Effect of extraction temperature on the phytochemicals, minerals and antioxidant properties of Telfairia occidentalis leaf extracts

Telfairia occidentalis leaves are known to possess many therapeutic potentials such as antidiabetic, anti-inflammatory, anticholesterolemic etc. To maximize their use in phytomedicine, the conditions used in preparation methods are crucial. Therefore, this study estimated the effect of extraction temperature on the phytochemicals, minerals, and antioxidant properties of T. occidentalis leaves. The powdered samples of T. occidentalis leaves were extracted using water at 1000C and 250C, respectively, followed by the phytochemical, mineral and antioxidant analyses of the plant extracts. The concentration of most constituent metabolites in the cold extract of T. occidentalis leaves was significantly (p < 0.05) higher than that of the hot extract. The highest mineral concentrations in hot and cold extracts of T. occidentalis leaves were sodium (2.22 mg/L) and potassium (2.77 mg/L), respectively. In the antioxidant study, the EC50  values (131.20 ± 1.70 μg/ml and 105.08 ± 0.54 μg/ml) of the hot extract of T. occidentalis leaves were significantly (p < 0.05) lower than those of the cold extract (228.17 ± 23.03 μg/ml and 151.47 ± 14.68 μg/ml). The study reveals that the extracts hold varying biological importance. The cold aqueous extract can be an excellent nutritional adjuvant for the supply of essential nutrients, whereas the hot aqueous extract can act as an important agent in ameliorating pathological conditions thrive on excessive free radical generation. Therefore, the different extraction procedures can be utilized based on the desired biological outcome.