Corrosion Mitigation by an Eco-Friendly Inhibitor: Nerium Oleander Leaf Extract on Carbon Steel in an Acidic Medium

The present study was initiated with an objective of investigating a plant extract as an effective corrosion inhibitor useful for protection of carbon steel in aqueous environment containing chloride ions. For this purpose, the leaf extract of the plant ‘Aerva lanata’ belonging to Amaranthaceae family of genus Aerva was chosen. The required optimum concentration of the extract for an effective inhibition was found to be 5 %, resulting in the inhibition efficiency of 95 % against corrosion of carbon steel in 200 ppm of NaCl solution. The extract introduced as a corrosion inhibitor was found to be effective in the pH range from 4.0 to 9.0. The extract could retain its inhibition efficiency for about an immersion period of 60 days and also up to a temperature of 333 K. The 5 % extract was found to control corrosion of carbon steel in highly aggressive medium containing 300 ppm of NaCl also. In order to maintain the protective nature, the required concentration of the extract was 2 %. From these studies, it was inferred that the Aerva lanata leaf extract exhibits good inhibitive properties for carbon steel in aqueous environment in wide ranges of pH, temperature and aggressiveness of medium.

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Comparative phytochemical profiling and effects of Nerium oleander extracts on the activities of murine peritoneal macrophages

Archives of Biological Sciences ◽

10.2298/abs150816042d ◽

2016 ◽

Vol 68 (3) ◽

pp. 515-531 ◽

Cited By ~ 5

Author(s):

Priyankar Dey ◽

Tapas Chaudhuri

Keyword(s):

Free Radical ◽

Leaf Extract ◽

Radical Scavenging ◽

Peritoneal Macrophages ◽

Nerium Oleander ◽

Gas Chromatography Mass Spectrometry ◽

Phytochemical Analysis ◽

Bioactive Constituents ◽

Root Extracts ◽

Murine Peritoneal Macrophages

Nerium oleander is a medicinal plant. Apart from its ethnopharmacological uses, pharmacognostic studies have revealed several of its bioactivities. Previously we demonstrated that the phenolic and flavonoid rich extracts of oleander leaf, stem and root possess potent antioxidant and free radical scavenging activities. Moreover, the leaf extract actively modulates the Th1/Th2 cytokine balance and exerts anti-inflammatory activities on murine splenic lymphocytes. Therefore, the present study was designed to evaluate the effect of oleander leaf, stem and root extracts on phagocytosis and the free radical-related activities of murine peritoneal macrophages. In addition, phytochemical profiling was performed using gas chromatography-mass spectrometry (GC-MS). The results demonstrated that the increase in phagocytosis and decrease in myeloperoxidase (MPO) were in the order of leaf>root>stem. The inhibition of cell adhesion, nitric oxide (NO) and elevation of respiratory burst activity was in the order of leaf>stem>root. However, the bioactivities of the leaf extract were much high than those of the stem and root extracts. Phytochemical analysis also revealed the presence of several bioactive constituents in oleander extracts. Therefore, the present study demonstrated that oleander possesses the capacity to modulate macrophage activities and the bioactivities are attributed to the numerous phytochemicals identified in oleander extracts.

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