Kenaf (Hibiscus cannabinus L.) Leaves and Seed as a Potential Source of the Bioactive Compounds: Effects of Various Extraction Solvents on Biological Properties.

Md. Adnan,Ki Kwang Oh,Myung Hwan Shin,Myeong-Hyeon Wang,Md Obyedul Kalam Azad,Dong Ha Cho

doi:10.3390/life10100223

Abstract

Hibiscus cannabinus (Kenaf) is a potential source of bioactive constituents and natural antioxidant. The current study determined the impact of various solvents on extraction yield, recovery of polyphenol and flavonoid, antioxidant, anticancer, and antibacterial properties of Kenaf leaves and seed. The powder of leaves and seed was separately extracted with n-hexane, ethyl acetate, ethanol, and water solvent. Among them, the ethanol extract of leaves and seed showed the highest extraction yield, and their GC-MS analysis revealed a total of 55 and 14 bioactive compounds, respectively. The total polyphenols (TP) and flavonoids (TF) content were quantified by a spectrophotometric technique where water extracts displayed a noteworthy amount of TP and TF content compared to other extracts. A similar demonstration was noticed in antioxidant activity, evaluated by DPPH (2,2-diphenyl-1-picrylhydrazyl) and hydrogen peroxide scavenging capacity. In addition, cytotoxicity and anti-lung cancer activity were identified against mouse embryonic fibroblast (NIH3T3) and human lung cancer (A549) cells. All extracts of leaves and seed were observed as non-toxic to the NIH3T3 cells, but slight toxicity was expressed by n-hexane extracts at the optimum dose (1000 µg/mL) of treatment. In parallel, n-hexane and ethanol extracts (leaves and seed) exposed promising anti-lung cancer activity at the same concentration. Furthermore, antibacterial activity was assessed using disc diffusion assay, and seed extracts exhibited a significant inhibition zone against Gram-positive and Gram-negative microorganisms. Overall, Kenaf seed extracted with polar solvents was found very potent in terms of important bioactive compounds and pharmacological aspects, which can be an excellent biological matrix of natural antioxidants.

Highlights

One of the common manifestations of living cells is the generation of harmful pro-oxidants and reactive oxygen species (ROS), produced either due to the biological dysfunctions or as a result of cellular metabolisms [1]
In this study, we aimed to identify the content of secondary metabolites, antioxidant, anticancer, and antibacterial properties of Kenaf leaves and seed
Various parts of a plant occupy a pool of bioactive compounds containing potential chemical groups which consistently protect both plants and humans from cellular oxidative damage [20]

Summary

Introduction

One of the common manifestations of living cells is the generation of harmful pro-oxidants and reactive oxygen species (ROS), produced either due to the biological dysfunctions or as a result of cellular metabolisms (byproducts) [1] Such free radicals may induce oxidative damage to proteins, lipids, and nucleic acids and lead to several life-threatening conditions, including cancer, neurodegenerative. Many synthetic antioxidants, including butylated hydroxytoluene (BHT), tertiary butyl hydroquinone (TBHQ), and butylated hydroxyanisole (BHA) are widely added during food processing, preservation, as well as when preventing deterioration of color and texture [4]. These antioxidants have emerged as hazardous for human health in recent times [5]. Investigation of valuable plants that possess abundant phenolics and other bio-active compounds must be screened meticulously in search for novel bioactive and safe antioxidants

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