Synergistic cytotoxicity of Delta(9)-tetrahydrocannabinol and butylated hydroxyanisole

Effect of Psidium guajava leaves extracts on thermo-lipid oxidation and Maillard pathway born food toxicant acrylamide in Indian staple food

Deep frying of food is a common practice that leads to the formation of lipid oxidation products. These lipid oxidation products have a role in the Maillard reaction, which ultimately leads to the formation of cancer-causing and neurotoxic substance acrylamide. In this regard, the Psidium guajava leaves extract-treated sunflower oil on oxidative stability and acrylamide content in pooris a popular deep-fried staple food in India were studied and compared with synthetic antioxidant butylated hydroxytoluene (BHT) till four frying cycles. P. guajava leaves contain 173.33 ± 1.95 mg GAE/g extract total phenolic content and 20.43 ± 0.25 mg RUE/g extract total flavonoid content. Some of the phytochemicals in the extract were identified and quantified by HPTLC. P. guajava leaves extract (1 g) contained 0.039 mg gallic acid, 0.196 mg rutin, 0.021 mg naringenin, 0.059 mg ferulic acid. The IC50 values for guava leaves extract, BHT, and ascorbic acid were 61.4, 30.4, 26.6 µg/mL, respectively. The peroxide and p-anisidine values indicated that P. guajava leaves extract inhibited lipid oxidation and provided oxidative stability. Pooris fried in P. guajava leaves extract-treated, BHT treated sunflower oil contained a lower acrylamide than pooris fried in control sunflower oil.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at (10.1007/s13197-021-04984-y).

Antioxidant Properties and Physicochemical Attributes of Meat from Berkshire Finishing Pigs Supplemented with Rubus coreanus By-Product

A 60-d feeding trial was conducted to evaluate the effects of diets supplemented with two concentrations (0% and 0.3%) of black raspberry (Rubus coreanus Miquel) fruit by-product (RCFB) on the physicochemical characteristics, oxidative stability, antioxidant capacity, antioxidant enzyme activity, and fatty acid profile of M. longissimus dorsi (LL) porcine muscle from Berkshire finishing pigs meat. Results revealed that regardless of the sex, diets supplemented with 0.3% RCFB reduced (p<0.05) the thiobarbituric acid reactive substances (TBARS) expressed as malonaldehyde (MDA) content effectively. A higher antioxidant capacity [2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity] was found (p<0.05) in response to feeding supplemented with 0.3% RCBF for male or female pigs. Moreover, 0.3% RCFB dietary feed increased (p<0.05) the glutathione peroxidase enzyme activities (GPX1) in blood plasma for male or female pigs. However, no influences were observed (p>0.05) on meat color, WHC, shear force, and fatty acid contents while fed diet supplemented with 0% or 0.3% RCFB for male or female pigs. Overall, this study suggests that a diet supplemented with 0.3% RCFB may beneficially affect owing to better oxidative stability, higher antioxidant capacity, and antioxidant enzyme activity (blood plasma) in pigs which could be a promising natural antioxidant without affecting meat quality traits.

Powerful Plant Antioxidants: A New Biosustainable Approach to the Production of Rosmarinic Acid

Modern lifestyle factors, such as physical inactivity, obesity, smoking, and exposure to environmental pollution, induce excessive generation of free radicals and reactive oxygen species (ROS) in the body. These by-products of oxygen metabolism play a key role in the development of various human diseases such as cancer, diabetes, heart failure, brain damage, muscle problems, premature aging, eye injuries, and a weakened immune system. Synthetic and natural antioxidants, which act as free radical scavengers, are widely used in the food and beverage industries. The toxicity and carcinogenic effects of some synthetic antioxidants have generated interest in natural alternatives, especially plant-derived polyphenols (e.g., phenolic acids, flavonoids, stilbenes, tannins, coumarins, lignins, lignans, quinines, curcuminoids, chalcones, and essential oil terpenoids). This review focuses on the well-known phenolic antioxidant rosmarinic acid (RA), an ester of caffeic acid and (R)-(+)-3-(3,4-dihydroxyphenyl) lactic acid, describing its wide distribution in thirty-nine plant families and the potential productivity of plant sources. A botanical and phytochemical description is provided of a new rich source of RA, Satureja khuzistanica Jamzad (Lamiaceae). Recently reported approaches to the biotechnological production of RA are summarized, highlighting the establishment of cell suspension cultures of S. khuzistanica as an RA chemical biofactory.

Antioxidant Molecules from Marine Fungi: Methodologies and Perspectives

The marine environment represents a prosperous existing resource for bioprospecting, covering 70% of the planet earth, and hosting a huge biodiversity. Advances in the research are progressively uncovering the presence of unknown microorganisms, which have evolved unique metabolic and genetic pathways for the production of uncommon secondary metabolites. Fungi have a leading role in marine bioprospecting since they represent a prolific source of structurally diverse bioactive metabolites. Several bioactive compounds from marine fungi have already been characterized including antibiotics, anticancer, antioxidants and antivirals. Nowadays, the search for natural antioxidant molecules capable of replacing those synthetic currently used, is an aspect that is receiving significant attention. Antioxidants can inactivate reactive oxygen and nitrogen species, preventing the insurgence of several degenerative diseases including cancer, autoimmune disorders, cardiovascular and neurodegenerative diseases. Moreover, they also find applications in different fields, including food preservation, healthcare and cosmetics. This review focuses on the production of antioxidants from marine fungi. We begin by proposing a survey of the available tools suitable for the evaluation of antioxidants, followed by the description of various classes of marine fungi antioxidants together with their extraction strategies. In addition, a view of the future perspectives and trends of these natural products within the "blue economy" is also presented.

Effect of Star Fruit (Averrhoa carambola L.)By-product on Oxidative Stability of Sesame (Sesamum indicum) Oil under Accelerated Oven Storage and during Frying

Aim of this study was to evaluate the effect of star fruit (Averrhoa carambola L.) by-products (peel and residue) on stability of sesame (Sesamum indicum) oil against oxidation. Antioxidant properties of extract of peel and residue at different time durations of extraction were determined and found that peel contains higher antioxidant potential than residue. Thus, extract of peel obtained after 24 h extraction was used to study its effectiveness on oxidative stability of sesame oil during accelerated oven storage and frying using the butylated hydroxytoluene (BHT) (200 ppm) as the reference antioxidant (positive control) and oil without added antioxidant as the negative control. The oxidative stability of the oil was determined by evaluating peroxide value, p-anisidine value, thiobarbituric acid reactive substances (TBARS) value, total oxidation (TOTOX) value, conjugated diene (CD) and conjugated triene (CT) values, and iodine value. Peel extract at different concentrations (200-1000 ppm) was tested. The oil added with peel extract exhibited higher stability against oxidation than the controls during oven storage test. Extract at 1000 ppm significantly increased the stability of sesame oil during frying as compared with controls. Thus, star fruit peel extract could be an alternative to synthetic antioxidants to suppress oxidation of edible oils.

Antioxidant potential of chrysanthemum morifolium flower extract on lipid and protein oxidation in goat meat patties during refrigerated storage

Flavonoid and phenolic acid profile of chrysanthemum morifolium flower extract (CME) was analyzed by using ultra-performance liquid chromatography (Q-TOF-MS, Xevo G2-S; Milford, MA, USA, Waters) system in tandem with a quadruple time-of-flight mass spectrometer. The effect of CME on lipid and protein oxidation was investigated in goat patties during 9 days of refrigerated storage (4 ± 1 °C). Patties were prepared from freshly minced meat with the addition of 0.1% and 0.2% CME and compared with the butylated hydroxytoluene (BHT) (0.01%) and control. High level of thiol and lower level of thiobarbituric acid reactive substances and carbonyl content were observed in CME-treated samples compared to control during storage period. The incorporation of CME in patties reduced the pH and water activity values markedly, but no effect was found on color and sensory analyses. These results show that increased level of CME is more effective against lipid and protein oxidation and therefore can be used as a natural antioxidant in meat products without affecting product acceptability. PRACTICAL APPLICATION: Chrysanthemum morifolium flower belongs to the family "Asteraceae" and is a novel natural antioxidant for meat processing industry. It possesses strong antioxidant activities having many phenolic compounds including gallocatechin, apigenin, rosmarinic acid, caffeic acid, rhamnetin, and quercetin, and can be used for development and production of functional food as a natural antioxidant agent.

Cannabinoids determination in bronchoalveolar lavages of cannabis smokers with lung disease

Background Cannabis smoke affects the lungs similarly to tobacco smoke, causing symptoms such as increased cough, sputum, hyperinflation and chronic bronchitis. Chronic use can also cause serious lung diseases and airway obstruction. We developed and validated a method for the identification and quantification of cannabinol (CBN), cannabidiol (CBD), Δ-9-tetrahydrocannabinol (THC) and its metabolites 11-hydroxy-THC (11-OH-THC) and 11-nor-9-carboxy-THC (THC-COOH) in bronchoalveolar lavages (BALs) from hospitalized former or current tobacco smoking patients with lung disease and a long history of cannabis consumption and limited current tobacco use. Methods For the extraction of cannabinoids from BALs, a 1 mL sample was added with 300 µL of 0.1 N NaOH and 3 mL of hexane/ethyl acetate (9:1). The solvent was then evaporated to dryness. Trimethylsilyl derivatives were prepared and then analyzed by gas chromatography/mass spectrometry. Results The method was linear for the analytes under investigation with coefficients of determination of at least 0.99. Absolute analytical recovery was always better than 80%, imprecision and inaccuracy was always under 15%. Six cases out of 15 were positive for THC, CBN and CBD. In two BALs samples, the presence of 11-OH-THC was also measured while THC-COOH was not detected. In the six positive cases, the last cannabis smoking occurred in the previous 2-14 days. Conclusions This is the first time that cannabinoids have been detected in BALs, demonstrating the presence of a drug with its metabolites in a target organ of consumers who present with a lung disease. This occurrence let us hypothesize a role of cannabinoids in the development of the disease and prompted an investigation on possible associations between cannabis smoking and clinical outcomes in patients with lung disease and eventually evaluate a cytotoxic effect of cannabinoids themselves.

Pharmacological Comparisons Between Cannabidiol and KLS-13019

Cannabidiol (CBD) exhibits neuroprotective properties in many experimental systems. However, development of CBD as a drug has been confounded by the following: (1) low potency; (2) a large number of molecular targets; (3) marginal pharmacokinetic properties; and (4) designation as a schedule 1 controlled substance. The present work compared the properties of CBD with a novel molecule (KLS-13019) that has structural similarities to CBD. The design strategy for KLS-13019 was to increase hydrophilicity while optimizing neuroprotective potency against oxidative stress toxicity relevant to hepatic encephalopathy. The protective responses of CBD and KLS-13019 were compared in dissociated rat hippocampal cultures co-treated with toxic levels of ethanol and ammonium acetate. This comparison revealed that KLS-13019 was 31-fold more potent than CBD in preventing neuronal toxicity from the combined toxin treatment, while both compounds exhibited complete protective efficacy back to control values. In addition, treatment with KLS-13019 alone was 5-fold less toxic (TC50) than CBD. Previous studies suggested that CBD targeted the Na⁺-Ca²⁺ exchanger in mitochondria (mNCX) to regulate intracellular calcium levels, an important determinant of neuronal survival. After treatment with an inhibitor of mNCX (CGP-37157), no detectable neuroprotection from ethanol toxicity was observed for either CBD or KLS-13019. Furthermore, AM630 (CB2 antagonist) significantly attenuated CBD-mediated neuroprotection, while having no detectable effect on neuroprotection from KLS-13019. Our studies indicated KLS-13019 was more potent and less toxic than CBD. Both compounds can act through mNCX. KLS-13019 may provide an alternative to CBD as a therapeutic candidate to treat diseases associated with oxidative stress.

Policosanol composition, antioxidant and anti-arthritic activities of milk thistle (Silybium marianum L.) oil at different seed maturity stages

BACKGROUND

Several anti-arthritic drugs and synthetic antioxidants have wide pharmaceutical uses and are often associated with various side effects on the human health. Dietary seed oils and their minor components like policosanol may offer an effective alternative treatment for arthritic and oxidative-stress related diseases. The biological effects of seed oils were affected by different parameters such as the stage of seed maturity. Hence, this study seeks to determine the policosanol content, antioxidant and anti-arthritic activities of milk thistle (Silybium marianum L.) oil extracted at various stages of seed maturation.

METHODS

Milk thistle oil samples were extracted from seeds collected at three maturation stages (immature, intermediate, and mature). The 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethyl-benzthiazoline-6-sulfonic acid) (ABTS) radical scavenging assays were used to determine the antioxidant activity of the extracted oils. The anti-arthritic activity of oil samples was evaluated with bovine serum protein denaturation and egg albumin denaturation methods. Gas chromatography coupled to mass spectrometry (GC-MS) was employed to determine the policosanol profile.

RESULTS

Policosanol profile, antioxidant and anti-arthritic activities of milk thistle oil were influenced by the seed maturity stages. The oil extracted from the immature seeds had the highest total policosanol content (987.68 mg/kg of oil) and displayed the maximum antiradical activity (96.42% and 90.35% for DPPH test and ABTS assay, respectively). Nine aliphatic alcohols were identified in the milk thistle oil. The dominant poliosanol in the mature seed oil was octacosanol (75.44%), while triacontanol was the major compound (40.25%) in the immature seed oil. Additionally, the maximum inhibition of bovine serum protein denaturation (92.53%) and egg albumin denaturation (86.36%) were observed in immature seed oil as compared to mature seed oil. A high correlation was found between the total policosanol content, anti-arthritic activity and antioxidant capacity of oil.

CONCLUSIONS

The milk thistle oil exhibited a potential anti-arthritic and antioxidant activities and that it might contribute to the protection of humans from a variety of diseases like rheumatoid arthritis. Also, it could serve as natural antioxidant and anti-arthritic agents for application in the food industries and pharmaceutic. Policosanol level in the seed oils might contribute to their anti-arthritic and antioxidant activities.

Small-molecule anticonvulsant agents with potent in vitro neuroprotection and favorable drug-like properties

Severe seizure activity is associated with reoccurring cycles of excitotoxicity and oxidative stress that result in progressive neuronal damage and death. Intervention with these pathological processes is a compelling disease-modifying strategy for the treatment of seizure disorders. We have optimized a series of small molecules for neuroprotective and anticonvulsant activity as well as altered their physical properties to address potential metabolic liabilities, to improve CNS penetration, and to prolong the duration of action in vivo. Utilizing phenotypic screening of hippocampal cultures with nutrient medium depleted of antioxidants as a disease model, cell death and decreased neuronal viability produced by acute treatment with glutamate or hydrogen peroxide were prevented. Modifications to our previously reported proof of concept compounds have resulted in a lead which has full neuroprotective action at <1 nM and antiseizure activity across six animal models including the kindled rat and displays excellent pharmacokinetics including high exposure to the brain. These modifications have also eliminated the requirement for a chiral molecule, removing the possibility of racemization and making large-scale synthesis more easily accessible. These studies strengthen our earlier findings which indicate that potent, multifunctional neuroprotective anticonvulsants are feasible within a single molecular entity which also possesses favorable CNS-active drug properties in vitro and in vivo.

Application and stability of natural antioxidants in edible oils in order to substitute synthetic additives

Antioxidants are components which prevent auto-oxidation of oils and fats by giving their hydrogen to free radicals formed in the initiation and propagation stages of autoxidation. During the past two decades, a lot of researches using natural plants extract in edible oils have been carried out due to the trend to minimize or avoid the use of synthetic food additives. According to the most studies, there are various natural antioxidants which can be extracted from low cost resources, such as most parts of olive plant, green tea, sesame, medicinal plants, etc. One of the most important requirements for a suitable antioxidant in oils and fats is the thermal stability during heat processing. It has been shown that most of natural additives have more antioxidants activity and thermal stability than synthetic ones in different edible oils. In this review, recent advances in the application of natural antioxidants in the food industry will be covered.

Small molecule anticonvulsant agents with potent in vitro neuroprotection

Severe seizure activity is associated with recurring cycles of excitotoxicity and oxidative stress that result in progressive neuronal damage and death. Intervention to halt these pathological processes is a compelling disease-modifying strategy for the treatment of seizure disorders. In the present study, a core small molecule with anticonvulsant activity has been structurally optimized for neuroprotection. Phenotypic screening of rat hippocampal cultures with nutrient medium depleted of antioxidants was utilized as a disease model. Increased cell death and decreased neuronal viability produced by acute treatment with glutamate or hydrogen peroxide were prevented by our novel molecules. The neuroprotection associated with this chemical series has marked structure activity relationships that focus on modification of the benzylic position of a 2-phenyl-2-hydroxyethyl sulfamide core structure. Complete separation between anticonvulsant activity and neuroprotective action was dependent on substitution at the benzylic carbon. Chiral selectivity was evident in that the S-enantiomer of the benzylic hydroxy group had neither neuroprotective nor anticonvulsant activity, while the R-enantiomer of the lead compound had full neuroprotective action at <40 nM and antiseizure activity in three animal models. These studies indicate that potent, multifunctional neuroprotective anticonvulsants are feasible within a single molecular entity.

Influence of PEI as a core modifying agent on PLGA microspheres of PGE₁, a pulmonary selective vasodilator

This study tests the hypothesis that large porous poly (lactic-co-glycolic acid) (PLGA) microparticles modified with polyethyleneimine (PEI) are viable carriers for pulmonary delivery of prostaglandin E(1) (PGE(1)) used in the treatment of pulmonary arterial hypertension (PAH), a pulmonary vascular disorder. The particles were prepared by a double-emulsion solvent evaporation method with PEI-25 kDa in the internal aqueous phase to produce an osmotic pressure gradient. Polyvinyl alcohol (PVA) was used for external coating of the particles. The particles were examined for morphology, size, aerodynamic diameter, surface area, pore volume and in-vitro release profiles. Particles with optimal properties for inhalation were tested for in-vivo pulmonary absorption, metabolic stability in rat lung homogenates, and acute toxicity in rat bronchoalveolar lavage fluid and respiratory epithelial cells, Calu-3. The micromeritic data indicated that the PEI-modified particles of PGE(1) are optimal for inhalation. Incorporation of PEI in the formulations resulted in an increased entrapment efficiency - 83.26 ± 3.04% for particles with 1% PVA and 95.48 ± 0.46% for particles with 2% PVA. The amount of cumulative drug released into the simulated interstitial lung fluid was between 50.8 ± 0.76% and 55.36 ± 0.06%. A remarkable extension of the circulation half-life up to 6.0-6.5h was observed when the formulations were administered via the lungs. The metabolic stability and toxicity studies showed that the optimized formulations were stable at physiological conditions and relatively safe to the lungs and respiratory epithelium. Overall, this study demonstrates that large porous inhalable polymeric microparticles can be a feasible option for non-invasive and controlled release of PGE(1) for treatment of PAH.

Prioritizing research for trace pollutants and emerging contaminants in the freshwater environment

Organic chemicals have been detected at trace concentrations in the freshwater environment for decades. Though the term trace pollutant indicates low concentrations normally in the nanogram or microgram per liter range, many of these pollutants can exceed an acceptable daily intake (ADI) for humans. Trace pollutants referred to as emerging contaminants (ECs) have recently been detected in the freshwater environment and may have adverse human health effects. Analytical techniques continue to improve; therefore, the number and frequency of detections of ECs are increasing. It is difficult for regulators to restrict use of pollutants that are a human health hazard; scientists to improve treatment techniques for higher priority pollutants; and the public to modify consumption patterns due to the vast number of ECs and the breadth of literature on the occurrence, use, and toxicity. Hence, this paper examines literature containing occurrence and toxicity data for three broad classes of trace pollutants and ECs (industrials, pesticides, and pharmaceuticals and personal care products (PPCPs)), and assesses the relevance of 71 individual compounds. The evaluation indicates that widely used industrials (BPF) and PPCPs (AHTN, HHCB, ibuprofen, and estriol) occur frequently in samples from the freshwater environment but toxicity data were not available; thus, it is important to establish their ADI. Other widely used industrials (BDE-47, BDE-99) and pesticides (benomyl, carbendazim, aldrin, endrin, ethion, malathion, biphenthrin, and cypermethrin) have established ADI values but occurrence in the freshwater environment was not well documented. The highest priority pollutants for regulation and treatment should include industrials (PFOA, PFOS and DEHP), pesticides (diazinon, methoxychlor, and dieldrin), and PPCPs (EE2, carbamazepine, βE2, DEET, triclosan, acetaminophen, and E1) because they occur frequently in the freshwater environment and pose a human health hazard at environmental concentrations.

Ozonation of endocrine disrupting chemical BHA under the suppression effect by salt additive--with and without H(2)O(2)

The oxidation of fresh and saline wastewater containing an endocrine disrupting chemical (butylated hydroxyanisole, BHA) under different reaction conditions by ozonation and O(3)/H(2)O(2) was investigated at various pH levels. The observed pseudo-first-order reaction kinetics was justified through a combined direct ozone and indirect radical oxidation approach for the ozonation process. The BHA decay rates increased with the increase of the solution pH, but decreased as the NaCl concentration increased because of the consumption of ozone by chloride. A kinetic model was therefore derived for predicting BHA degradation at various initial pH levels and NaCl concentrations. For the O(3)/H(2)O(2) and O(3)/H(2)O(2)/Cl(-) processes, the rate of BHA removal was investigated at hydrogen peroxide concentration ranged from 0.5 to 5mM at pH 7. Different optimal H(2)O(2) dosages and decay rates were found for both processes due to the participation of reactions among O(3), H(2)O(2), OH* and Cl(-) as discussed in the paper.

Reaction pathways and kinetics of butylated hydroxyanisole with UV, ozonation, and UV/O(3) processes

The chemical degradation of the endocrine disrupting chemical, butylated hydroxyanisole (BHA), was investigated by different treatment processes including ultraviolet (UV) irradiation, ozonation (O(3)), and UV/O(3). O demethylation, dimerization, and oxidation have been found to be the main degradation mechanisms. A systematic decay pathway was proposed based on ten identified intermediates in the studied processes, including a unique pathway leading to the formation of precipitates in the ozonation process. An unconventional minimum-type variation of BHA decay rate constants from acidic to caustic range has been found for both ozonation and UV/O(3) processes. The precipitates formed during ozonation can be removed during the process to optimize the treatment, while the UV/O(3) process can offer a relatively fast and clean process to degrade BHA and its associated intermediates.

The aqueous degradation of butylated hydroxyanisole by UV/S2O8(2-): study of reaction mechanisms via dimerization and mineralization

Three distinctive phases of BHA reactivity toward UV/ S2O8(2-) at acidic, neutral, and basic pH range were examined, where 80-100% mineralization has been observed within an hour of irradiation under 254 nm. A reduction in solution pH during the reaction was observed mainly due to the complete conversion of S2O8(2-) to sulfate ion together with proton generation. Seven measurable intermediates were found via an oxidation and dimerization process at all tested pH levels. The BHA decay mechanisms are quite different in acidic condition and at other pH levels. There are three unique intermediates that are only detectable at pH 3 via two additional pathways. This is due to the generation of weaker oxidants or radicals which results in a slower degradation of the BHA, and therefore, the accumulation of these intermediates to detectable levels. The rate of BHA decay generally increases from low to high pH levels; however, the corresponding mineralization at higher pH is retarded due to the futile process of recombining radicals and involvement of intermediates. Therefore, neutral pH was suggested to be the optimum condition in terms of mineralization and moderate efficiency in removing BHA.

Effects of Mandrax and Cannabis on the cellular function of chick embryonic neurons

Cannabis and Mandrax abuse is unique to South Africa; and most research has focused on the socio-economic impact rather than the adverse effects on the developing brain. Therefore, the aim of this study is to determine the effects of Mandrax and Cannabis alone and in combination on the developing brain by using primary and suspension cultures of the chick embryo brain. Exposure of primary chick embryo neuronal (CEN) cultures to the carrier ethanol, Mandrax and Cannabis, for 24h resulted in a significant dose dependent decrease in cell number for Mandarx alone. Increasing concentrations of Cannabis in combination with Mandrax inhibited the toxic effect of Mandrax. In CEN suspensions, Mandrax alone induced a significant time-concentration dependent decrease in esterase activity following 1 and 4h exposure. In combination with Cannabis, a significant increase in esterase activity was observed after 4h exposure. In conclusion Mandrax is toxic to CEN cells in vitro while Cannabis seemed to have a protective effect; however, this study does not investigate the abuse of these drugs in the form commonly abused, namely inhaled smoke.

Cytotoxicity of butylated hydroxyanisole in Vero cells

Butylated hydroxyanisole (BHA) is perhaps the most extensively used synthetic antioxidant in the food and cosmetic industry, although considerable controversy exists in the literature regarding the safety of this compound. Most in vitro studies describing the effects of BHA have been performed in cancer cells, but it is unclear whether normal cells are equally susceptible to BHA exposure. The present study investigate the toxic potential of BHA in mammalian cells, using biochemical and morphological parameters, which reveal interference with structures essential for cell survival, proliferation and/or function. Cell growth inhibition was assessed by using colorimetric assays, whereas cellular alterations after BHA exposure, were evaluated using conventional light and fluorescence microscopy. Low doses of BHA exerted a significant cytotoxic effect, associated with loss of mitochondrial function. As the concentration of BHA was increased, morphological alterations in critical subcellular targets such as lysosomes, mitochondria and actin cytoskeleton, were observed. In parallel, BHA induced an irreversible loss of cell proliferative capacity, preceding apoptosis induction. Thus, the dose-dependent activity of BHA on Vero cells appears to be cytotoxic as well as cytostatic. Our observations, although simplified with respect to the in vivo situations, allowed the assessment of the specific damage at the cellular level, and provide some clue about the effects of BHA in non-tumoral mammalian cells.

Delta-9-tetrahydrocannabinol protects cardiac cells from hypoxia via CB2 receptor activation and nitric oxide production

Delta-9-tetrahydrocannabinol (THC), the major active component of marijuana, has a beneficial effect on the cardiovascular system during stress conditions, but the defence mechanism is still unclear. The present study was designed to investigate the central (CB1) and the peripheral (CB2) cannabinoid receptor expression in neonatal cardiomyoctes and possible function in the cardioprotection of THC from hypoxia. Pre-treatment of cardiomyocytes that were grown in vitro with 0.1 - 10 microM THC for 24 h prevented hypoxia-induced lactate dehydrogenase (LDH) leakage and preserved the morphological distribution of alpha-sarcomeric actin. The antagonist for the CB2 (10 microM), but not CB1 receptor antagonist (10 microM) abolished the protective effect of THC. In agreement with these results using RT-PCR, it was shown that neonatal cardiac cells express CB2, but not CB1 receptors. Involvement of NO in the signal transduction pathway activated by THC through CB2 was examined. It was found that THC induces nitric oxide (NO) production by induction of NO synthase (iNOS) via CB2 receptors. L-NAME (NOS inhibitor, 100 microM) prevented the cardioprotection provided by THC. Taken together, our findings suggest that THC protects cardiac cells against hypoxia via CB2 receptor activation by induction of NO production. An NO mechanism occurs also in the classical pre-conditioning process; therefore, THC probably pre-trains the cardiomyocytes to hypoxic conditions.

Induction of bone marrow stromal cells to neurons: differentiation, transdifferentiation, or artifact?

Differentiation of stem cells toward a neuronal lineage normally involves a gradually progressive restriction in developmental potential and is regulated by a diverse set of specific and temporally precise genetic events. However, recent studies have indicated that both rodent and human bone marrow stromal cells (MSCs) can be rapidly (within minutes to hours) induced to differentiate into neurons in vitro by relatively simple chemical means (using beta-mercaptoethanol [BME] or dimethylsulfoxide [DMSO] and butylated hydroxyanisol [BHA]; Woodbury et al. [ 2000] J. Neurosci. Res. 61:364-370). The ability to transdifferentiate an easily accessible cell source into neurons could have substantial potential for promoting neural repair. We therefore explored the potential of simple chemical methods to transdifferentiate other cell types, including primary rat fibroblasts, primary human keratinocytes, HEK293 cells, rat PC-12 cells, and as positive control rat bone marrow stromal (BMS) cells. Surprisingly, all cells except for keratinocytes adopted at least partial "neuron-like" pyramidal cell morphology with fine-cellular extensions resembling neurites upon stimulation with BME or DMSO/BHA. However, time-lapse microscopy indicated that the chemical exposure of MSCs did not result in new neurite growth but rather cellular shrinkage, with retraction of the majority of existing cell extensions, leaving only few, fine neurite-like processes. To determine whether the chemically induced transdifferentiation resulted from simple cellular toxicity, MSCs were exposed to various stressors, including detergents, high-molarity sodium chloride, and extremes of pH. In all cases, cellular shrinkage and adoption of pseudoneuronal morphology were observed. Concomitantly with cellular shrinkage, apparent increases in immunolabeling for the neuronal markers NSE and NeuN were detected in the cell soma that could not be confirmed by RT-PCR. Furthermore, blockade of protein synthesis with cycloheximide did not prevent cells from adopting "neuron-like" morphology after chemical induction. Thus, morphological changes and increases in immunolabeling for certain cellular markers upon "chemical induction" of MSCs are likely the result of cellular toxicity, cell shrinkage, and changes in the cytoskeleton and do not represent regulated steps in a complicated cellular differentiation process.

Delta 9-tetrahydrocannabinol disrupts mitochondrial function and cell energetics

We have observed rapid and extensive depletion of cellular energy stores by Delta(9)-tetrahydrocannabinol (THC) in the pulmonary transformed cell line A549. ATP levels declined dose dependently with an IC(50) of 7.5 microg/ml of THC after 24-h exposure. Cell death was observed only at concentrations >10 microg/ml. Studies using JC-1, a fluorescent probe for mitochondrial membrane potential, revealed diminished mitochondrial function at THC concentrations as low as 0.5 microg/ml. At concentrations of 2.5 or 10 microg/ml of THC, a decrease in mitochondrial membrane potential was observed as early as 1 h after THC exposure. Mitochondrial function remained diminished for at least 30 h after THC exposure. Flow cytometry studies on cells exposed to particulate smoke extracts indicate that JC-1 red fluorescence was fivefold lower in cells exposed to marijuana smoke extract relative to cells exposed to tobacco smoke extract. Comparison with a variety of mitochondrial inhibitors demonstrates that THC produced effects similar to that of carbonyl cyanide p-trifluoromethoxyphenylhydrazone, suggesting uncoupling of electron transport. Loss of red JC-1 fluorescence by THC was suppressed by cyclosporin A, suggesting mediation by the mitochondrial permeability transition pore. This disruption of mitochondrial function was sustained for at least 24 h after removal of THC by extensive washing. These results suggest that exposure of the bronchopulmonary epithelium to THC may have important health and physiological consequences.