Comparative Studies of Resveratrol, Oxyresveratrol and Dihydrooxyresveratrol on Doxorubicin-Treated Lung Cancer Cells.

OBJECTIVES: This research aims to comparatively investigate the capability of resveratrol (RES) and RES analogues, oxyresveratrol (Oxy-RES) and dihydrooxyresveratrol (DHoxy-RES), to potentiate doxorubicin (DOX) effects against lung carcinoma epithelial cells. METHODS: All experiments were performed on lung carcinoma cell lines (A549) with DOX combination between DOX and RES or RES analogues. Cell viability or growth inhibitory effect was assessed by MTT assay and genes associated with survival and metastasis were monitored by real-time polymerase chain reaction (RT-PCR). RESULTS: DOX obviously demonstrated cytotoxic and anti-metastatic activities against A549 cells. Expression of gene-associated with both activities was potentiated by RES and RES analogues. Oxy-RES showed highest capability to potentiate DOX effects. DHoxy-RES showed nearly no effect to DOX activities. CONCLUSIONS: These results provided an important basis of DOX combination with RES analogues, especially Oxy-RES, for better therapeutic effect. Further studies in human should be performed on exploring combination of DOX and Oxy-RES.

Antimicrobial Activity against Foodborne Pathogens and Antioxidant Activity of Plant Leaves Traditionally Used as Food Packaging.

In accordance with Thai wisdom, indigenous plant leaves have been used as food packaging to preserve freshness. Many studies have demonstrated that both antioxidant and antimicrobial activities contribute to protecting food from spoilage. Hence, the ethanolic extracts of leaves from selected plants traditionally used as food packaging, including Nelumbo nucifera (1), Cocos nucifera (2), Nypa fruticans (3), Nepenthes mirabilis (4), Dendrocalamus asper (5), Cephalostachyum pergracile (6), Musa balbisiana (7), and Piper sarmentosum (8), were investigated to determine whether they have antioxidant and antimicrobial activities against spoilage microorganisms and foodborne pathogens that might be beneficial for food quality. Extracts 1-4 exhibited high phenolic content at 82.18-115.15 mg GAE/g and high antioxidant capacity on DPPH, FRAP and SRSA assay at 14.71-34.28 µg/mL, 342.92-551.38 µmol Fe2+/g, and 11.19-38.97 µg/mL, respectively, while leaf extracts 5-8 showed lower phenolic content at 34.43-50.08 mg GAE/g and lower antioxidant capacity on DPPH, FRAP, and SRSA at 46.70-142.16 µg/mL, 54.57-191.78 µmol Fe2+/g, and 69.05->120 µg/mL, respectively. Extracts 1-4 possessed antimicrobial activities against food-relevant bacteria, including Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, and Escherichia coli. Only N. mirabilis extract (4) showed antimicrobial activities against Salmonella enterica subsp. enterica serovar Abony and Candida albicans. Extracts 5-8 showed slight antimicrobial activities against B. cereus and E. coli. As the growth and activity of microorganisms are the main cause of food spoilage, N. fruticans (3) was selected for bioassay-guided isolation to obtain 3-O-caffeoyl shikimic acid (I), isoorientin (II) and isovitexin (III), which are responsible for its antimicrobial activity against foodborne pathogens. N. fruticans was identified as a new source of natural antimicrobial compounds I-III, among which 3-O-caffeoyl shikimic acid was proven to show antimicrobial activity for the first time. These findings support the use of leaves for wrapping food and protecting food against oxidation and foodborne pathogens through their antioxidant and antimicrobial activities, respectively. Thus, leaves could be used as a natural packaging material and natural preservative.

Antibacterial and osteogenic activities of clindamycin-releasing mesoporous silica/carboxymethyl chitosan composite hydrogels.

Conventional treatment of jaw bone infection is often ineffective at controlling bacterial infection and enhancing bone regeneration. Biodegradable composite hydrogels comprised of carboxymethyl chitosan (CMCS) and clindamycin (CDM)-loaded mesoporous silica nanoparticles (MCM-41), possessing dual antibacterial activity and osteogenic potency, were developed in the present study. CDM was successfully loaded into both untreated and plasma-treated MCM-41 nanoparticles, denoted as (p)-MCM-41, followed by the incorporation of each of CDM-loaded (p)-MCM-41 into CMCS. The resulting CDM-loaded composite hydrogels, (p)-MCM-41-CDM-CMCS, demonstrated slow degradation rates (about 70% remaining weight after 14-day immersion), while the CDM-free composite hydrogel entirely disintegrated after 4-day immersion. The plasma treatment was found to improve drug loading capacity and slow down initial drug burst effect. The prolonged releases of CDM from both (p)-MCM-41-CDM-CMCS retained their antibacterial effect against Streptococcus sanguinis for at least 14 days in vitro. In vitro assessment of osteogenic activity showed that the CDM-incorporated composite hydrogel was cytocompatible to human mesenchymal stem cells (hMSCs) and induced hMSC mineralization via p38-dependent upregulated alkaline phosphatase activity. In conclusion, novel (p)-MCM-41-CDM-CMCS hydrogels with combined controlled release of CDM and osteogenic potency were successfully developed for the first time, suggesting their potential clinical benefit for treatment of intraoral bone infection.

Differentiation of Cyanthillium cinereum, a smoking cessation herb, from its adulterant Emilia sonchifolia using macroscopic and microscopic examination, HPTLC profiles and DNA barcodes.

Cyanthillium cinereum (L.) H.Rob. is one of the most popular herbal smoking cessation aids currently used in Thailand, and its adulteration with Emilia sonchifolia (L.) DC. is often found in the herbal market. Therefore, the quality of the raw material must be considered. This work aimed to integrate macro- and microscopic, chemical and genetic authentication strategies to differentiate C. cinereum raw material from its adulterant. Different morphological features between C. cinereum and E. sonchifolia were simply recognized at the leaf base. For microscopic characteristics, trichome and pappus features were different between the two plants. HPTLC profiles showed a distinct band that could be used to unambiguously differentiate C. cinereum from E. sonchifolia. Four triterpenoid compounds, ß-amyrin, taraxasterol, lupeol, and betulin, were identified from the distinct HPTLC band of C. cinereum. The use of core DNA barcode regions; rbcL, matK, ITS and psbA-trnH provided species-level resolution to differentiate the two plants. Taken together, the integration of macroscopic and microscopic characterization, phytochemical analysis by HPTLC and DNA barcoding distinguished C. cinereum from E. sonchifolia. The signatures of C. cinereum obtained here can help manufacturers to increase the quality control of C. cinereum raw material in commercialized smoking cessation products.

Antioxidant Effect of Berberine and its Phenolic Derivatives Against Human Fibrosarcoma Cells.

Berberine (B1), isolated from stems of Coscinium fenestratum (Goetgh.) Colebr, was used as a principle structure to synthesize three phenolic derivatives: berberrubine (B2) with a single phenolic group, berberrubine chloride (B3) as a chloride counter ion derivative, and 2,3,9,10-tetra-hydroxyberberine chloride (B4) with four phenolic groups, to investigate their direct and indirect antioxidant activities. For DPPH assay, compounds B4, B3, and B2 showed good direct antioxidant activity (IC50 values=10.7±1.76, 55.2±2.24, and 87.4±6.65 µM, respectively) whereas the IC50 value of berberine was higher than 500 µM. Moreover, compound B4 exhibited a better DPPH scavenging activity than BHT as a standard antioxidant (IC50=72.7±7.22 µM) due to the ortho position of hydroxyl groups and its capacity to undergo intramolecular hydrogen bonding. For cytotoxicity assay against human fibrosarcoma cells (HT1080) using MTT reagent, the sequence of IC50 value at 7-day treatment stated that B1

Hexachloroethane: a highly efficient reagent for the synthesis of chlorosilanes from hydrosilanes.

A new and efficient chlorination protocol is presented for the preparation of chlorosilanes from hydrosilanes. A variety of chlorinating agents in combination with palladium(II) chloride as the catalyst are examined. Among them, hexachloroethane is found to be the best choice, furnishing the desired product in good to quantitative yields under mild conditions. Various hydrosilanes are used as starting materials to explore the scope of this reaction.