A Comprehensive Review on the Antioxidant and Anti-Inflammatory Bioactives of Kiwi and Its By-Products for Functional Foods and Cosmetics with Health-Promoting Properties

The Therapeutic Potential of Kiwi Extract as a Source of Cysteine Protease Inhibitors on DNCB-Induced Atopic Dermatitis in Mice and Human Keratinocyte HaCaT Cells

The discovery of effective cysteine protease inhibitors with crude protein kiwi extracts (CPKEs) has created novel challenges and prospects for pharmaceutical development. Despite extensive research on CPKEs, limited research has been conducted on treating atopic dermatitis (AD). Therefore, the objective of this work was to investigate the anti-inflammatory effects of CPKEs on TNF-α activation in a HaCaT cell model and in a DNCB (1-chloro-2, 4-dinitrochlorobenzene)-induced atopic dermatitis animal model. The molecular weight of the CPKE was determined using SDS-PAGE under non-reducing (17 kDa and 22 kDa) and reducing conditions (25 kDa, 22 kDa, and 15 kDa), whereas gelatin zymography was performed to examine the CPKE's inhibitory impact on cysteine protease (actinidin and papain) activity. Moreover, the CPKE remains stable at 60 °C, with pH levels varying from 4 to 11, as determined by the azocasein assay. CPKE treatment decreased the phosphorylation of mitogen-activated protein kinase (MAPK) and Akt, along with the activation of nuclear factor-kappa B (NF-κB)-p65 in tumor necrosis factor-α (TNF-α)-stimulated HaCaT cells. Five-week-old BALB/c mice were treated with DNCB to act as an AD-like animal model. The topical application of CPKE to DNCB-treated mice for three weeks substantially decreased clinical dermatitis severity and epidermal thickness and reduced eosinophil infiltration and mast cells into ear and skin tissues. These findings imply that CPKE derived from kiwifruit might be a promising therapy option for inflammatory skin diseases such as AD.

Evaluating the Efficacy of Actinidia deliciosa (Kiwi Fruit) Extract in Inhibiting Pseudomonas aeruginosa Biofilm Formation: An In Vitro Study With Therapeutic Implications

Background Gram-negative Pseudomonas aeruginosa is a common bacteria that is well-known for its capacity to build biofilms, which are organized cell communities encased in a self-produced polymeric matrix. Treating infections becomes more challenging due to biofilms' capacity to provide immunity and resistance to antibiotics. The search for novel anti-biofilm agents has gained significant momentum, and the diverse range of bioactive compounds found in natural products offers a promising avenue. Rich in vitamins, antioxidants, and various phytochemicals, Actinidia deliciosa (kiwi fruit) has demonstrated potential as an antibacterial agent. Aim of the study This study aims to assess the efficacy of A. deliciosa extract in inhibiting biofilm formation by P. aeruginosa in vitro, providing valuable insights into its potential as a natural therapeutic agent for preventing recurrent bacterial infections. Materials and methodology The antibacterial and antibiofilm properties of A. deliciosa (kiwi fruit) methanolic extract were assessed in this study against P. aeruginosa (PAO1). The fruit was gathered, examined by a botanist for authenticity, and then cold macerated in methanol to create an extract. A two-fold broth dilution procedure was used to calculate the minimum inhibitory concentration (MIC), and agar well-diffusion was used to evaluate the antimicrobial activity. Pyocyanin pigment quantification was carried out after the extract was applied, and the antibiofilm impact was evaluated using a crystal violet assay. GraphPad Prism (GraphPad Software, San Diego, CA) was used for statistical analysis. Results Based on our findings, A. deliciosa was shown to have significant antibacterial and antibiofilm properties against P. aeruginosa (PAO1). At 5 mg/mL, the methanolic extract of A. deliciosa exhibited antibacterial activity with an 8 mm zone of inhibition and suppressed PAO1 growth. At 2.5 mg/mL and 1.25 mg/mL doses, PAO1 significantly decreased the production of biofilms by 60% and 29%, respectively. In addition, pyocyanin pigment synthesis was decreased by 30% and 9.25%, respectively, at sub-MIC doses of 2.5 mg/mL and 1.25 mg/mL. When evaluated at 2.5 mg/mL, the extract did not, however, appreciably affect bacterial growth. Conclusion This study enhances the understanding of antibiotic resistance, alternative treatments, and pathogenic microbes. The in vitro findings suggest that A. deliciosa fruit extract may inhibit pyocyanin production in PAO1. Further research with different formulations is recommended to explore its anti-biofilm properties and potential pharmacological applications.