Therapeutic potential of Polyalthia cerasoides stem bark extracts against oxidative stress and nociception

BACKGROUND

Polyalthia cerasoides is a medicinal plant known for its ethnopharmacological importance. Despite this, investigation related to its therapeutic benefit is still unexplored.

AIM

To evaluate the stem bark extracts of Polyalthia cerasoides for pharmacological activities relating to inflammation, nociception and oxidative stress using in vivo and in vitro models.

MATERIALS AND METHODS

Pet ether, ethyl acetate and chloroform fractions of the stem bark were evaluated for anti-inflammatory activity by carrageenan-induced hind paw edema in rats. Anti-nociceptive activity in mice was assessed using thermally and chemically induced analgesic models. The free radical quenching potential of the extracts was initially analyzed using the in vitro DPPH photometric assay, Hydroxyl radical scavenging and Lipid Peroxidation assays. Then modulatory effect of the extracts on in vivo antioxidant system was evaluated by carbon tetrachloride induced hepatotoxicity and subsequent measurements of antioxidant enzymes such as Superoxide dismutase, Catalase and Peroxidase from the liver homogenate.

RESULTS

Among the tested fractions, ethyl acetate extract had substantially inhibited the inflammation by 68.5% that was induced by subcutaneous carrageenan injection whereas pet ether and chloroform extract showed only minimal inhibitory effect. Investigation of the anti-nociceptive activity revealed that the ethyl acetate fractions had significantly repressed the algesia in both the analgesic experimental models. In vitro and in vivo individual antioxidant assays demonstrated that the ethyl acetate fraction has strong free radical quenching potential which also restores the endogenous hepatic enzymes.

CONCLUSION

The ethyl acetate fraction enriched with flavinoids and steroids from Polyalthia cerasoides stem bark has potent bioactivity to combat inflammation, ROS and pain. This needs further characterization for potential therapeutic applications.

Effect of cross-linkers in fabrication of carrageenan-alginate matrices for tissue engineering application

The three-dimensional (3D) scaffold serves as a structural substrate and as a niche for cell proliferation to ensure tissue regeneration. Ideal scaffolds should have porous structures with high pore interconnectivity to allow cell adherence, differentiation, and proliferation while ensuring suitable mechanical strength and biodegradability without inflicting any immune response. Cross-linker is one of the major factors that affect the mechanical and biological properties of scaffolds. In this study, different chemical cross-linker effects on scaffold architecture were examined. Porous 3D scaffolds based on carrageenan and alginate (CA) were successfully fabricated by a freeze-drying technique and using various cross-linkers like glutaraldehyde (GA), genipin, and ethyl (dimethylamino propyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS). The chemical cross-linker effects on the CA scaffold were characterized by scanning electron microscopy, differential scanning calorimetry, and thermogravimetry. A human fibroblast cell line (L929) was seeded into the fabricated scaffold, and cell proliferation was assessed by MTT and live/dead assay. Overall results suggested the potential cross-linkers for ideal CA biomaterial could be EDC/NHS among other agents tested as the scaffold CAEN was found to be porous, interconnected, and physically and mechanically stable. When compared to matrices with other cross-linkers, higher cell attachment, better cellular response, and higher metabolic activity could be observed in the scaffold synthesized using EDC/NHS as cross-linker.