Evaluation of nitric oxide scavenging activity, In Vitro and Ex Vivo, of selected medicinal plants traditionally used in inflammatory diseases

Abstract

Steroidal and non-steroidal antiinflammatory drugs, despite their various side effects, are in great demand worldwide. Alternatively, herbal formulations provide relief to a large percentage of the population suffering from inflammatory diseases. Therefore, such practices need to be rationalized through a mechanistic approach. Thus, four traditional medicinal plants, namely Ventilago madraspatana Gaertn., Rubia cordifolia Linn., Lantana camara Linn. and Morinda citrifolia Linn. were selected for a study on the inhibition of nitric oxide (NO*), a key mediator in the phenomenon of inflammation, signifying the presence of effective antiinflammatory constituents therein. Plant samples were extracted with different solvents for evaluation of their inhibitory activity on NO* produced in vitro from sodium nitroprusside, and in LPS-activated murine peritoneal macrophages, ex vivo. Further, the inhibition of NO* synthesis was correlated with the reduction of iNOS protein expression through Western blot. Notable NO* scavenging activity was exhibited in vitro by some extracts of V. madraspatana, R. cordifolia and L. camara (IC(50) < 0.2 mg/mL). Most of them showed marked inhibition (60%-80%), ex vivo, at a dose of 80 microg/mL without appreciable cytotoxic effect on the cultured macrophages. Immunoblot analysis confirmed that the modulatory effect of the samples had occurred through suppression of iNOS protein.

Phytochemical Profile and Qualification of Biological Activity of an Isolated Fraction of Bellis perennis

“…Once generated, the NO interacts with oxygen and as a result nitrite is generated (Basu et al, 2006).…”

“…Hence, the brain has a specifi c pathway to metabolize free radicals (Gaté et al, 1999;Mandelker, 2008) which infl uences the process of lipid peroxidation (Basu et al, 2006), the content of nitric oxide Ferreira et al, 2009) and the production of TBARS (Serafi ni et al, 2011).…”

“…The method is based on the production of nitrite ions (NO 2 -) from the decomposition of sodium nitroprusside in aqueous solution. The NO interacts with oxygen to produce NO 2 -, which can be measured by Griess reaction (Basu et al, 2006), according to:…”

Phytochemical Constituents and Activities of Morinda citrifolia L.

“…Assays of free-radical-scavenging activity with 1,1-diphenyl-2-picrylhydrazyl (Su et al, 2005;Yang et al, 2007), inhibition of copper-induced low-density lipoprotein oxidation (Kamiya et al, 2004), nitric oxide scavenging activity (Basu & Hazra, 2006) and quenching of H 2 O 2 (Chong et al, 2004;Jeffers et al, 2007) have been performed to evaluate the antioxidative effects of M. citrifolia L. and its products. Polyphenols, reducing glycosides (Calzuola et al, 2006), lignin derivatives (Su et al, 2005) and anthraquinones (Chong et al, 2004) have been suggested as sources of antioxidative activity in M. citrifolia L. However, there is little available information with which to quantitatively evaluate the antioxidative activity of M. citrifolia L ingredients.…”

Rubia cordifolia: a review

“…The inhibition of NO is found to be a key mediator in the phenomenon of inflammation. Thus R. cordifolia was evaluated for inhibitory activity on NO produced in-vitro from sodium nitroprusside, and in LPS-activated murine peritoneal macrophages, ex vivo (Basu and Hazra, 2006). The inhibition of NO synthesis was correlated with the reduction of iNOS protein expression through Western blot.…”