Seyed Abdulmajid Ayatollahi

Biological Activities of Essential Oils: From Plant Chemoecology to Traditional Healing Systems

Essential oils are complex mixtures of hydrocarbons and their oxygenated derivatives arising from two different isoprenoid pathways. Essential oils are produced by glandular trichomes and other secretory structures, specialized secretory tissues mainly diffused onto the surface of plant organs, particularly flowers and leaves, thus exerting a pivotal ecological role in plant. In addition, essential oils have been used, since ancient times, in many different traditional healing systems all over the world, because of their biological activities. Many preclinical studies have documented antimicrobial, antioxidant, anti-inflammatory and anticancer activities of essential oils in a number of cell and animal models, also elucidating their mechanism of action and pharmacological targets, though the paucity of in human studies limits the potential of essential oils as effective and safe phytotherapeutic agents. More well-designed clinical trials are needed in order to ascertain the real efficacy and safety of these plant products.

Plants of the Genus Zingiber as a Source of Bioactive Phytochemicals: From Tradition to Pharmacy

Plants of the genus Zingiber (Family Zingiberaceae) are widely used throughout the world as food and medicinal plants. They represent very popular herbal remedies in various traditional healing systems; in particular, rhizome of Zingiber spp. plants has a long history of ethnobotanical uses because of a plethora of curative properties. Antimicrobial activity of rhizome essential oil has been extensively confirmed in vitro and attributed to its chemical components, mainly consisting of monoterpene and sesquiterpene hydrocarbons such as α-zingiberene, ar-curcumene, β-bisabolene and β-sesquiphellandrene. In addition, gingerols have been identified as the major active components in the fresh rhizome, whereas shogaols, dehydrated gingerol derivatives, are the predominant pungent constituents in dried rhizome. Zingiber spp. may thus represent a promising and innovative source of natural alternatives to chemical food preservatives. This approach would meet the increasing concern of consumers aware of the potential health risks associated with the conventional antimicrobial agents in food. This narrative review aims at providing a literature overview on Zingiber spp. plants, their cultivation, traditional uses, phytochemical constituents and biological activities.

Plants of the Melaleuca Genus as Antimicrobial Agents: From Farm to Pharmacy

Plants belonging to Melaleuca genus (Myrtaceae family) are native to Oceania, where they have been used for ages by Aborigine people in Australian traditional medicine, mainly because of their broad‐spectrum antimicrobial activity. Although, M. linariifolia, M. dissitiflora, and other species of Melaleuca can also be used, the tea tree oil, an essential oil obtained from M. alternifolia shows the longest history of medicinal uses. Tea tree oil contains for the 80–90% several monoterpenes (terpinen‐4‐ol, α‐terpinene, 1,8‐cineol, p‐cymene, α‐terpineol, α‐pinene, terpinolene, limonene, and sabinene). Sesquiterpenes and aromatic compounds further compose this oil. The essential oil of Melaleuca spp. has been reported to possess effective antibacterial and antifungal properties in vitro. In particular, data show that 1,8‐cineol, terpinen‐4‐ol and methyl eugenol play the key role in mediating this oils antimicrobial activity. Copyright

Antiglycation Activity of Otostegia persica (Burm.) Boiss

Diabetes mellitus is a common endocrine disorder characterized by hyperglycemia and long-term complications affecting the eyes, nerves, blood vessels, skin and kidneys. Increased glycation of proteins and accumulation of advanced glycation endproducts (AGEPs) have been implicated in the pathogenesis of diabetic complications. Glycation and AGEP formation are also accompanied by the formation of free radicals via autoxidation of glucose and glycated proteins. Compounds with combined antiglycation and antioxidant properties may offer therapeutic potential. Since the antioxidant activity of different extracts and fractions of aerial parts of Otostegia persica has been evaluated and this plant is used as an antidiabetic agent in Iranian traditional medicine, we evaluated the antiglycation activity of this species. Here, we report the isolation of known compound 3´, 7-dihydroxy-4´,6,8-trimethoxy-flavone for the antiglycation properties of this plant.

Bioactive chemical compounds in Eremurus persicus (Joub. & Spach) Boiss. essential oil and their health implications

The genus Eremurus is native to Eastern Europe and temperate Asia. Particularly, Eremurus persicus (Joub. & Spach) Boiss. is highly valued in traditional foods and medicine. Scientific knowledge about E. persicus chemical composition and bioactivity is required. Therefore, the present study is aimed to determine the volatile composition of E. persicus essential oil (EO) by means of gas chromatography coupled to flame ionization/mass spectrometry detection. Moreover, the antioxidant, antimicrobial, anticancer, and acetylcholinesterase inhibitory activities of the EO were tested. Interestingly, the anti-dermatophyte potency was close to that of the drug griseofulvin, with minimum fungicidal concentration ranging between 0.7 and 4.5% depending on the fungi strain. The EO was also effective against hepatocellular carcinoma (Hep-G2) and breast adenocarcinoma (MCF-7) human cancer cell lines in a concentration (200-1500 ng/mL)-dependent manner, with a decrease of the cell viability up to 65% and 52%, respectively. The E. persicus EO was rich in terpenes and oxygenated terpene derivatives. Individually, limonene (16.25%), geranylgeraniol (15.23%), n-nonanal (9.48%), geranyl acetone (9.12%), benzene acetaldehyde (8.51%), linalool (7.93%), α-pinene (6.89%), and 1,8-cineol (5.22%) were the most abundant volatile compounds and could be chosen as analytical markers of this essential oil. In conclusion, our results suggested that this EO possesses a wide range of bioactive properties that could be useful in nutraceutical, functional foods and cosmeceutical formulations.

Plants of the Genus Zingiber as Source of Antimicrobial Agents: from Tradition to Pharmacy

Plants of the genus Zingiber (Family Zingiberaceae) are widely used throughout the world 51 as food and medicinal plants. They represent very popular herbal remedies in various traditional 52 healing systems; in particular, rhizome of Zingiber spp. plants has a long history of ethnobotanical 53 uses because of a plethora of curative properties. Antimicrobial activity of rhizome essential oil has 54 been extensively confirmed in vitro and attributed to its chemical components, mainly consisting in 55 monoterpene and sesquiterpene hydrocarbons such as α-zingiberene, ar-curcumene, β-bisabolene 56 and β-sesquiphellandrene. In addition, gingerols have been identified as the major active 57 components in the fresh rhizome, whereas shogaols, dehydrated gingerol derivatives, are the 58 predominant pungent constituents in dried rhizome. Zingiber spp. may thus represent a promising 59 and innovative source of natural alternatives to chemical food preservatives. This approach would 60 meet the increasing concern of consumers aware of the potential health risks associated with the 61 conventional antimicrobial agents in food. This narrative review aims providing a literature 62 overview on Zingiber spp. plants, their cultivation, traditional uses, phytochemical constituents and 63 biological activities. 64