Free-radical-scavenging and antioxidant capacities with special emphasis on enzyme activities and in vitro studies in Caralluma flava N. E. Br

Antioxidant and Hypoglycemic Potential of Phytogenic Selenium Nanoparticle- and Light Regime-Mediated In Vitro Caralluma tuberculata Callus Culture Extract

In vitro plant cultures have emerged as a viable source, holding auspicious reservoirs for medicinal applications. This study aims to delineate the antioxidant and hypoglycemic potential of phytosynthesized selenium nanoparticle (SeNP)- and light stress-mediated in vitro callus cultures of Caralluma tuberculata extract. The morphophysicochemical characteristics of biogenic SeNPs were assessed through a combination of analytical techniques, including UV-visible spectrophotometry, scanning electron microscopy, energy-dispersive X-rays, Fourier transform infrared spectrometry, and zeta potential spectroscopy. The antioxidative potential of the callus extract 200 and 800 μg/mL concentrations was assessed through various tests and exhibited pronounced scavenging potential in reducing power (26.29%), ABTS + scavenging (42.51%), hydrogen peroxide inhibition (37.26%), hydroxyl radical scavenging (40.23%), and phosphomolybdate (71.66%), respectively. To inspect the hypoglycemic capacity of the callus extract, various assays consistently demonstrated a dosage-dependent relationship, with higher concentrations of the callus extract exerting a potent inhibitory impact on the catalytic sites of the alpha-amylase (78.24%), alpha-glucosidase (71.55%), antisucrase (59.24%), and antilipase (74.26%) enzyme activities, glucose uptake by yeast cells at 5, 10, and 25 mmol/L glucose solution (72.18, 60.58 and 69.33%), and glucose adsorption capacity at 5, 10, and 25 mmol/L glucose solution (74.37, 83.55, and 86.49%), respectively. The findings of this study propose selenium NPs and light-stress-mediated in vitro callus cultures of C. tuberculata potentially operating as competitive inhibitors. The outcomes of the study were exceptional and hold promising implications for future medicinal applications.

Exposure of Caralluma tuberculata to biogenic selenium nanoparticles as in vitro rooting agent: Stimulates morpho-physiological and antioxidant defense system

The commercial-scale production of Caralluma tuberculata faces significant challenges due to lower seed viability and sluggish rate of root growth in natural conditions. To overcome these obstacles, using phyto-mediated selenium nanomaterials as an in vitro rooting agent in plant in vitro cultures is a promising approach to facilitate rapid propagation and enhance the production of valuable therapeutic compounds. This study aimed to investigate the impact of phytosynthesized selenium nanoparticles (SeNPs) on the morphological growth attributes, physiological status, and secondary metabolite fabrication in in vitro propagated Caralluma tuberculata. The results demonstrated that a lower dose of SeNPs (100 μg/L) along with plant growth regulators (IBA 1 mg/L) had an affirmative effect on growth parameters and promoted earliest root initiation (4.6±0.98 days), highest rooting frequency (68.21±5.12%), number of roots (6.3±1.8), maximum fresh weight (710±6.01 mg) and dry weight (549.89±6.77 mg). However, higher levels of SeNPs (200 and 400 μg/L) in the growth media proved detrimental to growth and development. Further, stress caused by SeNPs at 100 μg/L along with PGRs (IBA 1 mg/L) produced a higher level of total chlorophyll contents (32.66± 4.36 μg/ml), while cultures exposed to 200 μg/L SeNPs alone exhibited the maximum amount of proline contents (10.5± 1.32 μg/ml). Interestingly, exposure to 400 μg/L SeNPs induced a stress response in the cultures, leading to increased levels of total phenolic content (3.4 ± 0.052), total flavonoid content (1.8 ± 0.034), and antioxidant activity 82 ± 4.8%). Furthermore, the combination of 100 μg/L SeNPs and plant growth regulators (1 mg/L IBA) led to accelerated enzymatic antioxidant activities, including superoxide dismutase (SOD = 4.4 ± 0.067 U/mg), peroxidase dismutase (POD = 3.3 ± 0.043 U/mg), catalase (CAT = 2.8 ± 0.048 U/mg), and ascorbate peroxidase (APx = 1.6 ± 0.082 U/mg). This is the first report that highlights the efficacy of SeNPs in culture media and presents a promising approach for the commercial propagation of C. tuberculata with a strong antioxidant defense system in vitro.

Phytochemical profile and antioxidant capacity of some wild edible plants consumed in Southwest Ethiopia

Wild edible plants (WEPs) such as Solanum nigrum L., Vigna membranacea A. Rich., Dioscorea praehensilis Benth., Trilepisium madagascariense DC., and Cleome gynandra L. are widely used for various forms of culinary and folk medicine in Southwest Ethiopia. However, the phytochemical content of these plants is not explored. Thus, this study aimed to determine the total phenols, flavonoids, antioxidants, vitamin C, and β-carotene in edible parts of the plants. Edible parts were oven-dried and extracted with methanol. Total phenolic content (TPC) and total flavonoid content (TFC) were determined using Folin Ciocalteu and Aluminium chloride colorimetric methods, respectively. In vitro, antioxidant activities were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) tests. β-carotene and vitamin C content were assessed using spectrophotometric and titration, respectively. TPC ranged from 0.25 ± 0.06 mg GAE/g in D. praehensilis tuber to 35.73 ± 2.52 mg GAE/g in S. nigrum leaf, while TFC varied from 0.85 ± 0.03 to 11.25 ± 0.01 mg CE/g in D. praehensilis tuber and C. gynandra leaf. In the DPPH assay, the antioxidant value ranged from 50.09% in D. praehensilis tuber to 87.63% in S. nigrum leaf; while in the FRAP assay, the value ranged from 49.16 ± 2.13 in D. praehensilis tuber to 188.12 ± 1.13 mM Fe²⁺/100 g in S. nigrum leaf. Similarly, β-carotene content was recorded between 11.81 ± 0.00 mg/100g in D. praehensilis tuber to 34.49 ± 0.95 mg/100g in V. membranacea leaf. The concentration of vitamin C ranged from 10.00 ± 0.61 in D. praehensilis tuber to 45 ± 1.80 mg/100g in V. membranacea leaf. The results showed strong positive correlations between FRAP and TPC (r = 0.94), and FRAP and vitamin C (r = 0.93). S. nigrum and C. gynandra contain abundant levels of TPC and TFC. V.membranacea leaf contains a good source of vitamin C and β-carotene. These WEPs contribute a natural supply of dietary antioxidants that prevent oxidative stress.

In vitro antioxidant activities of Carissa edulis ((Forssk) Vahl) and Pappea capensis (Eckyl. & Zeyh) extracts

Herbal medications are gaining popularity due to their long history of use in traditional medicine. They serve as a reservoir for a diverse array of phytocompounds linked to amelioration of oxidative stress. Oxidative stress is a disturbance in the balance between generation and elimination of reactive species in human body. Moreover, reactive species are implicated in the onset and progression of chronic disorders. The current therapeutic approaches despite showing efficacy are characterized by several limitations such as adverse effects and prohibitive costs. This drives the need to explore alternatives that can inhibit, ameliorate or reverse conditions caused by oxidative stress. Several studies have evaluated antioxidant effects of diverse plant extracts. C. edulis and P. capensis are used as traditional therapy among the African communities to manage oxidative stress-related ailments. However, there is limited research on the antioxidant effects of these medicinal plants. The current study, therefore, sought to evaluate the antioxidant and phytochemical profile, of C. edulis and P. capensis extracts. Samples were collected from Embu County, Kenya. In vitro antioxidant properties of the extracts were evaluated through ferric reduction, Iron chelating, hydroxyl radical, and DPPH radical scavenging activities. Activities of catalase, superoxide dismutase and glutathione reductases of the extracts were further determined. Phytochemical profiles were determined using Liquid Chromatography Mass Spectrophotometer (LC-MS) and Gas Chromatography Mass Spectrophotometer (GC-MS) analyses. The extracts displayed concentration dependent antioxidant activities. Phytochemical analyses revealed presence compounds which are associated with antioxidant activities including flavonoids, phenolics, tocopherols and terpenoids. The findings provide a scientific validation for the folklore use of C. edulis and P. capensis in management of oxidative stress. Nevertheless, there is a need for further purification and characterization of phytochemicals associated with antioxidant activities.

Phytochemical screening and in vitro evaluation of antioxidant and DNA inhibition activity of Caralluma bhupenderiana Sarkaria

Introduction and Aim: Phytochemicals isolated from medicinal plants have been receiving greater attention owing to their potential therapeutic efficiency. Despite rapid developments in the field of modern medicine various herbal medications are being used to treat different types of health disorders. Caralluma bhupenderiana Sarkaria is an endemic species of the genus Caralluma. Although selected species of Caralluma have been investigated for their medicinal properties, no studies have addressed the composition of bioactive phytochemicals and its therapeutic properties. The objective was to screen the endogenous composition of C. bhupenderiana extract and evaluate its antioxidant and DNA damaging inhibitory activity. Materials and Methods: Antioxidant potential of C. bhupenderiana was determined by measuring the ability of the extracts to scavenge free radicals. Chemical bonding and structural aspects of the phytochemicals were determined by FT-IR and GC-MS. Plasmid DNA (pBR322) damage inhibition was determined by photolyzing H2O2 and exposing to ultra-violet radiation. Results: The extract was rich in flavonoids, phenols, quinones, glycosides and saponins. FT-IR analysis revealed the presence of functional groups to be ‘polymeric’ OH stretch, /Methylene C-H asymmetric, esters with double bond, cyclic alkene/organic nitrates, nitro compound, ammonium ion, sulfonates. C. bhupenderiana exhibited significant antioxidant activity as evidenced by its free radical scavenging activity. The extract also exhibited complete protection against DNA damage caused by UV irradiation. Conclusion: C. bhupenderiana contains various endogenous phytochemicals that offer high antioxidant potential along with significant ability to attenuate DNA damage. C. bhupenderiana is highly therapeutic in nature and can be a good candidate for developing novel pharmacological and therapeutic molecules.

Effects of enhanced UV-B radiation on the interaction between rice and Magnaporthe oryzae in Yuanyang terrace

Enhanced ultraviolet-B (UV-B) radiation affected the growth of rice and Magnaporthe oryzae, and changed the interactions between them. Increased UV-B radiation (5.0 kJ m-2 d-1) on rice leaves in a Yuanyang terrace was conducted before, during, and after infection of the leaves with Magnaporthe oryzae. The relationship between rice blast and UV-B radiation on the disease resistance of rice and the pathogenicity of M. oryzae was studied, and the effects of enhanced UV-B radiation on the interactions between rice and M. oryzae were analysed. The results indicated the following: (1) enhanced UV-B radiation significantly reduced the rice blast disease index, but as infection progressed, the inhibitory effect of UV-B radiation on the disease was weakened. (2) UV-B radiation treatment before infection with M. oryzae (UV-B + M.) significantly increased the activity of the enzymes related to disease resistance (phenylalanine ammonia lyase, lipoxygenase, chitinase, and β-1,3-glucanase), and the plants exhibited light-induced resistance. (3) Exposure to UV-B radiation after M. oryzae infection (M. + UV-B) did not induce disease course-related protein (PR) activity, but the content of soluble sugar increased. The osmotic stress caused by pathogenic fungi infection was alleviated by active accumulation of soluble sugar; due to this lack of nutrients, it was difficult for the rice blast fungus to grow. (4) Enhanced UV-B radiation significantly inhibited the production of conidia by M. oryzae, and the expression of the pathogenic genes Chitinase, MGP1, MAGB, and CPKA was significantly downregulated. The pathogenicity of M. oryzae was reduced by UV-B radiation. The resistance of rice leaves was weakened by simultaneous exposure to UV-B radiation and M. oryzae (UV-B/M.). Hence, UV-B radiation can weaken the infectivity of M. oryzae, improve the resistance of traditional rice, and contain the disease.