Evaluation of antioxidant potential of ethyl acetate fraction of Rosmarinus officinalis L. and its major components

Transcriptome sequencing of medical herb Salvia Rosmarinus (Rosemary) revealed the phenylpropanoid biosynthesis pathway genes and their phylogenetic relationships

BACKGROUND

The Salvia rosmarinus spenn. (rosemary) is considered an economically important ornamental and medicinal plant and is widely utilized in culinary and for treating several diseases. However, the procedure behind synthesizing secondary metabolites-based bioactive compounds at the molecular level in S. rosmarinus is not explored completely.

METHODS AND RESULTS

We performed transcriptomic sequencing of the pooled sample from leaf and stem tissues on the Illumina HiSeqTM X10 platform. The transcriptomics analysis led to the generation of 29,523,608 raw reads, followed by data pre-processing which generated 23,208,592 clean reads, and de novo assembly of S. rosmarinus obtained 166,849 unigenes. Among them, nearly 75.1% of unigenes i.e., 28,757 were interpreted against a non-redundant protein database. The gene ontology-based annotation classified them into 3 main categories and 55 sub-categories, and clusters of orthologous genes annotation categorized them into 23 functional categories. The Kyoto Encyclopedia of Genes and Genomes database-based pathway analysis confirmed the involvement of 13,402 unigenes in 183 biochemical pathways, among these unigenes, 1,186 are involved in the 17 secondary metabolite production pathways. Several key enzymes involved in producing aromatic amino acids and phenylpropanoids were identified from the transcriptome database. Among the identified 48 families of transcription factors from coding unigenes, bHLH, MYB, WRKYs, NAC, C2H2, C3H, and ERF are involved in flavonoids and other secondary metabolites biosynthesis.

CONCLUSION

The phylogenetic analysis revealed the evolutionary relationship between the phenylpropanoid pathway genes of rosemary with other members of Lamiaceae. Our work reveals a new molecular mechanism behind the biosynthesis of phenylpropanoids and their regulation in rosemary plants.

Application of Rosmarinic Acid with Its Derivatives in the Treatment of Microbial Pathogens

The emergence of the antimicrobial resistance phenomena on and the harmful consequences of the use of antibiotics motivate the necessity of innovative antimicrobial therapies, while natural substances are considered a promising alternative. Rosmarin is an original plant compound listed among the hydroxycinnamic acids. This substance has been widely used to fight microbial pathology and chronic infections from microorganisms like bacteria, fungi and viruses. Also, various derivatives of rosmarinic acid, such as the propyl ester of rosmarinic acid, rosmarinic acid methyl ester or the hexyl ester of rosmarinic acid, have been synthesized chemically, which have been isolated as natural antimicrobial agents. Rosmarinic acid and its derivatives were combined with antibiotics to obtain a synergistic effect. This review reports on the antimicrobial effects of rosmarinic acid and its associated derivatives, both in their free form and in combination with other microbial pathogens, and mechanisms of action.

A Comprehensive Review of Rosmarinic Acid: From Phytochemistry to Pharmacology and Its New Insight

Polyphenolic acids are the widely occurring natural products in almost each herbal plant, among which rosmarinic acid (RA, C18H16O8) is well-known, and is present in over 160 species belonging to many families, especially the Lamiaceae. Aside from this herbal ingredient, dozens of its natural derivatives have also been isolated and characterized from many natural plants. In recent years, with the increasing focus on the natural products as alternative treatments, a large number of pharmacological studies have been carried out to demonstrate the various biological activities of RA such as anti-inflammation, anti-oxidation, anti-diabetes, anti-virus, anti-tumor, neuroprotection, hepatoprotection, etc. In addition, investigations concerning its biosynthesis, extraction, analysis, clinical applications, and pharmacokinetics have also been performed. Although many achievements have been made in various research aspects, there still exist some problems or issues to be answered, especially its toxicity and bioavailability. Thus, we hope that in the case of natural products, the present review can not only provide a comprehensive understanding on RA covering its miscellaneous research fields, but also highlight some of the present issues and future perspectives worth investigating later, in order to help us utilize this polyphenolic acid more efficiently, widely, and safely.

Sephadex® LH-20, Isolation, and Purification of Flavonoids from Plant Species: A Comprehensive Review

Flavonoids are considered one of the most diverse phenolic compounds possessing several valuable health benefits. The present study aimed at gathering all correlated reports, in which Sephadex^® LH-20 (SLH) has been utilized as the final step to isolate or purify of flavonoid derivatives among all plant families. Overall, 189 flavonoids have been documented, while the majority were identified from the Asteraceae, Moraceae, and Poaceae families. Application of SLH has led to isolate 79 flavonols, 63 flavones, and 18 flavanones. Homoisoflavanoids, and proanthocyanidins have only been isolated from the Asparagaceae and Lauraceae families, respectively, while the Asteraceae was the richest in flavones possessing 22 derivatives. Six flavones, four flavonols, three homoisoflavonoids, one flavanone, a flavanol, and an isoflavanol have been isolated as the new secondary metabolites. This technique has been able to isolate quercetin from 19 plant species, along with its 31 derivatives. Pure methanol and in combination with water, chloroform, and dichloromethane have generally been used as eluents. This comprehensive review provides significant information regarding to remarkably use of SLH in isolation and purification of flavonoids from all the plant families; thus, it might be considered an appreciable guideline for further phytochemical investigation of these compounds.

Rosemary (Rosmarinus officinalis L., syn Salvia rosmarinus Spenn.) and Its Topical Applications: A Review

Topical application is an important administration route for drugs requiring local action on the skin, thereby avoiding their systemic absorption and adverse side effects. Rosmarinus officinalis L. (syn. Salvia rosmarinus Spenn.), popularly known as rosemary, is an aromatic plant with needle-like leaves belonging to the Lamiaceae family. Rosemary has therapeutic properties and has been used in the folk medicine, pharmaceutical, and cosmetics industries, mainly for its antioxidant and anti-inflammatory properties, which are attributed to the presence of carnosol/carnosic and ursolic acids. The therapeutic use of rosemary has been explored for the treatment of inflammatory diseases; however, other uses have been studied, such as wound healing and skin cancer and mycoses treatments, among others. Besides it therapeutic uses, rosemary has potential applications in cosmetic formulations and in the treatment of pathological and non-pathological conditions, such as cellulite, alopecia, ultraviolet damage, and aging. This review aims to critically discuss the topical applications of rosemary found in the literature while also offering relevant information for the development of topical formulations of its bioactive compounds.

Rosmarinus plants: Key farm concepts towards food applications

Rosmarinus species are aromatic plants that mainly grow in the Mediterranean region. They are widely used in folk medicine, food, and flavor industries and represent a valuable source of biologically active compounds (e.g., terpenoids, flavonoids, and phenolic acids). The extraction of rosemary essential oil is being done using three main methods: carbon dioxide supercritical extraction, steam distillation, and hydrodistillation. Furthermore, interesting antioxidant, antibacterial, antifungal, antileishmanial, anthelmintic, anticancer, anti-inflammatory, antidepressant, and antiamnesic effects have also been broadly recognized for rosemary plant extracts. Thus the present review summarized data on economically important Rosmarinus officinalis species, including isolation, extraction techniques, chemical composition, pharmaceutical, and food applications.

Bioactivity-guided isolation of rosmarinic acid as the principle bioactive compound from the butanol extract of Isodon rugosus against the pea aphid, Acyrthosiphon pisum

Aphids are agricultural pest insects that transmit viruses and cause feeding damage on a global scale. Current pest control practices involving the excessive use of synthetic insecticides over many years have resulted in aphid resistance to a number of pesticides. In nature, plants produce secondary metabolites during their interaction with insects and these metabolites can act as toxicants, antifeedants, anti-oviposition agents and deterrents towards the insects. In a previous study, we demonstrated that the butanol fraction from a crude methanolic extract of an important plant species, Isodon rugosus showed strong insecticidal activity against the pea aphid, Acyrthosiphon pisum. To further explore this finding, the current study aimed to exploit a bioactivity-guided strategy to isolate and identify the active compound in the butanol fraction of I. rugosus. As such, reversed-phase flash chromatography, acidic extraction and different spectroscopic techniques were used to isolate and identify the new compound, rosmarinic acid, as the bioactive compound in I. rugosus. Insecticidal potential of rosmarinic acid against A. pisum was evaluated using standard protocols and the data obtained was analyzed using qualitative and quantitative statistical approaches. Considering that a very low concentration of this compound (LC90 = 5.4 ppm) causes significant mortality in A. pisum within 24 h, rosmarinic acid could be exploited as a potent insecticide against this important pest insect. Furthermore, I. rugosus is already used for medicinal purposes and rosmarinic acid is known to reduce genotoxic effects induced by chemicals, hence it is expected to be safer compared to the current conventional pesticides. While this study highlights the potential of I. rugosus as a possible biopesticide source against A. pisum, it also provides the basis for further exploration and development of formulations for effective field application.

Effect of Sunlight Radiation on the Growth and Chemical Constituents of Salvia plebeia R.Br

This study investigated the chemical composition changes of Salvia plebeia R.Br. cultivated under different light sources, including florescent light and sunlight. The plants were exposed to fluorescent light for four months and sunlight and then examined for the next 5-7 months. Plants were harvested monthly during the seven months, and we examined whether the difference in light source affected the phenolic and flavonoid contents and antioxidant activity. A simple and reliable HPLC method using a PAH C18 column was applied for the quantitative analysis of two triterpenoids from the S. plebeia groups. Oleanolic acid (OA) and ursolic acid (UA) showed good linearity (R² > 0.9999) within the test ranges (0.005-0.05 mg/mL), and the average percentage recoveries of the OA and UA were 95.1-104.8% and 97.2-107.1%, respectively. The intra- and inter-day relative standard deviations (RSDs) were less than 2.0%. After exposure to sunlight, the phenolic contents, including rosmarinic acid, showed a reduced tendency, whereas the flavonoid contents, including homoplantaginin and luteolin 7-glucoside, were increased. The content of the triterpenoids also showed an increased tendency under sunlight irradiation, but the variance was not larger than those of the phenolic and flavonoid contents. Among experimental groups, the group harvested at six months, having been exposed to sunlight for two months, showed the most potent antioxidant activity. Therefore, these results showed that the chemical composition and antioxidant activities of S. plebeia R.Br. was affected from environmental culture conditions, such as light source. Our studies will be useful for the development of functional materials using S. plebeia R.Br.