Recently, research investment in the improvement of food safety as a food source and specializing of nutritional source of edible insects is being actively conducted. Cricket especially has been attracting considerable interest in entomophagy; however, research on the safety assessment of cricket is limited. This study investigated the effects of cricket ethanol extract when orally administrated in Sprague-Dawley rats. Here, we performed a 4 wk repeated oral dose toxicity test in Sprague-Dawley rats following the Organization for Economic Cooperation and Development test guidelines 407 under Good Laboratory Practice regulation. Rats were randomly allocated 4 groups: vehicle control, 250, 500, 1,000 mg/kg test groups and administrated based on body weight for 28 d. The animals were observed for mortalities and clinical signs, body weight changes, food and water consumption. At the end of treatment period, blood and urine were collected and analyzed. Subsequently, the animals were sacrificed and subjected to gross pathological examination and organ weight measurement. The organs were preserved for histopathological examination. The results showed that there were no systemic toxicological effects related with the cricket ethanol extract in the 4 wk oral repeated dose toxicity study. It is considered that NOAEL of cricket ethanol extract is greater than 1,000 mg/kg/d and there was no target organ detected.
Since increase in consumption of grain and volatility in grain supply due to global warming, it has highlighted the importance for the food supply as world population is expected to be increase to 9.6 billion in 2050 (UN, 2013). The production of sufficient protein from bovine, poultry meat, and demersal fish represents a serious challenge for the future (van Huis
At necropsy, all animals were laparotomized under isoflurane anesthesia. Blood samples were withdrawn from the abdominal aorta and aliquoted into EDTA-K2 Tube, 3.2 % Sodium citrate Tube, Serum separating tube and Heparin Tube ABGA Syringe(20~30 IU/1 mL).
Hematology analyzer, ADVIA 2120 (SIEMENS), blood coagulation analyzer, ACL7000 (Instrumentation Laboratory, USA), biochemistry analyzer, Hitachi7180 (Hitachi, Japan) were used for blood analysis as described by Sung
During the 4 wk oral repeated test substance administration of 0, 250, 500 and 1,000 mg/kg doses, body weight changes (Figs. 1-1 and 1-2) and food consumptions (Figs. 2-1 and 2-2) for each sex were measured. There were no significant difference was detected on each week across the vehicle control groups. Morbidity or mortality was not observed in all test groups of both sexes and there were no abnormal clinical signs observed throughout the experimental period. In urinalysis and urine sediment analysis, parameters of treatment and recovery groups of both sexes were found to be comparable with the corresponding control group (Tables 1 and 2). The result of hematological and the plasma coagulation analysis showed no significant difference in either sex in the test groups compared with the control group (Tables 3-1, 3-2, and 4). In serum biochemical analysis, the aspartate aminotransferase, lactate dehydrogenase, and creatine phosphokinase of the male and female rats in 1,000 mg/kg test group was decreased compared with control group (Tables 5-1 and 5-2). However, we did not find any statistical significance in the other test items in the test groups compared with the vehicle control group.
[Table 1.] Urinalysis for the rats in the 4 wk repeated oral dose toxicity study
Urinalysis for the rats in the 4 wk repeated oral dose toxicity study
[Table 2.] Urine sediment for the rats in the 4 wk repeated oral dose toxicity study
Urine sediment for the rats in the 4 wk repeated oral dose toxicity study
[Table 3-1.] Hematological analysis for the male rats in the 4 wk repeated oral dose toxicity study
Hematological analysis for the male rats in the 4 wk repeated oral dose toxicity study
Hematological analysis for the female rats in the 4 wk repeated oral dose toxicity study
[Table 4.] Plasma coagulation values for the rats.
Plasma coagulation values for the rats.
Serum biochemical analysis for the male rats in the 4 wk repeated oral dose toxicity study
Serum biochemical analysis for the female rats in the 4 wk repeated oral dose toxicity study
At necropsy, enlargement of spleen was shown in one female rats in 500 mg/kg test group. There was no abnormal gross finding was shown in the other rats. In organ weights, absolute and relative organ weight of prostate in male 1,000 mg/kg test group was statistically significantly decreased compared with the vehicle control group (
Absolute organ weights of the male and female rats in the 4 wk repeated oral dose toxicity study
Relative organ weights of the male and female rats in the 4 wk repeated oral dose toxicity study
During histopathological examination of test and vehicle control groups in each sex (Tables 7-1 and 7-2), enlargement of spleen in female 500 mg/kg test group was confirmed as a congestion. However, it is not considered as a toxicological meaning because it does not show dose-dependency and it is a sporadic lesion. In male and female 1,000 mg/kg test and vehicle control group, focal mononuclear cell infiltration in liver, cyst in inner strip of kidney, tubule dilatation in inner and outer strip of kidney, scar with focal inflammation and tubular regeneration in kidney, ectopic thymus, ultimobranchial cyst, focal granulomatous inflammation in lung, spermatogranuloma in epididymis, mononuclear cell infiltration in prostate stroma were detected in both vehicle and control and 1,000 mg/kg test groups. However, it is considered not related to cricket ethanol extract administration as their severities were minimal to mild and they were present in vehicle control group as well. There was no difference in the incidence rate compared to the vehicle control group. Other than these findings, there were no abnormalities detected in the other organs.
Histopathological findings in the male rats in the 4 wk repeated oral dose toxicity study
Histopathological findings in the female rats in the 13 wk repeated oral dose toxicity study
In conclusion, under the study condition, there were not found target organs and systemic toxicological effects related with cricket ethanol extract in 4 wk oral repeated dose toxicity study. NOAEL of cricket ethanol extract administrated through oral gavage for 28 d in SD rats was found to be greater than 1,000 mg/kg body weight and acceptable daily intake is up to 10 mg per kg of body weight.
People worldwide mostly in Africa, Asia, and Latin America have been traditionally consuming about 2,000 species of insects (Premalatha
General contents of crickets have a very different trend compared to existing traditional food (Adebowale
Recent studies have supported that crickets can be used for medicinal food and health supplement. Ahn
To enhance the utilization of cricket as a food material, quality improvement is being made in accordance with the various processing methods (FAO, 2011). In recent study, Ahn