Chemistry and multibeneficial bioactivities of carvacrol (4-isopropyl-2-methylphenol), a component of essential oils produced by aromatic plants and spices

Acrylamide: inhibition of formation in processed food and mitigation of toxicity in cells, animals, and humans

Potentially toxic acrylamide is largely derived from the heat-inducing reactions between the amino group of the amino acid asparagine and carbonyl groups of glucose and fructose in plant-derived foods including cereals, coffees, almonds, olives, potatoes, and sweet potatoes. This review surveys and consolidates the following dietary aspects of acrylamide: distribution in food, exposure and consumption by diverse populations, reduction of the content in different food categories, and mitigation of adverse in vivo effects. Methods to reduce acrylamide levels include selecting commercial food with a low acrylamide content, selecting cereal and potato varieties with low levels of asparagine and reducing sugars, selecting processing conditions that minimize acrylamide formation, adding food-compatible compounds and plant extracts to food formulations before processing that inhibit acrylamide formation during processing of cereal products, coffees, teas, olives, almonds, and potato products, and reducing multiorgan toxicity (antifertility, carcinogenicity, neurotoxicity, teratogenicity). The herein described observations and recommendations are of scientific interest for food chemistry, pharmacology, and toxicology, but also have the potential to benefit nutrition, food safety, and human health.

Chemistry, Nutrition, and Health-Promoting Properties of Hericium erinaceus (Lion's Mane) Mushroom Fruiting Bodies and Mycelia and Their Bioactive Compounds

The culinary and medicinal mushroom Hericium erinaceus is widely consumed in Asian countries, but apparently not in the United States, for its nutritional and health benefits. To stimulate broader interest in the reported beneficial properties, this overview surveys and consolidates the widely scattered literature on the chemistry (isolation and structural characterization) of polysaccharides and secondary metabolites such as erinacines, hericerins, hericenones, resorcinols, steroids, mono- and diterpenes, and volatile aroma compounds, nutritional composition, food and industrial uses, and exceptional nutritional and health-promoting aspects of H. erinaceus. The reported health-promoting properties of the mushroom fruit bodies, mycelia, and bioactive pure compounds include antibiotic, anticarcinogenic, antidiabetic, antifatigue, antihypertensive, antihyperlipodemic, antisenescence, cardioprotective, hepatoprotective, nephroprotective, and neuroprotective properties and improvement of anxiety, cognitive function, and depression. The described anti-inflammatory, antioxidative, and immunostimulating properties in cells, animals, and humans seem to be responsible for the multiple health-promoting properties. A wide range of research advances and techniques are described and evaluated. The collated information and suggestion for further research might facilitate and guide further studies to optimize the use of the whole mushrooms and about 70 characterized actual and potential bioactive secondary metabolites to help prevent or treat human chronic, cognitive, and neurological diseases.

Antibiotic-resistant bacteria: prevalence in food and inactivation by food-compatible compounds and plant extracts

Foodborne antibiotic-resistant pathogenic bacteria such as Campylobacter jejuni, Bacillus cereus, Clostridium perfringens, Escherichia coli, Salmonella enterica, Staphylococcus aureus, Vibrio cholerae, and Vibrio parahemolyticus can adversely affect animal and human health, but a better understanding of the factors involved in their pathogenesis is needed. To help meet this need, this overview surveys and interprets much of our current knowledge of antibiotic (multidrug)-resistant bacteria in the food chain and the implications for microbial food safety and animal and human health. Topics covered include the origin and prevalence of resistant bacteria in the food chain (dairy, meat, poultry, seafood, and herbal products, produce, and eggs), their inactivation by different classes of compounds and plant extracts and by the use of chlorine and physicochemical methods (heat, UV light, pulsed electric fields, and high pressure), the synergistic antimicrobial effects of combinations of natural antimicrobials with medicinal antibiotics, and mechanisms of antimicrobial activities and resistant effects. Possible areas for future research are suggested. Plant-derived and other safe natural antimicrobial compounds have the potential to control the prevalence of both susceptible and resistant pathogens in various environments. The collated information and suggested research will hopefully contribute to a better understanding of approaches that could be used to minimize the presence of resistant pathogens in animal feed and human food, thus reducing adverse effects, improving microbial food safety, and helping to prevent or treat animal and human infections.

Plant compounds enhance the assay sensitivity for detection of active Bacillus cereus toxin

Bacillus cereus is an important food pathogen, producing emetic and diarrheal syndromes, the latter mediated by enterotoxins. The ability to sensitively trace and identify this active toxin is important for food safety. This study evaluated a nonradioactive, sensitive, in vitro cell-based assay, based on B. cereus toxin inhibition of green fluorescent protein (GFP) synthesis in transduced monkey kidney Vero cells, combined with plant extracts or plant compounds that reduce viable count of B. cereus in food. The assay exhibited a dose dependent GFP inhibition response with ~25% inhibition at 50 ng/mL toxin evaluated in culture media or soy milk, rice milk or infant formula, products associated with food poisonings outbreak. The plant extracts of green tea or bitter almond and the plant compounds epicatechin or carvacrol were found to amplify the assay response to ~90% inhibition at the 50 ng/mL toxin concentration greatly increasing the sensitivity of this assay. Additional studies showed that the test formulations also inhibited the growth of the B. cereus bacteria, likely through cell membrane disruption. The results suggest that the improved highly sensitive assay for the toxin and the rapid inactivation of the pathogen producing the toxin have the potential to enhance food safety.

TRPM7 inhibitor carvacrol protects brain from neonatal hypoxic-ischemic injury

BACKGROUND

Our previous study found that suppression of TRPM7 reduced neuronal death in adult rat ischemic brain injury. It was reported that carvacrol blocked TRPM7 and attenuated brain injury in an adult rat MCAO model. The effects of carvacrol on neonatal stroke remain unknown. This study investigated the effects of carvacrol on neuronal injury and behavioral impairment after hypoxia-ischemia in neonatal mice and the potential signaling pathway underlying these effects.

RESULTS

Carvacrol inhibited TRPM7 current in HEK293 cells over-expressing TRPM7 and TRPM7-like current in hippocampal neurons in a dose-dependent manner. Carvacrol (>200 μM) reduced OGD-induced neuronal injury in cortical neurons. 24 hours after HI, TRPM7 protein level in the ipsilateral hemisphere was significantly higher than in the contralateral hemisphere. Carvacrol (30 and 50 mg/kg) pre-treatment reduced brain infarct volume 24 hours after HI in a dose-dependent manner. Carvacrol pre-treatment also improved neurobehavioral outcomes. Furthermore, animals pre-treated with carvacrol had fewer TUNEL-positive cells in the brain compared to vehicle-treated animals 3 days after HI. Carvacrol pre-treatment also increased Bcl-2/Bax and p-Akt/t-Akt protein ratios and decreased cleaved caspase-3 protein expression 24 hours after HI.

CONCLUSIONS

Carvacrol pre-treatment protects against neonatal hypoxic-ischemic brain injury by reducing brain infarct volume, promoting pro-survival signaling and inhibiting pro-apoptotic signaling, as well as improving behavioral outcomes. The neuroprotective effect may be mediated by the inhibition of TRPM7 channel function. Carvacrol is a potential drug development target for the treatment of neonatal stroke.

Mechanism of the antiadipogenic-antiobesity effects of a rice hull smoke extract in 3T3-L1 preadipocyte cells and in mice on a high-fat diet

Photomicrographs and dose-dependent lipid reduction in adipocyte cells induced by the rice hull extract.