Aristolactam derivatives from Fissistigma glaucescens

The Chemistry and Pharmacological Properties of the Constituents of Toussaintia Orientalis - An Endangered Treasure of Biomedical Agents

Toussaintia orientalis Verdc. (Annonaceae) is a medicinal plant species endemic to Tanzania. It is classified under the International Union for Conservation of Nature (IUCN) as an extremely endangered species threatened with extinction. The review covers the phytochemistry of this plant species and the pharmacological properties of the compounds obtained therefrom. The chemistry of this plant species entails natural products with different structures including uncommon cinnamoyl tetraketide derivatives, aristolactam alkaloids, and flavonoids. The review identifies 27 compounds belonging to different subclasses of natural products obtained from this species for the past fourteen years (2010-2024). These compounds are discussed along with other 13 related natural products. T. orientalis derived compounds exhibit varied potential pharmacological applications as antibacterial, anticancer, anti-inflammatory, antiviral, and neuroprotective agents. Some of the reported compounds displayed pharmacological properties corroborating the use of this plant species in traditional medicine. This review provides baseline data as one comprehensive compilation that will ignite interest and guide future research and development of therapeutic agents inspired by the chemodiversity presented by this plant species while at the same time attracting the attention of plant conservationists to initiate efforts to conserve this highly endangered biomedical treasure.

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.

Oral subacute nephrotoxicity of aristololactam I in rats

Aristolactams (ALs) have been recognized as one kind of metabolites of aristolochic acids (AAs), the nephrotoxic components of Aristolochiaceae plants, and are more widely distributed than AAs in herbal medicines. This study evaluated the oral subacute nephrotoxicity of aristolactam I (AL I), a representative compound of ALs. AL I was intragastrically administered to rats at 20 mg·kg^-1·d^-1 for 10 or 20 days, with aristolochic acid I (AA I) used as positive control at the same dose. After 10-day treatment, AL I led to a significant increase in early renal injury-related indices in urine and obvious histopathological lesions in kidneys, including degeneration of tubular epithelial cells, inflammatory cell infiltration and fibrosis. The lesions induced by AL I were significantly aggravated after 20-day exposure. However, AL I induced less histopathological damage in kidneys than AA I in both 10- and 20-day groups. Our results indicated that oral AL I caused nephrotoxicity by inducing oxidative stress, inflammation, and overactivation of the complement system as AA I did. Three detected apoptosis-associated indicators were not affected by AL I but remarkably increased by AA I. In summary, oral AL I induced evident renal damage in rats after only 10 days of treatment, and the damage was aggravated after 20 days. However, AL I was obviously less nephrotoxic than AA I via oral gavage.