104 Journal of Pharmacy and Nutrition Sciences, 2012, 2, 104-114 ISSN: 2223-3806 / E-ISSN: 1927-5951/12 © 2012 Lifescience Global Phytochemical Screening and In-Vitro Evaluation of Antioxidant Activities of Various Extracts of Leaves and Stems of Kalanchoe crenata Manisha Bhatti 1 , Anjoo Kamboj* ,1 and Ajay Kumar Saluja 2 1 Chandigarh College of Pharmacy, Landran, Mohali, Punjab, India 2 A.R. College of Pharmacy, VV Nagar, Gujarat, India Abstract: Many diseases are associated with oxidative stress caused by free radicals. Current research is directed towards finding naturally occurring antioxidants of plant origin. Kalanchoe crenata Andr. (Crassulaceae), commonly known as "never die" or "Dog's liver," has been traditionally used for the treatment of ailments, such as, earache, smallpox, headache, inflammation, pain, asthma, palpitations, convulsion, and general debility. The aim of present research deals with phytochemical screening and in-vitro evaluation of antioxidant activities of the leaves & stems of K.crenata. Method: Successive extracts of leaves & stems was subjected for phytochemical screening. The preliminary screening reports the presence of saponins, phytosterols, flavanoids, phenols and alkaloids in the extracts. Various extracts of K.crenata leaves & stems was studied in-vitro for total antioxidant activity, for scavenging of nitric oxide, hydrogen peroxide, the antioxidant capacity by phosphomolybdenum, reducing power determination and determination of phenolic and flavonoid content in the extracts. 1,1-Diphenyl-2-picrylhydryzyl (DPPH) scavenging activity or the hydrogen donating capacity was quantified in presence of stable DPPH radical on the basis of Blois method. Nitric Oxide (NO) radical scavenging method was performed in the presence of nitric oxide generated from sodium nitroprusside using ascorbic acid as standard in both methods. The phenolic content was determined by using Folin-Ciocalteu reagent and flavonoid content was determined by aluminum chloride. Result: The radical scavenging activity was found to dose dependent. Thus extract has been established as an antioxidant. The reducing capacity serves as significant indicator of antioxidant activity. The reducing power was found to increase with the increasing concentration of extract. The 100mg plant powder yielded 0.34, 0.49, 0.72, 0.98%w/wand 0.15, 0.23, 0.39, 0.56%w/w phenolic content in the benzene, chloroform, acetone, ethanol extracts of leaves and stems respectively using gallic acid as standard. Plant contains about 0.19, 0.29, 0.48, 0.64%w/w and 0.11, 0.17, 0.32, 0.47 %w/w of flavonoid content in the benzene, chloroform, acetone, ethanol extracts of leaves and stems respectively using quercetin as standard. Conclusion: The present study provides evidence that different extracts of K.crenata leaves and stems is potential source of antioxidant activity. The extracts were found to contain phenolic compounds which could be responsible for the antioxidant properties. So K. crenata traditional use is justified in the present research work. Keywords: Kalanchoe crenata, DPPH scavenging activity, NO scavenging activity, phytochemical screening. INTRODUCTION Oxygen radicals, the products of some biochemical and physiological reactions, initiate cell signaling pathways, damage cellular lipids, proteins, and nucleic acids. Reactive oxygen species are pivotal for the onset of various conditions such as hypertension, atherosclerosis, cancer, and Alzheimer’s disease. During normal aerobic metabolism, activated oxygen popularly known as superoxides are formed in a stepwise reduction of oxygen to water. When these activated oxygen molecules diffuse into cells, they become reactive to damage these cells which continue till antioxidants are introduced to scavenge all the free radicals available. Williams reported that the body handles this cell damage process by producing a *Address corresponding to this author at the Chandigarh College of Pharmacy, Landran, Mohali, Punjab, India; E-mail: anjookamboj@gmail.com number of antioxidant enzymes which can be found both in the human body and in plants. Thus, antioxidants protect cells against the damaging effects of reactive oxygen species, such as singlet oxygen, superoxide, peroxyl radicals, hydroxyl radicals and peroxynitrite [7,22]. The external applications of Kalanchoe crenata are also very effective in treatment of skin diseases. The juice obtained by squeezing the leaves that have been passed over fire slightly, is most commonly used for the treatment of headache, general debility, dysentery, smallpox and convulsion. One or two drops of the leaf juice are dropped into the ear for earache. A poultice of the leaves is applied over wounds and sores. The leaves can be boiled in water and the extract is given as a sedative for asthma and palpitation. Also the leave juice mixed with salt and honey is a remedy for chronic cough. The extract of dried leaves is applied to septic wound [17].