Exploring the potential of underrated yet versatile crop Lunaria annua L.: New insights into honesty plant.

Lunaria annua is an underexplored crop with promising potential for use in various industries: food, oil etc. It grows rapidly, has low maintenance and high resistance to pathogens, which makes it a promising crop for sustainable cultivation. Herein, we investigated nutritional value, phenolic profile, and bioactive properties of L. annua seeds collected in the wild. The results we obtained indicate that seeds of L. annua have high energy value (406.6 kcal/100 g dw), with high share of carbohydrates (65.2 g/100 g dw), followed by proteins (26.47 g/100 g dw) and fat (4.46 g/100 g dw). Free sugar analysis showed presence of fructose, glucose and sucrose (0.77 g, 0.189 g and 3.85 g/100 g dw, respectively). Oxalic and malic acid were quantified <1.0 g/100 g dw and fumaric acid only in trace. Monounsaturated fatty acids were predominant over polyunsaturated and saturated fatty acids (erucic, nervonic and oleic acid were dominant). The content of flavonoid compounds was several times higher than the content of phenolic acids (58.5 vs 9.4 mg/g). Methanolic extract showed better antioxidant potential than dichloromethane extract (EC(50) = 0.32 vs. 1.25 mg/mL, in TBARS test). The antibacterial activity ranged from 0.50 to 2.00 mg/mL, with E. coli showing the highest susceptibility to the methanolic extract (MIC: 0.25 mg/mL, MBC: 0.50 mg/mL). The other tested microorganisms showed quite uniform susceptibility to the extracts, but better than the positive controls E211 and E224. The tested samples demonstrated encouraging antifungal/anticandidal properties, and no cytotoxic effects onto spontaneously immortalized keratinocytes cell line HaCaT, indicating its safe application in terms of dermal exposure. Overall, our results indicate that L. annua seeds may be considered as source of compounds used in food and pharmaceutical industry and a candidate for functional ingredient that provides additional health benefits beyond basic nutritional requirements.