Cannabis sativa extracts protect LDL from Cu2+-mediated oxidation.

BACKGROUND: Multiple therapeutic properties have been attributed to Cannabis sativa. However, further research is required to unveil the medicinal potential of Cannabis and the relationship between biological activity and chemical profile. OBJECTIVES: The primary objective of this study was to characterize the chemical profile and antioxidant properties of three varieties of Cannabis sativa available in Uruguay during progressive stages of maturation. METHODS: Fresh samples of female inflorescences from three stable Cannabis sativa phenotypes, collected at different time points during the end of the flowering period were analyzed. Chemical characterization of chloroform extracts was performed by 1H-NMR. The antioxidant properties of the cannabis sativa extracts, and pure cannabinoids, were measured in a Cu2+-induced LDL oxidation assay. RESULTS: The main cannabinoids in the youngest inflorescences were tetrahydrocannabinolic acid (THC-A, 242 ± 62 mg/g) and tetrahydrocannabinol (THC, 7.3 ± 6.5 mg/g). Cannabinoid levels increased more than twice in two of the mature samples. A third sample showed a lower and constant concentration of THC-A and THC (177 ± 25 and 1 ± 1, respectively). The THC-A/THC rich cannabis extracts increased the latency phase of LDL oxidation by a factor of 1.2-3.5 per µg, and slowed down the propagation phase of lipoperoxidation (IC50 1.7-4.6 µg/mL). Hemp, a cannabidiol (CBD, 198 mg/g) and cannabidiolic acid (CBD-A, 92 mg/g) rich variety, also prevented the formation of conjugated dienes during LDL oxidation. In fact, 1 µg of extract was able to stretch the latency phase 3.7 times and also to significantly reduce the steepness of the propagation phase (IC50 of 8 µg/mL). Synthetic THC lengthened the duration of the lag phase by a factor of 21 per µg, while for the propagation phase showed an IC50 ≤ 1 µg/mL. Conversely, THC-A was unable to improve any parameter. Meanwhile, the presence of 1 µg of pure CBD and CBD-A increased the initial latency phase 4.8 and 9.4 times, respectively, but did not have an effect on the propagation phase. CONCLUSION: Cannabis whole extracts acted on both phases of lipid oxidation in copper challenged LDL. Those effects were just partially related with the content of cannabinoids and partially recapitulated by isolated pure cannabinoids. Our results support the potentially beneficial effects of cannabis sativa whole extracts on the initial phase of atherosclerosis.

Atheroma Niche-Responsive Nanocarriers for Immunotherapeutic Delivery.

Nanomedicine is a promising, noninvasive approach to reduce atherosclerotic plaque burden. However, drug delivery is limited without the ability of nanocarriers to sense and respond to the diseased microenvironment. In this study, nanomaterials are developed from peptide amphiphiles (PAs) that respond to the increased levels of matrix metalloproteinases 2 and 9 (MMP2/9) or reactive oxygen species (ROS) found within the atherosclerotic niche. A pro-resolving therapeutic, Ac2-26, derived from annexin-A1 protein, is tethered to PAs using peptide linkages that cleave in response to MMP2/9 or ROS. By adjusting the molar ratios and processing conditions, the Ac2-26 PA can be co-assembled with a PA containing an apolipoprotein A1-mimetic peptide to create a targeted, therapeutic nanofiber (ApoA1-Ac226 PA). The ApoA1-Ac2-26 PAs demonstrate release of Ac2-26 within 24 h after treatment with MMP2 or ROS. The niche-responsive ApoA1-Ac2-26 PAs are cytocompatible and reduce macrophage activation from interferon gamma and lipopolysaccharide treatment, evidenced by decreased nitric oxide production. Interestingly, the linkage chemistry of ApoA1-Ac2-26 PAs significantly affects macrophage uptake and retention. Taken together, these findings demonstrate the potential of PAs to serve as an atheroma niche-responsive nanocarrier system to modulate the inflammatory microenvironment, with implications for atherosclerosis treatment.

Inhibition of LDL oxidation and inflammasome assembly by nitroaliphatic derivatives. Potential use as anti-inflammatory and anti-atherogenic agents.

We have previously shown the antioxidant and anti-inflammatory properties of several para-substituted arylnitroalkenes. Since oxidative stress and inflammation are key processes that drive the initiation and progression of atherosclerosis, in the present work the antioxidant, anti-inflammatory and anti-atherogenic properties of an extended library of aryl-nitroaliphatic derivatives, including several newly designed nitroalkanes, was explored. The antioxidant capacity of the nitroaliphatic compounds, measured using the oxygen radical absorbance capacity assay (ORAC) showed that the p-methylthiophenyl-derivatives were about three times more effective than Trolox to prevent fluorescein oxidation, independently of the presence or the absence of the double bond next to the nitro group. The peroxyl radical scavenger capacity of the p-dimethylaminophenyl-derivatives was even higher, being the reduced form of these compounds even more active. In fact, while the antioxidant capacity of 1-dimethylamino-4-(2-nitro-1Z-ethenyl)benzene and 1-dimethylamino-4-(2-nitro-1Z-propenyl)benzene was 4.2 ±â€¯0.1 and 5.4 ±â€¯0.1 Trolox Eq/mol, respectively; ORAC values obtained with the ethyl and the propyl derivatives were 10 ±â€¯1 and 13 ±â€¯2 Trolox Eq/mol, respectively. The p-dimethylamino-derivatives, especially the nitroalkanes, were also able to prevent LDL oxidation mediated by peroxyl radicals. Oxygen consumption due to the oxidation of fatty acids was delayed in the presence of the dimethylamino substituted compounds, only the alkanes interrupted the chain of lipid oxidations decreasing the rate of oxygen consumption. Although the formation of foam cells in the presence of oxidized-LDL (oxLDL) remained unaffected, the molecules containing the dimethylamino moiety were able to decrease the expression of IL-1ß in LPS/INF-γ challenged macrophages.