Characterization of Lacticaseibacillus rhamnosus, Levilactobacillus brevis and Lactiplantibacillus plantarum Metabolites and Evaluation of Their Antimicrobial Activity against Food Pathogens

Lactic acid bacteria (LAB) play an important role as natural food preservatives. However, the characterization of the variety of their metabolites is limited. The objective of this study was to determine the production of specific metabolites of Lacticaseibacillus rhamnosus, Levilactobacillus brevis and Lactiplantibacillus plantarum by an optimized liquid chromatography with an ultraviolet/diode detection (HPLC-UV/DAD) method and to investigate their potential antimicrobial activity against specific food pathogens. Based on the results of this study, the main metabolites detected in Levilactobacillus brevis were 103.4 μg mL−1 DL-p-Hydroxyphenyllactic acid (OH-PLA) and 2.59 μg mL−1 vanillic acid, while 216.2 μg mL−1 OH-PLA, 19.0 μg mL−1 salicylic acid, 3.7 μg mL−1 vanillic acid, 6.9 μg mL−1 ferulic acid, 4.2 μg mL−1 benzoic acid and 1.4 μg mL−1 4-Hydrocinnamic acid were identified in the Lactiplantibacillus plantarum strain and 147.6 μg mL−1 OH-PLA and 4.9 μg mL−1 ferulic acid were identified in Lacticaseibacillus rhamnosus. This study provides alternative approaches for the molecules involved in the antimicrobial activity of food microorganism fermentation. These molecules may be used as antimicrobial ingredients in the food industry instead of conventional chemical preservatives.

Assessment of Allelopathic Potential of Senna garrettiana Leaves and Identification of Potent Phytotoxic Substances

Senna garrettiana (Craib) Irwin & Barneby (Fabaceae) is a medicinal plant known to be rich in biologically active compounds that could be exploited to produce bioherbicides. The present study was conducted to explore the allelopathic potential and phytotoxic substances of S. garrettiana. Extracts of S. garrettiana leaves were found to significantly inhibit the growth of Lepidium sativum L. and Echinochloa crus-galli (L.) P. Beauv. (p ≤ 0.05). The phytotoxic substances were isolated and identified as vanillic acid and ferulic acid by bioassay-directed fractionation and spectral data analysis. The two compounds were shown to significantly inhibit the seed germination, seedling growth, and dry biomass of L. sativum. Based on the concentration required for 50% growth inhibition (defined as IC50), the roots of L. sativum were the most sensitive to the compounds, and the inhibitory effect of ferulic acid (IC50 = 0.62 mM) was >1.3 times more potent than that of vanillic acid (IC50 = 0.82 mM). In addition, a mixture of the two compounds (0.3 mM) resulted in synergistic inhibitory activity against the L. sativum roots compared with the individual compounds. These results suggest that the extracts of S. garrettiana leaves and their phytotoxic compounds have potential as candidate natural herbicides.

CHEMICAL CONSTITUENTS AND ACETYLCHOLINESTERASE ACTIVITY FROM Polyalthia sumatrana (Miq.) Kurz

This study was carried out to investigate the phytochemicals from Polyalthia sumatrana and their acetylcholinesterase inhibitory activity. Fractionation and purification of the leaves of P. sumatrana led to the isolation and identification of five alkaloids; boldine (1), norboldine (2), liriodenine (3), predicentrine (4), laurotetanine (5) together with β-sitosterol (6), β-sitostenone (7), vanillin (8), vanillic acid (9) and cinnamic acid (10). The structures of these compounds were obtained by analysis of their spectroscopic data, as well as the comparison with that of reported data. Acetylcholinesterase inhibitory activity revealed that all isolated alkaloids were found to inhibit AChE with percentage inhibition values ranged from 45.0 to 80.6%.

Symbiotic and adverse interplay of hypogeal germination periods on brown rice (Oryza sativa): nutrient and non-nutrient characteristics

This study investigated the symbiotic and adverse consequence of hypogeal germination periods on nutrients and non-nutrient characteristics of brown rice (Oryza sativa). Brown rice paddy was subjected to hypogeal germination for 0–72 h using one-factor design-response surface methodology (OFD-RSM) and evaluated for nutrients and non-nutrient characteristics. The results showed that hypogeal germination caused a significant (p < 0.05) change in the proximate composition: protein (9.42–12.36%), fat (0.88–1.38%), ash (1.87–2.50%); anti-nutrients: saponin (2.03–2.22%), oxalate (2.44–3.45 mg/100 g), phytate (6.99–8.81 mg/100 g); functional properties: water absorption capacity, WAC (121.23–147.78%), oil absorption capacity, OAC (121.39–147.26%); antioxidants properties: 2, 2-diphenyl-1-picrylhydrazyl, DPPH (35.30–43.60%), ferric reducing antioxidant power, FRAP (0.054–0.119 mMolFe2+), metal chelating activity, MCA (44.28–52.99%), total phenolic content, TPC (0.623–0.798 mg gallic acid equipvalent per gram (mgGAE/g)), total flavonoid content, TFC (43.47–50.63 mg rutin equivalent per gram (mgRUTIN/g)); and mineral content: calcium (36.0–41.76 mg/100 g), phosphorus (82.53–94.32 mg/100 g), and magnesium (162.70–168.36 mg/100 g). Germination had significant symbiotic effects (linear and quadratic) on the proximate, DPPH, FRAP, MCA, TPC, WAC, OAC, and anti-nutrients. Whereas, adverse effects (linear and quadratic) of germination were noted in total flavonoids and anti-nutrients. Optimum hypogeal germination period of 72.18 h was established and corresponding protein (12.37 g/100 g), fat (1.37 g/100 g), fibre (2.15 g/100 g), moisture (10.07 g/100 g), DPPH (43.66%), FRAP (0.105mMolFe2+), TPC (0.08mgGAE/g), TFC (50.25MgRUTIN/g), WAC (147.99%), OAC (147.29%), Calcium (41.77 mg/100 g), iron (0.207 mg/100 g), zinc (5.89 mg/100 g), phosphorus (94.77 mg/100 g). Phenolic compounds profile of the optimized germinated brown rice showed the presence of gallic acid (2.84 mg/100 g), 4-hydroxy benzoic acid (3.41 mg/100 g), caffeic acid (4.63 mg/100 g), vanillic acid (6.19 mg/100 g), catechin (3.88 mg/100 g), chlorogenic acid (1.93 mg/100 g), ferulic acid (4.16 mg/100 g), and quercetin (1.27 mg/100 g) whereas, the non-germinated rice showed gallic acid (2.05 mg/100 g), 4-hydroxy benzoic acid (2.53 mg/100 g), caffeic acid (4.11 mg/100 g), vanillic acid (6.08 mg/100 g), catechin (3.35 mg/100 g), chlorogenic acid (1.89 mg/100 g), ferulic acid (4.23 mg/100 g), and quercetin (1.29 mg/100 g). Hypogeal germinated brown rice could find application as a functional ingredient in food formulation.

Evaluation of The Antioxidant, Antimicrobial, and Anticancer Activities of Dicliptera bupleuroides Isolated Compounds Using In Vitro and In Silico Studies

Phytochemical investigation of chloroform fraction (DBC) and ethyl acetate fraction (DBE) of D. bupleuroides (Acanthaceae) resulted in the isolation of β-sitosterol (1) from DBC and vanillic acid (2) from DBE, which were first to be isolated from D. bupleuroides. β-Sitosterol (1) exhibited substantial antioxidant activity (IC50 = 198.87 µg/mL), whereas vanillic acid (2) showed significant antioxidant power (IC50 = 92.68 µg/mL) employing 1,1-diphenyl-2-picrylhydrazyl (DPPH*) radical scavenging capacity assay. Both compounds showed pronounced antimicrobial activity using the agar disc diffusion method, particularly against fungi showing MIC values of 0.182 and 0.02 concerning Candida albicans, respectively, and 0.001 mg/mL regarding Penicillium notatum. They revealed considerable antibacterial activity with MIC values ranging between 0.467 and 0.809 mg/mL. Vanillic acid (2) exhibited substantial anticancer potential displaying 48.67% cell viability at a concentration of 100 μg/mL using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-Diphenyl-2H-Tetrazolium Bromide) assay concerning HepG2 cell lines. These results were further consolidated by in silico studies on different enzymes, where vanillic acid displayed a high fitting score in the active pockets of DNA-gyrase, dihydrofolate reductase, aminoglycoside nucleotidyltransferase, and β-lactamase. It also inhibited human cyclin-dependent kinase 2 (CDK-2) and DNA topoisomerase II, as revealed by the in silico studies. ADME/TOPKAT (absorption, distribution, metabolism, excretion, and toxicity) prediction showed that vanillic acid exhibited reasonable pharmacodynamic, pharmacokinetic, and toxicity properties and, thus, could perfectly together with D. bupleuroides crude extract be incorporated in pharmaceutical preparations to counteract cancer and microbial invasion, as well as oxidative stress. Thus, it is concluded that D. bupleroides could be a potential source of therapeutically active compounds, which would be helpful for the discovery of clinically effective and safe drugs.

Effect of vanillic acid and exercise training on fatty liver and insulin resistance in rats: Possible role of fibroblast growth factor 21 and autophagy

Background and aims The prevalence of non-alcoholic fatty liver disease has been alarmingly increased with no lines of effective treatment. Vanillic acid is a naturally occurring polyphenol with promising therapeutic effects. Exercise is well known to be an effective tool against obesity and its consequences. Thus, we aim to study the effect of vanillic acid alone and along with exercise on fatty liver induced by a high-fat diet in a rat model and to investigate possible novel mechanisms involved in their action. Methods In this study, 40 male rats were divided equally into five groups: control (standard chow diet), HFD (high-fat diet), HFD+VA (HFD+ vanillic acid (50 mg/kg/day orally), HFD+EX (HFD+ swimming exercise 5 days/week), HFD+VA+EX (HFD+ vanillic acid+ swimming exercise) for eight weeks. Results Body mass, liver weight, liver enzymes, cholesterol, and triglycerides were significantly decreased in the combined VA+EX group, with marked improvement in hyperglycemia, hyperinsulinemia, and consequently HOMA-IR index compared to the HFD group. These improvements were also reflected in the pathological view. VA and swimming, either solely or in combination, markedly increased hepatic and circulating fibroblast growth factor 21. Additionally, VA and swimming increased the immunohistochemical expression of the autophagosomal marker LC3 and decreased the expression of P62, which is selectively degraded during autophagy. Conclusions These results suggest the hepatoprotective effect of VA and swimming exercise against fatty liver and the involvement of FGF21 and autophagy in their effect.