Evaluation of Genotoxicity and 28-day Oral Dose Toxicity on Freeze-dried Powder of Tenebrio molitor Larvae (Yellow Mealworm)

Sub-chronic toxicity determination of powdered Tenebrio molitor larvae as a novel food source

Tenebrio molitor larvae are the first insect species to be given a favorable assessment by the European Food Safety Authority (EFSA) as a novel food source, enabling consumption of whole insect larvae or larvae that have been powdered and processed into a variety of food products. Pressure from economic hardships and increase in population growth have paved a way for the realization of an alternative food source in Zimbabwe. This study focused on determining the potential toxicity of Tenebrio molitor larvae powder as an alternative food source for humans. To determine the sub-chronic toxicity of Tenebrio molitor, the powder was administered daily by oral gavage to Sprague-Dawley rats at dose levels of 0, 300, 1000 and 3000 mg/kg for 70 days. A toxicological assessment which included mortality, appearance of clinical symptoms, food consumption, organ and body weight changes were performed. There were no treatment-related mortalities, clinical signs, changes in food consumption, body and organ weights observed during the treatment period. The study's findings suggest Tenebrio molitor larvae to be a good alternative as it did not appear to affect the rats' normal physiological and metabolic processes hence can be considered safe for human consumption. However, further studies on hematological, histological and biochemical markers may be necessary for confirmation of these current results.

Safety of UV-treated powder of whole yellow mealworm (Tenebrio molitor larva) as a novel food pursuant to Regulation (EU) 2015/2283

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on UV-treated powder of whole yellow mealworm (Tenebrio molitor larva) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The term yellow mealworm refers to the larval form of the insect species T. molitor. The NF is the UV-treated powder of the whole, thermally dried yellow mealworm. The NF consists mainly of crude protein, fat, digestible carbohydrates and fibre (chitin). The Panel notes that the levels of contaminants in the NF highly depend on the occurrence levels of these substances in the insect feed. The Panel notes furthermore that there are no safety concerns regarding the stability of the NF if the NF complies with the proposed specification limits during its entire shelf life. The NF has a high protein content, although the true protein content in the NF is overestimated when using the nitrogen-to-protein conversion factor of 6.25, due to the presence of non-protein nitrogen. The applicant proposed to use the NF as an ingredient in various food products, such as bakery products, pasta, compotes of fruit/vegetables and cheese. The target population is the general population. The Panel notes that considering the composition of the NF, the proposed conditions of use and that the NF will not be the sole source of dietary protein, the consumption of the NF is not nutritionally disadvantageous. Despite the UV treatment, the Panel notes that the NF is not a significant dietary contributor of vitamin D3. The submitted toxicity studies from the literature did not raise safety concerns. The Panel considers that the consumption of the NF may induce primary sensitisation and allergic reactions to yellow mealworm proteins and may cause allergic reactions in subjects with allergies to crustaceans and dust mites. Additionally, allergens from the feed may end up in the NF. With the exception of possible allergenicity, the Panel concludes that the NF is safe under the proposed uses and use levels.

Evaluation of subchronic oral dose toxicity and allergen of freeze-dried powder of Locusta migratoria (Orthoptera: Acrididae) as a novel food source

The migratory locust, Locusta migratoria (Orthoptera: Acrididae), is a well-known edible insect which may serve as new source of human food and animal feed. However, potential toxicity and food safety of L. migratoria had not been investigated extensively until now. Therefore, in this study, we aimed to investigate toxicity of freeze-dried powder of L. migratoria (fdLM) and identify allergic components in ELISA and PCR techniques. In this subchronic study, fdLM was administered once daily by oral gavage at the doses of 750, 1500, and 3000 mg/kg/day. No toxicological changes were observed in both sexes of rats for 13 weeks in accordance with the OECD guidelines and GLP conditions. In addition, fdLM did not induced increases of serum immunoglobulin E and 21 homologous proteins were not detected under our present conditions. In conclusion, the NOAEL (no-observed-adverse-effect level) was 3000 mg/kg/day and no target organ was identified in both sexes. In conclusion, we found that fdLM is safe with no adverse effects and offers the potential of its use as an edible ingredient or other biological uses.

Administration of Alphitobius diaperinus or Tenebrio molitor before meals transiently increases food intake through enterohormone regulation in female rats

BACKGROUND

It has been previously shown that acutely administered insect Alphitobius diaperinus protein increases food intake in rats and modifies the ex vivo enterohormone secretory profile differently than beef or almond proteins. In this study, we aimed to evaluate whether these effects could be maintained for a longer period and determine the underlying mechanisms.

RESULTS

We administered two different insect species to rats for 26 days and measured food intake at different time points. Both insect species increased food intake in the first week, but the effect was later lost. Glucagon-like peptide 1 (GLP-1) and ghrelin were measured in plasma and ex vivo, and no chronic effects on their secretion or desensitization were found. Nevertheless, digested A. diaperinus acutely modified GLP-1 and ghrelin secretion ex vivo.

CONCLUSION

Our results suggest that increases in food intake could be explained by a local ghrelin reduction acting in the small intestine. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Growth performance and intestinal morphometric features of broiler chickens fed on dietary inclusion of yellow mealworm (Tenebrio molitor) larvae powder

BACKGROUND

Climate change and the lack of conventional feed ingredients have made edible insects a highly nutritious alternative to feed production. The use of insects as food may help solve socio-economic and environmental problems around the world and be in line with the United Nations Sustainable Development Goals.

OBJECTIVE

In this study, the growth performance and intestinal morphology of broiler chickens were evaluated under the influence of adding different levels of Tenebrio molitor larvae meal (TM meal) to their diets.

METHODS

One hundred and eighty one-day-old broiler chickens were divided into three treatments and five replications (12 chickens/pen). The experimental diets included a control diet and treatments containing 2.5% and 5% TM meal, which were fed to birds in the starter (0-10 days) and grower (11-25 days) stages, and during the final period (26-42 days), all birds were fed a regular finisher diet.

RESULTS

The results showed that the diet containing TM meal had no remarkable effect on the mortality rate and feed intake of broilers (p > 0.05). In the starter period, the addition of 2.5% TM meal to broilers' diet increased body weight gain than the control group (p ≤ 0.05). Also, the use of 2.5% TM meal in the starter period showed a significant effect on reducing the feed conversion ratio, compared to the birds fed by the control diet (p ≤ 0.05). Besides, the height of the villus, the depth of the crypt and their ratio were not altered among the different treatments (p > 0.05).

CONCLUSIONS

Overall, it can be concluded that TM meal could improve growth performance in the starter period and had no negative effects on broilers' performance and intestinal morphology in all the periods of the experiment.

Subacute Oral Toxicity Evaluation of Expanded-Polystyrene-Fed Tenebrio molitor Larvae (Yellow Mealworm) Powder in Sprague-Dawley Rats

Tenebrio molitor larvae, as known as edible insects, has advantages of being rich in protein, and has been recognized as a suitable alternate protein source for broiler and pig feed. Moreover, given their ability to biodegrade polystyrene, a major pollutant, Tenebrio molitor larvae has been proposed as an innovative solution to environmental problems. In the present study, we investigated the toxicity of Tenebrio molitor larvae powder (TMlp) ingested with expanded-polystyrene (W/ eps) through in vitro and in vivo experiments. The objective of this study was to determine whether TMlp W/ eps can be applied as livestock alternative protein source. For in vitro experiments, cytotoxicity test was performed to investigate the effects of TMlp-extract on the viability of estrogen-dependent MCF-7 cells. The possibility of estrogen response was investigated in two groups: Expanded-polystyrene-fed (W/ eps) TMlp group and without expanded-polystyrene-fed (W/o eps) TMlp group. For in vivo experiments, The male Sprague-Dawley rats were divided based on the dosage of TMlp administered and oral administration was performed to every day for 5 weeks. A toxicological assessments were performed, which included clinical signs, food consumption, body and organ weights, hematology, serum chemistry, and hematoxylin and eosin staining of liver and kidney. There were no specific adverse effect of TMlp W/ eps-related findings under the experimental conditions of this study, but further studies on both sexes and animal species differences should be investigated. In conclusion, TMlp W/ eps was considered non-toxic and observed to be applicable as an alternative protein source for livestock feed.

Potential of Antimicrobial Peptide-Overexpressed Tenebrio molitor Larvae Extract as a Natural Preservative for Korean Traditional Sauces

Here, we aimed to produce a natural food preservative using a crude extract from edible, immunized Tenebrio molitor larvae (iTME), injected with edible bacteria using an edible solvent. Results showed that iTME had concentration-dependent inhibitory activity against food-poisoning bacteria Escherichia coli, Bacillus cereus, and Staphylococcus aureus, as well as against harmful fungi Aspergillus flavus, Aspergillus parasiticus, and Pichia anomala. Moreover, iTME showed antimicrobial activity against beneficial microorganisms Bacillus subtilis and Aspergillus oryzae, but not Lactobacillus acidophilus. Furthermore, the minimum inhibitory concentration of iTME against E. coli, B. cereus, and S. aureus was 1 mg/mL, and iTME did not lose its inhibitory activity when treated at varying temperature, pH, and salinity. In addition, the antibacterial activity was lost after reacting the iTME with trypsin and chymotrypsin. The addition of iTME to Ganjang inoculated with harmful bacteria inhibited bacterial growth. Therefore, we propose that iTME can be used as a safe natural preservative to prolong food shelf life by inhibiting the growth of food-poisoning bacteria in a variety of foods, including traditional sauces.

Safety of frozen and dried formulations from whole yellow mealworm (Tenebrio molitor larva) as a novel food pursuant to Regulation (EU) 2015/2283

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on frozen and dried formulations from whole yellow mealworm (Tenebrio molitor larva) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The term yellow mealworm refers to the larval form of the insect species Tenebrio molitor. The NF comprises the frozen and freeze-dried formulations of the yellow mealworm, whole or in the form of powder. The frozen formulation consists mainly of water, crude protein and fat whereas the freeze-dried formulations of crude protein, fat, digestible carbohydrates and fibre (chitin). The Panel notes that the levels of contaminants in the NF depend on the occurrence levels of these substances in the insect feed. The Panel notes furthermore that there are no safety concerns regarding the stability of the NF if the NF complies with the proposed specification limits during its entire shelf-life. The dried formulations of the NF have a high protein content, although the true protein levels in the NF are overestimated when using the nitrogen-to-protein conversion factor of 6.25, due to the presence of non-protein nitrogen from chitin. The applicant proposed to use the NF as whole frozen or whole dried insect, or in the form of powder, added as an ingredient to various food products such as cereal bars, pasta, meat imitates and bakery products. The target population is the general population. The Panel notes that, considering that the NF will not be the sole source of dietary protein, and the composition of the NF and the proposed conditions of use, the consumption of the NF is not nutritionally disadvantageous. The submitted toxicity studies from the literature did not raise safety concerns. The Panel considers that the consumption of the NF may induce primary sensitisation and allergic reactions to yellow mealworm proteins and may cause allergic reactions in subjects with allergy to crustaceans and dust mites. Additionally, allergens from the feed may end up in the NF. The Panel concludes that the NF is safe under the proposed uses and use levels.

Safety of dried yellow mealworm (Tenebrio molitor larva) as a novel food pursuant to Regulation (EU) 2015/2283

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on dried yellow mealworm (Tenebrio molitor larva) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The term yellow mealworm refers to the larval form of the insect species Tenebrio molitor. The NF is the thermally dried yellow mealworm, either as whole dried insect or in the form of powder. The main components of the NF are protein, fat and fibre (chitin). The Panel notes that the levels of contaminants in the NF depend on the occurrence levels of these substances in the insect feed. The Panel notes that there are no safety concerns regarding the stability of the NF if the NF complies with the proposed specification limits during its entire shelf life. The NF has a high protein content, although the true protein levels in the NF are overestimated when using the nitrogen-to-protein conversion factor of 6.25, due to the presence of non-protein nitrogen from chitin. The applicant proposed to use the NF as whole, dried insect in the form of snacks, and as a food ingredient in a number of food products. The target population proposed by the applicant is the general population. The Panel notes that considering the composition of the NF and the proposed conditions of use, the consumption of the NF is not nutritionally disadvantageous. The submitted toxicity studies from the literature did not raise safety concerns. The Panel considers that the consumption of the NF may induce primary sensitisation and allergic reactions to yellow mealworm proteins and may cause allergic reactions in subjects with allergy to crustaceans and dust mites. Additionally, allergens from the feed may end up in the NF. The Panel concludes that the NF is safe under the proposed uses and use levels.

Effect of dietary inclusion of yellow mealworm (Tenebrio molitor) larvae meal on productive performance, egg quality indices and blood parameters of laying hens

Abstract Context Increasing demand for animal products, and scarcity and cost of conventional feed ingredients, drive the search for alternative energy and protein sources for poultry feed. Insects provide opportunities as a sustainable, high-quality and low-cost component of poultry feed. Aims This study evaluated the effects of dietary inclusion of powdered Tenebrio molitor (yellow mealworm) larvae meal on productive performance, egg quality characteristics and blood parameters of laying hens. Methods In total, 126 Bovans White laying hens, 63 weeks of age, were allocated to three dietary groups, each with seven replicate cages of six birds per cage. Treatments were: a basal diet, and two experimental diets comprising the basal diet plus T. molitor larvae meal at 2.5% or 5% inclusion rate. The duration of the study was 8 weeks. Key results Egg production, egg mass and feed conversion ratio were all improved (P < 0.05) by inclusion of T. molitor meal in the diet. The lower rate of inclusion was more effective with respect to egg production and feed conversion ratio. Inclusion of larvae meal did not influence (P > 0.05) feed intake, egg weight or bodyweight gain. Furthermore, egg quality characteristics and blood parameters were not influenced (P > 0.05) by dietary treatment. Conclusions The study showed that inclusion of T. molitor larvae meal in the diet of laying hens could improve productive performance, especially at the 2.5% level. Implications Powdered meal of T. molitor larvae is an appropriate, unconventional feed ingredient for laying hens, and may have a role in improving socioeconomic and environmental outcomes, aligning with the United Nations’ sustainable development goals.

The impact of polystyrene consumption by edible insects Tenebrio molitor and Zophobas morio on their nutritional value, cytotoxicity, and oxidative stress parameters

The objective of this study was to determine of nutritional value, in vitro cytotoxicity, and oxidative stress parameters in cells of selected insect species (Tenebrio molitor and Zophobas morio) after 30 days of Styrofoam consumption. Furthermore, part of our research is also a consumer survey on the willingness to eat insects fed with Styrofoam (EPS 80). Mealworms fed with Styrofoam were determined to have higher protein (48.66 ± 0.92%) and ash content (4.81 ± 0.22%) with reduced fat (24.05 ± 0.55%) and carbohydrate content (2.95 ± 0.15%) than insects with a conventional diet (48.66 ± 0.92, 2.82 ± 0.12, 43.74 ± 0.77, and 4.78 ± 0.18, respectively) while in the case of superworms, no significant difference in nutrient composition was observed. Moreover, Styrofoam has no influence on the health status of gut cells in examined insects. Additionally, in studied concentrations of insects extracts standardized for protein replacement of the traditional insect diet with polystyrene foam did not increase the cytotoxic properties.

Subacute Oral Toxicity Evaluation of Freeze-Dried Powder of Locusta migratoria

Novel food sources have enormous potential as nutritional supplements. For instance, edible insects are considered as an alternative food source due to their higher protein content; moreover, they are economically efficient reproducers and have high in nutritional value. In this study, we investigated the toxicity of the freeze-dried powder of Locusta migratoria (fdLM), known to contain rich proteins as well as fatty acids. The objective of the present study was to evaluate the subacute toxicity of fdLM in male and female Sprague-Dawley (SD) rats. The SD rats were divided into four groups based on the dosage of fdLM administered: dosage of 0 (vehicle control), 750, 1,500, and 3,000 mg/kg/day were administered for 28 days. Toxicological assessments including observations on food consumption, body and organ weights, clinical signs, mortality, ophthalmologic tests, urinalyses, hematologic tests, clinical chemistry tests, gross findings, and histopathology tests were performed. Clinical signs, urinalyses, hematology, serum biochemistry tests, and organ weight examinations revealed no fdLM-related toxicity. The no-observed-adverse-effect level for fdLM was higher than 3,000 mg/kg/day in rats of both sexes; therefore, fdLM, in conclusion, can be considered safe as an edible alternative human and animal food source material.

In Vitro Protective Effect of Paste and Sauce Extract Made with Protaetia brevitarsis Larvae on HepG2 Cells Damaged by Ethanol

We made paste and sauce using protein-rich Protaetia brevitarsis larvae (PBL) and evaluated their fermentation levels. After pretreatment with the paste and sauce extracts, HepG2 cells were damaged with ethanol (EtOH), and then the effects of the paste and sauce were evaluated. As a result, we confirmed that the PBL paste and sauce extracts reduced the aspartate aminotransferase (AST) and alanine aminotransaminase (ALT) content in the medium as compared to soybean (Glycine max) sauce and paste extracts. In addition, the PBL paste and sauce extracts significantly lowered the level of tumor necrosis factor (TNF)-α and interleukin (IL)-6, which are biomarkers of inflammation, and significantly increased the inhibition rate of superoxide dismutase (SOD) and reduced glutathione (GSH), which are antioxidative indicators, in proportion to the amount of PBL added to the paste and sauce. These results suggest that an intake of PBL paste and sauce, a novel type of fermented food made from insects, may be effective for liver protection through anti-inflammatory and antioxidative effects against hepatocyte injury caused by EtOH.

Antihypertensive, cardio- and neuro-protective effects of Tenebrio molitor (Coleoptera: Tenebrionidae) defatted larvae in spontaneously hypertensive rats

In pre-hypertension, moderate control of blood pressure (BP) can be obtained by a nutritional approach. The effects of a diet enriched with defatted larvae of the mealworm Tenebrio molitor (Coleoptera: Tenebrionidae) (TM) endowed with ACE inhibitory activity was studied in both spontaneously hypertensive rats (SHR) and in the age-matched normotensive Wistar Kyoto strain. These were fed for 4 weeks with standard laboratory rodent chow supplemented with or without TM or captopril. In SHR, the TM diet caused a significant reduction in BP, heart rate and coronary perfusion pressure, as well as an increase in red blood cell glutathione/glutathione disulphide ratio. Rat brain slices of SHR were more resistant to oxidative stress and contained lower levels of inflammatory cytokines, while vascular and liver enzyme-activities were not affected. These results suggest that TM can be considered a new functional food that can lower BP in vivo and thus control cardiovascular-associated risk factors such as hypertension.

Defatted Tenebrio molitor Larva Fermentation Extract Modifies Steatosis, Inflammation and Intestinal Microflora in Chronic Alcohol-Fed Rats

This study examined the effects of defatted mealworm fermentation extract (MWF) on alcoholic liver injury in rats. The rats were fed either a Lieber-DeCarli control (Con) or alcohol liquid diet (EtOH). The alcohol-fed rats were administered MWF (50, 100, or 200 mg/kg/day) and silymarin (200 mg/kg/day) orally for eight weeks. MWF prevented alcohol-induced hepatocellular damage by decreasing their serum aspartate transaminase, alanine transaminase, and gamma-glutamyl transpeptidase levels significantly compared to the EtOH group. MWF effectively reduced the relative hepatic weight, lipid contents, and fat deposition, along with the down-regulation of transcriptional factors and genes involved in lipogenesis compared to the EtOH group. It also enhanced the antioxidant defense system by elevating the glutathione level and glutathione reductase activity. MWF attenuated the alcohol-induced inflammatory response by down-regulating hepatic inflammation-associated proteins expression, such as phosphorylated-inhibitor of nuclear factor-kappa B-alpha and tumor necrosis factor-alpha, in chronic alcohol-fed rats. Furthermore, sequencing analysis in the colonic microbiota showed that MWF tended to increase Lactobacillus johnsonii reduced by chronic alcohol consumption. These findings suggest that MWF can attenuate alcoholic liver injury by regulating the lipogenic and inflammatory pathway and antioxidant defense system, as well as by partially altering the microbial composition.

Caspase 3-mediated cytotoxicity of mealworm larvae (Tenebrio molitor) oil extract against human hepatocellular carcinoma and colorectal adenocarcinoma

ETHNOPHARMACOLOGICAL RELEVANCE

Mealworm larvae (MWL) (Tenebrio molitor) have been traditionally used in Asian countries for the treatment of liver diseases, including cancer. However, to date, there is marginal information on the mechanisms underlying the anticancer activity of MWL oil.

AIM OF THE STUDY

This study aims to determine the in vitro effect of MWL oil on human hepatocellular carcinoma (HepG2) and colorectal adenocarcinoma (Caco-2) cells growth in order to produce insect-derived chemotherapeutic agents against cancer.

MATERIALS AND METHODS

MWL oil was extracted, and its effects on cancer cells growth were investigated, by the MTT reduction, AO/EB staining, Hoechst 33258 nuclear staining, apoptosis, comet, and caspase activity assays.

RESULTS

MWL oil inhibited HepG2 and Caco-2 growth, with IC₅₀ (48 h) values of 0.98% for HepG2 and 0.37% for Caco-2 cells. In addition, flow cytometry analysis demonstrated that 24 h-MWL oil treatment increased early and late apoptosis from 0.04% to 39.77% and from 2.06% to 74.34% on HepG2 and Caco-2 cells, respectively. The mechanism of apoptosis was associated with the death receptor pathway by the activation of caspases -8, -9, and -3, and correlated to its fatty acids action.

CONCLUSION

Results of this study demonstrated the potential of MWL oil in the development of natural anticancer therapeutic agents.

Effects of Heating Time and Temperature on Functional Properties of Proteins of Yellow Mealworm Larvae (Tenebrio molitor L.)

Although the yellow mealworm (Tenebrio molitor L.) is a promising alternative protein source, the effects of processing conditions on functional properties are unclear. In this study, a protein extract of yellow mealworm larvae (PEYM) was subjected to different heat temperature (55°C, 75°C, and 95°C) with different time (20, 40, and 60 min) to evaluate the functional properties and protein oxidation. Different heat temperature treatment significantly affected the exposure of surface hydrophobicity of the proteins and protein molecule aggregation, which reached maximum levels at 95°C for 60 min. Protein oxidation was inversely proportional to the temperature. Both the highest carbonyl value (1.49 nmol/mg protein) and lowest thiol value (22.94 nmol/mg protein) were observed at 95°C for 60 min. The heating time-temperature interaction affected several functional properties, including solubility, emulsifying potential, and gel strength (GS). Solubility decreased near the isoelectric point (pH 5 to 6). As the temperature and heating time increased, emulsifying properties decreased and GS increased. The oil absorption capacity and foaming properties decreased and the water absorption capacity increased. These results confirmed that PEYM is a suitable source of proteins for processing and applications in the food industry.

Toxicological characteristics of edible insects in China: A historical review

Edible insects are ideal food sources, which contain important nutrients and health-promoting compounds. With a rapid development of industrial insect farming, insect-derived food is a novel and emerging food industry. Edible insects have been traditionally consumed in various communities, while continuously gaining relevance in today's society; however, they currently remain underutilized. Although there are a large number of literature on edible insects, these literature primarily focus on the nutritional value edible insects. The toxicity assessment data of edible insects remain incomprehensive, especially for the new national standard that is currently in effect; and many data and conclusions are not accurately specified/reported. Therefore, we performed a literature review and summarized the data on the toxicological assessment of edible insects in China. The review first describes the research progress on safety toxicological assessment, and then offers references regarding the development of 34 edible insect species in China. These data can be a platform for the development of future toxicological assessment strategies, which can be carried out by a multidisciplinary team, possibly consisting of food engineers, agronomists, farmers, and so on, to improve the acceptability of edible insects.

Subchronic Oral Dose Toxicity Study of Enterococcus Faecalis 2001 (EF 2001) in Mice

As a part of general toxicity studies of Enterococcus Faecalis 2001 (EF 2001) prepared using heat-treatment bacillus mort body EF 2001 in mice, this study examined the toxicity of EF 2001 in single and repeated administrations following the previous report in order to apply this product to preventive medicine. The safety of oral ingestion of EF 2001 was examined in 6-week-old male and female ICR mice with 1,000 mg/kg, 3,000 mg/kg and 5,000 mg/kg body weight/day administrated by gavage of the maximum acceptable dose of EF 2001. The study was conducted using distilled water as a control following the methods for general toxicity studies described in the “Guidelines for Non-clinical Studies of Pharmaceutical Products 2002”. As a control, 1) observation of general conditions, 2) measurement of body weight, 3) determination of food consumption, 4) determination of water consumption, 5) blood test and urinalysis and 6) pathological examination were performed for the administration of EF 2001. Mice received EF 2001 for 13 weeks and results were compared with those of the control group that received distilled water. The results of the above examinations revealed no significant differences between control and EF 2001 groups for both males and females. Thus, no notable toxicity was confirmed with single and repeated oral administrations of EF 2001. Oral administration in the above doses did not result in abnormal symptoms or death during the observation period. No abnormalities in blood cell count or organ weights were seen. Without any evidence of toxicity to cells and organs, EF 2001 is speculated to not adversely affect living organisms. The 50% lethal dose of EF 2001 with oral administration in mice is estimated to be greater than 5,000 mg/kg body weight/day for both male and female mice. Therefore, LD₅₀ value for animals was 5,000 mg/kg or more.

Intraventricular administration of Tenebrio molitor larvae extract regulates food intake and body weight in mice with high-fat diet-induced obesity

We recently reported the in vitro and in vivo antiobesity effects of Tenebrio molitor larvae, a traditional food in many countries, but it remains unknown how the larvae affect appetite regulation in mice with diet-induced obesity. We hypothesized that the extract of T molitor larvae mediates appetite by regulating neuropeptide expression. We investigated T molitor larvae extract's (TME's) effects on anorexigenesis and endoplasmic reticulum (ER) stress-induced orexigenic neuropeptide expression in the hypothalami of obese mice. Intracerebroventricular TME administration suppressed feeding by down-regulating the expression of the orexigenic neuropeptides neuropeptide Y and agouti-related protein. T molitor larvae extract significantly reduced the expression of ER stress response genes. These results suggest that TME and its bioactive components are potential therapeutics for obesity and ER stress-driven disease states.

Tenebrio molitor Extracts Modulate the Response to Environmental Stressors and Extend Lifespan in Caenorhabditis elegans

Tenebrio molitor are large insects and their larvae are consumed as food in many countries. The nutritional composition of T. molitor has been studied and contains high amounts of proteins, unsaturated fatty acids, and valuable minerals. However, the bioactivity of T. molitor has not been fully understood. We examined the effects of T. molitor extracts on resistance to oxidative stress and organism's lifespan using Caenorhabditis elegans as a model system. The response to heat shock and ultraviolet (UV) irradiation was monitored in vivo. The extracts from T. molitor showed significant effects on resistance to oxidative stress and UV irradiation and extend both mean and maximum lifespan of C. elegans. The number of progeny produced significantly increased in animals supplemented with T. molitor extracts. In addition, the expression of hsp-16.2 and sod-3 was markedly upregulated by supplementation with T. molitor extracts. These findings suggest that T. molitor extracts can increase response to stressors and extend lifespan by the induction of longevity assurance genes in C. elegans.

Safety assessment of freeze-dried powdered Tenebrio molitor larvae (yellow mealworm) as novel food source: Evaluation of 90-day toxicity in Sprague-Dawley rats

Worldwide demand for novel food source has grown and edible insects are a promising food sources for humans. Tenebrio molitor, as known as yellow mealworm, has advantages of being rich in protein, and easy to raise as a novel food source. The objective of this study was to evaluate subchronic toxicity, including potential hypersensitivity, of freeze-dried powdered T. molitor larvae (fdTML) in male and female Sprague-Dawley rats. The fdTML was administered orally once daily at dose levels of 0, 300, 1000 and 3000 mg/kg/day for 90 days. A toxicological assessment was performed, which included mortality, clinical signs, body and organ weights, food consumption, ophthalmology, urinalysis, hematology, serum chemistry, gross findings, histopathologic examination and allergic reaction. There were no fdTML- related findings in clinical signs, urinalysis, hematology and serum chemistry, gross examination, histopathologic examination or allergic reaction. In conclusion, the No Observed Adverse Effect Level (NOAEL) for fdTML was determined to be in excess of 3000 mg/kg/day in both sexes of rats under the experimental conditions of this study.

Subchronic Oral Dose Toxicity of Freeze-dried Powder of Allomyrina dichotoma Larvae

The objective of this study was to investigate the toxicological information of freeze-dried powder from Allomyrina dichotoma (A. dichotoma) larvae as a food ingredient. The powder, suspended in distilled water, was administered once daily by oral gavage to four groups of Sprague-Dawley (SD) rats at dose levels of 0 (vehicle control), 250, 850, and 2500 mg/kg/day. After 13 wks of repeated administration, the standard toxicological parameters such as mortality, clinical signs, body weight, food consumption, ophthalmologic examination, clinical pathology, organ weights and macro/microscopic examination were applied for assessment of general toxicity. In addition, serum IgE and histamine levels were determined to evaluate allergenicity. The freeze-dried powder from A. dichotoma larvae did not produce treatmentrelated changes or findings in any toxicological parameters in either sex of any dosed groups except for slight increases in serum histamine levels at 2500 mg/kg/day. The changes were considered not to be adverse since the magnitude was minimal. In conclusion, the NOAEL (No Observed Adverse Effect Level) of the freeze-dried powder from A. dichotoma larvae was determined to be 2500 mg/kg/day or more in both sexes of SD rats and it is considered a candidate to be edible material.