Advanced Materials Research Vol. 1060

Abstract: The study was designed to evaluate the inhibitory effects of selected herbs on plant growth. Three insecticides containing plants (leaf of Azadirachta indica A. Juss var indica (AI), Nicotiana tabacum L. (NT), and root of Derris elliptica (Roxb.) (DE) were selected for various solvent extractions. Five extraction solvents: methanol, hexane, dichloromethane, butanol and aqueous were used in this study. The test method was lemna phytotoxicity assay which measured the inhibitory effect on duckweed, Lemna minor growth. This toxicity test proved to be a practical bioassay method because this method is simple, sensitive and cost effective. Butanol extracts of AI were shown to have more inhibition activity on duckweed growth than NT (% inhibition growth rate is 66.08, 27.08 respectively). Butanol extracts of AI had inhibitory effect (EC₁₀) of 40.87 μg/ ml while dichloromethane extracts had EC₁₀ of 131.72 μg/ ml. It could therefore be concluded that butanol extracts of AI showed the greatest inhibitory effects. The results from this study suggest that butanol extracts of AI were the most promising candidates for biological weed control and might be used as potential natural herbicides or as alternatives for the reduction of chemical herbicides. The study is worthy of further investigation since this could provide potential bioherbicide and may lead to the discovery of new effective and applicable bioherbicide.

Abstract: A lactobacillus strain isolated from the feces of a healthy baby was identified as Lactobacillus fermentum SK54. The probiotic properties of this strain including antimicrobial activity, survival in acid, bile, simulated gastric fluid [SGF] and simulated intestinal fluid [SIF], antibiotic susceptibility and adherence to Caco-2 cells were examined and compared them with a well known commercial probiotic strain Lactobacillus rhamnosus GG ATCC 53103 isolated from human intestine. L. fermentum SK54 and L. rhamnosus GG showed inhibitory properties toward gastrointestinal pathogens i.e., Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium, and Shigella sonnei by cylinder-plate assay. The inhibitory substances from L. fermentum SK54 composed of acid substances naturally produced by lactobacilli and high molecular weight proteinaceous compound [MW > 3.5 kDa] which sensitive to proteolytic enzymes, pH stability [pH 2.0-5.0] and heat stability [60, 80, 100°C for 10 min and 121°C for15 min]. L. rhamnosus GG produced only acid inhibitory substances. Both strains survived well at low pH [pH 2.0-4.0], bile salts [0.1-0.3% w/v], SGF and SIF. They also had the same 14 tested antibiotic sensitivity pattern and expressed high adherence to Caco-2 cells. This study provides a rationale to support L. fermentum SK54 as a potential probiotic to prevent or act as a therapeutic agent against pathogenic strains.

Abstract: DNA barcode is referred to specific ranges, sequences or fragments of DNA used for identification organisms at genus or species levels. There are several plant DNA barcodes which are currently studied, such as ITS (Internal Transcribed Spacer), ITS2 (Internal Transcribed Spacer 2), matK, psbA-trnH, rbcL, trnL-trnF. In this work, ITS, ITS2 and psbA-trnH sequences of many medicinal plants in the “Thai Medicinal Plant DNA Barcode Database” were studied. Total of 163 DNA barcodes from 75 plant families were processed and analysed. ATCG contents, %GC or %CG found, ATG patterns, and alignment patterns were investigated. Also, sequences relationships among families were discussed. This information will be useful for authentication and quality control of herbal medicine.

Abstract: Moringa oleifera Lamk (Moringaceae) is a worldwide use for food and traditional medicine. In this study, plants were separated into seven parts: 1) Leaf, 2) Drum, 3) Branching, 4) Seed, 5) Outer stem, 6) Stem bark, and 7) Root, respectively. Then, they were extracted by two different methods: methanol soxhlet extraction and ethanol maceration. All crude extracts were tested for anti-bacterial activity by agar diffusion method and colorimetric micro-dilution plate technique. The results showed that 7 parts of Moringa crude extracts had low anti-bacterial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa when compared with standard antibiotic (ampicillin or gentamycin). In conclusion, anti-bacterial effects of M. oleifera crude extracts had low anti-bacterial activity in vitro test.

Abstract: To overcome major side-effects, that is, cardiotoxicity of doxorubicin (DOX), pH-responsive dextrin nanogels (DNGs) were developed for using as a smart drug carrier. DOX-loaded DNGs were fabricated by emulsion cross-linking technique using glyoxal as a cross-linking agent to form acid-sensitive, acetal bonds. The objective of this study was to investigate the cytotoxicity of DOX-loaded DNGs on the human osteosarcoma 143B cell line. The cytotoxicity assay results showed that DOX-loaded DNGs retained high cell inhibition efficiency in 143B cells in a concentration- and treatment time-dependent manner. The cytotoxicity decreased with increasing ratio of glyoxal to dextrin. Observation of 143B cells by light microscopy showed the morphological changes after treatment with DOX-loaded DNGs. These results suggested that DOX-loaded DNGs with pH-sensitive properties is promising for use as a drug delivery system for cancer therapy.

Abstract: Moringa oleifera Lam. leaf capsules collected from markets in Nakhon Pathom, Thailand were determined for 11 heavy metals (Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn) by inductively coupled plasma-mass spectrometry (ICP-MS) using acid digestion for sample preparation. The concentrations of Al, As, Cr, Cu and Hg in all samples of M. oleifera capsules were found within permissible limits and normal ranges. In contrast, Fe, and Zn concentrations in all samples were higher than permissible limits. Furthermore, the concentrations of Cd, Mn, Ni, and Pb in some samples were higher than permissible limits and normal ranges. The presence of elevated levels of Cd, Fe, Mn, Ni, Pb, and Zn in M. oleifera capsules is a serious matter of concern. Therefore, it is important that doctors and consumers are aware of this matter especially during the routine taking of M. oleifera capsules.

Abstract: A simple, rapid and cost effective UV-VIS spectrophotometric method was validated and applied for stability assessment of 5% ceftazidime in extemporaneous ophthalmic solution in various conditions. Ceftazidime dissolving in sterile water showed the maximum absorbance (λ_max) at 256 nm and no interference was observed. The method validation was determined in term of linearity, intra-day and inter-day precision, accuracy, limit of detection (LOD) and limit of quantitation (LOQ) according to ICH guideline. Spectrophotometric response was linear with r² = 0.9998 in the range of 5-25 μg/mL. The mean recovery was 99.38% with percent relative standard deviations (%RSDs) of 0.83. Intra-day and inter-day precision showed %RSDs of < 1.00%. LOD and LOQ were 2.60 and 7.88 μg/mL, respectively. The method was reliable for stability study of extemporaneous ceftazidime ophthalmic solution. Results showed that the amount of ceftazidime in extemporaneous formulation stored in both ambient and accelerated conditions dramatically decreased within 1 day. However, the preparation was stable at 2-8 °C for 7 days. In conclusion, the storage temperature had greatly impact on ceftazidime ophthalmic solution therefore it should be kept in the refrigerator for a week and its stability could be monitored using the simple spectrophotometric method.