An Endophytic Fungi-Based Biostimulant Modulates Volatile and Non-Volatile Secondary Metabolites and Yield of Greenhouse Basil (Ocimum basilicum L.) through Variable Mechanisms Dependent on Salinity Stress Level

Salinity in water and soil is one of the major environmental factors limiting the productivity of agronomic and horticultural crops. In basil (Ocimum basilicum L., Lamiaceae) and other Ocimum species, information on the plant response to mild salinity levels, often induced by the irrigation or fertigation systems, is scarce. In the present work, we tested the effectiveness of a microbial-based biostimulant containing two strains of arbuscular mycorrhiza fungi (AMF) and Trichoderma koningii in sustaining greenhouse basil yield traits, subjected to two mild salinity stresses (25 mM [low] and 50 mM [high] modulated by augmenting the fertigation osmotic potential with NaCl) compared to a non-stressed control. The impact of salinity stress was further appraised in terms of plant physiology, morphological ontogenesis and composition in polyphenols and volatile organic compounds (VOC). As expected, increasing the salinity of the solution strongly depressed the plant yield, nutrient uptake and concentration, reduced photosynthetic activity and leaf water potential, increased the Na and Cl and induced the accumulation of polyphenols. In addition, it decreased the concentration of Eucalyptol and β-Linalool, two of its main essential oil constituents. Irrespective of the salinity stress level, the multispecies inoculum strongly benefited plant growth, leaf number and area, and the accumulation of Ca, Mg, B, p-coumaric and chicoric acids, while it reduced nitrate and Cl concentrations in the shoots and affected the concentration of some minor VOC constituents. The benefits derived from the inoculum in term of yield and quality harnessed different mechanisms depending on the degree of stress. under low-stress conditions, the inoculum directly stimulated the photosynthetic activity after an increase of the Fe and Mn availability for the plants and induced the accumulation of caffeic and rosmarinic acids. under high stress conditions, the inoculum mostly acted directly on the sequestration of Na and the increase of P availability for the plant, moreover it stimulated the accumulation of polyphenols, especially of ferulic and chicoric acids and quercetin-rutinoside in the shoots. Notably, the inoculum did not affect the VOC composition, thus suggesting that its activity did not interact with the essential oil biosynthesis. These results clearly indicate that beneficial inocula constitute a valuable tool for sustaining yield and improving or sustaining quality under suboptimal water quality conditions imposing low salinity stress on horticultural crops.

Ocimum Species: Ethnomedicinal Uses, Phytochemistry and Pharmacological Importance

Plant species belonging to the Ocimum genus are among the most popular medicinal plants and are being used for several purposes in ethnomedicine. Ocimum is universally cultivated however; the geographical distribution highlights three major centers of Ocimum diversity, these are: the tropical areas of America, the tropical region of Asia and the tropical and subtropical regions of Africa. Ocimum species have been employed traditionally for several medicinal purposes including antioxidant, antibacterial, hypoglycaemic, hepatoprotective, antiviral and other medicinal purposes. Though scientists have carried-out studies and chronicled the pharmacological potentials of Ocimum species, documents containing these data seem to be disassembled, making it difficult to really distinguish the pharmacologically useful species from those that are not and also to get comprehensive information about the medicinal species in this genus. Hence, the aim of this review is to outline classified information on the ethnopharmacology, phytochemistry and pharmacological importance of some Ocimum species that have been reported by different researchers. In carrying-out this review, the search for literature was done via relevant databases including PubMed, Springer, Web of Science, Science Direct, Embase, SciFinder, Google Scholar and Scopus. The species reviewed are the most widely used from the Ocimum genus in traditional medicine and they are also the most researched for intended use in conventional therapeutic practice. Literature reveals that these species contain several compounds which are responsible for the numerous pharmacological activities elicited by them including antimalarial, anticancer, antidiabetic, antiinflammatory and antioxidant effects.

Mechanistic Interventions of Selected Ocimum Species in Management of Diabetes, Obesity and Liver Disorders: Transformative Developments from Preclinical to Clinical Approaches

Metabolic disorders are usually categorized as inborn metabolism defects, including carbohydrate metabolism deficits in enzymes, amino acids derived from proteins, and fatty acids released from lipids. A metabolic disorder, which arises from elevated body weight, diabetes, and obesity, has reached epidemic proportions in countries. This review discusses the metabolic disorders with respect to diabetes, obesity and liver disorders and their therapeutic management with selective Ocimum species. Ocimum genus contains more than 200 species and is one of the richest sources of diverse phytoconstituents, including fatty acids, saponins, flavonoids, terpenoids, phenols, tannins, etc. that are documented to be beneficial in the management of various metabolic disorders. The potential of selected Ocimum species in metabolic disorders is discussed by reviewing available preclinical and clinical studies and associated mechanisms of action and their effect on gene expression.

Essential oils of basil cultivars selectively affect the activity of antioxidant enzymes in glial cells

The qualitative and quantitative composition of essential oils (EO) of Ocimum species, cultivated in high altitude Armenian landscape was quite different and the main components of O. basilicum var. purpureum; O. basilicum var. thyrsiflora and O. x citriodorum oils belong to the class of oxygenated monoterpenes. Investigated EOs possess remarkable antioxidant activity. They inhibit the tyrosinase activity, the enzyme responsible not only for the melanin production, but also for various aging-related metabolic processes. Investigated EOs had no any significant effect on catalase at the protein levels, but alter its activity in neuroglial BV-2 different cell lines. Treatment of the neuroglial cell lines with the sub-cytotoxic concentrations of three mentioned EOs influence also the activity of acetyl-CoA oxidase type 1. Practical Applications The microglial cells play a pivotal role as the neuroprotective agents against neuroinflammation. Different data included in the present article are stating that plant origin substances can play a role of regulators of enzymatic antioxidant capacity of cells. EOs extracted from the Ocimum different cultivars are able to trigger the activity of acetyl-CoA oxidase type 1 (or palmytoil-CoA oxidase type 1), which can serve as a basis of regulation of redox deviation in WT cells. So, it can be suggested them to be applied for the prevention of some processes, which can influence on the aging, as the process of ageing is commonly associated with mitochondrial dysfunction, oxidative stress caused by the increased level of free radical production, dysfunction of the microglia, high blood pressure and so on.