IJCBS, 3(2013):29-33 Ahmed et al., 2013 29 Chemical composition and biochemical activity of Aloe vera (Aloe barbadensis Miller) leaves Muaz Ahmed a , Fatma Hussain b * a,b Department of Chemistry and Biochemistry, Faculty of Sciences, University of Agriculture, Faisalabad-38040, Pakistan. Abstract Aloe.vera has a long history as a medicinal plant with diverse therapeutic applications. This study was conducted to determine chemical composition and biochemical activity of A. vera leaves. Proximate composition (moisture, ash, crude protein, crude lipid and crude fibre), ascorbic acid, superoxide dismutase, catalase, peroxidase, amylase, reducing sugars and total soluble sugars were determined. Moisture content of 97.42 ± 0.13% was observed, while average percent ash, fiber, protein and fat contents were 16.88 ± 0.04%, 73.35 ± 0.30%, 6.86 ± 0.06% and 2.91 ± 0.09% respectively along with traces of ascorbic acid (0.004 ± 0.05%). Variable levels (IU/mg) of superoxide dismutase (802.14 ± 55.6-2830.19 ± 37.09), peroxidase (1.46 ± 0.06-3.72 ± 0.19), catalase (1.56 ± 0.14-2.8 ± 0.19) and amylase (0.97 ± 0.82-24.02 ± 1.5) were observed in the extracts. Total soluble and reducing sugars accounted for 120.68 ± 7.24-363.03 ± 9.25 mg/mL and 97.23 ± 0.05-123.33 ± 0.74 mg/mL. Overall, this investigation has provided a succinct resume of information regarding the chemical composition and biochemical activity of A. vera leaves. It would be worthwhile embarking on an intensive scientific experimentation and investigation on this valuable medicinal plant and to promote its large-scale utilization. Key words: Aloe vera, proximate composition, ascorbic acid, superoxide dismutase, catalase, peroxidase Full length article Received: 28-09-2012 Revised: 25-12-2012 Accepted: 26-12-2012 Available online: 31-01-2013 *Corresponding Author, e-mail: fatmauaf@yahoo.com Tel: +92-41-9200161-170, Ext. 3313 1. Introduction There has been a revival of interest in herbal medicines. Plants are the basic source of knowledge of modern medicine. The burgeoning worldwide interest in medicinal plants reflects recognition of the validity of many traditional claims regarding the value of natural products in health care. The relatively lower incidence of adverse reactions to plant preparations compared to modern conventional pharmaceuticals, coupled with their reduced cost, is encouraging both the consumers and national health care institutions to consider plant medicines as alternatives to synthetic drugs [1, 2]. There are approximately 500 species of the genus Aloe (Lilliaceae). Aloe vera is the most widely used specie both commercially and for their therapeutic properties [3-5]. Enzymes carboxypeptidase and bradykinase known to relief pain, an anti-inflammatory compound aloeresin I and dihydrocoumarins with immune- modulatory and antioxidative properties are found in A. vera [6, 7]. Some polysaccharides in A. vera have therapeutic properties such as immune-stimulation, anti-inflammatory, wound healing, promotion of radiation damage repair, anti- bacterial, anti-viral, anti-fungal and anti-oxidant [8-12]. Several pre-clinical and clinical trials showed a blood glucose and lipid lowering effect for A. vera gel preparations [13-16]. The hepatoprotective action of A. vera was attributed to antioxidant activity [17]. Aloe gels have the ability to cure gastric ulcers or protect ulcer formation. These anti-ulcer activities of A. vera are due to several possible mechanisms including its anti-inflammatory properties, healing effects, mucus stimulatory effects and regulation of gastric secretions [18]. A. vera gel has also shown chemo-preventative and anti-genotoxic effects on benzo[α]pyrene- DNA adducts [19-23]. The present study was conducted to determine chemical composition and biochemical activity of Aloe vera leaves. 2. Materials and methods 2.1. Collection and Preparation of Test Samples Aloe vera leaves were obtained from the Botanical garden of the Department of Botany, University of Agriculture, Faisalabad, Pakistan. Samples were identified and authenticated at the Department of Botany, University of Agriculture, Faisalabad, Pakistan. Sample collection was conducted during the months of March and April 2011.The leaves were thoroughly washed with tap water and allowed to dry in an air-circulating oven at 50 o C followed by 105 o C until there were no further changes in weight at these two International Journal of Chemical and Biochemical Sciences Journal Home page: www.iscientific.org/Journal.html © International Scientific Organization