Mint species (Mentha longifolia and Mentha spicata L) growth, essential oil generation and chemical components are impacted by turmeric curcumin applications

Abstract

Mint essential oil has several applications in pharmacy and food industries. As mint species multiplied, active chemicals evolved, resulting in changes in their biological effects. Mint growth in Egypt’s sandy soils is hampered by abiotic stress. Phenols like turmeric curcumin reduce abiotic stress which plant suffers. Finding active chemicals in various aromatic plant species to substitute synthetic ones is an enticing approach to developing a new pharmaceutical regimen; these plants need to be studied to locate active components. Therefore, this study aimed to reduce the potential negative effects of abiotic stress in sand soil on horsemint (Mentha longifolia) and spearmint (Mentha spicata L) by applying turmeric curcumin (as organic elicitor), to assess if growing them in the new reclamation zones is a viable option in order to obtain essential oil naturally. Both species received 0, 30, 60, 90, and 120 mg L−1 turmeric curcumin. Horsemint exposed to 30 mg L−1 turmeric curcumin produced the maximum values of plant length (93 cm), fresh herb (114.73 g plant−1) and dry herb (33.81 g plant−1); spearmint × 30 mg L−1 turmeric curcumin resulted in the greatest amounts of chlorophyll a, chlorophyll b and carotenoids with values of 5.38, 1.83 and 1.45 mg g−1, respectively. The maximum values of eucalyptol (65.44%), camphor (23.81%), carvone (65.95%) and limonene (15.9%) were recorded under 90 mg L−1 turmeric curcumin. Horsemint plants subjected to 60 mg L−1 turmeric curcumin gave the highest essential oil yield (1.52 g plant−1), sesquiterpenes (31.4%), soluble sugars (102.19 mg g−1), free amino acids (8.73 mg g−1), phenols (3.71 mg g−1), flavonoids (5.28 mg g−1), free radical's inhibition (64.35%), protein (17.09%) and nitrogen (1.27 g plant−1); spearmint × 60 mg L−1 turmeric curcumin resulted in the greatest values of monoterpenes (98.76%), nitrogen (2.74%), phosphorous (0.54% or 0.17 g plant−1) and potassium (0.56% or 0.18 g plant−1). Control × spearmint gave the maximum value of sodium (0.17% or 0.04 g plant−1). To mitigate the detrimental effects of stress-related factors on sandy soil, turmeric curcumin can be applied to mint species; additionally, it could broaden the sources of natural products. On the other hand, this work provides as a guide for choosing mint species for usage in industries connected to essential oils based on pertinent components.