RESUMO
Background Study: The aim of this research was to examine possible antioxidant, cytotoxic and neurological activity of methanol and n-hexane extracts of Bixa orellana leaves. Additionally, we aimed to identify potential lead compounds through in-silico analysis. Methods: In-vitro antioxidative properties were investigated through different assays, including: total phenolic content assay (TPC), total flavonoid content assay (TFC), DPPH free radical scavenging assay and reducing power assay. Also, the cytotoxic effect of the samples was assessed using the brine shrimp lethality test. In addition, anxiolytic, locomotor, and CNS depressant activities were assessed utilizing various established methods. Moreover, reported compounds were used in the in silico study to explore the best-fit phytoconstituents against gamma-aminobutyric acid (GABAA) receptor. Results: MBOL displayed substantial antioxidative activities in various established assays compared to NBOL. In brine shrimp lethality bioassay, both MBOL and NBOL revealed cytotoxic activity in a concentration-dependent approach. Again, in Elevated Plus Maze test, 200 and 400 mg/kg of NBOL and MBOL demonstrated significant anxiolytic activities evident from time spent in open arms. In addition, maximum number of head dipping was demonstrated by MBOL at 400 mg/kg (53.90 ± 1.16) in Hole Board test. NBOL and MBOL at both doses significantly diminished the magnitude of movements from the 2nd to 5th observation periods in Open Field test. Furthermore, in Hole Cross test, MBOL remarkably dwindled the locomotor activity at 120 min and 180 min (3.60 ± 0.40 and 2.40 ± 0.51) at 400 mg/kg. Finally, in silico analysis revealed 13 compounds as promising leads with strong binding affinity to GABAA receptor along with good pharmacokinetics and toxicity profiles. Conclusion: Therefore, the present study's findings advocate the traditional usage of this plant and recommend both MBOL and NBOL as as a potential source of therapeutic candidate for the management of neurological disorders.
RESUMO
Hoya parasitica (Wall.) is extensively used in traditional medicine for the treatment of various diseases including rheumatism, kidney problems, jaundice, urinary tract disorders, fever, and pain. The present study was designed to explore new lead compound(s) to alleviate pain, pyresis, and diarrhea from methanol, ethyl acetate, and n-hexane extracts of H. parasitica (Wall.) leaves (MHP, EAHP, and NHP, respectively). Analgesic activity of the extracts was assessed through acetic acid induced writhing, tail immersion, and hot plate tests while brewer's yeast-induced pyrexia test was employed for the assessment of antipyretic activity. Besides, castor oil and magnesium sulfate induced diarrheal tests were utilized for the evaluation of antidiarrheal properties. Moreover, in silico study of the isolated compounds was undertaken to seek out best-fit phytoconstituent(s) against cyclooxygenase enzymes. MHP revealed substantial antioxidant activities in different in vitro assays compared to EAHP and NHP. In the acetic acid-induced writhing test, among the extracts, MHP (400 mg/kg) revealed maximum 74.15 ± 1% inhibition of writhing comparable to that of standard (85.77 ± 1.39%). Again, in tail immersion and hot plate tests, higher doses of all the test samples exhibited a significant increase of latent period in a time-dependent manner. In brewer yeast-induced pyrexia test, at 3rd and 4th hour of treatment, significant (P < 0.05) antipyretic action was found in the test samples. In both castor oil and magnesium induced diarrheal tests, MHP at 400 mg/kg showed the highest percent inhibition of diarrhea (68.62 ± 4.74 and 64.99 ± 2.90, respectively). Moreover, molecular docking analysis corroborated the results of the present study. The findings of the present study supported the traditional uses of this plant for the alleviation of pain and fever. Furthermore, hoyasterone was found to be the most effective lead compound as cyclooxygenase enzyme inhibitor.
