Cytotoxic, kinetics of inhibition of carbohydrate-hydrolysing enzymes and oxidative stress mitigation by flavonoids roots extract of Dicoma anomala(Sond.)

Objective: To investigate the free radical scavenging, antidiabetic, kinetics and cytotoxic potentials of flavonoids extract of Dicoma anomala root by using standard methods. Methods:Antioxidant activity of the flavonoids was investigated at scavenging free radicals such as 1,1-diphenyl-2-picrylhydrazyl, nitric oxide, hydroxyl radical, reducing capabilities, 2,2-azinobis(3-ethylbenzothiazoline-6) sulfonic acid as well as metal chelating capability at different concentrations(0.125-1.000 mg/mL) while the antidiabetic activity was evaluated via the inhibition and kinetics of carbohydrate digestive enzymes including, alpha glucosidase, sucrase and maltase. Brine shrimp lethality assay was also employed to examine the cytotoxic effects of the extract by using different range of concentrations(0.125-2.000 mg/mL). Results: The study revealed the best antioxidant activity of the extract in 1,1-diphenyl-2-picrylhydrazyl,2,2-azino-bis(3-ethylbenzothiazoline-6) sulfonic acid and nitric oxide having IC_(50) values of(386.90±4.91),(736.00±38.12),(629.30±9.62) μg/mL respectively compared with quercetin(standard) with IC_(50) [(522.20±12.38),(1 021.00±15.61) and(1 075.00±29.35) μg/mL]respective values while it was insignificantly(P>0.05) at par with quercetin for reducing power. Similarly, the extract exhibited a moderate inhibition of alpha glucosidase(43.1%),sucrase(33.4%) and maltase(29.9%) activities which were significantly(P<0.05) better than acarbose(18.4%, 12.7% and 24.9% respectively) although acarbose(46.1%) inhibited the higher activity of alpha amylase than the extract(13.7%). The kinetics of mode of inhibition of alpha amylase, alpha glucosidase, sucrase and maltase by flavonoids extract of Dicoma anomala revealed an uncompetitive, non-competitive, competitive and non-competitive inhibition respectively. The result of the lethality assay showed a potent cytotoxic effect of the flavonoids with LC_(50) value 0.510 mg/mL. Conclusions: The results obtained from this study are suggestive of the antioxidative, antidiabetic and cytotoxic potentials of flavonoids root extract of Dicoma anomala.

Antioxidant and hepatoprotective activities of Dicoma anomala Sond.aqueous root extract against carbon tetrachloride-induced liver damage in Wistar rats

OBJECTIVE:To evaluates the antioxidant and hepatoprotective potentials of Dicoma anomala Sond.(Asteraceae) on body weight,feed and water intake,biochemical parameters and organ histology.METHODS:Various concentrations(1.56-25 μg/m L)were used in the in vitro assays 1,1-diphenyl-2-picryl hydrazyl(DPPH,superoxide anion,hydroxyl radicals,etc.).The effects of treatment with 125,250 and 250 mg/m L Dicoma anomala aqueous roots extract(DARE) was investigated in vivo in the CCl4-induced hepatotoxic rats during the 15 days study.RESULTS:Water extract exhibited the best activity(IC50:15.20 ± 0.03,11.70 ± 0.10,and 0.84 ± 0.05 μg/m L) in vitro in DPPH,hydroxyl and superoxide anion radicals,respectively,when compared with standards.Pre-treatment and treatment with different concentrations of DARE significantly(P < 0.05)attenuated the elevated serum activities of aspartate transaminase,alanine transaminase levels while increasing the activities of superoxide dismutase,catalase and glutathione peroxidase.The histopathological evaluations revealed extensive liver damage characterized by severe vacuolar and cytoplasmic degeneration,hepatic necrosis,and cellular infilteration in pre-treated groups while in the treated groups;such liver damages were not observed most especially at 500 mg/kg dose.CONCLUSION:The results proved the hepatoprotective potential of DARE against CCl4-induced oxidative stress.Moreover,histopathological examinations revealed better therapeutic advantage of DARE than prophylactic use.