Title : Phytochemical analysis of Cissus verticillata berries
Abstract:
Cissus verticillata L. (syn C. sicyoides) otherwise known as Princess vine and curtain ivy belongs to the Vitaceae family. The leaves of this vine have been utilized in traditional medicine for the treatment of diabetes mellitus. There is however limited available information on the berries of this vine. This study was undertaken to evaluate the functional and nutritional properties of C. verticillata berries. Berry extracts were screened for the presence of bioactive components inclusive of saponins, tannins, and reducing sugars. The free radical scavenging activity and total phenolic content of the berries were determined. Extracts were also analyzed utilizing Fourier transform infrared and nuclear magnetic resonance spectroscopy. Phenylalanine ammonia lyase, a key enzyme in the phenylpropanoid pathway was characterized and purified utilizing aqueous two phase partitioning. Preliminary cytotoxicity assay was performed using the Brine shrimp assay. C. verticillata berries are low acid (pH 6) and have a titrable acidity of 0.165 g of tartaric acid per 100mL of juice. The berries exhibit a refractive index of 17 °Brix and are expected to be sweet in taste. Extracts tested positive for the presence of saponins, and reducing sugars. C. verticillata berries possess high free radical scavenging activity (84.4 ± 4.4%), with an IC50 value of 0.99 mg/mL which is intermediate to that of raspberries and blackberries, and contain a phenolic content of 3.2 ± 0.4 mg gallic acid/g dry weight. Phenylalanine ammonia lyase (PAL) activity of the berries was 0.10 ± 0.01U/mg protein. PAL exhibits Michaelis Menten kinetics with the substrate phenylalanine (Km, 1.21 ± 0.28 mM) and has a Vmax of 6.24 ± 0.28 M/min. The enzyme has a temperature optimum of 250C and a pH optimum of 7.5. Based on the Brine shrimp lethality assay, the berries appear to be non toxic with a LD50 value >1000μg/ml. Proximate analysis revealed that the berries contained 85 % moisture, 10 % ash and 5 % lipids. The major fatty acids identified include palmitic acid (43.6 ± 1.8 %), oleic acid (13.8 ± 1.7 %) and linoleic acid (13.9 ± 2.0 %). Ascorbic acid concentration was 2.8 ± 0.1 mg/mL and protein (0.17 ± 0.02 mg/ml). C. verticillata berries possess high levels of free radical scavenging activity and may be a novel source of antioxidants. The berries are also a source of the PAL enzyme which has biotechnology and medicinal applications. Future work will involve identification of the active components in C. verticillata berries.
