Aqueous Curry leaves extract protects against lead induced oxidative stress in rat spleen: a new insight

Background: Lead is a toxic heavy metal and a persistent environment pollutant. Exposure to lead induces oxidative stress and causes oxidative stress mediated damages in various organs including spleen in a living system. Murraya koenigii is a popular Indian spice herb with established antioxidant properties. We have earlier checked the potential of the Murraya koenigii leaves extract against lead induced oxidative stress in organs like heart, liver and kidneys. Aims and objectives: Aim of the study is to find therapeutic potentials of aqueous Curry Leaf (Murraya koenigii) Extract (MUR) against lead induced oxidative damage in spleen tissue using rat as an animal model. The objectives are to study the alterations of various stress parameters in lead induced toxicity in spleen and amelioration of the same with MUR. Methods: Rats were intra-peritoneally injected with lead acetate (15mg/kg body weight [bw]). Another group was pre-treated with MUR (50 mg / kg, fed orally).The positive control group was fed MUR (50 mg / kg bw), and the control animals received treatment with vehicle i.p. for 7 consecutive days. The alterations in the activity of the different bio-markers of organ damage, biomarkers of oxidative stress, activities of the antioxidant and some of the mitochondrial enzymes were studied. Histo-morphology was studied through routine H-E staining and concentration of lead in spleen tissue was estimated using atomic absorbtion spectrophotometry (AAS). Detailed changes in splenic cyto-architecture were studied using scanning electron microscopy (SEM). Results: Lead caused alterations in all the parameters studied. All these changes were mitigated when the rats were pre-treated with MUR. Also, the concentration of lead in tissues was found to be significantly lower in animals treated with MUR along with lead. Histo-morphological changes induced by lead exposure in spleen were significantly ameliorated with pre-treatment of the animals with MUR. Conclusions: The results indicate that the MUR ameliorates lead-induced oxidative stress mediated damage in spleen in experimental rats. The antioxidant and free radical scavenging mechanisms may be responsible for such protective effects. MUR may have future therapeutic relevance in the prevention of lead-induced toxicity and damage in spleen in humans exposed occupationally or environmentally to lead and may be used for development of new drug formulation of herbal origin with less cytotoxic effects.