The edible Bird's-nest, or Nest of the Java Swift (Collocalia Nidifica)

Identification of the original species of cubilose based on DNA barcode

Cubilose, a valuable traditional Chinese medicine, is mainly composed of the saliva by several species of Aerodramus or Collocalia in the Apodidae. Due to rarity, high economic value and huge market demand, its fake or adulteration is frequently found in the market. Therefore, it is urgent to establish a simple and accurate method for authenticating cubilose. DNA barcoding, which is an easy, quick and reliable method, is widely used to trace the origin of traditional Chinese medicine. For identifying the original species of cubilose, cytb gene of 18 cubilose samples including 15 officer cubilose and 3 feather cubilose were amplified and entered into the GenBank database using the BLAST search tool. The genetic distances among 18 cubilose samples were calculated based on the Kimura two parameter (K2P) model. To construct the reference database, 18 cytb sequences of Aerodramus or Collocalia were downloaded from GenBank. The neighbor-joining (NJ) and unweighted pair group method with arithmetic average (UPGMA) trees were constructed based on sequences from GenBank and our dataset. Blast analysis showed that all cubilose samples had the highest similarity with A. fuciphagus, and the sequence similarity reached over 99%. Genetic distance of 18 cubilose samples ranged from 0.000-0.010. Trees constructed by NJ and UPGMA gave similar topology: all cubilose samples clustered together with A. fuciphagus. These result demonstrated that the original species of all 18 cubilose samples were A. fuciphagus, and cytb gene is a good candidate for identifying cubilose.

Exploration of the Sialic Acid World

Sialic acids are cytoprotectors, mainly localized on the surface of cell membranes with multiple and outstanding cell biological functions. The history of their structural analysis, occurrence, and functions is fascinating and described in this review. Reports from different researchers on apparently similar substances from a variety of biological materials led to the identification of a 9-carbon monosaccharide, which in 1957 was designated "sialic acid." The most frequently occurring member of the sialic acid family is N-acetylneuraminic acid, followed by N-glycolylneuraminic acid and O-acetylated derivatives, and up to now over about 80 neuraminic acid derivatives have been described. They appeared first in the animal kingdom, ranging from echinoderms up to higher animals, in many microorganisms, and are also expressed in insects, but are absent in higher plants. Sialic acids are masks and ligands and play as such dual roles in biology. Their involvement in immunology and tumor biology, as well as in hereditary diseases, cannot be underestimated. N-Glycolylneuraminic acid is very special, as this sugar cannot be expressed by humans, but is a xenoantigen with pathogenetic potential. Sialidases (neuraminidases), which liberate sialic acids from cellular compounds, had been known from very early on from studies with influenza viruses. Sialyltransferases, which are responsible for the sialylation of glycans and elongation of polysialic acids, are studied because of their significance in development and, for instance, in cancer. As more information about the functions in health and disease is acquired, the use of sialic acids in the treatment of diseases is also envisaged.

Edible bird's nest: food or medicine?

Edible bird's nest (EBN) is derived from the saliva of certain types of swiftlets. It is consumed in many parts of the world for its nutritional and medicinal values. Although many claims have been made on the therapeutic and health-promoting effects of EBN, scientific documentations regarding these effects are very limited in published literature. It is not until recently that the biological effects of EBN are being investigated and evidence-based studies are being conducted. Several studies have found that EBN may enhance cell proliferation and differentiation and various beneficial effects have been reported in vitro as well as in vivo. While these studies point towards the potential use of EBN in the treatment or even prevention of several diseases, the mechanisms of action of EBN remain largely unknown and more explorations are needed. This review is one of the very few scientific reviews on EBN which focuses on recent evidence-based discoveries.