Stem extract of Albizia richardiana exhibits potent antioxidant, cytotoxic, antimicrobial, anti-inflammatory and thrombolytic effects through in vitro approach

Abstract
Background: Albizia richardianabelongs Fabaceae family which different parts like fruits, flowers, barks, and roots are used medicinally. The study reports the in vitro anti-inflammatory, thrombolytic, cytotoxicity and antimicrobial activity of methanolic extract ofA. richardianastem and its different fractions.Method: The methanolic extract ofA. richardianastem (MEAR) extracted with n-hexane (HXFAR), carbon tetrachloride (CTFAR), chloroform (CFAR), and aqueous (AQFAR) and subjected for DPPH scavenging activity and total phenol content (TPC). The cytotoxic activity evaluated by brine shrimp lethality bioassay, while the disk diffusion method used for the antimicrobial study. The anti-inflammatory and thrombolytic activities of the extracts evaluated by the hypotonic solution induced hemolysis, heat-induced hemolysis and human blood clot lysis, respectively.Results: All the extracts exhibited excellent antioxidant activity in the DPPH scavenging assay and maximum total phenol content observed by HXFAR. Secondly, the extract showed a moderate LC50value in brine shrimp lethality bioassay, where the CTFAR extract exhibited potential antimicrobial activities against sixteen different microorganisms. In anti-inflammatory, all the extract exhibited a significant (P < 0.0001) protection against lysis of human erythrocyte membrane induced by heat and hypotonic solution, as compared to the standard acetyl salicylic acid. An extremely significant (P < 0.0001) clot lysis was found in MEAR (16.66%) while the standard drug streptokinase (70.94%).Conclusion: All the fractions revealed the significant free radical scavenging activity. Moreover, CTFAR showed wide spectrum of antimicrobial activity. Thus, the results of the present study provided scientific evidence for the use ofAlbizia richardianaas traditional medicine.