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About this resource
This 2024 review updated the record of monoterpene indole alkaloids (MIAs) and reported biological activities in species of Tabernaemontana occurring in Brazil. It is included as background for positioning the sananga-associated Tabernaemontana sananho within broader chemistry and ethnopharmacology at the genus level.
The review states that 30 Tabernaemontana species occur in Brazil and also mentions varied records of use by Indigenous and local communities. These include use involving eye irritation, but they are collected genus-level plant-use records, not clinical tests of sananga eye drops. It is crucial not to treat another species, another plant part, a crude extract, an isolated constituent, and a finished product as the same evidence.
Study design
The authors used the Brazilian Flora 2020 database to identify species occurring in Brazil. Plant names and synonyms were checked in the World Flora Online Plant List and used as search terms to collect literature from Web of Science, Scopus, PubMed, and SciFinder. The review covered 1960 through June 2023.
From the collected literature, the authors organized structures of MIAs reported for each species and alkaloid extracts, fractions, and isolated compounds that showed biological activity. This was not a systematic review pooling clinical research alone; it was an updated review spanning plant classification, natural-products chemistry, experimental pharmacology, and ethnopharmacology.
Content
The literature review organized a total of 121 MIAs, 48 of which had not appeared in the preceding 2016 review. This does not mean that all 48 were newly discovered compounds; it includes reports added through the updated scope and period. The review maps a chemically diverse genus by relating species to publications.
Experimental biological activities included cytotoxic, anti-inflammatory, antinociceptive, antimicrobial, antiparasitic, antiviral, and snake-venom assays. The subject of activity differed by compound, extract, and fraction, and experimental systems ranged from cultured cells to animal models. A statement that “this activity has been reported in the genus” does not mean that every species or product has the same effect.
The authors highlighted cytotoxicity of some compounds, including voacamine and affinisine, against tumor cell lines and discussed their value for further natural-product drug discovery. At the same time, they noted the risk that ecosystem loss in the Amazon will erase understudied plant diversity. Interest in chemical resources and the need to protect biodiversity and knowledge sit together in the review.
Results
The review’s direct achievement was updating the map of Brazilian Tabernaemontana species, 121 MIAs, and reports of basic biological activity from literature published between 1960 and 2023. It can serve as a guide for future phytochemistry, mechanism studies, quality assessment, and candidate discovery.
For sananga, this resource connects studies focusing on T. sananho with genus-wide evidence while also making clear that genus-level results cannot be shortened into effects of an eye preparation. The review provided no comparative trial of sananga in the human eye, safety range, or product specification. It organized chemical and basic-activity literature; it did not establish a clinical effect.
Limitations
Natural-products studies differ by plant part, geographic origin, season, and extraction method even within 1 species, making direct comparison difficult. Biological assays also vary in target, concentration, controls, and cell or animal model and cannot be pooled into a single effect size. Positive reports may be affected by publication bias and reproducibility problems.
The review concerns literature on the genus as distributed in Brazil and does not cover every product marketed as sananga or all traditional uses in other countries. Cytotoxicity of a candidate compound is early drug-discovery information, not evidence of efficacy or safety in the human body. Generalization to eye drops separately requires quantitative analysis of actual products and ophthalmic safety research.
Safety
Diversity of bioactive alkaloids indicates a need for toxicity assessment alongside possible activity. Some compounds are studied specifically for their capacity to injure cells, so the labels “plant-derived” and “traditional” cannot determine safety for the eye.
The review did not assess sterility, pH, osmolality, corneal toxicity, or adverse events from eye drops. It does not provide product amounts or methods of use and is not a basis for self-administration, diagnosis, or treatment.
Source and rights
Original source: Nogueira TSR, Vieira MGC, Robaina RRS, Braz-Filho R, Gontijo DC, Oliveira AB, Vieira IJC. An update review on monoterpene indole alkaloids and biological activities of Tabernaemontana species occurring in Brazil. Journal of Ethnopharmacology. 2024;328:117921. DOI: 10.1016/j.jep.2024.117921. PMID 38369065.
The content was checked against public bibliographic and abstract information at PubMed and the publisher. Copyright and reuse terms for the full text are governed by the original publisher. This page is an independently organized detailed introduction to the subject and evidence boundaries, not a reproduction or verbatim translation.