Cytotoxic cardiac glycosides from the fruit (pods) of Adenium obesum (Forssk.) Roem. & Schult

Phytochemicals, Trace Element Contents, and Antioxidant Activities of Bark of Taleh (Acacia seyal) and Desert Rose (Adenium obesum)

Acacia seyal and Adenium obesum are used in traditional medicines by indigenous communities of the Asir region of Saudi Arabia. The present study aimed to acquire the phytochemical profiles, quantify the trace element contents and the total phenolic (TPC) and flavonoid (TFC) contents, and evaluate the antioxidant activity of the two species. Phytochemical screening was conducted to detect the presence of the phytochemical constituents. Bark samples were digested with a microwave, and ICP-MS was used for the elemental analysis. The antioxidant capacities in DPPH, H₂O₂, and FRAP assays and the TPC and TFC were determined by spectrophotometry, and their correlation with the IC₅₀ of the DPPH and H₂O₂ and the EC₅₀ of the FRAP capacities were analyzed by Pearson's correlation. Both plant extracts contain a variety of phytochemicals. A. obesum had the highest concentrations of all 11 elements measured. In both plants, manganese was found at the highest concentration, and cadmium exhibited the lowest concentration. The aqueous-methanolic extract of A. seyal showed the highest TPC (309.32 ± 2.15 mg gallic acid equivalent/g), whereas the aqueous-methanolic extract of A. obesum exhibited the highest TFC (32.16 ± 3.16 mg quercetin equivalent/g). Significant differences in the IC₅₀ and EC₅₀ values were observed among the tested plant extracts. The highest antioxidant activity was found in aqueous-methanolic extract of A. obesum. Correlation analysis showed significant correlations between the DPPH and FRAP activities and the TFC. The present findings highlight that these plants are good sources of phenolic compounds and essential elements and support their therapeutic use as antioxidant drugs.

Anticancer potential of cardiac glycosides and steroid-azole hybrids

Steriods are well-known scaffolds that have a widespread occurrence in different compounds characterized by extensive biological properties including anticancer activity. Structural modifications on steroids always generate potential lead compounds with superior bioactivity, and creation of steroid hybrids by combining steroid with other anticancer pharmacophores in one molecule, which can exert the anticancer activity through different mechanisms, is one of the most promising strategies to enhance efficiency, overcome drug resistance and reduce side effects. Sugars and azoles, can act on diverse receptors, proteins and enzymes in cancer cells, are pharmacologically significant scaffolds in the development of novel anticancer agents. Therefore, steroid-sugar hybrids cardiac glycosides and steroid-azole hybrids are privileged scaffolds for the discovery of novel anticancer candidates. This review emphasized on the development, the structure-activity relationship and the mechanism of action of cardiac glycosides and steroid-azole hybrids with potential application for fighting against various cancers including drug-resistant forms to facilitate further rational design of novel drug candidates covering articles published between 2015 and 2020.

Cytogenotoxic effects of Adenium obesum seeds extracts on breast cancer cells

The extracts prepared from various areal parts of the Adenium obesum (Forssk.) Roem. & Schult. (Family: Apocynaceae) including leaves, fruit and seeds ethanolic extracts and seed aqueous extract were evaluated against MCF-7 cells in order to investigate its potential of cytogenotoxicity and induction of apoptosis. The ethanolic seeds extract had comparatively higher cytotoxicity (IC₅₀ ∼ 337 µg/ml). Further, apoptosis and DNA damaging potential of seeds ethanolic extract was analyzed by applying multiple sub-lethal concentrations and durations. Flow cytometry results revealed that maximum percentage of early apoptosis (37%) and late apoptosis (35%) were observed after 12 h exposure in concentrations 200 µg/ml and 300 µg/ml, respectively. Similarly, the higher effect of extract in terms of DNA damage by alkaline comet assay was registered after 12 h treatment at concentrations 200 and 300 µg/mL. The calculated total damage score (TDS) for these concentrations were 614 and 617, respectively. The above findings indicate that A. obesum ethanolic seeds extracts has cytogenotoxic properties that could be further explored for the potential source of chemotherapeutic lead against cancer.