Chemical Diversity, Biological Activity, and Genetic Aspects of Three Ocotea Species from the Amazon

Volatile Oil Containing Plants as Phytopharmaceuticals to Treat Psoriasis: A Review

INTRODUCTION

Psoriasis is a chronic skin condition caused by an autoimmune response that accelerates the life cycle of skin cells, resulting in the characteristic symptoms of scaling, inflammation, and itching.

METHODS

Palliative treatment options for psoriasis often prioritize the use of volatile oils. These oils contain monoterpenes, sesquiterpenes, and phenylpropanoids that are intricately linked to the molecular cascades involved in the pathogenesis and symptoms of psoriasis. To evaluate the antipsoriatic efficacy of volatile oils and their components, we conducted a systematic review of scientific studies. Our literature search encompassed various online databases, including PubMed, BIREME, SCIELO, Open Grey, Scopus, and ScienceDirect. The selected studies included experimental in vitro/in vivo assessments as well as clinical studies that examined the potential of volatile oils and their extracts as antipsoriatic agents. We excluded conference proceedings, case reports, editorials, and abstracts. Ultimately, we identified and evaluated a total of 12 studies for inclusion in our analysis.

RESULTS

The data collected, compiled, and analyzed strongly support the interaction between volatile oils and their constituents with the key molecular pathways involved in the pathogenesis of psoriasis and the development of its symptoms. Volatile oils play a significant role in the palliative treatment of psoriasis, while their chemical constituents have the potential to reduce the symptoms and recurrence of this condition.

CONCLUSION

The current review highlights that the constituents found in volatile oils offer distinct chemical frameworks that can be regarded as promising starting points for the exploration and development of innovative antipsoriatic agents.

Effects of Harvest Time and Hydrodistillation Time on Yield, Composition, and Antioxidant Activity of Mint Essential Oil

In this study, we assessed the effects of different harvest times (9 a.m., 1 p.m., and 5 p.m.) and hydrodistillation times (60, 90, and 120 min) on the yield, chemical composition, and antioxidant activity of the spearmint (Mentha spicata L.) essential oil (EO) sourced from the Amazon region. EO yield was ≥1.55% and was not significantly influenced (p ≥ 0.05) by the different harvest times and hydrodistillation times. Thirty-one different organic compounds were identified, of which menthol (91.56-95.68%), menthone (0.6-2.72%), and isomenthone (0.55-1.46%) were the major constituents. The highest menthol content in the EO was obtained from samples collected at 9 a.m., with a hydrodistillation time of 60-90 min, compared to other harvest and hydrodistillation times. This suggests that exposure to sun and light, which is greater at harvest times of 1 p.m. and 5 p.m., decreased the menthol content and altered the chemical composition of Mentha EO. Furthermore, the sample harvested at 9 a.m. and hydrodistilled for 60 min showed the highest antioxidant activity (61.67 equivalent mg of Trolox per g of EO), indicating that antioxidant activity is strongly affected by light exposure and the contact duration of the sample with boiling water during hydrodistillation.

Extraction and purification of α-pinene; a comprehensive review

Extensive use of α-pinene in cosmetics, and medicine, especially for its antioxidant/antibacterial, and anti-cancer properties, and also as a flavoring agent, has made it a versatile product. α-Pinene (one of the two pinene isomers) is the most abundant terpene in nature. When extracting α-pinene from plants and, to a lesser extent, fruits, given that its purity is essential, purification methods should also be used as described in this study. Also, an attempt has been made to describe the extraction techniques of α-pinene, carried out by conventional and novel methods. Some disadvantages of conventional methods (such as hydrodistillation or solvent extraction) are being time consuming, low capacity per batch and being labor intensive and the requirement of trained operators. Most novel methods, such as supercritical fluid extraction and microwave-assisted extraction, can reduce the extraction time, cost, and energy compared to conventional methods, and, in fact, the extraction and preservation efficiency of α-pinene in these methods is higher than conventional methods. Although the above-mentioned extraction methods are effective, they still require rather long extraction times. In fact, advanced methods such as green and solvent-free ultrasonic-microwave-assisted extraction are much more efficient than microwave-assisted extraction and ultrasound-assisted extraction because the extraction efficiency and separation of α-pinene in these methods are higher; furthermore, no solvent consumption and maximum extraction efficiency are some crucial advantages of these techniques. However, the application of some novel methods, such as ultrasound-assisted extraction, in industry scale is still problematic because of their intricate design data.

The Volatile Profiles and DNA Barcodes of Lauraceae Species from the Ocotea Complex with Occurrence in the Brazilian Amazon

The Ocotea complex accommodates most of the taxonomic diversity of Neotropical Lauraceae with economic importance and biological potential attributed to their essential oils (EOs) and extracts. However, the botanical taxonomy has had limitations due to the difficulty of identifying and delimiting species and genera. The chemical and molecular markers of Ocotea complex species in Pará state, Brazil, were assessed according to their EO compositions and DNA sequences of matK, trnL-trnF, and ITS regions. The multivariate analysis of EOs constituents has classified them into two main clusters characterized by oils rich in (I) terpenoids and phenylpropanoids and (II) sesquiterpenes. We conducted a phylogenetic analysis of species based on DNA barcode sequences on the Bayesian Inference (PP: 0.70-1,0) and Maximum Likelihood (BS: 72-100 %). The comparison between the volatile profiles and phylogenetic data indicates two main groups for these species collected from the Ocotea complex.

Essential Oil of the Plants Growing in the Brazilian Amazon: Chemical Composition, Antioxidants, and Biological Applications

Essential oils are biosynthesized in the secondary metabolism of plants, and in their chemical composition, they can be identified different classes of compounds with potential antioxidant and biological applications. Over the years in the Amazon, several species of aromatic plants were discovered and used in traditional medicine. The literature has shown that essential oils extracted from amazon species have several biological activities, such as antioxidant, antibacterial, antifungal, cytotoxic, and antiprotozoal activities. These activities are related to the diversified chemical composition found in essential oils that, by synergism, favors its pharmacological action. In light of this vital importance, this study aimed at performing a review of the literature with particular emphasis on the chemical composition and biological activities in studies conducted with species collected in the Amazon, taking into consideration in particular the last 10 years of collection and research.

Essential oils from Ocotea species: Chemical variety, biological activities and geographic availability

This review describes the chemical composition and biological properties of essential oils from plants of the Ocotea genus, from different origin. This taxon belongs to the Laureaceae family, which in turn, is best known for medicinal use, often related to the essential oils. The text includes studies about Ocotea species distributed mainly on the South American continent, but also reporting species located in North America and Africa. Brazil, Colombia, Costa Rica and Ecuador are countries with highest number of species mentioned in the review. Also, the major components of each essential oil, its chemical structures, as well as the description and extent of biological activities related to essential oils are detailed in this review. Finally, the text discusses the chemical and biological aspects of these studies in a comparatively way, also informing additional data such as yield, biome of origin and pharmacobotanical location.

Enhancement of the antibiotic activity mediated by the essential oil of Ocotea odorifera (VELL) ROWHER and safrole association

In a recent study, our research group demonstrated that the essential oil of Ocotea odorifera (EOOO) and its major compound safrole potentiated the action fluoroquinolones, modulating bacterial resistance possibly due to direct inhibition of efflux pumps. Thus, in the present study, we investigated whether these treatments could enhance the activity of gentamicin and erythromycin against multidrug-resistant (MDR) bacteria. The EOOO was extracted by hydrodistillation, and the phytochemical analysis was performed by gas chromatography coupled to mass spectrometry (GC-MS). The antibiotic-enhancing effect of the EOOO and safrole against MDR strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa was analyzed by the broth microdilution method. The chemical analysis confirmed the presence of safrole as a major component among the 16 compounds identified in the EOOO. Both the essential oil and the isolated compound showed clinically relevant antibacterial activities against S. aureus. Regarding the modulation of antibiotic resistance, the EOOO was found to enhance the activity of erythromycin against the strains of P. aeruginosa and S. aureus, as well as improving the action of gentamicin against S. aureus. On the other hand, safrole potentiated the activity of gentamicin against the S. aureus strain alone. It is concluded, therefore, that the EOOO and safrole can enhance the activity of macrolides and aminoglycosides, and as such are useful in the development of therapeutic tools to combat bacterial resistance against these classes of antibiotics.

Essential Oil Composition and DNA Barcode and Identification of Aniba species (Lauraceae) Growing in the Amazon Region

Lauraceae species are widely represented in the Amazon, presenting a significant essential oil yield, large chemical variability, various biological applications, and high economic potential. Its taxonomic classification is difficult due to the accentuated morphological uniformity, even among taxa from a different genus. For this reason, the present work aimed to find chemical and molecular markers to discriminate Aniba species collected in the Pará State (Brazil). The chemical composition of the essential oils from Aniba canelilla, A. parviflora, A. rosaeodora, and A. terminalis were grouped by multivariate statistical analysis. The major compounds were rich in benzenoids and terpenoids such as 1-nitro-2-phenylethane (88.34-70.85%), linalool (15.2-75.3%), α-phellandrene (36.0-51.8%), and β-phellandrene (11.6-25.6%). DNA barcodes were developed using the internal transcribed spacer (ITS) nuclear region, and the matK, psbA-trnH, rbcL, and ycf1 plastid regions. The markers psbA-trnH and ITS showed the best discrimination for the species, and the phylogenic analysis in the three- (rbcL + matK + trnH - psbA and rbcL + matK + ITS) and four-locus (rbcL + matK + trnH - psbA + ITS) combination formed clades with groups strongly supported by the Bayesian inference (BI) (PP:1.00) and maximum likelihood (ML) (BS ≥ 97%). Therefore, based on statistical multivariate and phylogenetic analysis, the results showed a significant correlation between volatile chemical classes and genetic characteristics of Aniba species.

Chemical constituents of Algerian mandarin (Citrus reticulata) essential oil by GC-MS and FT-IR analysis

Medicinal plants are potential sources of natural compounds with biological activities and therefore attract the attention of researchers worldwide. Citrus oils are a complex mixture of more than a hundred components of differing chemical natures. Qualitative and quantitative analysis by gas chromatography coupled with mass spectrometry (GCMS) of the Citrus reticulata essential oil collected from El Hadaïk, Skikda City (Algeria), identified 28 compounds representing a total of 99.41%. The essential oil is constituted mainly of: D-Limonene (85.10%), Sabinene (2.49%), Linalyl acetate (2.00%), Copaene (1.80%) et α-Pinene (1.75%) totaling approximately 93.14%. The essential oil was also analyzed by Fourier transform infrared spectroscopy analysis (FTIR). FTIR spectroscopy allowed us to identify 10 volatile compounds and indicated that the functional groups of the essential oils are C-H (Alkene), C-H (aromatic) and C=C. The obtained results have shown that the essential oil can be fully utilized for pharmacy, cosmetology and industry.

Chemical Diversity and Biological Activities of Essential Oils from Licaria, Nectrandra and Ocotea Species (Lauraceae) with Occurrence in Brazilian Biomes

Lauraceae species are known as excellent essential oil (EO) producers, and their taxa are distributed throughout the territory of Brazil. This study presents a systematic review of chemical composition, seasonal studies, occurrence of chemical profiles, and biological activities to EOs of species of Licaria, Nectandra, and Ocotea genera collected in different Brazilian biomes. Based on our survey, 39 species were studied, with a total of 86 oils extracted from seeds, leaves, stem barks, and twigs. The most representative geographic area in specimens was the Atlantic Forest (14 spp., 30 samples) followed by the Amazon (13 spp., 30 samples), Cerrado (6 spp., 14 samples), Pampa (4 spp., 10 samples), and Caatinga (2 spp., 2 samples) forests. The majority of compound classes identified in the oils were sesquiterpene hydrocarbons and oxygenated sesquiterpenoids. Among them, β-caryophyllene, germacrene D, bicyclogermacrene, caryophyllene oxide, α-bisabolol, and bicyclogermacrenal were the main constituents. Additionally, large amounts of phenylpropanoids and monoterpenes such as safrole, 6-methoxyelemicin, apiole, limonene, α-pinene, β-pinene, 1,8-cineole, and camphor were reported. Nectandra megatopomica showed considerable variation with the occurrence of fourteen chemical profiles according to seasonality and collection site. Several biological activities have been attributed to these oils, especially cytotoxic, antibacterial, antioxidant and antifungal potential, among other pharmacological applications.

Biological Activities and Safety of Citrus spp. Essential Oils

Citrus fruits have been a commercially important crop for thousands of years. In addition, Citrus essential oils are valuable in the perfume, food, and beverage industries, and have also enjoyed use as aromatherapy and medicinal agents. This review summarizes the important biological activities and safety considerations of the essential oils of sweet orange (Citrus sinensis), bitter orange (Citrus aurantium), neroli (Citrus aurantium), orange petitgrain (Citrus aurantium), mandarin (Citrus reticulata), lemon (Citrus limon), lime (Citrus aurantifolia), grapefruit (Citrus × paradisi), bergamot (Citrus bergamia), Yuzu (Citrus junos), and kumquat (Citrus japonica).

Genetic and Chemical Diversity in Perovskia abrotanoides Kar. (Lamiaceae) Populations Based on ISSRs Markers and Essential Oils Profile

Genetic and the essential oil composition variability among twelve Perovskia abrotanoides populations (PAbPs) growing wild in Iran were assessed by ISSR markers, GC-FID and GC/MS, respectively. Nine selected ISSR primers produced 119 discernible bands, of them 96 (80.7%) being polymorphic. Genetic similarity values among populations ranged between 0.07 and 0.79 which indicated a high level of genetic variation. Polymorphic information content, resolving power and marker index generated by ISSR primers were, 0.31, 6.14, and 3.32, respectively. UPGMA grouped PAbPs into four main clusters. Altogether, 38 chemical compounds were identified in the oils, and a relatively high variation in their contents was found. Camphor (11.9 - 27.5%), 1,8-cineole (11.3 - 21.3%), α-bisabolol (0.0 - 13.1%), α-pinene (5.9 - 10.8%), and δ-3-carene (0.1 - 10.5%) were the major compounds. Oxygenated monoterpenes (32.1 - 35.8%) and monoterpene hydrocarbons (25.7 - 30.4%) were the main groups of compounds in the oils studied. Cluster analysis and principal-component analysis were used to characterize the samples according to oil components. Four main chemotypes were found to be Chemotype I (camphor/1,8-cineol), Chemotype II (1,8-cineole/camphor), Chemotype III (camphor/1,8-cineol/α-bisabolol), and Chemotype IV (camphor/δ-3-carene/α-bisabolol). The information, provided here on P. abrotanoides populations, will be useful to introduce this plant into agricultural systems.

Phytochemical Screening and Biological Activity of Mentha × piperita L. and Lavandula angustifolia Mill. Extracts

The present study aimed to investigate the phytochemical composition of Mentha × piperita L. (MP) and Lavandula angustifolia Mill. (LA) extracts in terms of hydroxycinnamic acid (HCAs) content, in particular, caffeic (CA), p-cumaric (CU), ferulic (FE), and rosmarinic (RS) acids using LC-MS. Also, the in vitro antimicrobial effect against Staphylococcus aureus and the antiproliferative activity against two cancerous cell lines (A375 and MDA-MB-231) using the MTT assay were tested. The extracts were prepared using aromatic water which resulted from the extraction of oils from plants as extraction medium, with/without acid. The results showed that RS and FE represent the majority of HCAs compounds; the highest content of FE is found in LA (7.47 mg·g-1d.m.), and the maximum content of RS in MP (6.36 mg·g-1d.m.). Regarding the antimicrobial effect against Staphylococcus aureus, the two extracts showed a simulative role on the growth rate of Staphyloccocus aureus, but a slightly inhibitory effect (69.12%) can be attributed to the acidic environment. In terms of biological activity against MDA-MB-231 breast carcinoma cell line, and A375 human melanoma cell line, at the highest employed concentration, 150 μg·mL-1, the tested extracts present a weak antiproliferative effect.