Functional evaluation of cis-vaccenic acid in cordia dichotoma with tissue-specific biochemical insights
摘要
This study systematically elucidates the biochemical composition and tissue-specific pharmacodynamic properties of Cordia dichotoma, with a particular emphasis on the distribution and functional implications of cis-vaccenic acid across distinct plant parts, including pulp, seeds, leaves and bark. Comprehensive phytochemical analyses were performed to quantify total phenolic content (TPC) and total flavonoid content (TFC), alongside in vitro assessments of antioxidant, antidiabetic, antibacterial and neuroprotective activities. Gas chromatography-mass spectrometry (GC-MS) profiling identified cis-vaccenic acid as a predominant bioactive compound, especially abundant in seeds and bark. This monounsaturated fatty acid, recognized for its pivotal role in lipid metabolism and cardiovascular health, was found to significantly contribute to the bioactivity of these tissues. Notably, the ethyl acetate fraction of seeds showed the highest α-amylase (68.25%) and α-glucosidase (84.68%) inhibition. Pulp ethyl acetate and acetone fractions also demonstrated strong α-glucosidase inhibition (81.53% and 80.63%, respectively). Leaf and bark fractions showed moderate activity. Overall, ethyl acetate and acetone fractions were the most active across plant parts. The ethyl acetate fractions of C. dichotoma seed, leaf and bark showed the strongest antioxidant activity with low DPPH IC₅₀ values (21.82, 19.98, and 16.97 µg/mL, respectively) and high FRAP and metal chelation values, comparable to ascorbic acid. These results highlight their potent free radical scavenging potential. The study demonstrated significant acetylcholinesterase inhibitory activity, with methanolic extracts of pulp (45%) and bark (43%) showing the highest inhibition. Acetone and chloroform fractions also displayed notable activity, particularly in seed (51% and 26% respectively), while hexane fractions showed no activity. Hierarchical clustering and correlation matrix analysis indicated strong positive correlations between FRAP values and metal ion-chelation activity, suggesting potential synergistic antioxidant mechanisms. Extracts and fractions of C. dichotoma exhibited mild antibacterial activity, with the ethyl acetate and chloroform fractions showing the highest inhibition zones (up to 1.3 mm) against K. pneumoniae, S. aureus and B. subtilis, though less effective than the positive control. These findings highlight the multifaceted bioactive potential of different plant tissues and their role in mitigating oxidative stress and microbial proliferation. The study integrates these results with existing literature, positing that the cardiovascular and lipid-regulatory effects of cis-vaccenic acid may extend to tissue-specific bioactivities in C. dichotoma. This integrative functional assessment provides a robust foundation for future exploration of the plant’s therapeutic potential, emphasizing its applicability in developing antioxidant, antibacterial, antidiabetic and neuroprotective interventions.