ANTIOXIDANT ACTIVITY OF METHANOL LEAF EXTRACT OF Chanca piedra (Phyllanthus niruri Linn.) AGAINST CCL4-INDUCED OXIDATIVE STRESS IN WISTAR STRAIN RATS AND IN-SILICO DOCKING ANALYSIS

Ali Abdullahi Damasak¹*, Maryam Ado Mahmud³, Bawagana Kyari¹, Mohammed Yakubu² and Yagana Shettima Abba²

ABSTRACT

Oxidative stress is referred to as the excessive production of reactive oxygen species (ROS) relative to antioxidant defense that initiates and advances liver injury. This study was carried out to determine the antioxidant activity of methanol leaf extract of Chanca piedra (Phyllanthus niruri Linn.)  in CCl₄-induced oxidative stress in Wistar strain rats. The sample was obtained from Maiduguri, Borno State, Nigeria. The active components were identified using Gas Chromatography-Mass Spectrometry (GC-MS) and docked with Autodock 4.0 program. The catalase activity was assessed using standard method. Administration of the plant leaf extract at different doses of 100 mg, 200 mg and 400 mg/kg body weight significantly increased (P˂0.05) the activity of catalase with values of 0.033±0.01, 0.038±0.03 and 0.040±0.02 µmol/min, respectively, compared to the negative control group 0.020±0.00 µmol/min. The results of the docking studies of the identified phytomolecules with catalase enzyme (2CAG) revealed that these compounds possessed distinct affinities with the catalase enzyme, ranging from -9.88 kcal/mol (6,10,14-trimethyl-pentadecan-2-ol (CID_530418) to -5.32 kcal/mol (1H-Indole, 3,3′-[1-(4-pyridinyl)-1,2-ethanediyl]bis[2-ethyl- (CID_616782). The results however, showed that 6,10,14-trimethyl-pentadecan-2-ol had best binding affinity for the enzyme (-9.88 kcal/mol) to act as antioxidant and was observed to interact with His362 (distance = 2.89Å) and Asp335 (distance = 2.60Å). Moreover, the in silico and in vivo antioxidant activity demonstrated by the extract of Phyllanthus niruri Linn. (Chanca piedra) might be attributed to bioactive compounds such as 6,10,14-trimethyl-pentadecan-2-ol which displayed potential hydrogen bond interactions with catalase enzyme (2CAG) in silico. Finally, the phytocompounds associated with Chanca piedra (Phyllanthus niruri Linn.) plants might be regarded as valuable source of antioxidants, given their potentials for medicinal use and lack of side effects.

Keywords: Chanca piedra, oxidative stress, catalase, antioxidant activity.