Major essential oil constituents, total phenolics and flavonoids content and antioxidant activity of Salvia officinalis plant in response to nano-titanium dioxide

Abstract

Medicinal plants produce a wide range of secondary metabolites to increase their performance upon exposure to various kinds of elicitors. The present study was undertaken to evaluate the impacts of various concentrations of nano-titanium dioxide (TiO 2 ) particles, viz., 0, 10, 50, 100, 200 and 1000 mg l -1 on growth, biosynthesis of secondary metabolites such as essential oils, total phenolics, flavonoids and antioxidant efficacy of the extracts obtained from the treated Salvia officinalis plants, assayed using DPPH free radical scavenging and b-carotene/linoleic acid bleaching test systems. The results showed that the highest and the lowest dry weights of root and shoot tissues were obtained from plants exposed to 100 and 1000 mg l -1 TiO 2 , respectively. The highest total phenolic (35.2 mg GAE g -1 dry wt.) and flavonoid (21.9 mg CE g -1 dry wt.) contents were obtained in plants exposed to 200 and 100 mg l -1 nano-TiO 2 , respectively. Gas chromatography and mass spectrometry analysis showed that the major components of essential oils were monoterpenes, including Camphene, p-Cymene, 1,8-Cineol, Cis-Thujene and Camphor. The highest value of Cis-Thujene (34.5 %) and 1,8-Cineol (21.2 %) were achieved in extracts obtained from plants exposed to 200 mg l -1 nano-TiO 2 . However, the maximal content of Camphene (12.1 %) was obtained from plants exposed to 1000 mg l -1 nano-TiO 2 treatment. Although the extract from all treated plants improved antioxidant activity, it was highest for the extract obtained from plants treated with nano-TiO 2 at 200 mg l -1 with an IC 50 value of 2.44 lg g -1 dry wt. as compared to that of control plants (6.42 lg g -1 dry wt.) and butylated hydroxytoluene as positive probe (3.68 lg g -1 dry wt.). It was suggested for the first time that nano-TiO 2 may act as an elicitor to improve secondary metabolism in S. officinalis plants for biosynthesis of natural antioxidants.

Titanium dioxide nanoparticles (TiO2 NPs) promote growth and ameliorate salinity stress effects on essential oil profile and biochemical attributes of Dracocephalum moldavica

“…Considering the importance of its essential oils, any treatment with positive effects on its essential oil content and dominant constituents could be of great value to growers. The positive effect of TiO 2 NPs was previously reported in Salvia officinalis essential oil content and constituents 55 . Taking into account these factors, the current study examined the effect on Moldavian balm under normal and salt stress conditions.…”

“…Superoxide dismutase (SOD), as the primary ROS scavenger localizing in chloroplasts, mitochondria, peroxisomes and cytosol, catalyzes the disproportion of two O 2 • − radicals to H 2 O 2 and O 2 54 . Moreover, H 2 O 2 is scavenged by ascorbate-peroxidase (APX) in ascorbate-glutathione cycle and through guaiacol peroxidase (GP) and catalase (CAT) in cytoplasm and divided into water and oxygen 55 . The increased activity of the mentioned enzymes by TiO 2 treatments in the present study might be another reason for the observed decrease in H 2 O 2 values under salinity stress compared with control conditions.…”

Nanoparticles in Agroindustry: Applications, Toxicity, Challenges, and Trends

“…Monoterpenes (mayor component in essential oils) were increased in plants exposed to 200 mg∙L −1 of TiO 2 NPs. Monoterpenes increase could be considered as a defense mechanism against free radicals generated by the NPs [ 207 ]. Meanwhile, Mentha piperita L. treated with 150 mg∙L −1 of TiO 2 NPs also showed an increase in essential oil contents by 105.1% compared to control.…”

Advances in nanomaterials as novel elicitors of pharmacologically active plant specialized metabolites: current status and future outlooks

“…87,88 Various research groups have also investigated the elicitation potential of TiO 2 -NPs on plant SMs production using both in vivo and in vitro systems. [89][90][91] Using in vitro systems, aloin (118%) content was increased in cell suspension culture of Aloe vera when treated with TiO 2 NPs. 35 Similarly, the phenolic and avonoid contents in callus culture of Cicer arietinum were increased when exposed to different concentrations of TiO 2 NPs.…”