RESEARCH ARTICLE Invulnerability of bromelain against oxidative degeneration and cholinergic deficits imposed by dichlorvos in mice brains Bharti Chaudhary, Sonam Agarwal, Renu Bist (✉) Department of Bioscience and Biotechnology, Banasthali University, Banasthali, Rajasthan, India © Higher Education Press and Springer-Verlag GmbH Germany, part of Springer Nature 2018 BACKGROUND: The present study elucidates the protective potential of bromelain against dichlorvos intoxication in mice brains. Dichlorvos induces the oxidative stress by disproportionating the balance between free radicals generation and their scavenging in neurons which leads to neuronal degeneration. METHODS: In this study, mice were divided into four groups- group I (control), group II (dichlorvos treated), group III (bromelain treated) and group IV (exposed to both bromelain and dichlorvos both). RESULTS: Dichlorvos treatment increased the levels of thiobarbituric acid reactive substances (TBARS) and protein carbonyl content (PCC) which indicate the increased oxidative stress. Meanwhile, brain endogenous antioxidants and cholinesterases level was decreased after dichlorvos exposure. Levels of TBARS and PCC decreased whereas cholinesterases level was recorded to be elevated after bromelain exposure. CONCLUSION: Bromelain offered neuroprotection by decreasing oxidative stress and augmenting cholinesterases in mice brains. This study highlights the invulnerability of bromelain against oxidative and cholinergic deficits in mice brains. Keywords oxidative stress, dichlorvos, bromelain, neuroprotection, neurotransmitter Introduction Dichlorvos is an organophosphate pesticide (OP) which is used in agriculture to protect plants, fruits and vegetables from insects (Chaudhary et al., 2014). It is highly toxic via inhalation, dermal absorption and ingestion (Gallo and Lawryk, 1991). Exposure to dichlorvos adversely affects almost all organs in the body but majorly affect is on the nervous system (Raheja and Gill, 2002; Cankayali et al., 2005). It is known to be a classical acetylcholinesterase (AChE) inhibitor (Assis et al., 2007). Dichlorvos can lead to generation of free radicals, inhibition of enzymatic activities and changes in the neurotransmitters (NTs) levels like dopamine, AChE and norepinephrine in the brain (Choudhary et al., 2002; Binukumar et al., 2010). Disproportion between the radical-generating and radical scavenging systems may cause an increase in free radical production or decrease in the antioxidant defense (Jones, 2006; Kangralkar et al., 2010). Treatment with dichlorvos increases the levels of malondial- dehyde (MDA) and reactive oxygen species (ROS) and diminishes the activities of antioxidant enzymes (Eroglu et al., 2013). Dichlorvos is reported to cause the cholinergic toxicosis (Assis et al., 2007) and central apnea (Gaspari and Paydarfar, 2011) in the nervous system. It inhibits the AChE (Schulz et al., 1995; Hinz et al., 1996; Abdelsalam, 1999; Assis et al., 2012; Atanasov et al., 2013; Silva et al., 2013) and glutathione reductase (GR) activities in the brain which are biomarkers of neurotoxicity and oxidative stress (Pena- Llopis et al., 2003). Oxidative stress, NTs levels and antioxidant status are essential indices of dichlorvos induced toxicity in the brain which can be attenuated by natural antioxidants supplements. In the present study bromelain was attempted to ameliorate the toxic effects of dichlorvos in mice brains. Bromelain is the proteolytic enzyme which is found in the pineapple plant (Ananas comosus). Bromelain is reported to have anti-inflammatory (Lotz-Winter, 1990; Maurer, 2001; Hale et al., 2005), anticarcinogenic (Maurer, 2001), immu- nomodulatory (Eckert et al., 1999; Hale et al., 2002; Hale, 2004), antidiarrheal, (Chandler et al. 1998), cardiovascular and circulatory improvement (Bhattacharyya, 2008) effects. It Received June 12, 2017; accepted December 26, 2017 Correspondence: Renu Bist E-mail: renu_bisht22@yahoo.co.in Front. Biol. https://doi.org/10.1007/s11515-018-1479-1