Exploring the therapeutic potential of rosemary in metabolic syndrome: From traditional use to modern research.

Acer truncatum Bunge is a versatile, oil-producing, woody tree natively and widely distributed in northern China. In 2011, The People’s Republic of China’s Ministry of Health certified Acer truncatum seed oil (Aoil) as a new food resource. Unsaturated fatty acids account for up to 92% of the entire Aoil. When Aoil is processed or stored, it can easily oxidize. In this study, the effects of rosemary (Rosmarinus officinalis L.) extract on the oxidation stability of Aoil were analysed from multiple angles. The results of radical scavenging ability, malondialdehyde, and free fatty acid reveal that rosemary crude extract (RCE), rosmarinic acid (RA), and carnosic acid (CA) can significantly inhibit the oxidation of Aoil, and CA has the best oxidative stability for Aoil among the tested components of the crude rosemary. The delayed oxidation ability of CA for Aoil was slightly weaker than that of tert-butylhydroquinone (TBHQ), but stronger than that of butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and α-tocopherol (α-T), which was confirmed by microstructures, kinematic viscosity, Aoil weight change, and functional group. Additionally, CA-enriched Aoil had the smallest content of volatile lipid oxidation products. Moreover, lecithin-CA particles were added to enhance the oxidative stability of Aoil. These findings show that CA is a potent antioxidant, capable of successfully preventing Aoil oxidation.

Differential activation of pregnane X receptor by carnosic acid, carnosol, ursolic acid, and rosmarinic acid

The objective of this work was to correlate the phytochemistry of rosemary (Salvia rosmarinus), a botanical with known antioxidant properties, to a UV protection benefit in hair. These data will give insights into mechanisms of UV damage, the ROS formed and their reactivity. LC-MS was used to compare the compounds in 10 commercial extracts of rosemary. ORAC (oxygen radical antioxidant capacity) and FRAP (ferric reducing antioxidant power) were used to measure the antioxidant capacity of the rosemary extracts. The ORAC assay measures ability of an antioxidant to react with a peroxyl radical via hydrogen atom extraction and FRAP measures electron transfer through reduction of ferric iron (Fe3+ ) to ferrous iron (Fe2+ ) by antioxidants present in the samples. Correlation of extract composition with antioxidant measures was performed using principal component analysis. Selected extracts were assessed for their ability to protect hair from UV damage in a model peptide system and on hair. In addition, the same methods were used to test rosmarinic acid and carnosic acid, key phytochemistries in the rosemary extracts. The model system was a peptide and its decomposition on exposure to UV was monitored by LC-MS in the absence and presence of the rosemary extracts. Hair degradation in the presence of UV was measured by exposure of UV in an Atlas weatherometer followed by extraction of degraded protein in water. A fragment of the S100A3 protein was used as a marker of UV damage (m/z = 1278) and quantified via LC-MS. Ten rosemary extracts were assessed for antioxidant performance and correlated with their compositions. The phytochemistry in each extract varied widely with a total of 33 individual compounds identified. The differences were most likely driven by the solvent and extraction method used by the supplier with extracts varying in the proportion of polar or non-polar compounds. This did influence their reactivity in the ORAC and FRAP assays and their efficacy in preventing protein damage. Two of the key compounds identified were rosmarinic acid and carnosic acid, with rosmarinic acid dominating in extracts with mainly polar compounds and carnosic acid dominating in extracts with mainly nonpolar compounds. Extracts with higher rosmarinic acid correlated with ORAC and FRAP scores, with UV protection on hair and in the peptide model system. The extracts chosen for hair experiments showed hair protection. UV protection was also measured for rosmarinic and carnosic acid. Despite the variation in the profile of phytochemistries in the 10 rosemary extracts, likely driven by the chosen extraction method, all rosemary extracts had antioxidant activity measured. This study suggests that the polyphenols (e.g. rosmarinic acid, glycosides of selgin) and abietane diterpenes (e.g. carnosic acid) are the principal compounds which enables the extracts to protect hair from UV.

Rosemary plants were analysed using HPLC and eight different compounds (vanillic acid, caffeic acid, rosmarinic acid, naringin, hispidulin, cirsimaritin, carnosol and carnosic acid) were identified and quantified. The analysis of the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity revealed that rosmarinic and carnosic acids were the best rosemary scavengers with IC sun(50) values of 27 and 32 micro M, respectively. Environmental influences on rosmarinic and carnosic acids content in rosemary plants were studied over a period of one year under southern UK conditions. Carnosic acid reached the maximum concentrations in December, decreasing by 50% during the summer months, while rosmarinic acid showed a constant concentration during the year. The significance of these results has been discussed later in this paper.

Impaired insulin action in muscle leads to insulin resistance and Type 2 diabetes mellitus, a disease on the rise. Elevated blood free fatty acids (FFAs), as seen in obesity, are associated with insulin resistance and studies have shown increased serine phosphorylation of the insulin receptor substrate (IRS‐1) and reduced insulin‐stimulated glucose uptake in muscle cells exposed to FFA palmitate. A number of serine/threonine kinases including JNK, IKKβ, mTOR and p70 6SK have been implicated in serine phosphorylation of IRS‐1 and insulin resistance. On the other hand, activation of the energy sensor AMP‐activated protein kinase (AMPK) increases glucose uptake and has become an important target to counteract insulin resistance. We reported recently that rosemary extract (RE) increased skeletal muscle cell glucose uptake and activated AMPK. The polyphenols carnosic acid (CA) and rosmarinic acid (RA) are found in high concentration in RE and in the present study we investigated their effect on palmitate‐induced insulin resistant L6 muscle cells. Glucose uptake was measured using [3H]‐2‐deoxy‐D‐glucose and the signaling molecules involved were investigated by immunoblotting.Exposure of L6 myotubes to the FFA palmitate (P) (0.2 mM, 16 hours) resulted in significant reduction of insulin‐stimulated glucose uptake (I: 201±1.21% , P+I: 117±15.6% of control, P<0.001) indicating insulin resistance. Importantly, in the presence of 2 mM CA or 5 mM RA, the insulin‐stimulated glucose uptake was restored (CA+P+I: 185±7.8%, RA+P+I: 181±14.4% of control, P<0.001). Treatment with palmitate increased serine phosphorylation of IRS‐1, increased the phosphorylation/activation of JNK, mTOR and p70 6SK and significantly decreased the insulin‐stimulated phosphorylation of Akt. The effects of CA and RA on these signaling molecules are under investigation. Our data indicate that treatment with CA or RA attenuates the FFA‐induced muscle insulin resistance. These polyphenols may have potent effects against insulin resistance and deserve further study.Support or Funding InformationThe research was funded by the Natural Sciences and Engineering Research Council (NSERC) grant to ET.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The worldwide epidemic of obesity has drastically worsened with the increase in more sedentary lifestyles and increased consumption of fatty foods. Increased blood free fatty acids, often observed in obesity, lead to impaired insulin action, and promote the development of insulin resistance and type 2 diabetes mellitus. c-Jun N-terminal kinase (JNK), inhibitor of kappa B (IκB) kinase (IKK)-nuclear factor-kappa B (NF-κB), and signal transducer and activator of transcription 3 (STAT3) are known to be involved in skeletal muscle insulin resistance. We reported previously that carnosic acid (CA) and rosmarinic acid (RA) attenuated the palmitate-induced skeletal muscle insulin resistance, an effect that was associated with increased AMPK activation and reduced mammalian target of rapamycin-p70S6K signaling. In the present study, we examined the effects of CA and RA on JNK, IKK-NF-κB, and STAT3. Exposure of cells to palmitate increased the phosphorylation/activation of JNK, IKKα/β, IκBα, NF-κBp65, and STAT3. Importantly, CA and RA attenuated the deleterious effects of palmitate. Our data indicate that CA and RA have the potential to counteract the palmitate-induced skeletal muscle cell insulin resistance by modulating JNK, IKK-NF-κB, and STAT3 signaling.

In this study, the effects of rosemary (Rosmarinus officinalis L.), thyme (Thymus vulgaris L.), sage (Salvia officinalis L.) and bay (Laurus nobilis) extracts on the oxidative stability of canola oil and its purified triacylglycerols (TAGs) were studied. The effects of extraction solvents (methanol, ethanol and acetone) on the extraction yields, phenolic contents and antioxidant activities of these plant extracts were also determined. Methanol extracts had the highest total phenolics (78.4–177.4 mg gallic acid equivalent/g extracts), with the exception of thyme extract. In linoleic acid emulsion, antioxidant activities of all plant extracts were above 89.7% at the studied concentrations. The highest 2,2′‐diphenyl‐1‐picrylhydrazyl radical scavenging activities were found for methanol extracts. There was no significant difference between induction periods of canola oils supplemented with ethanol, methanol or acetone extracts of rosemary, thyme and bay (P > 0.05) in differential scanning calorimeter. Protection factors of rosemary and thyme extracts were higher than those of the sage and bay extracts in canola oil and its purified TAGs in Rancimat test.Practical ApplicationsRosemary, sage, thyme and bay extracts had high antioxidant and antiradical activities. They contain many bioactive components such as, carnosic acid, carnosol, methyl carnosate, rosmarinic acid, rosmanol, thymol, carvacrol and hydroxycinnamic acid. In addition to this, when the rosemary and thyme extracts were added into canola oil, they increased induction period of oil. These herbal extracts can be incorporated into oils or lipid‐containing foods to prevent oxidation.

Two rosemary accessions were subjected to chilling temperatures in control environmental cabins analyzing their variations in rosmarinic and carnosic acids together with their adaptability to these stress conditions. Cold stressed plants of both accessions showed increases in caffeic acid and carnosic acid concentration levels, while other secondary metabolites such as rosmarinic acid, naringin, cirsimaritin, hispidulin, and carnosol showed different responses in both accessions. In addition, cold stressed plants exhibited significant reductions in chlorophylls, beta-carotene, and violaxanthin levels as well as the maximum quantum yield of PSII in both accessions. Hydrogen peroxide and lipid peroxidation levels showed similar responses in both accessions, which were positively and negatively correlated with rosmarinic and carnosic acids. From these results it is therefore suggested that carnosic acid biosynthesis in rosemary plants is induced by chilling periods. On the other hand, we demonstrate that not all rosemary accessions are equally well adapted to chilling temperatures. In fact, for (one) accession cold treated plants severe losses in chlorophyll, beta-carotene, and even xanthophylls (including zeaxanthin and antheraxanthin) were observed, despite no visual symptoms of leaf injury. More research is needed to understand rosmarinic acid variations in rosemary plants under stress conditions.

Mast cells are sentinel immune cells that drive normal and pathological inflammatory responses, most notably allergic inflammation. Allergen-induced mast cell activation results in rapid degranulation of preformed pro-inflammatory mediators in the early phase, and sustained release of newly synthesized pro-inflammatory mediators in the late phase. Plant compounds known as polyphenols, have been examined in models of pathology due to their inhibition of pro-inflammatory mediator release. Rosemary extract (RE) and three polyphenolic constituents: carnosic acid (CA), carnosol (CO) and rosmarinic acid (RA) have been found to inhibit signaling cascades required for pro-inflammatory mediator release. The objective of this study was to establish the inhibitory effects of RE in a mast cell model and dissect the polyphenolic mixture, focusing on CA, CO, and RA, evaluating their potential as novel therapeutics. Sensitized mast cells were stimulated with allergen and treated with RE (5–50 μg/ml), CA, CO or RA (1–100 μM). The β-hexosaminidase release assay was used to measure degranulation, and cytokine release was measured by ELISA. Degranulation was inhibited dose dependently to 10% when treated with RE, 14% CA and 17% CO (p<0.001), while RA had no effect. ELISA analysis showed RE and CA inhibit release of IL-6 (p<0.05, p<0.0001), TNF (p<0.05, p<0.0001), and IL-13 (p<0.05, p<0.0001) while CO and RA had no effect. These novel findings identify RE and CA as potent regulators of mast cell functional responses. Further dissecting the mechanism behind RE and CA mediated inhibition of pro-inflammatory mediator release, will support the establishment of these natural plant products as effective anti-inflammatory therapeutics.

Pulmonary fibrosis is characterized by over-population and excessive activation of fibroblasts and myofibroblasts disrupting normal lung structure and functioning. Rosemary extract rich in carnosic acid (CA) and rosmarinic acid (RA) was reported to cure bleomycin-(BLM)-induced pulmonary fibrosis. We demonstrate that CA decreased human lung fibroblast (HLF) viability with IC50 value of 17.13±1.06 μM, while RA had no cytotoxic effect. In the presence of 50 μM of RA, dose-response for CA shifted to IC50 value of 11.70±1.46 μM, indicating synergic action. TGFβ-transformed HLF, rat lung fibroblasts and L929 cells presented similar sensitivity to CA and CA+RA (20μM+100μM, respectively) treatment. Rat alveolar epithelial cells died only under CA+RA treatment, while A549 cells were not affected. Annexin V staining and DNA quantification suggested that HLF are arrested in G0/G1 cell cycle phase and undergo apoptosis. CA caused sustained activation of phospho-Akt and phospho-p38 expression and inhibition of p21 protein.Addition of RA potentiated these effects, while RA added alone had no action.Only triple combination of inhibitors (MAPK-p38, pan-caspase, PI3K/Akt/autophagy) partially attenuated apoptosis; this suggests that cytotoxicity of CA+RA treatment has a complex mechanism involving several parallel signaling pathways. The in vivo antifibrotic effect of CA and RA was compared with that of Vitamine-E in BLM-induced fibrosis model in rats. We found comparable reduction in fibrosis score by CA, RA and CA+RA, attenuation of collagen deposition and normalization of oxidative stress markers. In conclusion, antifibrotic effect of CA+RA is due to synergistic pro-apoptotic action on lung fibroblasts and myofibroblasts.

Rosmarinus officinalis leaves (ROLs) are widely used in the food and cosmetics industries due to their high antioxidant activity and fascinating flavor properties. Carnosic acid (CA) and rosmarinic acid (RA) are regarded as the characteristic antioxidant components of ROLs, and the selective separation of CA and RA remains a significant challenge. In this work, the feasibility of achieving the selective separation of CA and RA from ROLs by solid-phase extraction (SPE) and liquid–liquid extraction (LLE) was studied and compared. The experiments suggested that SPE with CAD-40 macroporous resin as the adsorbent was a good choice for selectively isolating CA from the extracts of ROLs and could produce raw CA with purity levels as high as 76.5%. The LLE with ethyl acetate (EA) as the extraction solvent was more suitable for extracting RA from the diluted extracts of ROLs and could produce raw RA with a purity level of 56.3%. Compared with the reported column chromatography and LLE techniques, the developed SPE–LLE method not only exhibited higher extraction efficiency for CA and RA, but can also produce CA and RA with higher purity.

Oxidative damage is one of the hallmarks of the aging process. The current study evaluated effects of two proprietary antioxidant-based ingredients, rosemary extract and spearmint extract containing carnosic acid and rosmarinic acid, respectively, on learning and memory in the SAMP8 mouse model of accelerated aging. The two rosemary extracts contained carnosic acid (60% or 10% carnosic acid) and one spearmint extract contained 5% rosmarinic acid. Three doses of actives in each extract were tested: 32, 16, 1.6 or 0mg/kg. After 90days of treatment mice were tested in T-maze foot shock avoidance, object recognition and lever press. Rosemary extract containing 60% carnosic acid improved acquisition and retention in T-maze foot shock, object recognition and lever press. Rosemary extract with 10% carnosic acid improved retention in T-maze foot shock avoidance and lever press. Spearmint with 5% rosmarinic acid improved acquisition and retention in T-maze foot shock avoidance and object recognition. 4-hydroxynonenal (HNE) was reduced in the brain cortex after treatment with all three extracts (P<0.001) compared to the vehicle treated SAMP8. Protein carbonyls were reduced in the hippocampus after administration of rosemary with 10% carnosic acid (P<0.05) and spearmint containing 5% rosmarinic acid (P<0.001). The current results indicate that the extracts from spearmint and rosemary have beneficial effects on learning and memory and brain tissue markers of oxidation that occur with age in SAMP8 mice.

This study was aimed at evaluating the antioxidant activity of a commercial rosemary extract and the active constituents carnosol, carnosic acid, and rosmarinic acid, in inhibiting the formation and decomposition of hydroperoxides in tocopherol-stripped corn oil and in the corresponding corn oil-in-water emulsions. In bulk corn oil, the rosemary extract, carnosic acid, rosmarinic acid, and α-tocopherol were significantly more active than carnosol. In contrast, in corn oil-in-water emulsion, the rosemary compounds were less active than in bulk oil, and the rosemary extract, carnosic acid, carnosol, and α-tocopherol were more active than rosmarinic acid. Similar results were obtained in corn oil-in-water phosphate buffer emulsion at pH 5, but α-tocopherol was less active. Carnosol and carnosic acid were much more active antioxidants in corn oil-in-water emulsions buffered at pH 4 and 5 than at pH 7. The decreased antioxidant activity of the polar hydrophilic rosemary compounds in the emulsion system may be explained by their interfacial partitioning into the water, thus becoming less protective than in the bulk oil system. The effect of pH may be related to the stability of the rosemary antioxidants. Keywords: Antioxidants; rosemary extracts; corn oil; hydroperoxides; hexanal; bulk oil; emulsion

ABSTRACT: The anti‐Listeria monocytogenes effects of 8 phenolic compounds, carnosol, carnosic acid, 12‐methoxy carnosic, ferulic and caffeic acid, rosmarinic acid, luteolin and luteolin‐7‐glucoside were evaluated with a Plackett and Burman design in mixtures mimicking the phenolic composition of rosemary extract without essential oils. At 30°C carnosic acid was the most efficient compound during 24 h, whereas luteolin became more active after 72 h. The antibacterial effect of pure carnosic acid was modeled under a range of different pH and NaCl concentration, using a Doehlert design. Under moderately acidified conditions, carnosic acid displayed a bactericidal effect at low concentration (5.5 μg/ml). Its activity was not greatly influenced by NaCl.

Antioxidant effect rosemary ( Rosmarinus officinalis L.) and oregano ( Origanum vulgare L.) extracts on TBARS and colour of model raw pork batters