Sub-lethal Camphor Exposure Triggers Oxidative Stress, Cardiotoxicity, and Cardiac Physiology Alterations in Zebrafish Embryos.

Camphor is a terpene ketone with aromatic and volatile properties in nature derived from the bark of Cinnamomum camphora or synthesized from turpentine. Camphor exhibits various biological properties such as anti-microbial, anti-viral, anti-coccidial, and anti-cancer. It is also used as a form of topical medication for skin irritation, joint pain, and as a relief for itching from insect bites. However, even though the high dose of camphor has been documented to be toxic/lethal in humans in different studies, camphor's developmental toxicity has not yet been explored, and its extensive mechanism of action is still unclear. In the present study, we aimed to assess the toxic effects of camphor in zebrafish embryos in the initial developmental stages. The obtained results demonstrated that a sub-lethal dose of camphor caused a decrease in hatching rate, body length, and substantial elevation in malformation rate on zebrafish embryos. On further observation, in the following time frame, curved body and pericardial edema of zebrafish were also observed. Furthermore, exposure to a sub-lethal dose of camphor was also able to trigger cardiotoxicity in zebrafish larvae. Later, on subsequent biochemical analysis, it was found that the antioxidant capacity inhibition and oxidative stress elevation that occurred after camphor exposure might be associated with the inhibition of total superoxide dismutase (SOD) activity and an increase in reactive oxygen species (ROS) and malondialdehyde (MDA) concentration. In addition, compared to the control group, several apoptotic cells in treated zebrafish were also found to be elevated. Finally, after further investigation on marker gene expressions, we conclude that the developmental toxicity of camphor exposure might be associated with apoptosis elevation and oxidative stress. Taken together, the current study provides a better understanding of the developmental toxicity of camphor on zebrafish, a promising alternative animal model to assess the developmental toxicity of chemical compounds.

Genipin induces developmental toxicity through oxidative stress and apoptosis in zebrafish.

Genipin, an iridoid substance, is mainly derived from Gardenia jasminoides Ellis of the traditional Chinese medicine and is widely used in raw materials for the food additive gardenia blue and biological materials. The developmental toxicity of genipin has not been investigated, and its underlying mechanism is unclear. Therefore, in this study we attempt to investigate the potential developmental toxicity of genipin in zebrafish embryos/larvae. The results showed zebrafish embryos treated with 50 µg/ml dose of genipin display inhibited hatching rates and body length. The pericardial edema was observed. It was also found that genipin could induce cardio-toxicity, hepatotoxicity and nephrotoxicity in zebrafish larvae. After genipin treatment, the suppression of antioxidant capacity and increase of oxidative stress were showed for the triggered generation of ROS and MDA, and decreased activity of SOD. Compared with the 0.5% DMSO group, a number of apoptotic cells in zebrafish were increased after genipin exposure. By measuring marker gene expression with the using of qRT-PCR, we proposed that developmental toxicity after genipin treatment might be associated with oxidative stress and apoptosis increase. Our research offers a better understanding for developmental toxicity of genipin.

[Traditional medicinal plants for arthropod-borne diseases of five countries in Lancang-Mekong region:a review].

Arthropod-borne diseases, such as malaria and dengue fever, have frequently beset five countries(Cambodia, Vietnam, Laos, Myanmar, and Thailand) in the tropical rainy Lancang-Mekong region, which pose a huge threat to social production and daily life. As a resort to such diseases, chemical drugs risk the resistance in plasmodium, non-availability for dengue virus, and pollution to the environment. Traditional medicinal plants have the multi-component, multi-target, and multi-pathway characteristics, which are of great potential in drug development. Exploring potential medicinals for arthropod-borne diseases from traditional medicinal plants has become a hot spot. This study summarized the epidemiological background of arthropod-borne diseases in the Lancang-Mekong region and screened effective herbs from the 350 medicinal plants recorded in CHINA-ASEAN Traditional Medicine. Based on CNKI, VIP, and PubMed, the plants for malaria and dengue fever and those for killing and repelling mosquitoes were respectively sorted out. Their pharmacological effects and mechanisms were reviewed and the material basis was analyzed. The result is expected to serve as a reference for efficient utilization of medicinal resources, development of effective and safe drugs for malaria and dengue fever, and the further cooperation between China and the other five countries in the Lancang-Mekong region.

Gemmobacter lanyuensis sp. nov., isolated from a freshwater spring.

A bacterial strain designated Orc-4(T) was isolated from a freshwater spring in Taiwan and characterized using the polyphasic taxonomic approach. Cells of strain Orc-4(T) were facultatively anaerobic, Gram-reaction-negative, poly-ß-hydroxybutyrate-accumulating, non-motile rods surrounded by a thick capsule and forming cream-white colonies. Growth occurred at 15-40 °C (optimum, 25-30 °C), at pH 6.0-9.0 (optimum, pH 7.0) and with 0-1 % NaCl (optimum, 0-0.5 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain Orc-4(T) belonged to the genus Gemmobacter within the family Rhodobacteraceae of the class Alphaproteobacteria and its most closely related neighbour was Gemmobacter fontiphilus JS43(T) with sequence similarity of 97.8 %. Strain Orc-4(T) contained C18 : 1ω7c as the predominant fatty acid. The major respiratory quinone was Q-10. The DNA G+C content of the genomic DNA was 63.5 mol%. The polar lipid profile consisted of a mixture of phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, one uncharacterized aminolipid and several uncharacterized phospholipids. The DNA-DNA relatedness of strain Orc-4(T) with respect to recognized species of the genus Gemmobacter was less than 48 %. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain Orc-4(T) represents a novel species of the genus Gemmobacter, for which the name Gemmobacter lanyuensis sp. nov. is proposed. The type strain is Orc-4(T) ( = BCRC 80378(T) = LMG 26667(T) = KCTC 23714(T)).

Sphingobium fontiphilum sp. nov., isolated from a freshwater spring.

To investigate the biodiversity of bacteria in the spring water of the Chengcing Lake Park in Taiwan, a Gram-stain-negative, rod-shaped, non-motile, non-spore-forming and aerobic bacterial strain, designated strain Chen16-4(T), was isolated and characterized in a taxonomic study using a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that the closest relatives of strain Chen16-4(T) were Sphingobium amiense YT(T), Sphingobium yanoikuyae GIFU 9882(T) and Sphingobium scionense WP01(T), with sequence similarities of 97.6, 97.1 and 97.0 %, respectively. A phylogenetic tree obtained with 16S rRNA gene sequences indicated that strain Chen16-4(T) and these three closest relatives formed an independent phylogenetic clade within the genus Sphingobium. The polar lipid pattern, the presence of spermidine and ubiquinone Q-10, the predominance of C18 : 1ω7c in the cellular fatty acid profile and the DNA G+C content also supported affiliation of the isolate to the genus Sphingobium. The DNA-DNA relatedness of strain Chen16-4(T) with respect to recognized species of the genus Sphingobium was less than 70 %. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain Chen16-4(T) represents a novel species in the genus Sphingobium, for which the name Sphingobium fontiphilum sp. nov. is proposed. The type strain is Chen16-4(T) ( = BCRC 80308(T) = LMG 26342(T) = KCTC 23559(T)).