Phytochemical Evaluation and In-silico Studies of Bioactive Compound from the Seeds of Afrostyrax lepidophyllus to Identify Potential Anti-inflammatory Agents

Abstract

Afrostyrax lepidophyllus commonly known as country onions from the Huaceae family has been acclaimed to be used in treatment of several health conditions such as inflammation, prevention of infection and cancer, improve digestion, use traditionally as remedy for pain relief etc ethnomedically. This study was carried out to determine the bioactive composition  of A. lepidophyllus seed and to evaluate the anti-inflammatory activities of seed extract using GC-MS) and in silico molecular docking. The GC-MS result revealed the presence of 18 bio-active compounds of which eugenol (47.14%), 3-ally-6-methoxylphenol (24.23%), Caryophyllene (10.35%) and oleic acid (7.91%) were the most abundant. The result revealed that the efficacy of the plant against inflammatory diseases could be linked to eugenol, 3-ally-6-methoxylphenol and Caryophyllene found in the crude extract. The bioactive compounds from the extract were docked on the inflammatory protein crystal structure of diclofenac bound to the cyclooxygenase active site of COX-2 (1pxx) to know their binding affinities and compared with that of some known anti-inflammatory drugs. The docking result showed that the standard drugs Diclofenac has the best binding affinity of -8.5 kcal/mol, followed by Naproxen (-8.1kcal/mol), Caryophyllene (-7.5kcal/mol), Bicyclo [7.2.0] undec-4-ene (-7.4 kcal/mol) have better affinity than the standard drug Ibuprofen (-7.3 kcal/mol). All the compounds from the exact have high binding affinities within the range of -7.5 – 6.1kcal/mol except 2,4,5,7-tetrathiaoctane that is -3.5 kcal/mol. The interaction results of the extracts with the diseased protein proved the anti-inflammatory efficacy of the seed as acclaimed therefore validating the traditional use of the seed against inflammatory diseases.