Tenebrio molitor beetles have been widely used in traditional and folklore medicines to treat various human diseases worldwide. Alzheimer’s disease (AD) is a neurodegenerative disorder and the most prevalent form of dementia in developed and developing countries. The human β-amyloid cleaving enzyme (BACE-1) is a target for AD treatments. This study was performed to determine BACE-1 inhibitory activity of 12 compounds that were extracted from T. molitor adults and their 65 related compounds using a fluorescence resonance energy transfer-based enzyme assay. The results were compared with those of two positive controls for BACE-1, the cell-permeable isophthalamide BACE-1 inhibitor IV and the natural BACE-1 inhibitor, epigallocatechin gallate (EGCG). Based on IC50 values, linoleic acid, ergosterol, palmitoleic acid, and tryptopol (28.41‒46.16 μM) were the most potent BACE-1 inhibitors and the anti-BACE-1 activity of these compounds was lower than either inhibitor IV (13.13 μM) or EGCG (1.12 μM). Multiple regression analysis of the anti-BACE-1 activities of compounds was examined using their IC50 values and the values of the physical parameters (molecular weight (MW), log P, and molecular refraction (MR)) for the 41 fatty acids (R2 = 0.674 (P = 0.044)) and 29 flavonoids (R2 = 0.587 (P = 0.063)). Correlation coefficient (r) analysis showed that MW, log P, and MR may be positively correlated with IC50 of the fatty acids (MW, r = 0.658; log P, r = 0.471; and MR, r = 0.713) and IC50 of the flavonoids (MW, r = 0.547; log P, r = 0.644; and MR, r = 0.591). Further studies will warrant possible applications of T. molitor adults as therapeutic BACE-1 blocker.

Tenebrio molitor beetles have been widely used in traditional and folklore medicines to treat various human diseases worldwide. This study was performed to determine radical scavenging activity of nine compounds that were extracted from T. molitor adults and their 64 related compounds using a 2,2-diphenyl-1-picrylhydrazyl assay. The results were compared with those of three positive controls, ascorbic acid, butylated hydroxytoluene (BHT), and epigallocatechin gallate (EGCG). Based on IC50 values, linolenic acid (77.65 μM) was the most potent antioxidant and the antioxidant activity of this compound was higher than that of either ascorbic acid, BHT or EGCG. The antioxidant activity of protocatechuic acid (IC50, 153.68 μM) and ascorbic acid did not differ significantly. The antioxidant activity of catechin (IC50, 192.32 μM) was higher than that of either BHT or EGCG. Multiple regression analysis of the antioxidant activities of compounds was examined using their IC50 values and the values of the physical parameters (molecular weight (MW), log P, and molecular refraction (MR)) for the 41 fatty acids (R2 = 0.729 (P = 0.031)) and 29 flavonoids (R2 = 0.521 (P = 0.054)). Correlation coefficient (r) analysis showed that MW, log P, and MR may be positively correlated with IC50 of the fatty acids (MW, r = 0.743; log P, r = 0.642; and MR, r = 0.815) and IC50 of the flavonoids (MW, r = 0.642; log P, r = 0.495; and MR, r = 0.643). Further studies will warrant possible applications of T. molitor adults as an antioxidant.

Bee pollen have been used for centuries as a kind of traditional medicine and food diets additive due to their nutritional and biological properties. The present study was to evaluate the biological features of ethanol extracts of 18 different bee pollen (EEBP) samples collected from 16 locations of South Korea. Our results indicated most of the EEBP samples showed 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, inhibitory activities against human β-amyloid precursor cleavage enzyme (BACE-1), and antiproliferative activities towards five cancer cell lines. However, these EEBP samples did not present human acetylcholinesterase (AChE) inhibitory activities, and intestinal bacteria growth inhibitory activities.

Aedes aegypti and Aedes albopictus and Culex pipiens pallens mosquitoes transmit dengue fever and West Nile virus diseases, respectively. This study was conducted to determine the toxicity and mechanism of action of four flavonoids and seven fatty acids from Millettia pinnata (Fabaceae) seed as well as four fatty acid esters toward third instar larvae from insecticide-susceptible C. p. pallens and A. aegypti as well as wild A. albopictus. Potent toxicity was produced by karanjin, oleic acid, karanjachromene, linoleic acid, linolenic acid, pongamol, pongarotene, and elaidic acid toward C. p. pallens larvae (24 h LC50, 14.61–28.22 mg/L) and A. aegypti larvae (16.13–37.61 mg/L). Against wild A. albopictus larvae, oleic acid (LC50, 18.79 mg/L) and karanjin (35.26 mg/L) exhibited potent toxicity. Acetylcholinesterase (AChE) is the main site of action of the flavonoids, oleic acid, and palmitic acid.,Linoleic acid and linolenic acid might act on both AChE and octopaminergic receptor. Further studies will warrant possible applications of M. pinnata seed-derived products as potential larvicides for the control of mosquito populations.

Propolis collected from botanical sources by honey bee, has been used as a popular natural remedies in folk medicine throughout the world. This study was conducted to assess growth inhibitory effects of ethanol extracts of propolis (EEPs) from 20 different regions in South Korea on human intestinal bacteria as well as BACE-1, AChE inhibitory, antioxidant, antiproliferative, and anti-human rhinovirus activities. Correlation coefficient (r) analysis of the biological activities of EEP samples was determined using their 50% inhibition concentration or minimal inhibitory concentration values and their polyphenol or flavonoid contents in 20 Korean EEP samples. Correlation coefficient analysis showed that total polyphenol contents may be negatively correlated with DPPH free radical scavenging activity (r = –0.872) and total flavonoid content has no correlation with the activity (r = 0.071). No direct correlation between BACE-1 inhibition, AChE inhibition, or antiproliferative activity and total polyphenol or total flavonoid content in Korean EEP samples was found.