Laser Seed Pretreatment Alters the Silybin Content and Anti-Dictyostelium discoideum Cell Growth Activity of Silybum marianum (L.) Fruit

Silybum marianum is a medicinal plant that produces silybins A and B, which exhibit liver-protective activities. The He–Ne laser pre-sowing seed treatment has been used as a physical biostimulator in numerous plants to promote seed germination, plant growth, and secondary metabolite production. Thus, in this study, a He–Ne laser at 632.8 nm was used to irradiate S. marianum seeds with the aim of promoting plant growth as well as enhancing the production of silybin (A + B). The seeds were irradiated with a He–Ne laser for 2, 4, 6, 8, and 10 min. The growth attributes of the plants, as well as the silybin (A + B) content and bioactivities of fruit extracts from various treatment groups, were compared. The results indicated that all laser seed treatments resulted in a subsequent increase in plant growth, with the highest yield observed in the 10 min laser treatment. An increase in fruit silybin (A + B) content and in chalcone synthase gene expressions were observed in plants from the 6-, 8-, and 10-min laser-irradiated seeds. The highest silybin (A + B) contents were observed in plants from the 6-min-irradiated seeds. Furthermore, the corresponding fruit extract also exhibited elevated cell growth inhibition in the Dictyostelium discoideum cell model

<i>Spirulina platensis</i> Foliar Spraying <i>Curcuma longa</i> Has Improved Growth, Yield, and Curcuminoid Biosynthesis Gene Expression, as Well as Curcuminoid Accumulation

The application of Spirulina platensis aqueous extract (SAE) in foliar spraying has been shown to promote plant growth and yield, as well as to modify the compositions of bioactive chemicals in various plant species. Curcuma longa is an antioxidant-rich medicinal herb that is used as a spice and culinary additive. The application of a natural plant growth enhancer, SAE, to C. longa plants was used in this study to test the effect of SAE for increasing active chemical production. The effects of SAE on the growth, yield and chemical composition of C. longa were investigated. SAE boosted the C. longa growth, yield and curcuminoid content, with SAE at 2 g/L having the most impact. The CURS-1, -2, -3 and DCS genes were found to be differentially elevated by SAE treatments in this investigation. When the plant was sprayed with SAE at 2 g/L, the curcuminoid content (bisdemethoxycurcumin, dimethoxycurcumin and curcumin) increased, which corresponded with the curcuminoid gene’s expression level

Foliar Spraying of Salicylic Acid Enhances Growth, Yield, and Curcuminoid Biosynthesis Gene Expression as Well as Curcuminoid Accumulation in <i>Curcuma longa</i>

The application of exogenously applied salicylic acid plays important roles in improving the growth, yield, and bioactive compound compositions of different plant species. Curcuma longa is a medicinal plant that is commonly used as a spice and food additive, and has antioxidant potential. In this study, an innovative strategy for enhancing active compound production was investigated by applying a natural plant growth enhancer—namely, salicylic acid (SA)—to C. longa plants. The experiment was conducted using a complete randomized block design. The effects of SA on the growth, yield, and chemical compound contents of C. longa were recorded. Our findings demonstrated that SA significantly improved C. longa growth, yield, and curcuminoid content when compared to control treatment, with SA at 10−3 M having the greatest effect. The study also indicated that the increase in the curcuminoid content was accompanied by the overexpression of the curcumin synthase 1 (CURS1), 2 (CURS2), and 3 (CURS3) genes, as well as the diketide-CoA synthase (DCS) gene, which have been implicated in the synthesis of curcuminoids

Salicylic Acid Foliar Spray Enhanced <i>Silybum marianum</i> Growth and Yield, as Well as Its Chemical Constituents and <i>Chalcone Synthase</i> Gene Activity

Silymarin, a secondary metabolite found mainly in the Silybum marianum L. fruits, has been associated with the hepatoprotective activity of the plant. Among various elicitors, salicylic acid, a “Generally Regarded As Safe” compound recognized by the Food and Drug Administration, is one of those being used in the induction and enhancement of valuable plant secondary metabolite production in various plant species. In this study, two concentrations (10−4 and 10−3 molar) of salicylic acid have been applied to the S. marianum plants as foliar spray to investigate their effects on plant growth and yield, as well as the production of its bioactive compound, silymarin. Our results indicated that both concentrations of salicylic acid increased the plant height, the number of branches, leaves, and capitula, as well as the dried weight of roots, aerial parts, and fruits. The enhancement effects in plant growth and yield were accompanied by an increase in photosynthetic pigments such as chlorophyll-a, b, and carotenoids as well as element contents such as nitrogen, phosphorus, and potassium. The potential of salicylic acid as an elicitor for the enhancement of secondary metabolites in S. marianum was supported by the increase in silymarin’s major components, silybin (A + B), in the salicylic acid-treated plants. Concomitant expressions of CHS1, 2, and 3 genes that have been associated with the production of silymarin in S. marianum were also observed in the salicylic acid-treated plants. A lower concentration (10−4 M) of salicylic acid was found to be a better elicitor as compared with the 10−3 M salicylic acid. An increase of 3.4 times in capitula number and fruit dried weight as well as 2.6 times in silybin (A + B) contents were observed in plants sprayed with 10−4 M of salicylic acid as compared with the control

Selection of Salt-Tolerant Jojoba (<i>Simmondisa chinensis</i> L.) Cultivars via In Vitro Culture

Jojoba (Simmondsia chinensis L.) is a perennial shrub adapted to dry and hot climates. It produces high-quality seed oil that is widely used in the industrial, cosmetic, and pharmaceutical sectors. Soil salinity is often a constraint to plants grown under dry and hot desert conditions. Thus, in the present study, we aim to select and establish salt tolerant-jojoba cultivars using in vitro culture. Jojoba seeds were sown on germination media that were supplemented with various amounts of seawater to achieve the final solute concentrations of 2000-, 3000-, and 5000 ppm. Shoot tips from seedlings selected on germination media with different solute levels were subsequently cultured on multiple-shoot induction media, followed by root induction media at the same solute levels as the germination media from which the explants were selected. We germinated, multiplied, rooted, and acclimatized cultivars that could sustain solute levels up to 3000 ppm. Among all cultivars selected at different salinity levels, those selected at 2000 ppm were found to have the highest growth and multiplication parameters during the multiple-shoot induction and rooting stages. In addition, these cultivars also contained high levels of chlorophyll a, b, and carotenoid contents

Bio-Stimulant for Improving <i>Simmondsia chinensis</i> Secondary Metabolite Production, as Well as Antimicrobial Activity and Wound Healing Abilities

Simmondsia chinensis is a dioecious, long-lived perennial shrub. Its leaves contain several antioxidant flavonoids that have numerous pharmacological effects. Various strategies have been explored to propagate jojoba with enhanced pharmacological values. This research evaluates the bio-stimulatory impacts of He–Ne laser seed irradiation on seed germination, plantlet growth, and alteration of the composition and bioactivities of phytochemicals in jojoba plants. Jojoba seeds were irradiated for 5, 10, and 15 min before in vitro germination. Germination, growth, and multiplication parameters were recorded during germination, multiple-shoot induction, and rooting stages. The wound healing and antimicrobial activities of methanolic extracts from plant lines obtained from the non-irradiated (control) and 10 min irradiated seeds were compared by excision wound model in Wistar male rats and zone of inhibition assay. Our study revealed that laser irradiation increased seed germination, with the highest percentage observed in seeds irradiated for 10 min. Plant lines from the 10 min irradiated seeds produced more explants with higher explant heights and numbers of leaves, more roots, and higher photosynthetic pigment contents than those of control and other laser testings. By comparing plant extracts from the control and 10 min treatments, we observed that extracts from the 10 min treatment exhibited higher percentages of wound contraction and shorter epithelialization periods. In addition, these extracts also resulted in higher levels of angiogenesis elements (VEGF, TGF-β1, and HIF-1α) and reduced the inflammation regulators (IL-1β, IL-6, TNF-α, and NFκB) in the experimental rats. In concordance, extracts from the 10 min treatment also explained raised antibacterial activities towards Staphylococcus aureus and Escherichia coli. Our findings show that pre-sowing seed treatment with a He–Ne laser (632.8 nm) could be a good technique for stimulating S. chinensis plant growth and increasing the impact compound levels and biological activities

In Vitro Micropropagation of Endangered <i>Achillea fragrantissima</i> Forssk. Combined with Enhancement of Its Antihyperglycemic Activity

Achillea fragrantissima Forssk. (Family: Asteraceae) has been used as a natural remedy in the Arabian region for its antihyperglycemic activity. As a result of the intensive demand for this plant in folk medicinal uses, its scarcity has become problematic. This study has explored methods that produce an efficient in vitro culture protocol for the conservation of this plant as well as the enhancement of its hypoglycemic activity. A. fragrantissima cultures on Murashige and Skoog (MS) medium supplemented with 3.6 µM/L of 6-benzyl aminopurine (BAP) for a two month period resulted in maximum in vitro shoot proliferation (12.33 shoots/explant) while MS medium supplemented with 2.4 µM/L 1-naphthalene acetic acid (NAA) provided maximum in vitro adventitious root formation (2.46 roots/shoot tip explant). Callus induction was favored by leaf explants cultured on MS medium and supplemented with 3 µM/L BAP and 3 µM/L IAA media in dark conditions. Further in vivo study of some selected feedings determined that the best hypoglycemic activity was obtained in either indole-3-butyric acid (IBA)-fed plants (24%) or NAA-fed plants (22%). Both treatments enhanced insulin-like activity in STZ-treated diabetic Sprague-Dawley rats when compared with the wild plant (10%). Moreover, the IBA-fed plants showed significant antioxidant activity while the NAA-fed plants inhibited salivary alpha amylase. The framework of this study provides in vitro culture methods that can sustain the cultivation of this over-exploited A. fragrantissima plant as well as increase its antioxidant and insulin-like activities

In Vitro Micropropagation of Endangered Achillea fragrantissima Forssk. Combined with Enhancement of Its Antihyperglycemic Activity

Achillea fragrantissima Forssk. (Family: Asteraceae) has been used as a natural remedy in the Arabian region for its antihyperglycemic activity. As a result of the intensive demand for this plant in folk medicinal uses, its scarcity has become problematic. This study has explored methods that produce an efficient in vitro culture protocol for the conservation of this plant as well as the enhancement of its hypoglycemic activity. A. fragrantissima cultures on Murashige and Skoog (MS) medium supplemented with 3.6 &micro;M/L of 6-benzyl aminopurine (BAP) for a two month period resulted in maximum in vitro shoot proliferation (12.33 shoots/explant) while MS medium supplemented with 2.4 &micro;M/L 1-naphthalene acetic acid (NAA) provided maximum in vitro adventitious root formation (2.46 roots/shoot tip explant). Callus induction was favored by leaf explants cultured on MS medium and supplemented with 3 &micro;M/L BAP and 3 &micro;M/L IAA media in dark conditions. Further in vivo study of some selected feedings determined that the best hypoglycemic activity was obtained in either indole-3-butyric acid (IBA)-fed plants (24%) or NAA-fed plants (22%). Both treatments enhanced insulin-like activity in STZ-treated diabetic Sprague-Dawley rats when compared with the wild plant (10%). Moreover, the IBA-fed plants showed significant antioxidant activity while the NAA-fed plants inhibited salivary alpha amylase. The framework of this study provides in vitro culture methods that can sustain the cultivation of this over-exploited A. fragrantissima plant as well as increase its antioxidant and insulin-like activities