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Folk medicine is widely used in Angola, even for human African trypanosomiasis (sleeping sickness) in spite of the fact that the reference treatment is available for free. Aiming to validate herbal remedies in use, we selected nine medicinal plants and assessed their antitrypanosomal activity. A total of 122 extracts were prepared using different plant parts and solvents. A total of 15 extracts from seven different plants exhibited in vitro activity (>70% at 20 µg/mL) against Trypanosoma brucei rhodesiense bloodstream forms. The dichloromethane extract of Nymphaea lotus (leaves and leaflets) and the ethanolic extract of Brasenia schreberi (leaves) had IC 50 values ≤ 10 µg/mL. These two aquatic plants are of particular interest. They are being co-applied in the form of a decoction of leaves because they are considered by local healers as male and female of the same species, the ethnotaxon "longa dia simbi". Bioassay-guided fractionation led to the identification of eight active molecules: gallic acid (IC 50 0.5 µg/mL), methyl gallate (IC 50 1.1 µg/mL), 2,3,4,6-tetragalloyl-glucopyranoside, ethyl gallate (IC 50 0.5 µg/mL), 1,2,3,4,6-pentagalloyl-β-glucopyranoside (IC 50 20 µg/mL), gossypetin-7- O -β-glucopyranoside (IC 50 5.5 µg/mL), and hypolaetin-7- O -glucoside (IC 50 5.7 µg/mL) in B. schreberi , and 5-[(8Z,11Z,14Z)-heptadeca-8,11,14-trienyl] resorcinol (IC 50 5.3 µg/mL) not described to date in N. lotus . Five of these active constituents were detected in the traditional preparation. This work provides the first evidence for the ethnomedicinal use of these plants in the management of sleeping sickness in Angola.

Introduction: Sennosides are the main active constituents of the dried leaves and/or pods of Senna alexandrina Mill. that are used as laxatives. A hypothesis is that aglycones are formed during the degradation of sennosides. However, it is unknown, whether this happens under visible light exposure and how photosensitive sennosides behave in solution., Objectives: Pure anthraquinone glycosides were tested on their behaviour during sample preparation in the lab under visible light exposure in dependence on the instability of the solvent., Materials and Methods: Samples before and after exposure were analysed using UHPLC with UV/Vis and MS detection., Results: Under visible light protection, the solutions were stable for 14 days at room temperature whereas a loss of 20%-60% was measured after 1 day of light exposure. The loss of sennosides due to degradation can be as fast as up to 2%-2.5% per hour, which might have a tremendous impact on phytochemical analysis results during the course of an analysis. The formation of aglycones was not observed in the degradation of sennosides and rhein-8-O-glucoside., Conclusion: Aglycones could not be found as a result of the forced degradation. The solutions of sennosides clearly need to be protected from light to obtain reliable analytical results, and light protection is a major point for the stability of liquid preparations., (© 2024 John Wiley & Sons, Ltd.)

Glioblastoma is the most frequent primary malignant brain tumor without effective treatment, which makes this work extremely relevant. The study of the bioactive compounds from medicinal plants plays an important role in the discovery of new drugs.This research investigated the constituents of Tapirira guianensis and its antitumor potential ( in vitro and in vivo) in glioblastoma. The T. guianensis extracts were characterized by mass spectrometry. The ethyl acetate partition (01ID) and its fractions 01ID-F2 and 01ID-F4 from T. guianensis showed potential antitumor treatment evidenced by selective cytotoxicity for GAMG with IC50 14.1 µg/mL, 83.07 µg/mL, 59.27 µg/mL and U251 with IC50 25.92 µg/mL, 37.3 µg/mL and 18.84 µg/mL. Fractions 01ID-F2 and 01ID-F4 were 10 times more selective when compared to TMZ and 01ID for the two evaluated cell lines. T. guianensis also reduced matrix metalloproteinases 2 - 01ID-F2 (21.84%), 01ID-F4 (29.6%) and 9 - 01ID-F4 (73.42%), ID-F4 (53.84%) activities, and induced apoptosis mainly through the extrinsic pathway. Furthermore, all treatments significantly reduced tumor size (01ID p < 0,01, 01ID-F2 p < 0,01 and 01ID-F4 p < 0,0001) and caused blood vessels to shrink in vivo . The present findings highlight that T. guianensis exhibits considerable antitumor potential in preclinical studies of glioblastoma. This ability may be related to the phenolic compounds and sesquiterpene derivatives identified in the extracts. This study deserves further in vivo research, followed by clinical investigation., Competing Interests: The authors declare that they have no conflicts of interest., (Thieme. All rights reserved.)