Polyphenolic characterization and biological assessment of Acacia nilotica (L.) wild. Ex delilie: An In vitro and In vivo appraisal of wound healing potential.

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE Acacia nilotica (L.) Wild. Ex Delilie is a shrub with significant ethnomedicinal stature. Therefore, in the undertaken study, its wound healing attributes are determined. AIM OF THE STUDY The current study provided evidence of the traditional use of A. nilotica species and conferred A. nilotica bark extract as a potent candidate for wound healing agents. MATERIALS & METHODS: A. nilotica leaves extract (ANL-E); A. nilotica bark extract (ANB-E), and A. nilotica stem extract (ANS-E) were prepared using methanol-chloroform (11). Phytochemical analysis was performed using gallic acid equivalent (GAE) total phenolic content (TPC), quercetin equivalent (QE) total flavonoid content (TFC) assays and High-performance liquid chromatography (HPLC). In vitro antioxidant potential (free radical scavenging activity (FRSA), total antioxidant capacity (TAC), and ferric reducing antioxidant power (FRAP) assay), antibacterial activity (broth microdilution method) and hemolytic analysis was carried out. Wound healing proficiency of ANB-E was determined by wound excision model followed by estimating hydroxyproline content and endogenous antioxidant markers. RESULTS: Maximum phenolic and flavonoid content were depicted by ANB-E i.e., 50.9 ± 0.34 µg gallic acid equivalent/mg extract and 28.7 ± 0.13 µg quercetin equivalent/mg extract, respectively. HPLC analysis unraveled the presence of a significant amount of catechin in ANL-E, ANB-E and ANS-E (54.66 ± 0.02, 44.9 ± 0.004 and 31.36 ± 0.02 µg/mg extract) respectively. Highest percent free radical scavenging activity, total antioxidant capacity, and ferric reducing action power (i.e., 93.3 ± 0.42 %, 222.10 ± 0.76, and 222.86 ± 0.54 µg ascorbic acid equivalent/mg extract) were exhibited by ANB-E. Maximum antibacterial potential against Staphylococcus aureus was exhibited by ANB-E (MIC 12.5 µg/ml). Two of the extracts i.e., ANL-E and ANB-E were found biocompatible with less than 5 % hemolytic potential. Based upon findings of in vitro analysis, ANB-E (10, 5, and 2.5 % w/w, C1, C2, and C3, respectively) was selected for evaluating its in vivo wound healing potential. Maximum contraction of wound area and fastest epithelization i.e., 98 ± 0.05 % and 11.2 ± 1.00 (day) was exhibited by C1. Maximum hydroxyproline content, glutathione, catalase, and peroxidase were demonstrated by C1 i.e., 15.9 ± 0.52 µg/mg, 9.3 ± 0.17 mmol/mg, 7.2 ± 0.17 and 6.2 ± 0.14 U/mg, respectively. Maximal curbed lipid peroxidation i.e., 0.7 ± 0.15 mmol/mg was also depicted by C1. CONCLUSIONS: In a nutshell, the current investigation endorsed the wound healing potential of ANB-E suggesting it to be an excellent candidate for future studies.