Abstract
Purpose: To determine total phenolic and flavonoid contents, as well as the cytotoxic, immunemodulatory and anti-inflammatory potentials of the whole plant of Astragalus creticus (Fabaceae). Methods: Folin-Ciocalteu (FCR) method was used for determination of total phenolic and flavonoid contents of the methanol and dichloromethane extracts of Astragalus creticus. The cytotoxic potential of the extracts on 3T3 and HeLa cell lines were evaluated using MTT assay. Brine shrimp larvae mortality was determined by lethality bioassay, while inhibitory effects were determined on mouse fibroblast (3T3) and cervical cancer (HeLa) cell lines. In vitro immunomodulatory and in vivo anti-inflammatory effects were assessed using reactive oxygen species (ROS) chemiluminescence and formalin-induced rat paw edema assays, respectively. Results: Dichloromethane extract had higher contents of phenolics (TPC = 324.75 +/- 2.47 mg GAE/g) and flavonoids (TFC = 95.51 +/- 0.82 QE/g) than the methanol extract (TPC = 79.82 +/- 1.53 mg GAE/g, TFC = 56.11 +/- 0.93 QE/g). The dichloromethane extract exhibited high cytotoxic and immunomodulatory potentials, with 76.66 % mortality in brine shrimp lethality bioassay and 83.9 % inhibition (IC50 = 18.0 +/- 1.1 mu g/mL) in chemiluminescence assay. The extract also resulted in 22 and 13 % inhibition of viability of HeLa and 3T3 cells, respectively, while the methanol extract produced 13 % inhibition of both cell lines. The methanol extract produced very significant anti-inflammatory activity, with a maximum of 49 % inhibition of paw edema at a dose of 160 mg/kg (p < 0.01). Conclusion: These results suggest that the dichloromethane and methanol extracts of Astragalus creticus (Fabaceae) exert cytotoxic, immunomodulatory and anti-inflammatory effects. These findings provide scientific validation for the traditional medicinal use of the Astragalus genus.