In Vitro Investigation of the Antioxidant and Cytotoxic Potential of Tabernaemontana ventricosa Hochst. ex A. DC. Leaf, Stem, and Latex Extracts

Abstract

Tabernaemontana ventricosa (Apocynaceae) a latex-bearing plant is used in traditional medicine for its therapeutic benefits in reducing fever and hypertension and wound healing. Due to limited information on the plant’s pharmacological activities, this study aimed to investigate the antioxidant potential of the leaf, stem, and latex extracts of T. ventricosa, using the Folin-Ciocalteu (total phenolics), aluminum chloride colorimetric (total flavonoids), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays. The cytotoxic activity was evaluated in the human HEK293 (embryonic kidney), HeLa (cervical carcinoma), and MCF-7 (breast adenocarcinoma) cell lines using the MTT assay. The latex extracts possessed the highest total phenolic content (115.36 ± 2.89 mg GAE/g), followed by the stem hexane extracts (21.33 ± 0.42 mg GAE/g), the chloroform leaf (7.89 ± 0.87 mg GAE/g), and the chloroform stem (4.69 ± 0.21 mg GAE/g) extracts. The flavonoid content was substantially high ranging from 946.92 ± 6.29 mg QE/g in the stem hexane, 768.96 ± 5.43 mg QE/g in the latex, 693.24 ± 4.12 mg QE/g in the stem chloroform, and 662.20 ± 1.00 mg QE/g in the leaf hexane extracts. The DPPH assays showed the highest percentage of inhibition at 240 µg/mL, for the stem hexane (70.10%), stem methanol (65.24%), and stem chloroform (60.26%) extracts, with their respective IC50 values of 19.26 µg/mL (stem hexane), 6.19 µg/mL (stem methanol), and 22.56 µg/mL (stem chloroform). The FRAP assays displayed minimal inhibition ranging from 4.73% to 14.40%, except for the latex extracts which displayed moderate inhibition at 15 µg/mL (21.82%) and substantial inhibition at 240 µg/mL (98.48%). The HeLa and MCF-7 cell lines were the most sensitive to the extracts, with the hexane, chloroform, and methanol leaf and stem, and latex extracts significantly affecting the percentage cell survival. Overall, the various parts of T. ventricosa exhibited strong antioxidant activity correlating to its cytotoxicity. Further studies should focus on the isolation of specific antioxidant compounds that could be investigated for their anticancer potential.

Phytochemical Composition of Combretum molle (R. Br. ex G. Don.) Engl. & Diels Leaf and Stem Extracts

“…With regards to the rest of the phytoconstituents detected in the present study, another investigation on the ethanolic extracts of leaves of C. molle produced similar findings with the detection of tannins, flavonoids, saponins and phenols; however, that study also reported the absence of alkaloids [55]. The differences in phytochemical composition within the species may be attributed to variations in locality, climate, season and extraction methods [56,57]. Several reports on the phytochemical composition of other Combretum species including C. erythrophyllum, C. leprosum, Combretum album and Combretum glutinosum revealed the presence of similar phytoconstituents to the present investigation [49,50,58,59].…”

Extracts of Eucalyptus alba Promote Diabetic Wound Healing by Inhibiting α-Glucosidase and Stimulating Cell Proliferation

“…Free radical scavenging activity of the E. alba was estimated using DPPH assay with some modifications from Ref. [19].…”

Antibiofilm Activity of Invasive Plants against Candida albicans: Focus on Baccharis halimifolia Essential Oil and Its Compounds

“…58 %). Naidoo and collaborators observed similar results when studying Tabernaemontana ventricosa stems and leaves’ extracts [16] . This difference may be explained by the fact that leaves are photosynthetic organs and they produce high concentrations of metabolites [17] .…”

“…Naidoo and collaborators observed similar results when studying Tabernaemontana ventricosa stems and leaves' extracts. [16] This difference may be explained by the fact that leaves are photosynthetic organs and they produce high concentrations of metabolites. [17] For the five studied plants, the extractions with the most polar solvents: EtOH (for B. halimifolia leaves) or a mixture EtOH-H 2 O (for the other tested samples) showed the best yields (1.77-41.4 %).…”