Preliminary assessment of free radical scavenging, thrombolytic and membrane stabilizing capabilities of organic fractions of Callistemon citrinus (Curtis.) skeels leaves

Abstract

BackgroundCallistemon citrinus (Curtis.) (Family- Myrtaceae) is a popular evergreen shrub in Bangladesh. In the present study, the leaves of this plant have been assessed comprehensively for free radical scavenging, thrombolytic and membrane stabilizing activities.MethodsThe leaves were collected, powdered and extracted with methanol. The extract was then concentrated and successively fractionated into petroleum ether, carbon tetrachloride, chloroform and aqueous soluble fractions. The extractives were investigated for free radical scavenging, thrombolytic and membrane stabilizing activities.ResultsIn case of 1,1 diphenyl-2-picrylhydrazyl (DPPH) and hydrogen peroxide radical scavenging assays, the crude methanol extract of the leaves showed the highest free radical scavenging activity among the tested materials including standard ascorbic acid (p = 0.0000). Besides, this extract was also found significantly rich (p = 0.0000) in phenolics and flavonoids compared to other organic fractions. In thrombolytic study, the petroleum ether fraction exhibited significantly stronger thrombolysis (p = 0.024) than other leaf extractives but was weaker than the standard streptokinase. In membrane stabilizing assay, the activity of chloroform fraction was similar to that of standard acetylsalicylic acid (p = 1.000) in hypotonic solution induced hemolysis. However, membrane stabilization activity of this chloroform fraction was found significantly stronger than that of the standard (p = 0.0000) in heat induced hemolysis.ConclusionThis study has revealed the medicinal capabilities of different organic fractions of C. citrinus displaying free radical scavenging, thrombolysis and membrane stabilizing antiinflammatory potentials. Further bioactivity guided isolation is required to obtain pharmacologically secondary metabolites.

Comparativein vitroantioxidant and antibacterial activities of leaf extract fractions of Crimson bottlebrush,Callistemon citrinus(Curtis.) Skeels

“…Here also it is clear that the last fraction of the successive extraction procedure, which acts as the most potent antioxidant fraction, is rich in bioactive phytochemicals and extracted with the most polar solvent. An earlier study indicated that the crude leaf methanolic extract of C. citrinus and its extract fractions have differential free radical scavenging potentials and that also supports our findings that water is more suitable than petroleum ether for extracting bioactive antioxidant molecules from C. citrinus leaf 23 . Recently, through a comparative study, our laboratory reported that the successive leaf aqueous extract fraction of Crinum asiaticum having the highest antioxidant and antibacterial potentials along with the highest phenolics contents 8 .…”

“…Leaves and flowers of C. citrinus constitute a major compound, 1-(2,6-dihydroxy-4-methoxyphenyl)-3-methylbutan-1-one (phloroglucinol) which was reported for potent dose-dependent antinociceptive and anti-inflammatory properties correlating its strong in vivo antioxidant activity 22 . Different medicinal properties like thrombolytic, membrane-stabilizing, free radical scavenging and anti-inflammatory potentials of the different organic solvent-mediated leaf extracts of C. citrinus were studied and revealed to be very promising 23 .…”

Phytochemical profiling and seasonal variation of essential oils of three Callistemon species cultivated in Egypt

“…Stabilization of the lysosomal membrane is necessary to limit the inflammatory response through inhibition of the release of lysosomal constituents of activated neutrophils such as proteases and bactericidal enzymes. Exposure of erythrocytes to a hypotonic medium results in membrane lysis [31]. A possible mechanism for membrane stabilization activity of Callistemon essential oil observed herein could be attributed to the ability of essential oil constituents to integrate into cellular membranes, increasing the surface area to volume ratio of the cells that might be brought about by expansion of the membrane or shrinkage of the cell, as well as an interaction with membrane proteins [17].…”

“…Ahmed et al reported that C . citrinus chloroform fraction exhibited membrane stabilizing anti-inflammatory potentials in hypotonic solution-induced hemolysis, results were comparable to acetylsalicylic acid, the standard drug [31].…”

Biological Investigations of the Whole Plant of Argemone mexicana (L.)

“…Phenolic content in the plant extractives is a sign of antioxidant potentials, which can be measured by using Folin-Ciocalteu reagent. 11 By using gallic acid as standard, the highest phenolic content was found in MEAM (305.61 mg of GAE/g of extractives). The order of phenolic contents in the extractives was MEAM > CTCAM > CAM > PEAM (Figure 2a).…”