Assessment of the Phytochemicals, Antioxidant, and GC-MS Evaluation of Methanolic Leaf Extract of an Antidiabetic Plant, Cola millenii

Abstract

The phytochemicals present in Cola millenii have been described in different reports as an effective anti-diabetic plant. This study evaluated the phytochemical contents and antioxidant potential of Cola millenii leaves. Using methanol, the phytochemicals in the leaves were extracted, and the methanol was distilled from the Cola millenii extract using a rotary evaporator. The total phenolic and flavonoid contents were determined spectrophotometrically. Using the 2,2-diphenylpicrylhydrazyl (DPPH) radical scavenging assay and Ferric Reducing Antioxidant Power (FRAP) assay, the in-vitro antioxidant potential of the extract was determined, respectively. The extract was also analyzed using Gas Chromatography-Mass Spectrometry (GC-MS) to determine the presence of volatile compounds. The results from this study showed a high total phenolic content (32.71.97mg/100g GAE), and the total flavonoid content in the extract had a concentration of (0.970.11 mg QE/g). The in-vitro antioxidant activity determined by DPPH showed an IC₅₀ of 213.80 μg/mL compared to the standard Vitamin C, 1.87 μg/mL. The evaluation done by Ferric Reducing Antioxidant Power (FRAP) assay showed an increase in % of reducing power with an increase in extract concentration. The Gas Chromatography-Mass Spectrometry (GC-MS) analysis showed that the leaf extract possesses 25 different compounds. However, five of the compounds, namely n-Hexadecanoic acid, 6-Octadecenoic acid, Octadecanoic acid, Squalene, and Vitamin E, had higher concentrations of 32.53%, 32.85%, 3.87%, 7.71%, and 7.86%, respectively. The antioxidant activity property and presence of the identified phytochemicals in Cola milenii leaf extract from this study may be responsible for its anti-diabetic activity in herbal medicine and other pharmacological benefits.