Phenolic aporphine-benzylisoquinoline alkaloids from Thalictrum faberi

The Emerging Role of Natural Products in Cancer Treatment

The exploration of natural products as potential agents for cancer treatment has garnered significant attention in recent years. In this comprehensive review, we delve into the diverse array of natural compounds, including alkaloids, carbohydrates, flavonoids, lignans, polyketides, saponins, tannins, and terpenoids, highlighting their emerging roles in cancer therapy. These compounds, derived from various botanical sources, exhibit a wide range of mechanisms of action, targeting critical pathways involved in cancer progression such as cell proliferation, apoptosis, angiogenesis, and metastasis. Through a meticulous examination of preclinical and clinical studies, we provide insights into the therapeutic potential of these natural products across different cancer types. Furthermore, we discuss the advantages and challenges associated with their use in cancer treatment, emphasizing the need for further research to optimize their efficacy, pharmacokinetics, and delivery methods. Overall, this review underscores the importance of natural products in advancing cancer therapeutics and paves the way for future investigations into their clinical applications.

Ethnobotany, botany, phytochemistry and ethnopharmacology of the genus Thalictrum L. (Ranunculaceae): A review

ETHNOPHARMACOLOGICAL RELEVANCE

Thalictrum (Ranunculaceae) is known for its important alkaloids which have been reported to exhibit various pharmacological activities, viz. antitumor, antimicrobial, antitussive, antiamebic, hypotensive effects, HIV antiviral, etc. Throughout the world, the plant has been used as a tonic, purgative, stimulant, aperient and is utilized in various systems of medicine in the treatment of various ailments like snake bite, jaundice, rheumatism, stomachache, wounds, swellings, uterine tumors, paralysis, joints pain, nervous disorders, toothache, diarrhea, piles, fever, peptic ulcer, ophthalmic, headache, diuretic, dyspepsia, convalescence, etc. AIMS OF THIS REVIEW: To bring together all the information regarding the botany, phytochemistry, ethnobotany and ethnopharmacology of Thalictrum and identify the gaps in the existing studies so that full medicinal potential of the genus can be realized.

METHODS

Available literature on botany, geography, traditional uses, phytochemicals, and pharmacology was gathered by referring to library and electronic searches in PubMed, Science Direct, Google Scholar, relevant journals and books.

RESULTS

A variety of phytochemicals like alkaloids, essential oils, glycosides, phenols and terpenoids have been reported from Thalictrum species. Alkaloids are the most dominant diverse group with 178 different types. The crude extracts and isolates exhibit a gamut of pharmacological activities, namely anticancer, antimalarial, antioxidant, antipyretic, anti-tumor, ant-influenza virus, contraceptive and immunosuppressive. Northalrugosidine, an alkaloid from T. alpinum shows in vivo antileishmanial activity. So far, cytotoxic effects of only three Thalictrum species, viz. T. dasycarpum, T. foliolosum and T. simplex have been reported. Thl isolated from T. simplex is found to be 50% toxic (CC50%) at the concentration ranging from 53 to 95 μM.

CONCLUSIONS

Thalictrum has tremendous medicinal values used in many traditional systems of medicine. It has multiple chemical components and still there is scope to explore more. Multiple chemical constituents and its utilization signify its high demand in the drug markets or pharmaceutical companies. In depth phytochemical studies along with in vitro studies with respect to their active principles can help in tapping the full medicinal potential of the genus.

Dimeric benzylisoquinoline alkaloids from Thalictrum delavayi and their biological activities

A phytochemical investigation of the whole plants of T. delavayi led to the isolation of five new dimeric benzylisoquinoline alkaloids, thalidelavines A-E (1-5), together with six known congeners (6-11). The structures and absolute configurations of new compounds were established based on analyses of spectroscopic data, ECD calculations, and single crystal X-ray crystallography. Thalidelavines A-E (1-5) were structurally complex bisbenzylisoquinoline alkaloids with various configurations. These isolated alkaloids were evaluated for their cytotoxic and immunosuppressive effects. Among them, both 9 and 10 displayed significant cytotoxicities against T98G cell lines with an IC₅₀ value of 2.1 μM, compared with the positive CPT-11 (IC₅₀ = 3.0 μM). In addition, 5-7 showed remarkable immunosuppressive effects. These findings not only enrich the structural diversity of bisbenzylisoquinoline alkaloids, but also provide potential candidates for the further development of the antitumor and immunosuppressive agents.

8-, 9-, and 11-Aryloxy Dimeric Aporphines and Their Pharmacological Activities

Aporphines, a major group of aporphinoid alkaloids, exhibit interesting and diverse pharmacological activities. A set of dimeric aporphines with an aryloxy group at C8, C9, and C11 have been isolated from six genera and shown to elicit various biological activities such as antitumor, antimalarial, antimicrobial, antiplatelet aggregation, antifibrotic, immunosuppressive, and vasorelaxant properties. In this review, the nomenclature, chemical structures, botanical sources, pharmacological activities, and synthetic approaches of this set of dimeric alkaloids are presented.

Three new isoquinoline alkaloids from the whole plants of Thalictrum tenue with cytotoxic activities

Three new isoquinoline alkaloids, including two aporphines (1 and 2) and one oxoaporphine (3), were isolated from the 90% EtOH extract of the whole plants of Thalictrum tenue Franch. The structures of the isolated compounds were established based on 1D and 2D (¹H-¹H COSY, HMQC, and HMBC) NMR spectroscopy, in addition to high resolution mass spectrometry, respectively. The isolated alkaloids were tested in vitro for cytotoxic activity against six esophageal carcinoma cell lines. Consequently, alkaloids 1-3 exhibited some cytotoxic activities against all the tested tumor cell lines with IC₅₀ values less than 20 μM. [Formula: see text].

Antiproliferative Dimeric Aporphinoid Alkaloids from the Roots of Thalictrum cultratum

Inspired by the intriguing structures and bioactivities of dimeric alkaloids, 11 new thalifaberine-type aporphine-benzylisoquinoline alkaloids, thalicultratines A-K, a tetrahydroprotoberberine-aporphine alkaloid, thalicultratine L, and five known ones were isolated from the roots of Thalictrum cultratum. Their structures were defined on the basis of NMR and HRESIMS data. The antiproliferative activities of compounds 1-17 were evaluated against human leukemia HL-60 and prostate cancer PC-3 cells. Most alkaloids showed potent cytotoxicity against selected cancer cells. Preliminary SARs are discussed. The most active new compound (3), with an IC₅₀ value of 1.06 μM against HL-60 cells, was selected for mechanism of action studies. The results revealed that compound 3 induced apoptosis and arrested the HL-60 cell cycle at the S phase with the loss of mitochondria membrane potential. The nuclear morphological Hoechst 33258 staining assay was also carried out, and the results confirmed apoptosis.

Plant-derived antimalarial agents: new leads and efficient phythomedicines. Part I. Alkaloids

Malaria remains one of the most serious world health problem and the major cause of mortality and morbidity in the endemic regions. Brazil is among the 30 high-burden countries and most of the cases occur in the Legal Amazonian Region. New chemotherapeutical agents are needed for the treatment of malaria. Many plant species are used in traditional medicines of malarious countries and a relatively few number of these have been investigated for evaluation of their antimalarial effect. Still lower is the number of those that have had the active natural compounds isolated and the toxicity determined. This area is, then, of great research interest. discovery project of antimalarial natural products from plants traditionally used to treat malaria must include in vitro and in vivo assays as well as bioguided isolation of active compounds. The final products would be antimalarial chemical entities, potential new drugs or templates for new drugs development, and/or standardized antimalarial extracts which are required for pre-clinical and clinical studies when the aim is the development of effective and safe phythomedicines. This review discusses these two approaches, presents briefly the screening methodologies for evaluation of antimalarial activity and focuses the activity of alkaloids belonging to different structural classes as well as its importance as new antimalarial drugs or leads and chemical markers for phytomedicines.

Antiplasmodial Activity of Some Medicinal Plants Used in Sudanese Folk-medicine

Ten plants indigenous to Sudan and of common use in Sudanese folk-medicine, were examined in vitro for antimalarial activity against schizonts maturation of Plasmodium falciparum, the major human malaria parasite. All plant samples displayed various antiplasmodial activity. Three plant extracts caused 100% inhibition of the parasite growth at concentrations of plant material Collapse

Key Words

• antiplasmodial activity
• folk-medicine
• medicinal plants

Collapse

MESH Headings Collapse

Grants Collapse

Affiliation(s)

El-Hadi M. Ahmed Department of Chemistry and Pharmacognosy, Faculty of Pharmacy, University of Gezira, P.O. Box 20 Wad Medani, Sudan
Bakri Y.M. Nour Blue Nile National Institute for Communicable Diseases, University of Gezira, P.O. Box 20 Wad Medani, Sudan
Yousif G. Mohammed Department of Chemistry and Pharmacognosy, Faculty of Pharmacy, University of Gezira, P.O. Box 20 Wad Medani, Sudan
Hassan S. Khalid Medicinal and Aromatic Plants Research Institute, National Council for Research, Khartoum, Sudan.

Collapse

In vitro screening for antiplasmodial activity of isoquinoline alkaloids from Brazilian plant species

In the search for new antimalarial agents, nine Brazilian plant species were selected, from the Annonaceae (6), Menispermaceae (2) and Siparunaceae (1) families naturally occurring at the cerrado and Atlantic rainforest regions, in order to investigate their in vitro antiplasmodial activity. The ethanol and the alkaloid extracts were tested against K1, chloroquine-resistant, and Palo Alto, chloroquine-sensitive, strains of Plasmodium falciparum. The majority of the alkaloid extracts were more active than the ethanol ones, with IC(50) ranging 0.3-8.2 microg/mL. The crude Guatteria australis alkaloids were the most active against K1 with an IC(50) = 0.3 microg/mL. The most promising total alkaloid fractions for further bioguided isolation are those with the IC(50) < or = 5 microg/mL: G. australis, Cissampelos ovalifolia and Duguetia lanceolata.

Cytotoxic and antioxidant activities of alkylated benzoquinones from Maesa lanceolata

The natural and semi-synthetic analogs of substituted 1,4-benzoquinones were evaluated for in vitro cytotoxic and antioxidant activities. Maesanin, dihydromaesanin, maesanin dimethyl ether and isomeric mixtures of 3-[(Z)-10'-pentadecenyl]-benzoquinone derivatives exhibited cytotoxic activity against HL-60 cell line (IC50 values 4.5, 2.2, 0.43 and 2.8 microg/mL, respectively), while it was found to be inactive against ROS (Reactive Oxygen Species) generation in HL-60. In contrast, the isomeric acylated benzoquinones with shorter alkyl substituents, namely, 2-acetoxy-5-hydoxy-6-methyl-3-tridecyl-1,4-benzoquinone and 2-hydoxy-5-acetoxy-6-methyl-3-tridecyl-1,4-benzoquinone showed most prominent antioxidant and antiproliferative effect on HL-60 (IC50 values 6.2 and 2.2 microg/mL, respectively), as well as cytotoxicities against SK-MEL, KB, BT-549 and SK-OV-3 carcinomas (IC50 values <1.1-4.2 microg/mL). All benzoquinones were found to be inactive against cell aggregation and cell adhesion assays, thus showing no effect on immune responses and inflammation.