Absorption and Transport Characteristics and Mechanisms of Carnosic Acid

Exploring the Potential of Rosemary Derived Compounds (Rosmarinic and Carnosic Acids) as Cancer Therapeutics: Current Knowledge and Future Perspectives

Cancer is a global health challenge with high morbidity and mortality rates. However, conventional cancer treatment methods often have severe side effects and limited success rates. In the last decade, extensive research has been conducted to develop safe, and efficient alternative treatments that do not have the limitations of existing anticancer medicines. Plant-derived compounds have shown promise in cancer treatment for their anti-carcinogenic and anti-proliferative properties. Rosmarinic acid (RA) and carnosic acid (CA) are potent polyphenolic compounds found in rosemary (Rosmarinus officinalis) extract. They have been extensively studied for their biological properties, which include anti-diabetic, anti-inflammatory, antioxidant, and anticancer activities. In addition, RA and CA have demonstrated effective anti-proliferative properties against various cancers, making them promising targets for extensive research to develop candidate or leading compounds for cancer treatment. This review discusses and summarizes the anti-tumor effect of RA and CA against various cancers and highlights the involved biochemical and mechanistic pathways.

A Validated Method for the Determination of Carnosic Acid and Carnosol in the Fresh Foliage of Salvia rosmarinus and Salvia officinalis from Greece

In the framework of a project aiming at identifying genotypes of Greek rosemary and sage producing high amounts of carnosic acid, an HPLC-PDA method was developed for the determination of the main antioxidant in the fresh leaves. To this end, an effective and repeatable extraction process of the labile diterpene was developed to ensure a good extraction yield. A fast RP-HPLC protocol was developed and optimized to allow for a short and reliable analysis of the unstable target constituent. The HPLC-PDA method was validated for precision and accuracy according to ICH guidelines. Finally, the overall method was validated for precision and accuracy at three concentration levels. The precision was acceptable with % RSD values ranging between 1.42 and 4.35. The recovery ranged between 85.1% and 104.6% with RSD values < 5%, within the acceptable limits. The developed assay was fast and simple and allowed for the fast and accurate determination of carnosic acid and carnosol in the fresh herbs. The methodology was applied to the quantitative analysis of several cultivated samples of S. rosmarinus and S. officinalis, and some of them were revealed to be promising starting materials for the development of Greek genotypes rich in carnosic acid.

Paradoxical Radiosensitizing Effect of Carnosic Acid on B16F10 Metastatic Melanoma Cells: A New Treatment Strategy

Carnosic acid (CA) is a phenolic diterpene characterized by its high antioxidant activity; it is used in industrial, cosmetic, and nutritional applications. We evaluated the radioprotective capacity of CA on cells directly exposed to X-rays and non-irradiated cells that received signals from X-ray treated cells (radiation induced bystander effect, RIBE). The genoprotective capacity was studied by in vivo and in vitro micronucleus assays. Radioprotective capacity was evaluated by clonogenic cell survival, MTT, apoptosis and intracellular glutathione assays comparing radiosensitive cells (human prostate epithelium, PNT2) with radioresistant cells (murine metastatic melanoma, B16F10). CA was found to exhibit a genoprotective capacity in cells exposed to radiation (p < 0.001) and in RIBE (p < 0.01). In PNT2 cells, considered as normal cells in our study, CA achieved 97% cell survival after exposure to 20 Gy of X-rays, eliminating 67% of radiation-induced cell death (p < 0.001), decreasing apoptosis (p < 0.001), and increasing the GSH/GSSH ratio (p < 0.01). However, the administration of CA to B16F10 cells decreased cell survival by 32%, increased cell death by 200% (p < 0.001) compared to irradiated cells, and increased cell death by 100% (p < 0.001) in RIBE bystander cells (p < 0.01). Furthermore, it increased apoptosis (p < 0.001) and decreased the GSH/GSSG ratio (p < 0.01), expressing a paradoxical radiosensitizing effect in these cells. Knowing the potential mechanisms of action of substances such as CA could help to create new applications that would protect healthy cells and exclusively damage neoplastic cells, thus presenting a new desirable strategy for cancer patients in need of radiotherapy.

Multitargeted Molecular Docking and Dynamic Simulation Studies of Bioactive Compounds from Rosmarinus officinalis against Alzheimer’s Disease

Alzheimer’s disease (AD) has been associated with the hallmark features of cholinergic dysfunction, amyloid beta (Aβ) aggregation and impaired synaptic transmission, which makes the associated proteins, such as β-site amyloid precursor protein cleaving enzyme 1 (BACE I), acetylcholine esterase (AChE) and synapsin I, II and III, major targets for therapeutic intervention. The present study investigated the therapeutic potential of three major phytochemicals of Rosmarinus officinalis, ursolic acid (UA), rosmarinic acid (RA) and carnosic acid (CA), based on their binding affinity with AD-associated proteins. Detailed docking studies were conducted using AutoDock vina followed by molecular dynamic (MD) simulations using Amber 20. The docking analysis of the selected molecules showed the binding energies of their interaction with the target proteins, while MD simulations comprising root mean square deviation (RMSD), root mean square fluctuation (RMSF) and molecular mechanics/generalized born surface area (MM/GBSA) binding free energy calculations were carried out to check the stability of bound complexes. The drug likeness and the pharmacokinetic properties of the selected molecules were also checked through the Lipinski filter and ADMETSAR analysis. All these bioactive compounds demonstrated strong binding affinity with AChE, BACE1 and synapsin I, II and III. The results showed UA and RA to be potential inhibitors of AChE and BACE1, exhibiting binding energies comparable to those of donepezil, used as a positive control. The drug likeness and pharmacokinetic properties of these compounds also demonstrated drug-like characteristics, indicating the need for further in vitro and in vivo investigations to ascertain their therapeutic potential for AD.

Carnosic Acid Encapsulated in Albumin Nanoparticles Induces Apoptosis in Breast and Colorectal Cancer Cells

Carnosic acid (CA) is a natural phenolic compound with several biomedical actions. This work was performed to study the use of CA-loaded polymeric nanoparticles to improve the antitumor activity of breast cancer cells (MCF-7) and colon cancer cells (Caco-2). CA was encapsulated in bovine serum albumin (BSA), chitosan (CH), and cellulose (CL) nanoparticles. The CA-loaded BSA nanoparticles (CA-BSA-NPs) revealed the most promising formula as it showed good loading capacity and the best release rate profile as the drug reached 80% after 10 h. The physicochemical characterization of the CA-BSA-NPs and empty carrier (BSA-NPs) was performed by the particle size distribution analysis, transmission electron microscopy (TEM), and zeta potential. The antitumor activity of the CA-BSA-NPs was evaluated by measuring cell viability, apoptosis rate, and gene expression of GCLC, COX-2, and BCL-2 in MCF-7 and Caco-2. The cytotoxicity assay (MTT) showed elevated antitumor activity of CA-BSA-NPs against MCF-7 and Caco-2 compared to free CA and BSA-NPs. Moreover, apoptosis test data showed an arrest of the Caco-2 cells at G2/M (10.84%) and the MCF-7 cells at G2/M (4.73%) in the CA-BSA-NPs treatment. RT-PCR-based gene expression analysis showed an upregulation of the GCLC gene and downregulation of the BCL-2 and COX-2 genes in cells treated with CA-BSA-NPs compared to untreated cells. In conclusion, CA-BSA-NPs has been introduced as a promising formula for treating breast and colorectal cancer.

Carnosic acid ameliorated Aβ-mediated (amyloid-β peptide) toxicity, cholinergic dysfunction and mitochondrial defect in Caenorhabditis elegans of Alzheimer's Model

Amyloid-β peptide (Aβ)-induced cholinergic system and mitochondrial dysfunction are major risk factors for Alzheimer's disease (AD). Our previous studies found that carnosic acid (CA), an important polyphenol antioxidant, could significantly delay Aβ_1-42-mediated acute paralysis. However, many details and underlying mechanisms of CA's neuroprotection against Aβ-induced cholinergic system defects and mitochondrial dysfunction remain unclear. Herein, we deeply investigated the effects and the possible mechanisms of CA-mediated protection against Aβ toxicity in vivo through several AD Caenorhabditis elegans strains. The results showed CA delayed age-related paralysis and Aβ deposition, and significantly protected neurons from Aβ-induced toxicity. CA might downgrade the expression of ace-1 and ace-2 genes, and upregulate cha-1 and unc-17 genes to inhibit acetylcholinesterase activity and relieve Aβ-caused cholinergic system defects. Furthermore, CA might also ameliorate Aβ-induced mitochondrial imbalance and oxidative stress through up-regulating the expression of phb-1, phb-2, eat-3, and drp-1 genes. The enhancements of the cholinergic system and mitochondrial function might be the reasons for the amelioration of Aβ-mediated toxicity and Aβ aggregation mediated by CA. These findings have helped us to understand the CA anti-Aβ activity in C. elegans and the potential mechanism of action.