https://doi.org/10.17113/fftb.63.02.25.8873

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Development and Application of a Novel ‘Green’ Antibacterial Black Garlic (Allium sativum)-Based Nanogel in Epidermal Wound-Healing

Mariah Sadaf¹, Anamika Das^1,2, Satadal Das³, Subhankar Saha⁴, Ketousetuo Kuotsu⁴ and Paramita Bhattacharjee^1*

¹Department of Food Technology and Biochemical Engineering, Faculty of Engineering and Technology, Jadavpur University, 700032 Kolkata , India

²School of Bio-Science and Engineering, Faculty of Interdisciplinary Science and Technology, Jadavpur University, 700032 Kolkata, India

³Department of Microbiology, Peerless Hospital & B. K. Roy Research Centre, 70009 Kolkata 4, India

⁴Department of Pharmaceutical Technology, Faculty of Engineering and Technology, Jadavpur University, 700032 Kolkata, India

Copyright © 2024 This is a Diamond Open Access article published under CC-BY licence. Copyright remains with the authors, who grant third parties the unrestricted right to use, copy, distribute and reproduce the article as long as the original author(s) and source are acknowledged.

Article history:

Received: 16 September 2024

Accepted: 27 May 2025

Keywords:

black garlic; alliin-rich extract; skin pathogens; epidermal wound-healing; antibacterial topical nanogel

The content of this publication has not been approved by the United Nations and does not reflect the views of the United Nations or its officials or Member States.

Summary:

Research background. Black garlic has been reportedly known to have several health promoting properties compared to fresh, raw garlic. Besides, it is reportedly known that the enzyme alliinase, which converts alliin to allicin is deactivated at a moderately high temperature and therefore strips the typical pungent odor of fresh garlic during fermentation and renders black garlic devoid of the “garlic-like smell”. The alliin-rich extract obtained from black garlic powder has not been reported for its antimicrobial activity till date. The objectives of this study were: to explore the antibacterial/antifungal activity of alliin-rich black garlic extract against Staphylococcus aureus, Escherichia coli and Candida albicans, and furthermore, based on the efficacy of the extract, formulate a topical drug using non-toxic, green ingredients in the form of a nanogel with promising wound-healing property and safe for human use.

Experimental approach. Authenticated fresh garlic (Allium sativum) cloves were first fermented to yield black garlic. Post fermentation, the brownish-black garlic cloves were peeled and ground into powder followed by Soxhlet extraction to obtain an alliin-rich extract. For the second objective, nanogels were formulated using the alliin-rich extract and were subjected to an in vitro release kinetics study. The antibacterial potency of the nanogels was also evaluated against Staphylococcus aureus (ATCC 29213) and Escherichia coli (ATCC 25922 and MDR), following which a skin irritation study was conducted on New Zealand albino rabbits.

Results and conclusions. Soxhlet extraction of pulverized black garlic cloves using distilled water yielded an alliin-rich extract (6.4 mg/100 g garlic), which also contained additional bioactive organosulfur compounds with no reported toxicity. The antimicrobial potency (in terms of its MIC value) of the extract was evaluated against potent skin pathogens and was found to be ~15 µg/mL. The nanogels formulated with the alliin-rich extract exhibited shear-thinning rheology and demonstrated admirable sensory properties when tested by a human panel. The in vitro release kinetics study revealed that there was a burst release of alliin (75 % of its content) from either gel within 5 min. Following skin irritation test performed in New Zealand white Albino male rabbits, no clinical signs of toxicity/mortality, redness or swelling were observed in the animals. Thereafter, the nanogels when applied individually on the epidermal wounds, prevented external infection and accelerated wound healing from day 2 onwards, achieving complete healing by day 7. Moreover, the gel with 4 % extract did not leave a scar on the wounded area after complete healing on day 7, establishing the same to be a promising topical antibacterial nanogel with accelerated epidermal wound-healing property, vis-à-vis a commercial broad spectrum topical gel used as a positive control.

Novelty and scientific contribution. This study is the first to report on a newly developed ‘green’ nanogel containing antimicrobial bioactives, namely, organosulfur compounds (diallyl disulfide, diallyl trisulfide, methyl-allyl-disulfide, methyl-allyl-trisulfide). The nanogel demonstrated promising epidermal wound-healing properties and thus holds promise in clinical applications against common and potent human skin pathogens.