Acute Toxicity and Determination of the Active Constituents of Aqueous Extract ofUncaria tomentosaBark inHyphessobrycon eques

Abstract

Uncaria tomentosa is a medicinal plant used in folk medicine by Amazon tribes. In this study the constituents of aqueous extract of U. tomentosa bark were quantified by chromatographic technique and its lethal concentration 50 (48 h) in Hyphessobrycon eques was determined. The chromatography showed high levels of oxindole alkaloids, quinovic acid glycosides, and low molecular weight polyphenols. The CL50 48 h was 1816 mg/L. Fish showed behavior changes at concentrations above 2000 mg/L, accompanied by a significant decrease of dissolved oxygen. At the highest concentration 100% mortality was observed attributed to oxygen reduction by the amount of oxindole alkaloids, polyphenols accumulation of the extract in the gills, and the interaction of these compounds with dopamine. In conclusion, the aqueous extract of U. tomentosa did not alter the chemical components and it was shown that U. tomentosa has low toxicity to H. eques; therefore, it can be used safely in this species.

Investigating Potential Inhibitory Effect of Uncaria tomentosa (Cat’s Claw) against the Main Protease 3CLpro of SARS‐CoV‐2 by Molecular Modeling

“…Bioactive constituents of U. tomentosa extracts include proanthocyanidins (proanthocyanidin B2 or epicatechin-(4 β ⟶ 8)-epicatechin, the main component; proanthocyanidin B4, proanthocyanidin C1, an epicatechin trimer, epiafzelechin-4 β ⟶ 8-epicatechin, and an epicatechin tetramer) [ 13 ], oxindole alkaloids (isopteropodine, pteropodine, rhynchophylline, mytraphylline, speciophylline, uncarine F, and uncarine E) [ 14 ], indole alkaloidal glucosides (cadambine, 3-dihydrocadambine, and 3-isodihydrocadambine) [ 15 , 16 ], quinovic acid glycosides, tannins, polyphenols, catechins, beta-sitosterol, and proteins which individually or synergistically contribute to their therapeutic properties [ 8 , 17 – 24 ].…”

Hybrid Nanoparticles of Proanthocyanidins from Uncaria tomentosa Leaves: QTOF-ESI MS Characterization, Antioxidant Activity and Immune Cellular Response

“…Other studies in the fish model demonstrated dietary supplementation of U. tomentosa enhanced the immune activity and growth performance [71]. In this case, the most important bioactive compounds found in this plant were oxindole alkaloids, derivatives of quinovic acid glycosides, and low molecular weight polyphenols [72], while our PA-E is composed of proanthocyanidins. Therefore, results on this extract and its nanoformulations F-1 and F-2, constitute to our knowledge, the first report on this DTH activity due to proanthocyanidins present in U. tomentosa leaves and further, according to our findings, the immune response to the antigen is augmented when these compounds are nanoformulated in F-1 and F-2 samples.…”

Dietary camu camu, Myrciaria dubia, enhances immunological response in Nile tilapia

“…Serum biochemistry results suggested that camu camu extract has no toxicological action in fish [18]. However, it is necessary further studies using higher concentration of the plant extract to affirm this statement [42].…”