Fissistigma genus – a review on phytochemistry and pharmacological activities

Three new indole alkaloid derivatives from Fissistigma oldhamii Levl. and their anti-inflammatory effects

Three new indole alkaloid derivatives, fissindoalkas A-C (1-3) together with one known biogenetically related polysubstituted indole alkaloid (4) were isolated from the roots of Fissistigma oldhamii (Hemsl.) Merr. The structures of compounds 1-4 were elucidated using comprehensive spectroscopic methods. The inhibitory activities of compounds 1-4 against nitric oxide (NO) production induced by lipopolysaccharide (LPS) were evaluated in vitro using mouse macrophage RAW264.7 cells. Compounds 2 and 3 showed potent inhibitory activities on NO production with IC50 values of 2.52 ± 0.18 and 2.33 ± 0.16 μM. These results indicate that the discovery of indole alkaloid derivatives, from the roots of F. oldhamii, which show significant anti-inflammatory properties, could be of great importance to the research and for the development of novel natural anti-inflammatory agents.

Mosloflavone from Fissistigma petelotii ameliorates oncogenic multidrug resistance by STAT3 signaling modulation and P-glycoprotein blockade

BACKGROUND

Oncogenic multidrug resistance (MDR) is a tough question in cancer therapy. However, no effective medications targeting oncogenic MDR are currently available. Studies have demonstrated that mosloflavone exerts anti-inflammatory effects, yet, its potential to ameliorate MDR remains unclear.

PURPOSE

This study aimed to access the capability and elucidate molecular mechanisms of mosloflavone as a MDR resensitizing candidate.

METHODS

We investigated the ability of mosloflavone to reverse oncogenic MDR and investigated its underlying mechanisms through cytotoxicity assay, cell cycle assay, apoptosis assay, and zebrafish xenograft model. The modulatory interplay between mosloflavone and P-gp was investigated through analysis of calcein-AM uptake, substrate efflux, ATPase assays, and molecular docking simulation.

RESULTS

Mosloflavone inhibited P-gp efflux function in an uncompetitive manner without altering ABCB1 gene expression. In addition, it stimulated P-gp ATPase activity by binding to an active site distinct from that of verapamil. Regarding MDR reversal potential, mosloflavone resensitized MDR cancer cells to chemotherapies by arresting cell cycle and triggering apoptosis, possibly by enhancing reactive oxygen species accumulation and reducing phospho-STAT3. Moreover, in the zebrafish xenograft model, mosloflavone significantly potentiated the antitumor effect of paclitaxel.

CONCLUSION

Our findings underscore the potential of mosloflavone as a novel dual modulator of STAT3 and P-gp, indicating it is a promising candidate for overcoming MDR in cancer treatment.

Fissistigma oldhamii (Hemsl.) Merr.: Ethnomedicinal, Phytochemistry, and Pharmacological Aspects

The species Fissistigma oldhamii (Hemsl.) Merr. (Annonaceae) has long been used as a traditional herbal medicine in China to treat diverse human diseases. Decoctions from the roots of the plant (Guā Fù Mù) are used to treat body pain and inflammatory pathologies, such as rheumatic syndromes, sciatica, and osteoarthritis. The phytochemical content of the plant and the associated pharmacological activities have been analyzed. Seventy natural products were identified in the different parts of the plants, namely, the roots, stems, leaves, fruits, and seeds. The compounds comprise many tri- and tetracyclic alkaloids (aporphine-type), anthraquinones, terpenoids, flavonoids, and others. The pharmacological properties of these molecules were analyzed to point out the anti-inflammatory, antioxidant, anticancer, and/or antimicrobial effects, together with the underlying modulated pathways and molecular targets in some cases. The panel of phytoconstituents present in F. oldhamii extracts is large, with the majority of bioactive products identified in the roots and stems. Multiple molecules can contribute to the anti-inflammatory properties of the extracts. Network pharmacology analyses of the phytoconstituents are needed to better delineate the effective components and their targets.

Bioactive Isoquinoline Alkaloids with Diverse Skeletons from Fissistigma polyanthum

Six new isoquinoline alkaloids, including aporphine alkaloids (2, 3, 9, and 10), a benzylisoquinoline alkaloid (13), and a protoberberine alkaloid (17), were isolated from the roots of Fissistigma polyanthum, along with a new furanone (20) and 13 known isoquinoline alkaloids (1, 4-8, 11, 12, 14-16, 18, and 19). The structures of the new compounds were elucidated by the analysis of spectroscopic data. Compounds 1 and 2 are rare oxalyl-fused dehydroaporphine alkaloids. Compound 12 presented the most potent dual-target activities on AChE inhibition and Aβ aggregation inhibition, while compounds 13 and 19 simultaneously exhibited discernible AChE and BChE inhibitions with antioxidant activities. The activity results indicate that F. polyanthum alkaloids have a potential of inhibition and prevention of Alzheimer's disease mainly through both ChEs and β-amyloid pathways in addition to antioxidant activity.

Fissistiganoids A and B: two new flavonoids from the Fissistigma tungfangense

Two new flavanoids fissistiganoids A and B (1 and 2), together with two known pterocarpans derivatives (3 and 4), were isolated from the stems of Fissistigma tungfangense. The structures of these compounds were elucidated using comprehensive spectroscopic methods. The absolute configurations of fissistiganoids A and B (1 and 2) were determined by comparing their ECD spectra with quantum-mechanics ECD calculations. The inhibitory activities of all compounds against three cancer cell lines HeLa, MCF-7 and A549 were evaluated. Compounds 1-4 showed moderate inhibitory effects on HeLa, MCF-7 and A549 cells with IC₅₀ values ranging from 12.5 to 42.3 μM.