Table 4.

Application of DES/NADES to improve bioactivity of plant metabolites.

Plants	Bioactive Compounds	Extraction Methods Using DES/NADES	Conventional Solvents for Comparison	Results	Refs.
Rosemary (Rosmarinus officinalis L.)	Phenolics	Choline chloride-lactic acid (3:1) and 10% water at 40 °C, 50–60 Hz, for 120 min using UAE.	Pure ethanol	DES-based extracts presented higher antioxidant capacity than the alcohol extract (DPPH and FRAP assays).	[43]
Curcuma longa L.	Curcuminoids	Citric acid-glucose (1:1) and 15% water; matrix-solvent ratio was 0.1/10 g/mL, at 50 °C for 30 min with constant stirring.	Ethanol and methanol	Radical scavenging activity (RSA) of curcuminoids was greater in NADES (87.0%) than in methanol (86.3%) but lower than ethanol (90.0%).	[28]
Fruit Wastes (peel and kernel) of Mangifera pajang Kosterm.	-	Choline chloride-ascorbic acid and 10% water.	Water	Antioxidant capacity against DPPH free radicals of the extract in NADES increased (1.3–14.64%) compared to the antioxidant extract in water.	[47]
Ixora javanica (Blume) DC. flower	Flavonoids and anthocyanins	Choline chloride-propylene glycol (1:1) for 5 min at 57 °C; matrix-solvent ratio was 0.02 g/mL, using UAE.	Ethanol	The selected NADES extract had higher inhibition of DPPH free radical and tyrosinase activity than ethanolic extract.	[52]
Elderberry (Sambucus nigra L.) Flowers	Polyphenols	l-lactic acid-glycine and 15% water; solvent-matrix ratio was 60 mL/g, and stirring at 200 rounds per min.	Deionized water, 60% ethanol, and 60% methanol	The NADES extract showed the highest reducing power and antiradical activity toward DPPH than conventional solvent extracts.	[56]
Onion (Allium cepa L.) peel	Phenolics	Choline chloride-urea-water (1:2:4); MAE at 100 Watt, solvent-matrix ratio was 54.97 mL/g, for 15.03 min.	70% aqueous methanol with Soxhlet extraction	Under the optimized MAE conditions, the NADES extract had the higher antioxidant activity in FRAP assay (636.18 μmol AAE/g dry weight) than extract from conventional solvent.	[48]
Lavandula pedunculata subsp. lulsitanica (Chaytor) Franco	Phenolic	Choline chloride-urea (1:2); UAE for 60 min.	Water, 80% ethanol and methanol	The extract in selected NADES showed higher antioxidant activity (DPPH and ABTS assay) than extract in the conventional solvent. In addition, this extract also provides good activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes, but it was less potent against tyrosinase (Tyr).	[49]
Cinnamon bark (Cinnamomum burmannii (Nees & T.Ness) Blume))	trans-cinnamaldehyde, coumarin, and trans-cinnamic acid	Choline chloride-glycerol (2:1) with 20% water content; matrix-solvent ratio was 1:4 w/w; UAE, 35 W, 42,000 Hz for 30 min.	96% ethanol	NADES extraction from cinnamon had DPP IV inhibitory activity of 205.0 μg/mL.	[53]
Sappan wood (Caesalpinia sappan L.)	Brazilin	Choline chloride-glycerol (1:2) 47.6 % water content; matrix-solvent ratio was 2:1 w/w; UAE, 35 W, 42,000 Hz for 50 min.	96% ethanol	NADES extract from sappan wood had DPP IV inhibitory activity 1254.0 μg/mL.	[53]
The aerial part of Sideritis scardica Griseb. and Plantago major L.	Phenolics and flavonoids	Choline chloride-glycerol (1:2) with 30% water; citric acid-1,2-propanediol (1:4); extraction using UAE without heating for 1 h.	70% ethanol	NADES extracts were effective against Streptococcus pyogenes, Escherichia coli, Staphylococcus aureus, and Candida albicans. They also have minimal genotoxicity and cytotoxicity.	[55]
Grape pomace from Vitis vinifera L. and Olive pomace	Phenolics	Choline chloride-citric acid (2:1) with 30% water; extraction using UAE and MAE.	70% ethanol	In HeLa and MCF-7 cells, the NADES extracts of both pomaces were more cytotoxic than the ethanolic extract.	[57]
Astragali Radix (Mikvetch Root)	Flavonoids and saponins (acetylastragaloside I)	Glucose-fructose-sucrose (32:32:5 by weight) and water.	-	The NADES-imitated honey enhanced the quantities of active components as well as their immunological effectiveness.	[58]
Grape skin (Vitis vinifera L.)	Phenolics	Choline chloride-malic acid (1:1) with 30% water; UAE, at 65 °C, for 50 min.	70% methanol	The NADES extract had the highest antioxidant (ORAC values were 371 μmol TE/g dry weight) and antiproliferative activities (about 20% of the cells were viable.).	[59]
Mentha piperita L.	Phenolics	Choline chloride-malic acid (1:1) Choline chloride-sorbitol (1:1) Choline chloride-fructose (1:1)	70% ethanol	The NADES containing organic acids showed bacterial growth inhibition at a lower concentration than conventional solvent. In FRAP test, most NADES extracts were able to neutralize DPPH radicals better than 70% ethanol and had a similar capacity to decrease Fe3+ to Fe2+ ions.	[36]