The Susceptibility of Aphids, Aphis gossypii Glover to Lauric Acid Based Natural Pesticide

The susceptibility of aphids to lauric acid, a type of middle-chain fatty acids, based pesticide formulation was investigated. The insecticidal properties of lauric acid based pesticide formulation against aphids were evaluated through the three main routes of exposure: topical application, leaf-dipping (ingestion) and inhalation. Surface tension dependent aphids toxicity was also investigated by measuring the surface tension value of each formulation prepared. The relationship of surface tension and formulation toxicity was then observed on aphid tested. The obtained results indicate that all tested formulations had insecticidal activity against tested aphids depending on exposure method and lauric acid concentration. The topical application method recorded 100% mortality rates compared to the other two methods. With topical application method, most of the aphids died soon after treatment. Toxicity symptoms from lauric acid to aphids included unusual abdominal contractions which caused quick loss of coordination and decreased activity, and finally dehydration and necrosis within 24 hours. Results from surface tension study revealed close connection between toxicity and surface tension. This might lead to the conclusion that toxicity was possibly related to aphid suffocation in the highly wettable solution. Results from this research also demonstrated that there were possibility that lauric acid do not only kill aphids by suffocation, but also through change of cuticle and cell permeability and desiccation that lead to speedy death due to the chemical nature of lauric acid. Overall, the results recommend that lauric acid based pesticide formulation has both physical and chemical mode of action on aphids

The possibility of employing cysteine and gold nanoparticles for skin sensitization analysis: current status

Determination of the toxicity potential of the ingredients is the first step in hazard assessment of cosmetics and personal care products. Skin sensitization analysis is one of the tests needed for the safety evaluation of these products. More countries in the world are turning their backs on animal testing for cosmetics and personal care products. This has led to the search for alternatives in skin sensitization analysis. Skin sensitization is defined as an allergic response to a skin sensitizer upon contact with the skin. Skin sensitization is induced through the covalent binding of a skin sensitizer to skin proteins (haptenation process). OECD Test Guideline No. 442C has adopted direct peptide reactivity assay (DPRA) and amino acid derivative reactivity assay (ADRA) as validated in chemico alternatives in the testing of skin sensitization potential of chemicals. The most cited nucleophilic amino acid that complexes with skin sensitizers (hapten) through covalent bonds is cysteine. Gold nanoparticles are mostly used to fabricate electrodes for the detection of analytes due to their chemical stability, high chemical conductivity, and biocompatibility. Cysteine has the capability to interact with gold due the formation of a strong cysteine-gold nanoparticles thiolate bond. The status of the possibility of employing cysteine and gold nanoparticles for skin sensitization analysis is discussed in this review article

Formulation and characterization of [6]-gingerol loaded nanostructured lipid carrier (NLC)

Nanostructured lipid carrier (NLC) is the blend of solid lipid, liquid lipid and suitable surfactant for the purpose of encapsulated poorly water soluble drugs. [6]-gingerol is the main bioactive compound in Zingiber officinale, widely known as ginger in Malaysia. Zingiber officinale extract has been discovered to have anti-oxidant, anti-inflammatory, and anti-microbial effects to human body. The aim of this study is to develop NLC formulation for [6]-gingerol and to estimate the potential of NLC as a delivery system for these water insoluble drugs. In this work, the preparation of ginger oil loaded onto nanostructured lipid carrier (GO-NLC) was done by using ultrasonication method. The GO-NLCs were assessed by evaluating the morphology and its entrapment efficiency. The morphological study was performed by using Zetasizer Nano S and the entrapment efficiency analysis of NLC was performed using HPLC by detecting [6]-gingerol as active biomarker. The average particle size for GO-NLCs ranged from size 100 to 250 nm and the average encapsulation efficiency was 92.7± 3.03%.Based on analysis, it is proved that nanostructured lipid carriers has high potential to be nanocarriers for [6]-gingerol

Relationships between Malaysians Cultivars of Tongkat Ali (Eurycoma Longifolia Jack) Obtained through RAPD Analysis

Abstract: Random Amplified Polymorphic DNA (RAPD) analysis was done on Eurycoma Longifolia Jack (ELJ) cultivars originating from 7 different locations in Malaysia to determine whether the originality of ELJ cultivars can be preserved in an uncontrolled cultivation area. Out of 60 arbitrary 10-mer primers, a total of 320 DNA fragments were amplified with an average of 53.3 RAPD markers per primer. 71 (22%) of the 320 DNA-fragments was found to be monomorphic. The remaining 249 (78%) were polymorphic. The approximate size of the largest fragment produced was 3000 base pair (bp) and the easily recognizable fragment produced was 300 bp. Similarity index of RAPD banding patterns was used to investigate the relationships between ELJ cultivars. Mantel test showed that the correlation between Jaccard and Dice similarity matrices was high and significant (0.9907). The dendogram showed that ELJ cultivars can be clustered into three main clusters. Cluster 1 consisted of Sabah cultivars (East Malaysia), Cluster 2 consisted of Pahang and Terengganu cultivars (middle part of West Malaysia) while cluster 3 consisted of Kedah and Kelantan cultivars (east part of West Malaysia). The results of Principle Coordinates Analysis (PCA) were comparable to the Dendogram by UPGMA. The first two principle coordinates explained 53.62% of total variations and separated the 37 ELJ cultivars into three main clusters with a slight overlap between each other

Faculty of Chemical and Energy Engineering

The toxicological effect of lauric acid based insecticide was investigated in terms of mode of action on aphids target system. Treated leaves were sprayed with different insecticides, which were lauric acid, cinnamaldehyde and malathion at 50µg/ml concentration to compare the effect of the pesticides on reproduction, growth development and feeding activity of aphids. The total number of new born nymphs produced and the relative development stage of nymphs were significantly reduced in all treatments compared to untreated leaves. Number of new born nymphs treated using lauric acid based pesticide was 6.0 ± 1.41 nymphs/day and the growth development rate at second day post treatment was rDS=1.07 ± 0.10. This data showed no significant difference with the data obtained when cinnamaldehyde and malathion were used as positive controls but the results were significantly different from the results obtained using untreated leaves (22.5 ± 3.54 nymphs/day, rDS=1.82 ± 0.02). Lauric acid was also shown to reduce the feeding activity of aphids. The study demonstrated that lauric acid was toxic to aphids. It has the ability to slow down the reproduction system, reduce growth development rate and decrease feeding activity of aphids (Aphis gosyypii Glover)

A review and survey of Problem-Based Learning application in Engineering Education

This paper gives a review of Problem-Based Learning (PBL) applied in engineering courses worldwide, and a survey of academic staff who have implemented PBL in engineering classes in Universiti Teknologi Malaysia. The review of PBL application illustrates the extent of acceptance and success of PBL in schools of engineering in the international arena. The survey, on the other hand, illustrates the acceptance of PBL among engineering lecturers and the possibility of applying PBL in Malaysia. The main purpose of the survey is to obtain feedback on PBL regarding the impressions, set-backs and constraints faced, as well as innovations and tips for successful implementation from the faculty members involved

Incorporation of Nanoparticles Based on Zingiber Officinale Essential Oil into Alginate Films for Sustained Release

This research focused on the formulation of Ca2+ cross-linked alginate (Alg) gels containing Zingiber officinale oil extract (ZOE) loaded into a nanostructured lipid carrier (NLC). The NLC is intended to protect the Zingiber officinale oil against physical and chemical degradation during topical administration to sustain the drug release and reduce drug leakage during storage. The NLC was prepared using hot homogenisation and ultrasonication of glyceryl monostearate. Virgin coconut oil was used as the liquid lipid. The NLC-ZOE had a mean size diameter of 100 nm and a zeta potential value of −40 mV. The ZOE released from NLC followed the Korsmeyer-Peppas model case I (Fickian diffusion). The NLC-ZOE formulation was then incorporated into Alg. The gels were prepared via ionotropic gelation in the presence of calcium. Scanning electron microscopy (SEM) images of Alg films revealed successful intercalation of NLC within the Alg matrix. The in vitro ZOE release from NLC-ZOEAlg occurred in a sustained manner from the cross-linked Alg hydrogels compared to the free NLC. The profiles of NLC-ZOE released from the Alg films depended on the nanoparticles amount. The results demonstrated the importance of designing a local delivery system to entrap and control the release of the bioactive components of ZOE from within the Alg matrix. Ca2+ cross-linked Alg gels containing ZOE loaded into NLC was found to be suitable for topical delivery applications, as shown by the sustained release of ZOE from calcium cross-linked Alg films containing NLC that was demonstrated in this study.Fil: Rosli, Nur Ayshah. Universiti Sains Malaysia; MalasiaFil: Islan, German Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Hasham, Rosnani. Universiti Teknologi Malaysia; MalasiaFil: Castro, Guillermo Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; Argentina. Universidad Federal do Abc; BrasilFil: Aziz, Azila Abdul. Universiti Teknologi Malaysia; Malasi

Usage of sugar ester in the preparation of avocado oil nanoemulsion

Objectives: Due to the high dynamics of pharmaceutical products markets, developments of new products using latest innovative technology are becoming a norm of many pharmaceutical companies. Nanoscale materials such as nanoemulsion (NE) offer advantages such as the controllable droplet size, long-term stability, and power solubilization ability. It is beneficial in various delivery systems either for transdermal, ocular, nasal, vaginal, and parenteral drug delivery. The objective of the study was to prepare avocado oil NE using different surfactants to find the most suitable nanosized droplets, as avocado oil offers a variety of purported nutritional and medicinal benefits. Methods: Sucrose esters, glycerol, and avocado oil with different ratio were used to produce pre-NE by phase inversion technique then pre-NE were self-emulsified with water to produce NE. The influence of the sucrose esters surfactants on the NE formulations were determined using three different types of sucrose esters surfactant (laureate, oleate, and palmitate). Stability study was conducted for NE at different temperatures (4°C, 25°C, and 40°C) for 6 months. Results: The NE contained sucrose laureate produced best nanosized formulations compared to other oleate and palmitate, with optimum droplet size 106 ± 1.70 nm, size distribution 0.156 ± 0.01, and zeta potential -30.4 ± 0.70. The NE formulations were very stable at 4°C compared to 25°C and 40°C while at 25°C NE showed moderate stability, but it was unstable at 40°C. Conclusion: Sucrose laureate was able to produce NE with phase inversion and self-emulsification techniques and the ideal storage condition for NE is 4°C

Promising drug delivery approaches to treat microbial infections in the vagina: a recent update

An optimal host–microbiota interaction in the human vagina governs the reproductive health status of a woman. The marked depletion in the beneficial Lactobacillus sp. increases the risk of infection with sexually transmitted pathogens, resulting in gynaecological issues. Vaginal infections that are becoming increasingly prevalent, especially among women of reproductive age, require an effective concentration of antimicrobial drugs at the infectious sites for complete disease eradication. Thus, topical treatment is recommended as it allows direct therapeutic action, reduced drug doses and side effects, and self-insertion. However, the alterations in the physiological conditions of the vagina affect the effectiveness of vaginal drug delivery considerably. Conventional vaginal dosage forms are often linked to low retention time in the vagina and discomfort which significantly reduces patient compliance. The lack of optimal prevention and treatment approaches have contributed to the unacceptably high rate of recurrence for vaginal diseases. To combat these limitations, several novel approaches including nano-systems, mucoadhesive polymeric systems, and stimuli-responsive systems have been developed in recent years. This review discusses and summarises the recent research progress of these novel approaches for vaginal drug delivery against various vaginal diseases. An overview of the concept and challenges of vaginal infections, anatomy and physiology of the vagina, and barriers to vaginal drug delivery are also addressed

Advancement on sustained antiviral ocular drug delivery for herpes simplex virus keratitis: recent update on potential investigation

The eyes are the window to the world and the key to communication, but they are vulnerable to multitudes of ailments. More serious than is thought, corneal infection by herpes simplex viruses (HSVs) is a prevalent yet silent cause of blindness in both the paediatric and adult population, especially if immunodeficient. Globally, there are 1.5 million new cases and forty thousand visual impairment cases reported yearly. The Herpetic Eye Disease Study recommends topical antiviral as the front-line therapy for HSV keratitis. Ironically, topical eye solutions undergo rapid nasolacrimal clearance, which necessitates oral drugs but there is a catch of systemic toxicity. The hurdle of antiviral penetration to reach an effective concentration is further complicated by drugs’ poor permeability and complex layers of ocular barriers. In this current review, novel delivery approaches for ocular herpetic infection, including nanocarriers, prodrugs, and peptides are widely investigated, with special focus on advantages, challenges, and recent updates on in situ gelling systems of ocular HSV infections. In general congruence, the novel drug delivery systems play a vital role in prolonging the ocular drug residence time to achieve controlled release of therapeutic agents at the application site, thus allowing superior ocular bioavailability yet fewer systemic side effects. Moreover, in situ gel functions synergistically with nanocarriers, prodrugs, and peptides. The findings support that novel drug delivery systems have potential in ophthalmic drug delivery of antiviral agents, and improve patient convenience when prolonged and chronic topical ocular deliveries are intended