Neomycin is an aminoglycoside antibiotic and a phospholipase C (PLC) inhibitor [2].
It inhibits nuclear translocation of angiogenin in human endothelial cells, an essential step for angiogenin-induced angiogenesis [2].

Neomycin is efficient against Pseudomonas aeruginosa and anaerobic bacteria, but not the majority of Gram-negative bacteria. Its increased efficacy against Staphylococcus aureus is occasionally restricted to Gram bacteria, but prolonged use results in bacterial pathogenicity [1].

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In human umbilical vein endothelial (HUVE) cells, neomycin (100 μM) decreased the amount of ¹²⁵I-angiogenin accumulated in the cell nucleus by up to 60% after 30 minutes incubation, indicating inhibition of nuclear translocation [2].
Neomycin inhibits nuclear translocation of angiogenin in a dose-dependent manner. At 10 μM, nuclear translocation was inhibited by 42%; at 200 μM, inhibition reached 65%; at 500 μM, nuclear accumulation was reduced to 14% of control [2].
Neomycin inhibits angiogenin-induced proliferation of HUVE cells in a dose-dependent manner. At 5 μM, it inhibited proliferative activity by 49%; at 25 μM, inhibition reached 69%; at 50 μM, angiogenin-induced proliferation was completely abolished. Neomycin alone neither induced nor inhibited cell proliferation at concentrations up to 100 μM [2].
Neomycin at concentrations up to 50 μM did not inhibit the ribonucleolytic activity of angiogenin against yeast tRNA (activity was 87%, 105%, and 88% of control at 5, 10, and 50 μM respectively), indicating its anti-angiogenic effect is not due to inhibition of angiogenin's enzymatic activity [2].
Other aminoglycoside antibiotics including gentamicin, streptomycin, kanamycin, amikacin, and paromomycin (100 μM each) did not inhibit angiogenin-induced cell proliferation, suggesting the inhibitory effect is specific to neomycin [2].

In the chicken chorioallantoic membrane (CAM) assay, neomycin alone at doses of 20-200 ng per egg did not induce angiogenesis nor cause any visible adverse effects. Angiogenin alone (10 ng) induced a positive angiogenic response in 55% of eggs. Co-administration of neomycin at 4 ng decreased the positive response to 40%, while 20 ng completely inhibited angiogenin-induced angiogenesis to background level (20%), comparable to water control [2].

The effect of neomycin on the ribonucleolytic activity of angiogenin was examined using yeast tRNA as substrate. Angiogenin, or its mixture with neomycin, was added to an assay mixture containing 0.6 mg yeast tRNA, 30 μg ribonuclease-free BSA, 30 mM Hepes (pH 6.8), and 30 mM NaCl in a final volume of 300 μl. After incubation for 2 hours at 37°C, 700 μl of 3.4% ice-cold perchloric acid was added, the mixture was vortexed, kept on ice for 10 minutes, and centrifuged at 15,000 × g for 10 minutes at 4°C. The absorbance of supernatants was measured at 260 nm [2].

For nuclear translocation assays, HUVE cells were seeded at 5 × 10³ cells/cm² in 35-mm dishes and cultured for 24 hours. Cells were washed three times with prewarmed HE-SFM and incubated with ¹²⁵I-angiogenin (1 μg/ml) at 37°C for 30 minutes. Inhibitors were either premixed with ¹²⁵I-angiogenin or cells were pretreated with inhibitors for 10-30 minutes before adding ¹²⁵I-angiogenin. After incubation, dishes were cooled at 4°C for 10 minutes, cells were washed, detached, and lysed with 0.5% Triton X-100. Nuclear fractions were isolated by centrifugation at 1,200 × g for 5 minutes and radioactivity was determined [2].
For cell proliferation assays, HUVE cells were seeded at 4 × 10³ cells/cm² in attachment factor-coated 35-mm dishes in HE-SFM, and incubated with 1 μg/ml angiogenin in the presence or absence of inhibitors at 37°C for 48 hours. Cells were detached by trypsinization and cell numbers were determined with a Coulter Counter [2].

For the chicken chorioallantoic membrane (CAM) assay, fertilized chicken eggs were used. Samples (5 μl volume) containing angiogenin (10 ng), neomycin (4-200 ng), or combinations were applied to the CAM. Growth of blood vessels was observed microscopically and recorded as either positive or negative after 48 hours of incubation [2].

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For the chicken chorioallantoic membrane (CAM) assay, fertilized chicken eggs were used. Samples (5 μl volume) containing angiogenin (10 ng), neomycin (4-200 ng), or combinations were applied to the CAM. Growth of blood vessels was observed microscopically and recorded as either positive or negative after 48 hours of incubation [2].

Neomycin at concentrations up to 200 μM showed no cytotoxicity to HUVE cells as determined by trypan blue dye exclusion assay [2].
In the CAM assay, neomycin at doses of 20-200 ng per egg did not cause necrosis or any other visible adverse effects on chicken embryos [2].
The study notes that in hair cells of the outer ear, neomycin binds to phosphatidylinositol 4,5-bisphosphate, disturbing inositol phosphate synthesis, which may contribute to aminoglycoside-induced ototoxicity. However, the concentration required for significant ototoxicity (30 mM) is much higher than that required to inhibit angiogenin-induced angiogenesis (20 ng per egg) [2].

[1]. Sasseville D. Neomycin. Dermatitis. 2010;21(1):3-7.

[2]. Hu GF. Neomycin inhibits angiogenin-induced angiogenesis. Proc Natl Acad Sci U S A. 1998;95(17):9791-9795.

Neomycin sulfate is the sulfate form of neomycin, a broad-spectrum aminoglycoside antibiotic derived from Streptomyces fradiae, possessing antibacterial activity. Neomycin is an antibiotic complex composed of three components: two isoforms, B and C, are the active ingredient, and neomycin A is the minor component. Neomycin irreversibly binds to the 16S rRNA and S12 protein of the bacterial 30S ribosomal subunit. Therefore, the drug interferes with the assembly of the initiation complex between mRNA and the bacterial ribosome, thereby inhibiting the initiation of protein synthesis. Furthermore, neomycin induces misreading of the mRNA template, leading to frameshift translation and premature termination of translation. Ultimately, this results in bacterial cell death.
An aminoglycoside antibiotic complex produced by Streptomyces fradiae. It consists of neomycin A, B, and C, and exerts its effect by inhibiting translation during protein synthesis.
See also: Neomycin sulfate (note moved to).

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Neomycin is an aminoglycoside antibiotic that inhibits translation by binding to the small subunit of prokaryotic ribosomes, causing misreading of mRNA. Unlike geneticin (G418), neomycin does not bind to eukaryotic ribosomes [2].
The study identifies neomycin as an inhibitor of angiogenin-induced angiogenesis, acting through inhibition of nuclear translocation of angiogenin in endothelial cells. This effect appears to be related to its PLC-inhibiting activity, as another PLC inhibitor (U-73122) also inhibited nuclear translocation while its inactive analog (U-73343) did not [2].
Structural specificity is evident: paromomycin, which differs from neomycin only by substitution of -NH₂ with -OH at position 6 of the glucose ring, shows no inhibitory activity against angiogenin-induced cell proliferation, indicating the amino group at this position is critical for anti-angiogenic activity [2].
The study suggests that neomycin and its analogs represent a potential new class of anti-angiogenin agents that might be developed for clinical treatment of angiogenesis-related diseases including cancer, arthritis, psoriasis, and diabetic retinopathy [2].

614.312

1405-10-3

Framycetin;119-04-0

62403

White to light yellow solid powder

1046.1ºC at 760 mmHg

>187°C (dec.)

586.5ºC

0mmHg at 25°C

56 ° (C=10, H2O)

15

23

9

47

953

18

S(=O)(=O)(O[H])O[H].O([C@]1([H])[C@]([H])([C@]([H])([C@]([H])(C([H])([H])O[H])O1)O[C@@]1([H])[C@@]([H])([C@@]([H])([C@]([H])([C@]([H])(C([H])([H])N([H])[H])O1)O[H])O[H])N([H])[H])O[H])[C@]1([H])[C@]([H])([C@@]([H])(C([H])([H])[C@]([H])([C@@]1([H])O[C@]1([H])[C@]([H])([C@@]([H])([C@]([H])([C@]([H])(C([H])([H])N([H])[H])O1)O[H])O[H])N([H])[H])N([H])[H])N([H])[H])O[H]

OIXVKQDWLFHVGR-GQTDVWSESA-N

InChI=1S/C23H46N6O13.H2O4S/c24-2-7-13(32)15(34)10(28)21(37-7)40-18-6(27)1-5(26)12(31)20(18)42-23-17(36)19(9(4-30)39-23)41-22-11(29)16(35)14(33)8(3-25)38-22;1-5(2,3)4/h5-23,30-36H,1-4,24-29H2;(H2,1,2,3,4)/t5-,6+,7-,8+,9-,10-,11-,12+,13-,14-,15-,16-,17-,18-,19-,20-,21-,22?,23+;/m1./s1

(2R,3S,4R,5R,6R)-5-amino-2-(aminomethyl)-6-[(1R,2R,3S,4R,6S)-4,6-diamino-2-[(2S,3R,4S,5R)-4-[(3R,4R,5S,6S)-3-amino-6-(aminomethyl)-4,5-dihydroxyoxan-2-yl]oxy-3-hydroxy-5-(hydroxymethyl)oxolan-2-yl]oxy-3-hydroxycyclohexyl]oxyoxane-3,4-diol;sulfuric acid

Framycetin Neomycin BNeomycinMycifradin Soframycin

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

H2O : ~250 mg/mL (~275.06 mM)

Solubility in Formulation 1: 50 mg/mL (55.01 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.

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 (Please use freshly prepared in vivo formulations for optimal results.)