techniques such as microspheres, nanoparticles, liposomes, solid lipid nanoparticles, nano and microemulsions, sponges and wafers, and so on, that are successfully applied as carriers for wound healing drugs. Results of various studies including in vitro and in vivo experiments are also discussed. EXPERT OPINION: Controlled and localized delivery of wound healing drugs to the wounds is more convenient than systemic administration as higher concentrations of the medication are delivered directly to the desired area in a sustained manner. They are also capable of providing optimum environmental conditions to facilitate wound healing while eliminating the need for frequent changes of dressings. As the number of people suffering from chronic wounds is increasing around the world, controlled delivery of wound healing agents have enormous potential for patient-friendly wound management.

Characterization and in vitro antioxidant activity of Albizia stipulata Boiv. gum exudates.

The objective of the present study is to characterize the physicochemical properties and to determine the in vitro antioxidant activity of Albizia stipulata Boiv. gum exudates collected from Northeast India. The total carbohydrate, uronic acid and protein contents, monosaccharide composition and the molecular weight distribution of the purified gum was determined. The powder flow property and preliminary compressibility test were performed on the dried gum exudates. Fourier transform infrared spectroscopy (FTIR) study was performed to analyze the functional groups present in the structure. Differential scanning calorimetry (DSC) and thermogravimetry (TGA/DTA) analyses were performed to study the thermal stability of the gum. The antioxidant properties of the gum were evaluated by determining 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl scavenging activities and reducing power. The total carbohydrate and protein contents of the gum were found to be 75.17±3.21% and 2.60±1.05% respectively. The viscosity of 2% aqueous solution of the gum exhibited non-Newtonian type of flow showing pH dependent swelling. Arabinose and galactose were found to be the main monosaccharides present in the gum exudates and the molecular weight distribution of the gum was also found to be polydispersed. Results from DPPH, hydroxyl scavenging and reducing power studies showed the gum possesses antioxidant properties.

Physicochemical characteristics and antioxidant activity of Prunus cerasoides D. Don gum exudates.

The physicochemical properties and antioxidant activity of Prunus cerasoides D. Don gum exudates was investigated in this study. The total carbohydrate and protein content were found to be 73.72±2.44% and 2.33±1.25%, respectively. Analysis of monosaccharide composition by HPLC-RI system after acid hydrolysis of the gum showed the presence of arabinose, galactose, glucose, rhamnose and xylose. The molecular weight of the gum was also found to be 5.55×10(5)Da. FTIR and DSC studies showed characteristics typical of a natural polysaccharide. The viscosity of 2% aqueous solution of the gum exhibited non-Newtonian type of flow and the gum was also found to show pH dependent swelling. Determination of the angle of repose, Carr's index and Hausner ratio indicate the gum possess fairly good powder flow property. The antioxidant properties of the gum were evaluated by determining DPPH and hydroxyl scavenging activities, reducing power and total phenolic contents which showed the gum possess antioxidant property.

Colonic drug delivery systems based on natural polysaccharides and their evaluation.

Natural polysaccharides are found in abundance, are inexpensive, safe and available in a variety of structures which can easily be modified chemically and biochemically. A number of natural gums and mucilages along with their chemically modified forms have been evaluated as controlled drug delivery devices. They are reported to be capable of providing the desired drug release profiles and in some cases, have shown comparable drug release properties with currently available sustained release products in the market. Colon specific drug delivery based on natural polysaccharides has highly been acclaimed in recent years. A colon specific drug delivery system should prevent drug release in the stomach as well as the small intestine. Several polysaccharides have been reported to be capable of preventing drug release in the upper GI tract while being susceptible to enzymatic degradation by colonic bacterial enzymes. A wide range of natural or modified polysaccharides has been investigated for peroral delivery of drugs to the colon. As the release of drug from these polysaccharides based systems is independent of pH and gastric emptying time these polysaccharides based systems are considered the most effective and preferable means for colonic drug delivery in terms of target specificity.

Evaluation of Albizia procera gum as compression coating material for colonic delivery of budesonide.

The purpose of this research was to develop and evaluate Albizia procera gum as compression-coating polymer for colonic delivery of budesonide. Tablets were prepared by direct compression method using spray-dried lactose and microcrystalline cellulose as filler binders. The compatibility between the drug and the polymer was studied through TGA and FTIR spectroscopy. In vitro drug release were studied in dissolution media with or without 2% rat cecal contents while in vivo X-ray study was conducted on rabbits. The results indicate that procera gum and the drug were compatible with each other and tablet coated with procera gum was suitable for colonic delivery of drugs.

Albizia procera gum as an excipient for oral controlled release matrix tablet.

The purpose of this research was to develop and evaluate controlled release matrix tablets of paracetamol based on natural gum exudates of Albizia procera. Procera gum was characterized of its properties like compressibility index, angle of repose, viscosity and moisture content. The interaction between the gum and paracetamol was also studied through differential scanning calorimetry (DSC) and FTIR spectroscopy. Matrix tablets were then prepared by wet granulation method with different concentrations of procera gum and hydroxypropyl methylcellulose (HPMC) and evaluated for their physical properties like weight variation, hardness, friability and content uniformity. Dissolution study was conducted to characterize release mechanism from the matrix system and data were fitted to various kinetic models. The mechanism of drug release from both types of matrix tablets was found to be anomalous type. Results from various evaluations suggested that A. procera gum could be used as drug release retardant in controlled release matrix systems.