Chemical Characterisation, Antioxidant and Antibacterial Activities of Pinus pinaster Ait. and Pinus pinea L. Bark Polar Extracts: Prospecting Forestry By-Products as Renewable Sources of Bioactive Compounds

Unveiling the Chemical Constituents and Inhibitory Roles of Extracts from Pinus Pinea L. Nut and Nutshell: A Novel Source for Pharmaceutical Antimicrobials

Antibiotic resistance in infectious diseases has been a serious problem for the last century, and scientists have focused on discovering new natural antimicrobial agents. Pinus pinea has been used as a natural pharmacotherapeutic agent with antimutagenic, anticarcinogenic, and high antioxidant properties. In this study, GC-MS and LC-HR/MS were employed to analyze Pinus pinea L. nut and nutshell extracts. DPPH radical scavenging assay was performed to analyze the antioxidant properties of the extracts, but no activity was determined. GC-MS analysis showed that linoleic, oleic, and palmitic acids were the three most dominant fatty acids in nut and nutshell extracts, with ratios between 6.75 % and 47.06 % (v/v). LC-HR/MS revealed that the nutshell methanol extract had a higher phenolic content than other extracts, with vanillic acid (1.4071 mg/g). Antimicrobial activity assays showed that the minimum inhibitory concentrations (MIC) of the extracts varied between 5.94 and 190 mg/mL, and the most significant inhibition was seen in the nutshell methanol extract (MICs: between 5.94 and 47.5 mg/mL). Consequently, the antimicrobial activity of the extracts can be attributed to the dense fatty acids they contain, and the nutshell methanol extract showed the most potent inhibition related to the abundance of phenolic compounds in the extract.

Chemical Characterization of Pruning Wood Extracts from Six Japanese Plum (Prunus salicina Lindl.) Cultivars and Their Antitumor Activity

The Japanese plum tree (Prunus salicina Lindl.) is mainly cultivated in temperate areas of China and some European countries. Certain amounts of wood (from pruning works) are generated every year from this crop of worldwide commercial significance. The main objective of this work was to value this agricultural woody residue, for which the chemical composition of pruning wood extracts from six Japanese plum cultivars was investigated, and the antiproliferative activity of extracts and pure phenolics present in those extracts was measured. For the chemical characterization, total phenolic content and DPPH radical-scavenging assays and HPLC‒DAD/ESI‒MS analyses were performed, with the procyanidin (-)-ent-epicatechin-(2α→O→7,4α→8)-epicatechin (5) and the propelargonidin (+)-epiafzelechin-(2β→O→7,4β→8)-epicatechin (7) being the major components of the wood extracts. Some quantitative differences were found among plum cultivars, and the content of proanthocyanidins ranged from 1.50 (cv. 'Fortune') to 4.44 (cv. 'Showtime') mg/g of dry wood. Regarding the antitumoral activity, eight wood extracts and four phenolic compounds were evaluated in MCF-7 cells after 48 h of induction, showing the wood extract from cv. 'Songold' and (‒)-annphenone (3), the best antiproliferative activity (IC50: 424 μg/mL and 405 μg/mL, respectively).

Development of bioactive films loaded with extract and polysaccharide of Pinus brutia bark

Society's interest in natural and clean products in many areas, such as food and cosmetics, has increased considerably. It has led to the development of new techniques in the packaging of products so that the wastes from the preferred products can be recycled. In this context, Pinus brutia bark was preferred within the scope of the study to transform natural wastes into functional components and use them as packaging material. P. brutia bark (PBB) samples were collected from Bursa, Turkey. PBB samples were ultrasonically extracted using various solvents (acetone, butanol, ethanol, ethyl acetate, hexane, methanol, petroleum ether, and water) and a solvent-acidic hydrolysis system. The phenolic content profile of PBB samples was determined using high-performance liquid chromatography with diode-array detection, and total flavonoid content, antioxidant capacity, and total phenolic content were determined. Chitosan-polyvinyl alcohol (CS-PVA) films loaded with polysaccharides and containing methanolic extract were developed. The physical, chemical, and mechanical properties of the films were characterized. It is known that the thickness of the films determines the mechanical properties required to maintain the integrity of the packaging during storage and transport. From the results of the study, it was concluded that the elongation at break value was higher in CS-PVA-PBB-M films (111.08% ± 10.46%), Young's modulus (31.74 ± 21.37 N/mm2), and tensile strength (3.01 ± 0.50 N/mm2) values were higher in CS-PVA films. In this case, it was concluded that adding proanthocyanidin to edible films gives flexibility to the films.

Effect of pine bark extract and its phenolic compounds on selected pathogenic and probiotic bacterial strains

Introduction

Inflammatory bowel disease (IBD) comprises a heterogeneous group of chronic diseases as ulcerative colitis (UC) and Crohn's disease (CD). IBD is the result of a dysregulation of intestinal homeostasis with a host's loss of tolerance toward normal enteric microflora. Plant-based extracts as phenolic compounds can play a role by modulating the intestinal inflammation response.

Methods

The in vitro antimicrobial activity of French maritime pine bark extract (PBE) and its phenolic constituents has been investigated in this study. Furthermore, the ability of PBE and phenolic compounds (caffeic acid, chlorogenic acid, ferulic acid, gallic acid and taxifolin) to modulate the microbiota has been assessed.

Results

Phenolic compounds and PBE showed a great inhibitory effect on the pathogens growth at the highest concentration assessed (1.25 mg/mL). The growth of E. sakazakii and E. faecalis were affected by the effect of caffeic acid and ferulic acid. Taxifolin showed a very strong activity against Listeria sp. (with a reduction ~98%). Gallic acid revealed antibacterial effect on S. aureus at different concentrations. The inhibitory effect of PBE was highly significant on the growth of E. coli O157:H7. PBE, caffeic acid and chlorogenic acid seem to provide the greatest beneficial effect on the probiotic bacteria. However, the highest concentrations of taxifolin may have impaired the growth of beneficial microbiota.

Conclusion

Present findings could be of interest for considering PBE and/or its phenolic constituents as protectors against gastrointestinal disturbances which lead to ulcerative colitis and Crohn's disease.

The survival of multi-drug resistant bacteria on raw Douglas fir material

In today's age of ecological transition, the use of materials such as renewable wood in construction is particularly relevant, but also a challenge in the healthcare sector where the hygiene dimension also comes into play. In this study we have investigated the survival of multi-resistant bacteria commonly responsible for healthcare-associated infections (HAIs) (ESBL-positive Klebsiella pneumoniae and glycopeptide-resistant Enterococcus faecalis) on two different types of wood (Douglas fir : Pseudotsuga menziesii and Maritime Pine : Pinus pinaster) compared to other materials (smooth: stainless steel and rough: pumice stone) and the effect of a disinfection protocol on the bacterial survival on Pseudotsuga menziesii. Approximately 108 bacteria were inoculated on each material and bacterial survival was observed over several days (D0, D1, D2, D3, D6, D7 and D15). Each analysis was performed in triplicate for each time and material. The results show an important reduction of the bacterial inoculum for Klebsiella pneumoniae and Enterococcus faecalis on Douglas fir, in contrast with the results obtained on maritime pine, stainless steel and pumice stone. No bacterial survival was detected on Douglas fir after application of a hospital disinfection protocol. These different results show that wood may have a place in the future of healthcare construction. Further studies would be interesting to better understand the different properties of wood.

Diterpenes of Pinus pinaster aiton with anti-inflammatory, analgesic, and antibacterial activities

ETHNO-PHARMACOLOGICAL RELEVANCE

The P. pinaster species, known as 'Pino nigral or rodeno', is used in the treatment of colds, asthma, flu, and tuberculosis.

AIM OF THE STUDY

This study determined the anti-inflammatory, analgesic, and antibacterial activities of the P. pinaster resin, identifying the compounds with higher biological activity.

MATERIALS AND METHODS

A bio-guided isolation of the compounds of P. pinaster was carried out by selecting the most active extracts with anti-inflammatory and analgesic effects in the HBEC3-KT, MRC-5, and THP-1 cell lines. The antibacterial activity was determined against the S. aureus, S. pneumoniae, K. pneumoniae and P. aeruginosa strains.

RESULTS

The following compounds were identified by NMR: dehydroabietic acid (1), ( + )-cis-abienol (2), pimaric acid (3), isopimaric acid (4), 7α-hydroxy-dehydroabietic acid (5), 7-oxo-dehydroabietic acid (6), 15-hydroxy-abietic acid (7), 7-oxo-15-hydroxy-dehydroabietic acid (8), 13-oxo-8 (14)-podocarpen-18-oic acid (9), and pinyunin A (10). Regarding their anti-inflammatory activity, all compounds inhibited NF-κB. Compound 9 was the most active (IC50 = 3.90-12.06 μM). Concerning the analgesic activity, all the compounds inhibited NK-1, yet compound 9 was the most active (IC50 = 0.28-0.33 μM). Finally, compounds 6 (MIC = 12.80-25.55 μM) and 9 (MIC = 9.80-24.31 μM) were the most promising antibacterial compounds in all strains.

CONCLUSION

This study managed to identify, for the first time, six diterpenes from the resin of P. pinaster, with anti-inflammatory, analgesic, and antibacterial activity. Among the identified compounds, compound 9 was the most active, being considered a promising candidate as an antagonist of the tachykinin NK-1 receptor and as an analgesic agent against inflammation and neuropathic pain. It also had an antibacterial effect against Gram negative bacteria.

Biological Activity and Metabolomics of Griffonia simplicifolia Seeds Extracted with Different Methodologies

Griffonia simplicifolia, a tropical plant endemic to West Africa, is highly regarded for its significant pharmacological potential. The objective of this study was to evaluate the metabolomic profile and to explore the antioxidant properties, antiproliferative activity, and antimicrobial potential of G. simplicifolia seed extracts obtained through either maceration, microwave-assisted extraction (MAE), or Soxhlet extraction using water, acetone, methanol and ethanol as solvents. Overall, methanol possessed superior total extraction efficiency. HPLC analyses confirmed the efficacy of acetone and ethanol as optimal solvents for the extraction of flavonoids and flavan-3-ols, whereas MAE exhibited enhanced effectiveness in extracting N-containing compounds, including 5-hydroxytryptophan (5-HTP). HPLC-MS analyses identified forty-three compounds, including thirty-four phenolic compounds and nine N-containing molecules. Isomyricitrin, taxifolin and a flavonol glucuronide were the main polyphenols, whereas 5-HTP was the main N-containing compound. Hydroalcoholic G. simplicifolia extracts showed the highest radical scavenging and metal-reducing antioxidant power, suggesting that most of the contribution to antioxidant activity depends on the more polar bioactive compounds. G. simplicifolia extracts showed dose-dependent antiproliferative activity against three distinct cancer cell lines (HeLa, HepG2, and MCF-7), with notable variations observed among both the different extracts and cell lines and divergent GI50 values, emphasizing substantial discrepancies in cell sensitivity to the various extracts. Furthermore, G. simplicifolia extracts revealed antibiotic activity against Staphylococcus aureus. Our results highlight the potential of G. simplicifolia phytochemicals in the development of functional foods, nutraceuticals, and dietary supplements.

Assessment of metabolic, mineral, and cytotoxic profile in pineapple leaves of different commercial varieties: A new eco-friendly and inexpensive source of bioactive compounds

Pineapple is among the most produced and consumed fruits worldwide, and consequently, its agroindustrial production/processing generates high amounts of agricultural waste, which are routinely discarded. Thus, it is crucial to seek alternatives to reuse this agricultural waste that are in high availability. Therefore, this work aims to evaluate the chemical composition of a specific residue (leaves) of seven commercial varieties of pineapples, to attribute high added value uses, and to evaluate its potential as a source of secondary metabolites and minerals. Thereby, twenty-eight metabolites were annotated by UPLC-QTOF-MS^E, including amino acids, organic acids, and phenolic compounds. The following minerals were quantitatively assessed by ICP-OES: Zn (5.30-19.77 mg kg^-1), Cr, Cd, Mn (50.80-113.98 mg kg^-1), Cu (1.05-4.01 mg kg^-1), P (1030.77-6163.63 mg kg^-1) and Fe (9.06-70.17 mg kg^-1). In addition, Cr and Cd (toxic materials) present concentration levels below the limit of quantification of the analytical method (LOQ_Cr and LOQ_Cd = 0.02 mg kg^-1) for all samples. The multivariate analysis was conceived from the chemical profile, through the tools of PCA (principal component analysis) and HCA (hierarchical cluster analysis). The results show that pineapple leaves have similarities and differences concerning their chemical composition. In addition, the cytotoxicity assays of the extracts against tumor and non-tumor strains shows that the extracts were non-toxic. This fact can corroborate and enhance the prospection of new uses and applications of agroindustrial co-products from pineapple, enabling the evaluation and use in different types of industries, such as pharmacological, cosmetic, and food, in addition to the possibility of being a potential source of bioactive compounds.

Bioactive Properties of Instant Chicory Melanoidins and Their Relevance as Health Promoting Food Ingredients

Instant chicory is a caffeine-free brew worldwide consumed as a coffee substitute. Like coffee grounds processing, chicory roots suffer a roasting process, which may lead to the formation of high-molecular weight nitrogen-brown compounds, the melanoidins. It is hypothesized that similarly to coffee, chicory melanoidins have health promoting potential. In this work, the chemical composition and biological activity of chicory high molecular weight material (HMWM) was evaluated. The chicory HMWM is composed by 28.9% (w/w) of carbohydrates, mainly fructose-rich polysaccharides (18.7% w/w) and 5.7% (w/w) of protein, distinct from coffee. The phenolic compounds constituent of the HMWM were mainly present in glycosidically linked and condensed structures (0.9 g/100 g and 5.8 g/100 g), showing in vitro ABTS^•+ scavenging (IC₅₀ = 0.28 mg/mL) and ferric ion reducing capacity (ca. 11 µg Fe²⁺ eq/mg). Chicory HMWM revealed to be effective against Gram-positive bacteria, mainly Staphylococcus aureus and Bacillus cereus, although not so efficient as coffee. It also showed potential to inhibit α-glucosidase activity (15% of inhibition), higher than coffee HMWM, approaching acarbose activity that is used in type 2 diabetes mellitus treatment. Thus, chicory melanoidins, when used as a food ingredient, may contribute to an antioxidant diet and to prevent diabetes, while increasing the protective effects against pathogenic bacteria.

Tackling the Future Pandemics: Broad-Spectrum Antiviral Agents (BSAAs) Based on A-Type Proanthocyanidins

A-type proanthocyanidins (PAC-As) are plant-derived natural polyphenols that occur as oligomers or polymers of flavan-3-ol monomers, such as (+)-catechin and (-)-epicatechin, connected through an unusual double A linkage. PAC-As are present in leaves, seeds, flowers, bark, and fruits of many plants, and are thought to exert protective natural roles against microbial pathogens, insects, and herbivores. Consequently, when tested in isolation, PAC-As have shown several biological effects, through antioxidant, antibacterial, immunomodulatory, and antiviral activities. PAC-As have been observed in fact to inhibit replication of many different human viruses, and both enveloped and non-enveloped DNA and RNA viruses proved sensible to their inhibitory effect. Mechanistic studies revealed that PAC-As cause reduction of infectivity of viral particles they come in contact with, as a result of their propensity to interact with virion surface capsid proteins or envelope glycoproteins essential for viral attachment and entry. As viral infections and new virus outbreaks are a major public health concern, development of effective Broad-Spectrum Antiviral Agents (BSAAs) that can be rapidly deployable even against future emerging viruses is an urgent priority. This review summarizes the antiviral activities and mechanism of action of PAC-As, and their potential to be deployed as BSAAs against present and future viral infections.

Ultrasound-Assisted Extraction of Polyphenols from Maritime Pine Residues with Deep Eutectic Solvents

Deep eutectic solvents represent an important alternative in the field of green solvents due to their low volatility, non-toxicity, and low synthesis cost. In the present investigation, we propose the production of enriched polyphenolic extracts from maritime pine forest residues via an ultrasound-assisted approach. A Box-Behnken experimental design with a response surface methodology was used with six variables to be optimized: solid-to-solvent ratio, water percentage, temperature and time of extraction, amplitude, and catalyst concentration. The mixture of levulinic and formic acids achieved the highest extraction yield of polyphenols from pine needle and bark biomass. In addition, the solid-to-solvent ratio was found to be the only influential variable in the extraction (p-value: 0.0000). The optimal conditions were established as: 0.1 g of sample in 10 mL of LA:FA (70:30%, v/v) with 0% water and 0 M H₂SO₄ heated to 30 °C and extracted during 40 min with an ultrasound amplitude of 80% at 37 kHz. The bioactive properties of polyphenol-enriched extracts have been proven with significant antioxidant (45.90 ± 2.10 and 66.96 ± 2.75 mg Trolox equivalents/g dw) and antimicrobial activities. The possibility to recycle and reuse the solvent was also demonstrated; levulinic acid was successfully recovered from the extracts and reused in novel extractions on pine residues. This research shows an important alternative to obtaining polyphenol-enriched extracts from forest residues that are commonly discarded without any clear application, thus opening an important window toward the valorization of such residues.

Microwave-Assisted Water Extraction of Aspen (Populus tremula) and Pine (Pinus sylvestris L.) Barks as a Tool for Their Valorization

The barks of aspen (Populus tremula) and pine (Pinus sylvestris) are byproducts of wood processing, characterized by their low economic value. In the present study, microwave-assisted one-cycle water extraction was explored as a tool for the valorization of this biomass as a source of biologically active compounds. The microwave extractor of the original construction equipped with a pressurized extraction chamber and a condenser section was used. The microwave-assisted extraction (MAE), specially including dynamic dielectric heating up to 70 °C followed by 30 min of isothermal heating, promoted the isolation of salicin from aspen bark, allowing for the obtention of a two-times-higher free salicin concentration in water extracts (−14% vs. 7%) reached by multi-cycle accelerated solvent extraction (ASE), which is an advanced technique used as a reference. The MAE of pine bark with dynamic heating up to 90–130 °C, avoiding the isothermal heating step, allowed for the obtention of a 1.7-times-higher concentration of proantocyanidin dimers-tetramers, a 1.3-times-higher concentration of catechin and a 1.2-times-higher concentration of quinic acid in water extracts in comparison to a more time- and solvent-consuming ASE performed at the same temperature. The biological activity of the obtained extracts was characterized in terms of their ability to inhibit xahntine oxidase enzyme, which is a validated target for the therapeutic treatment of hyperuricemia.