Ying Feng

Edible insects in China: Utilization and prospects

The use of edible insects has a long history in China, where they have been consumed for more than 2000 years. In general, the level of acceptance is high for the consumption of insects in China. Many studies on edible insects have been conducted in the last 20 years, and the scope of the research includes the culture of entomophagy and the identification, nutritional value, farming and breeding of edible insects, in addition to food production and safety. Currently, 324 species of insects from 11 orders are documented that are either edible or associated with entomophagy in China, which include the common edible species, some less commonly consumed species and some medicinal insects. However, only approximately 10 to 20 types of insects are regularly consumed. The nutritional values for 174 species are available in China, including edible, feed and medicinal species. Although the nutritional values vary among species, all the insects examined contain protein, fat, vitamins and minerals at levels that meet human nutritional requirements. Edible insects were, and continue to be, consumed by different ethnic groups in many parts of China. People directly consume insects or food products made from insects. The processing of products from insect protein powder, oil and chitin, and the development of healthcare foods has been studied in China. People also consume insects indirectly by eating livestock that were fed insects, which may be a more acceptable pathway to use insects in human diets. Although limited, the data on the food safety of insects indicate that insects are safe for food or feed. Incidences of allergic reactions after consuming silkworm pupae, cicadas and crickets have been reported in China. Insect farming is a unique breeding industry in rural China and is a source of income for local people. Insects are reared and bred for human food, medicine and animal feed using two approaches in China: the insects are either fully domesticated and reared completely in captivity or are partially raised in captivity, and the insect habitat is manipulated to increase production. Depending on the type of relationship the insect has with humans, plants and the environment, different farming strategies are used. The social and scientific communities must work together to promote the use of insects as food and feed.

Hair growth promoting effect of white wax and policosanol from white wax on the mouse model of testosterone-induced hair loss

White wax (WW) has been traditionally used to treat hair loss in China. However there has been no reporter WW and its extract responsible for hair growth-promoting effect on androgenetic alopecia. In this paper, we examined the hair growth-promoting effects of WW and policosanol of white wax (WWP) on model animal of androgenetic alopecia and the potential target cell of WW and WWP. WW (1, 10 and 20%) and WWP (0.5, 1 and 2%) were applied topically to the backs of mice. Finasteride (2%) was applied topically as a positive control. MTS assays were performed to evaluate cell proliferation in culture human follicle dermal papilla cells (HFDPCs). The inhibition of WW and WWP for 5α- reductase were tested in Vitro. Results showed more lost hairs were clearly seen in mice treated with TP only and TP plus vehicle. Mice which received TP plus WW and WWP showed less hair loss. WW and WWP showed an outstanding hair growth-promoting activity as reflected by the follicular length, follicular density, A/T ratio, and hair bulb diameter. The optimal treatment effect was observed at 10% WW and 1% WWP, which were better than 2% finasteride treatment. MTS assay results suggested that WW and WWP remarkably increased the proliferation of HFDPCs. Inhibitor assay of 5α- reductase showed that WW and WWP inhibited significantly the conversion of testosterone to dihydrotesterone, and the IC50 values of WW and WWP were higher than that of finasteride. In Conclusion, WW and WWP could act against testosterone-induced alopecia in mice, and they promoted hair growth by inhibiting 5α-reductase activity and HFDPCs proliferation. DPCs is the target cell of WW and WWP.

Characterization of a new insect cell line that is derived from the neonate larvae of Papilio xuthus (Lepidoptera: Papilionidae) and its susceptibility to AcNPV.

The cell line RIRI-PX1 was established from neonate larval tissues of Papilio xuthus by performing primary cultures in the modified Grace medium that was supplemented with 20% fetal bovine serum (FBS). The cell line primarily consisted of spindle-shaped and spherical cells which attached themselves to the flask. The population-doubling times (PDTs) at the 50th and 60th passage were 42.5 h and 42.1 h respectively. The average chromosome numbers of RIRI-PX1 cell line from passage 5 to passage 50 ranged from 103 to 199. It was confirmed that RIRI-PX1 cell line was derived from P. xuthus by comparing the mitochondrial cytochrome c oxidase subunit I gene (COI) of RIRI-PX1 cells and P. xuthus eggs. This cell line was susceptible to the Autographa californica nucleopolyhedrovirus (AcNPV) and produced high yield of polyhedral occlusion bodies (43.9OBs/cell) after 10 days of infection by AcNPV. The virus titer of AcNPV infected RIRI-PX1 cells was 3.25×10⁷ TCID₅₀/ml. We concluded that the RIRI-PX1 cell line is established from the neonate larvae tissues successfully and the cells of the cell line are sensitive to AcNPV.

The complete mitochondrial genome of a medicinal insect Martianus dermestoides (Coleoptera, Tenebrionidae)

Abstract In this study, the complete mitogenome sequence of Martianus dermestoides (Coleoptera, Tenebrionidae) has been amplified and sequenced employing the long polymerase chain reaction method. The mitogenome, consisting of 15,434 base pairs (bp), had the typical invertebrate mitochondrial gene arrangement, including 13 protein-coding, 22 transfer RNAs, 2 ribosomal RNAs genes and a noncoding control region (CR). The CR of 798 bp length is rather compact and located between srRNA and tRNAiLe. The overall base composition of M. dermestoides is 40.97% for A, 18.53% for C, 31.13% for T and 9.38% for G, with a high AT bias of 72.09%. The complete mitogenome may provide useful DNA molecular data for further phylogenetic analyses for higher taxa of Tenebrionidae.

Complete Coding Region of the Mitochondrial Genome of Monochamus alternatus Hope (Coleoptera: Cerambycidae)

The Japanese pine sawyer, Monochamus alternatus Hope, 1842, an important forest pest, mainly occurs in Far East. It is the main vector of pine wood nematode Bursaphelenchus xylophilus, which causes pine wilt disease. We determined the complete mitochondrial genome coding region of M. alternatus using long PCR and conserved primer walking. Our results show that the entire mitogenome coding region is 14,649 bp long, with 78.22% A+T content [deposited in GenBank (JX987292)]. Positions and arrangement of the 37 genes encoded by the coding region are identical to those of two other longhorn beetles (Psacothea hilaris and Anoplophora glabripennis) for which the complete gene content and arrangement are known. All protein-coding genes start with a typical initiation codon ATN in insects. All tRNAs show standard clover-leaf structure, except the tRNASer (AGN), which lacks dihydrouridine (DHU) arm. The most unusual feature found is the use of TCT as tRNASer (AGN) anticodon instead of GCT, which is used in most other arthropods. This provides further insights into the diversity and evolution of the Cerambycidae family of long-horned beetles.

DNA barcoding analysis of processed medicinal insect Catharsius molossus

The identification of medicinal insects is a complex task, especially when they are processed into pieces or powders. This difficulty has potential to create severe complications. For example, inaccurate identification can affect the safety of clinical application for corresponding medicinal insects. A quick and accurate method to identify these kinds of organisms is needed. Here, we amplified and sequenced the mtCOI gene in processed product of Catharsius molossus, including intact individuals and broken individuals, to test the feasibility of DNA barcoding this kind of sample. After comparing results of different DNA extraction methods, we finally succeed in amplifying and sequencing the barcoding segments in these samples. Our methods barcoding sequences could clearly distinguish between C. molossus and its allied species. The data also indicated that a degree of interfusion of other insects was present in the broken medicinal C. molossus product. These results are quite promising to the establishment of performance criteria for future identification of medicinal C.molossus that will help ensure the safety application of these medicinal insects.