Effect of the Solvent Type on Phenolic and Flavonoid Substances and Antioxidant Properties of Leaves of 15 Medicinal Plants in Roodān Region of Southern Iran

Introduction: Phenolic compounds and flavonoids have several biological properties, such as antioxidant properties, trapping free radicals, and anti-inflammatory properties. Different solvents have different capabilities in extracting phenolic materials and antioxidant properties. This study aimed to investigate and compare the different plants in the south of Iran regarding phenolic content and antioxidant properties; moreover, it was attempted to evaluate the effect of the solvent type on the mentioned issues. Material & Methods: A total of 15 genotypes of medicinal plants (Ficus religiosa L, Terminalia catappa, Ficus carica, Cordia myxa, Black mulberry, Grewia asiatica, Psidium guajava, Mangifera 1, Mangifera 2, Eucalypteae, Syzygium cumini, Ziziphus 1, Citrullus colocynthis, Ziziphus 2, Punica granatum) were obtained from Roodān region (Hormozgan Province in Iran) and were also evaluated based on two types of methanolic and acetone extracts in terms of antioxidant properties, as well as phenolic and flavonoid substances in a factorial design in a completely randomized format with three replications. Data were analyzed using Statistic software (version 10), and the means were compared using the least significant difference at a 1% probability level. Findings: The results of the analysis of variance showed that the mutual effect of the plant and antioxidant properties (based on the DPPH) for acetone and methanolic extracts was significant at a 1% probability level. In the use of acetone solvent, the highest amount of phenol was in eucalyptus (7.43 mg/gFW), followed by Syzygium cumini (Java Plum) (6.52 mg/gFW). Furthermore, the highest amount of flavonoids was in mango 1 (23.21 mg/gFW), followed by Terminalia catappa (Indian-almond) (18.75 mg/gFW) and eucalyptus (15.36 mg/gFW). The most antioxidant properties were in Psidium guajava (Guava) (85.24%), followed by Ziziphus mauritiana 1 (Jujube 1) (82.68%) and Terminalia catappa (Indian-almond) (82.31%). In the use of methanol solvent, the highest amount of phenol was in Syzygium cumini (Java Plum) (7.82 mg/gFW), followed by eucalyptus (7.34 mg/gFW). In addition, the highest amount of flavonoids was in Terminalia catappa (Indian-almond) (mangroves) and mango 1 (24.46 mg/gFW and 25.06 mg/gFW, respectively) and then Grewia asiatica (Phalsa) (16.07 mg/gFW) and Ziziphus mauritiana 1(Jujube 1) (13.51 mg/gFW). The highest antioxidant properties were obtained from Terminalia catappa (Indian-almond) (82.07%), pomegranate (78.97%), and Ziziphus mauritiana 1(Jujube 1) (78.16%). Discussion & Conclusion: The most critical solvent for the extraction of phenol and Flavonoid substances with high oxidative properties is acetone. The most useful plants in terms of the presence of materials and antioxidant properties were Terminalia catappa (Indian-almond) and Ziziphus mauritiana (Jujube).