Attenuation of inflammatory mediators, oxidative stress and toxic risk evaluation of Aporosa lindleyana Baill bark extract.

Ethnopharmacological Relevance: Traditionally, Aporosa lindleyana Baill. has been used against various ailments viz. jaundice, fever, headache, seminal loss and insanity. The present study aims to evaluate the anti-inflammatory and anti-oxidant activity of the ethanolic extract of Aporosa lindleyana Baill. bark and its fractions.

Method: The anti-inflammatory activity of ethanolic extract of Aporosa lindleyana Baill. bark and its various fractions at doses of 200mg/kg and 300mg/kg b.w. has been carried out by a carrageenan induced hind paw edema method. To establish the probable mechanism of action, TNF-α and NO levels have been estimated by an ELISA method and the effect of active fraction on COX-2 and NF-κB expressions has been evaluated. The effect on the levels of anti-oxidative enzymes (CAT, SOD & GPX) by the ethanolic extract and its fractions has also been investigated. Furthermore, peptic ulcer and hepatotoxic risk evaluation has also been carried out at three times higher dose than that used in inflammatory in vivo model.

Results: Among the extract and its various fractions tested for anti-inflammatory activity, the methanolic fraction at a dose of 300mg/kg showed significant inhibition in paw edema by 73% as compared to Indomethacin which showed 77% inhibition after 5h. The same dose of methanolic fraction also caused significant reduction in TNF-α (59.27%) and NO concentration (57.12%) while Indomethacin showed inhibition of 63.91% and 60.12%. The active methanolic fraction was also found to inhibit the expression of NF-κB and COX-2 induced by carrageenan. Histological studies showed that the ethanolic extract and its fractions did not cause any damage to the stomach as well as to liver. Moreover, the active fractions also decreased lipid peroxidation levels and increased the antioxidant enzyme activities (SOD, CAT, GPX).

Conclusion: The results of present study demonstrated that significant anti-inflammatory activity of methanolic fraction of Aporosa lindleyana may be attributed to the modulation of pro-inflammatory mediators. Same fraction was also found to be effective against oxidative stress as it was found to elevate the levels of anti-oxidative enzymes. It can therefore be concluded that the methanolic fraction could be explored as a disease modifying agent against inflammation and oxidative stress.