INHIBITORY EFFECTS OF DIFFERENT ALKALOIDS IN DENDROBIUM NOBILE EXTRACTS ON OXIDATIVE DAMAGE IN CATARACT LENS EPITHELIAL CELLS

Cataracts, a leading cause of acquired blindness, are associated with apoptosis of lens epithelial cells (LEC).This study investigates the mechanisms by which alkaloids extracted from Dendrobium nobile, a traditional Chinese medicinal plant, inhibit oxidative stress in LECs.Alkaloids were fractionated into four groups: fat-soluble alkaloids (FSA), weakly polar alkaloids (WPA), low-polarity alkaloids (LPA) and water-soluble alkaloids (WSA).Optimal extraction conditions were determined.Samples were collected from 10 cataract patients and 10 individuals with normal lenses, and LECs were isolated and cultured.An oxidative damage model was induced using 500 mol/L HO, and alkaloid fractions were applied at 20 g/mL.Apoptosis and proliferation were assessed via flow cytometry, while oxidative stress markers (GSH-Px, SOD, MDA) and protein expression (Bcl-2, Bax, p38 MAPK, p-JNK) were analyzed by ELISA and Western blot.Compared to normal LECs, cataract and oxidative stress models exhibited higher apoptosis, decreased GSH-Px/SOD and elevated MDA.Treatment with alkaloid fractions, particularly WSA, significantly reduced apoptosis, increased proliferation, restored oxidative balance and suppressed p38 MAPK/JNK pathway activation.These findings suggest Dendrobium nobile alkaloids effectively mitigate oxidative damage and apoptosis in cataract-affected LECs, with WSA demonstrating the most potent anti-oxidative effects. RezumatCataracta, o cauz major de orbire, este asociat cu apoptoza celulelor epiteliale ale cristalinului (LEC).Studiul de fa investigheaz mecanismul prin care alcaloizii extrai din Dendrobium nobile, o plant utilizat n medicina tradiional chinez, inhib stresul oxidativ asupra LEC.Alcaloizii au fost separai n patru fraciuni: liposolubili, slab polari, cu polaritate redus i solubili n ap.Au fost stabilite condiiile optime de extracie.Au fost incluse probe de la 10 pacieni cu cataract i 10 pacieni sntoi, iar celulele epiteliale ale cristalinului au fost cultivate.Modelul de stres oxidativ a fost indus cu HO (500 mol/L), iar fraciunile de alcaloizi au fost aplicate n doz de 20 g/mL.Apoptoza i proliferarea au fost evaluate prin citometrie n flux, iar markerii de stres oxidativ (GSH-Px, SOD, MDA), expresia proteinelor Bcl-2, Bax i a cii p38 MAPK/JNK au fost analizate prin ELISA i Western blot.Comparativ cu grupul normal, grupul cataract i modelul de stres oxidativ au artat o cretere a apoptozei, reducerea GSH-Px/SOD i creterea MDA.Alcaloizii, n special cei solubili n ap, au redus semnificativ apoptoza, au crescut proliferarea i au inhibat activarea cii p38 MAPK/JNK, demonstrnd un efect anti-stres oxidativ promitor.