DNA barcoding continues to identify endangered species of shark sold as food in a globally significant shark fin trade hub

Shark fins are a delicacy consumed throughout Southeast Asia. The life history characteristics of sharks and the challenges associated with regulating fisheries and the fin trade make sharks particularly susceptible to overfishing. Here, we used DNA barcoding techniques to investigate the composition of the shark fin trade in Singapore, a globally significant trade hub. We collected 505 shark fin samples from 25 different local seafood and Traditional Chinese Medicine shops. From this, we identified 27 species of shark, three species are listed as Critically Endangered, four as Endangered and ten as Vulnerable by the International Union for Conservation of Nature (IUCN). Six species are listed on CITES Appendix II, meaning that trade must be controlled in order to avoid utilization incompatible with their survival. All dried fins collected in this study were sold under the generic term "shark fin"; this vague labelling prevents accurate monitoring of the species involved in the trade, the effective implementation of policy and conservation strategy, and could unwittingly expose consumers to unsafe concentrations of toxic metals. The top five most frequently encountered species in this study are Rhizoprionodon acutus, Carcharhinus falciformis, Galeorhinus galeus, Sphyrna lewini and Sphyrna zygaena. Accurate labelling that indicates the species of shark that a fin came from, along with details of where it was caught, allows consumers to make an informed choice on the products they are consuming. Doing this could facilitate the avoidance of species that are endangered, and similarly the consumer can choose not to purchase species that are documented to contain elevated concentrations of toxic metals.

Screening of Thai medicinal plant extracts and their active constituents forIn Vitro antimalarial activity

To discover antimalarial substances from plants cultivated in Thailand 80%-EtOH extracts from selected plants were screened for in vitro antimalarial activity against the drug resistant K1 strain of Plasmodium falciparum. In total, 86 Thai medicinal plant samples representing 48 species from 35 genera in 16 families were screened and two species (Polyalthia viridis and Goniothalamus marcanii) were found to show notable antimalarial activity (IC50: 10.0 and 6.3 microg/mL). Marcanine A and 16-hydroxycleroda-3,13(14)Z-dien-15,16-olide were identified as the respective major active constituents in P. viridis and G. marcanii, respectively.