This page respects the original work's rights terms and independently introduces its bibliography, abstract, main results, and limitations. It is not a full translation.
About this resource
This resource describes a 2018 conference abstract that directly added a liquid intended for use as sananga eye drops to bacterial culture systems and examined inhibition and killing of Staphylococcus epidermidis and a bacterium then identified as Propionibacterium acnes (now usually called Cutibacterium acnes). Because the sample was the eye preparation itself, the study is more direct than research limited to another plant part or an isolated constituent and should not have been omitted from the existing 5 resources.
What the researchers directly observed, however, was bacteria in culture dishes and microplates—not the human eye, conjunctivitis, visual acuity, intraocular pressure, cataracts, or another clinical outcome. The title and purpose use a word corresponding to “efficacy,” but the abstract alone cannot establish preventive or therapeutic effects in people. This page is not a full-text translation; it distinguishes the sample, methods, results, and limits of evidence.
Study design
The sample was described as sananga eye drops produced and used in Indigenous communities in the Envira River and upper Juruá region of Amazonas state. The researchers used the standard strains S. epidermidis ATCC 12228 and P. acnes ATCC 6019, reactivated them on blood agar, and cultured them for 24 hours at 37°C.
Antibacterial activity was assessed with a broth-dilution method following Clinical and Laboratory Standards Institute procedures. Sananga was serially diluted in a 96-well microplate, bacterial suspensions were added, and the lowest concentration preventing growth was designated the minimum inhibitory concentration (MIC). Material was then transferred to agar and cultured; the minimum concentration at which surviving bacteria were 0.01% was designated the minimum bactericidal concentration (MBC). The experiment was reported as repeated 3 times.
Content
The study’s value is that it contacted standard bacterial strains with a liquid identified as a particular sananga sample rather than relying only on records of traditional use or guesses about compounds. MIC means the concentration at which visible growth was inhibited under the test conditions; MBC means the concentration at which almost no viable bacteria remained after transfer back to growth medium. These measures support initial screening for antimicrobial candidates, but they do not reproduce a concentration achievable in an infected eye, a safe exposure time, dilution by tears, corneal irritation, or immune responses.
Sananga composition may vary with botanical species, plant part, water quality, extraction time, storage, and place of origin. The abstract provides insufficient detail on a voucher specimen, quantitative constituents, pH, osmolality, sterility, or storage duration to establish identity with another product. The results therefore need to remain tied to the sample and conditions tested.
Results
For S. epidermidis, MIC was reported at 25% sananga and MBC at 50%. No antibacterial activity was observed against P. acnes. The preparation therefore did not act uniformly against 2 bacterial species; under these test conditions, results differed by organism.
This observation provides limited basic data for part of the question “does sananga have antibacterial activity?” It did not compare potency with a positive-control medication, show reproducibility across multiple batches, identify active constituents in the concentrations, or demonstrate an effect in ocular tissue. A culture-system result against S. epidermidis cannot be transferred directly to cure of an infection or prevention of eye disease.
Limitations
This was a short electronic-poster abstract presented at the 11º Congresso Paulista de Infectologia, with less detail about methods, statistics, raw data, and controls than a conventional full paper. Standard strains support reproducibility but do not represent the diversity of patient isolates or resistant strains. The sample was described as 1 line and cannot be generalized to sananga from other places or preparations.
A culture assay has no ocular epithelium, tears, blood flow, metabolism, or immune system. MIC and MBC are not clinical doses, and the value of 50% does not establish a concentration safe for the eye. Separate staged research would be needed on product standardization, ocular toxicity, sterility, and appropriate controls before clinical efficacy could be assessed.
Safety
This study measured bacterial growth and did not assess adverse events or damage to the cornea or conjunctiva in human participants. The relationship between a concentration showing antibacterial activity and one safe for ocular tissue is unknown. Neither intense irritation nor natural origin guarantees safety.
Unstandardized eye drops also raise separate issues of botanical identification, concentration, pH, microbial contamination, foreign material, and storage. This resource does not recommend preparation or self-administration and is not a substitute for diagnosis or treatment of eye symptoms.
Source and rights
Original source: Abilio C, Kozusny-Andrean DI, Chalub LR. Eficácia do colírio sananga frente às bactérias Staphylococcus epidermidis e Propionibacterium acnes. The Brazilian Journal of Infectious Diseases. 2018;22(S1):42–43. DOI: 10.1016/j.bjid.2018.10.080.
The source page displays the material as Open Access and under a Creative Commons license. This page does not reproduce the abstract at length or translate it verbatim; it is an independently worded detailed introduction to the bibliographic information and research content. The exact license terms displayed by the source page take precedence.