Exploring Chemical Profiles and Bioactivities of Harungana madagascariensis Lam. ex Poir. Leaves and Stem Bark Extracts: A New Source of Procyanidins

Abstract

This study attempts to valorize the multiple pharmacological properties of Harungana madagascariensis Lam. ex Poir., also known as dragon’s blood tree, with wide applications in African traditional medicine. The antioxidant and inhibitory activity of H. madagascariensis leaves and stem bark extracts (ethyl acetate, aqueous extracts, and methanol) against enzymes related to diabetes (α-glucosidase, α-amylase), epidermal hyperpigmentation problems (tyrosinase), and Alzheimer’s disease (acetyl and butyryl cholinesterase) were evaluated. The phytochemical profiles of the extracts were studied by high-performance liquid chromatography with diode array detection and mass spectrometry (HPLC-DAD-MS), observing the presence of procyanidins and flavonoids, particularly in the leaves’ extracts. The radical scavenging and reducing power of H. madagascariensis leaves’ extracts were greater than the stem bark extracts. The methanol extracts of leaves (4.61 mg galantamine equivalent (GALAE)/g extract) and stem bark (4.68 mg galantamine (GALAE)/g extract) of H. madagascariensis inhibited acetyl cholinesterase. Methanol extracts (153.55 and 147.07 mg kojic acid equivalent (KAE)/g extract, for leaves and stem bark extracts, respectively) of H. madagascariensis showed high tyrosinase inhibition. Correlation and principal component analysis (PCA) were also performed. The observed pharmacological effects of H. madagascariensis support that this plant may be a promising candidate for the development of novel pharmacophores for the treatment of diabetes, epidermal hyperpigmentation problems, Alzheimer’s disease, and other oxidative-stress-related complications.

Keywords:

• Alzheimer’s disease
• diabetes
• high-performance liquid chromatography with diode array and mass spectrometry detection (HPLC-DAD-MS)
• phenolic
• principal component analysis (PCA)

Acknowledgements

The technical and human support provided by CICT of Universidad de Jaén (UJA, MINECO, Junta de Andalucía, FEDER) is gratefully acknowledged.