Chemical constituents of peppers (Piper spp.) and application to food preservation: naturally occurring antioxidative compounds

Spices as Sustainable Food Preservatives: A Comprehensive Review of Their Antimicrobial Potential

Throughout history, spices have been employed for their pharmaceutical attributes and as a culinary enhancement. The food industry widely employs artificial preservatives to retard the deterioration induced by microbial proliferation, enzymatic processes, and oxidative reactions. Nevertheless, the utilization of these synthetic preservatives in food products has given rise to significant apprehension among consumers, primarily stemming from the potential health risks that they pose. These risks encompass a spectrum of adverse effects, including but not limited to gastrointestinal disorders, the disruption of gut microbiota, allergic reactions, respiratory complications, and concerns regarding their carcinogenic properties. Consequently, consumers are displaying an increasing reluctance to purchase preserved food items that contain such additives. Spices, known for their antimicrobial value, are investigated for their potential as food preservatives. The review assesses 25 spice types for their inherent antimicrobial properties and their applicability in inhibiting various foodborne microorganisms and suggests further future investigations regarding their use as possible natural food preservatives that could offer safer, more sustainable methods for extending shelf life. Future research should delve deeper into the use of natural antimicrobials, such as spices, to not only replace synthetic preservatives but also optimize their application in food safety and shelf-life extension. Moreover, there is a need for continuous innovation in encapsulation technologies for antimicrobial agents. Developing cost-effective and efficient methods, along with scaling up production processes, will be crucial to competing with traditional antimicrobial options in terms of both efficacy and affordability.

Comparative Quantification of the Phenolic Compounds, Piperine Content, and Total Polyphenols along with the Antioxidant Activities in the Piper trichostachyon and P. nigrum

India is the largest producer in the world of black pepper and it is the center of origin for Piper. The present study gives a comparative account of the chemical composition of the Piper nigrum and its wild putative parent the P. trichostachyon. Microextractions were performed and the quantification of six phenolic compounds (namely epicatechin, gallic acid, catechol, chlorogenic acid, caffeic acid, and catechin), piperine from leaves, petioles, and the fruits of both the species, were accomplished using the RP-UFLC system. The polyphenols (phenolic, flavonoid) and their antioxidant activities were also estimated. Among the six phenolic compounds studied, only three were detected and quantified. The polyphenol content correlating to the antioxidant activities was higher in the P. trichostachyon, whereas the piperine content was 108 times greater in the P. nigrum fruits. The Piper trichostachyon comparatively showed a higher content of polyphenols. The microextractions reduced the solvent consumption, the quantity of the plant material, and the amount of time used for the extraction. The first report on the TPC, TF, and the antioxidant activity of the P. trichostachyon has been described, and it also forms a scientific basis for its use in traditional medicine. The petioles of both species are good sources of phenolic compounds. A quantitative chemical analysis is a useful index in the identification and comparison of the species.

Piperidine nucleus in the field of drug discovery

Background

Piperidine is an essential heterocyclic system and a pivotal cornerstone in the production of drugs. Piperidine byproducts showed several important pharmacophoric features and are being utilized in different therapeutic applications.

Main text

Piperidine derivatives are being utilized in different ways as anticancer, antiviral, antimalarial, antimicrobial, antifungal, antihypertension, analgesic, anti-inflammatory, anti-Alzheimer, antipsychotic and/or anticoagulant agents.

Conclusions

This review article sheds a light on the most recent studies proving the importance of piperidine nucleus in the field of drug discovery.

Piper nigrum CYP719A37 Catalyzes the Decisive Methylenedioxy Bridge Formation in Piperine Biosynthesis

Black pepper (Piper nigrum) is among the world's most popular spices. Its pungent principle, piperine, has already been identified 200 years ago, yet the biosynthesis of piperine in black pepper remains largely enigmatic. In this report we analyzed the characteristic methylenedioxy bridge formation of the aromatic part of piperine by a combination of RNA-sequencing, functional expression in yeast, and LC-MS based analysis of substrate and product profiles. We identified a single cytochrome P450 transcript, specifically expressed in black pepper immature fruits. The corresponding gene was functionally expressed in yeast (Saccharomyces cerevisiae) and characterized for substrate specificity with a series of putative aromatic precursors with an aromatic vanilloid structure. Methylenedioxy bridge formation was only detected when feruperic acid (5-(4-hydroxy-3-methoxyphenyl)-2,4-pentadienoic acid) was used as a substrate, and the corresponding product was identified as piperic acid. Two alternative precursors, ferulic acid and feruperine, were not accepted. Our data provide experimental evidence that formation of the piperine methylenedioxy bridge takes place in young black pepper fruits after a currently hypothetical chain elongation of ferulic acid and before the formation of the amide bond. The partially characterized enzyme was classified as CYP719A37 and is discussed in terms of specificity, storage, and phylogenetic origin of CYP719 catalyzed reactions in magnoliids and eudicots.

In vitro α-amylase and α-glucosidase enzyme inhibition and antioxidant activity by capsaicin and piperine from Capsicum chinense and Piper nigrum fruits

In the present study, α-amylase and α-glucosidase inhibitory effect and antioxidant activity of capsaicin and piperine from the ethanolic extract of Capsicum chinense (EECch) and Piper nigrum (EEPn) fruits were investigated. Results revealed that EECch exhibited the highest phenolic (154 mg GAE/100 g of tissue) and flavonoid content (75 mg RtE/100 g of tissue) in comparison with EEPn. The predominant compound detected in EECch and EEPn by GC-EIMS analysis was the capsaicin and piperine, respectively. The capsaicin and piperine showed the highest α-amylase and α-glucosidase inhibitory effect and antioxidant activity rather than extracts. The EEPn (IC₅₀= 216 µg/mL) and piperine (IC₅₀= 105 µg/mL) present a highest α-amylase inhibitory effect, while the EECch (IC₅₀= 225 µg/mL) and capsaicin (IC₅₀= 117 µg/mL) showed highest anti-α-glucosidase activity. Molecular docking established that capsaicin and piperine bind at the α-glucosidase and α-amylase through hydrophobic interactions, hydrogen bond, and charge interactions with amino acid residues. The enzyme inhibitory activity and antioxidant properties exhibited by EECch and EEPn could be attributed to the capsaicin and piperine content and other compounds present such as phenolic compounds and flavonoids. These fruits are potential sources of natural antioxidant agents and α-amylase and α-glucosidase inhibitors.

Piper Species: A Comprehensive Review on Their Phytochemistry, Biological Activities and Applications

Piper species are aromatic plants used as spices in the kitchen, but their secondary metabolites have also shown biological effects on human health. These plants are rich in essential oils, which can be found in their fruits, seeds, leaves, branches, roots and stems. Some Piper species have simple chemical profiles, while others, such as Piper nigrum, Piper betle, and Piper auritum, contain very diverse suites of secondary metabolites. In traditional medicine, Piper species have been used worldwide to treat several diseases such as urological problems, skin, liver and stomach ailments, for wound healing, and as antipyretic and anti-inflammatory agents. In addition, Piper species could be used as natural antioxidants and antimicrobial agents in food preservation. The phytochemicals and essential oils of Piper species have shown strong antioxidant activity, in comparison with synthetic antioxidants, and demonstrated antibacterial and antifungal activities against human pathogens. Moreover, Piper species possess therapeutic and preventive potential against several chronic disorders. Among the functional properties of Piper plants/extracts/active components the antiproliferative, anti-inflammatory, and neuropharmacological activities of the extracts and extract-derived bioactive constituents are thought to be key effects for the protection against chronic conditions, based on preclinical in vitro and in vivo studies, besides clinical studies. Habitats and cultivation of Piper species are also covered in this review. In this current work, available literature of chemical constituents of the essential oils Piper plants, their use in traditional medicine, their applications as a food preservative, their antiparasitic activities and other important biological activities are reviewed.

Alkamides from Piper nigrum L. and Their Inhibitory Activity against Human Liver Microsomal Cytochrome P450 2D6 (CYP2D6)

Drug–herb interaction through inhibition of cytochrome P450 alters the pharmacological response and/or toxicities of drug used concomitantly. In our screening, Piper nigrum L. was observed to inhibit cytochrome P450 2D6 (CYP2D6) in human liver microsomes. Thus, the MeOH extract of this plant was investigated for their chemical constituents and 19 alkamides including a new pipercyclobutanamide were isolated. Their structures were elucidated on the basis of spectroscopic analyses. The isolated compounds were tested for their inhibition on human liver microsomal dextromethorphan O-demethylation activity, a selective marker for CYP2D6, and pipercyclobutanamide A (17) showed the most potent inhibition with an IC50 value of 0.34 μM. The result demonstrated the potential of drug–alkamides interaction on concomitant consume of white pepper with the drugs being metabolized by CYP2D6.

MEDICINAL HERBS USED BY HIV-POSITIVE PEOPLE IN LESOTHO

BACKGROUND

The use of medicinal herbs whose efficacy and toxicities are not known by HIV-positive people in Lesotho is a threat to the effectiveness of antiretroviral treatment. This study explored some medicinal herbs used by HIV-positive people in Lesotho and the reasons for their use.

METHODS

This was a cross sectional study based on a questionnaire distributed to purposively-sampled HIV-positive people in Leribe and Maseru districts of Lesotho. The participants' socio-demographic and clinical variables were summarized using frequency tables in Stata version 13 statistical software. Data variables for medicinal herbs used, frequency of use, uses by the participants and in the literature, parts of plants used and the method of preparation were also explored.

RESULTS

Out of 400 questionnaires distributed to the participants, 389 were returned with data acceptable for analysis. Ages of the participants ranged from 18 to 75 years (Mean=43 + 11.6). Out of the 272 (69.9%) participants who conceded that they had used medicinal herbs at least once, 30 (7.7%) participants used medicinal herbs frequently while 242 (62.2 %) rarely used the herbs. At least 20 plant species belonging to 16 families were reportedly used by the participants. Asteraceae was the most common plant family reportedly used by the participants. Allium sativum and Dicoma anomala, reportedly used by 21.0% and 14.3% respectively, were the most commonly used medicinal herbs in this population. In addition, boosting the immune system and treating gastrointestinal ailments, apparently cited by 32% and 28% participants respectively, were the most commonly reported reasons for using medicinal herbs.

CONCLUSION

A considerable proportion (69.9%) of HIV-positive people use medicinal herbs in this population, and 7.7% use them frequently. At least 20 plant species belonging to 16 families were reportedly used by the participants. HIV counselling protocols in Lesotho should emphasize the dangers of using medicinal herbs whose safety and compatibility with antiretroviral drugs is not known. The efficacy and toxicity profiles of the medicinal plants identified in this study need to be investigated. Furthermore, the effects of these plants on antiretroviral treatment outcomes including herb-drug interactions need to be explored.

Black pepper essential oil to enhance intravenous catheter insertion in patients with poor vein visibility: a controlled study

OBJECTIVES

To evaluate the effect of topically applied black pepper essential oil on easing intravenous catheter insertion (IVC) in patients with no palpable or visible veins compared to a control group (standard nursing practice).

DESIGN

Randomized, controlled study.

SUBJECTS

One hundred twenty hospitalized patients, who were referred to a hospital vascular team because of difficulty in accessing veins for IVC insertion.

INTERVENTIONS

Topical application of 20% essential oil of black pepper in aloe vera gel or standard nursing care (hot packs with or without vigorous tactile stimulation).

OUTCOME MEASURES

Pre- and post-test vein visibility and/or palpability and number of attempts at IVC insertion.

RESULTS

A higher percentage of patients achieved optimal scoring (vein score=2) or improved scoring (vein score of 1 or 2) to black pepper intervention than standard nursing care. The black pepper group also reduced the number of patients whose veins were still not visible or palpable after the intervention to nearly half that of the control group (p<0.05). The number of IVC attempts following black pepper was also half that of the control group.

CONCLUSION

Topical application of black pepper is a viable and effective way to enhance vein visibility and palpability prior to intravenous insertion in patients with limited vein accessibility; it also improves ease of IVC insertion.

Phenolic acid amides of phenolic benzylamines against UVA-induced oxidative stress in skin

UVA-radiation is suspected to be a main cause for extrinsic skin ageing in humans. Recent studies showed that topically administered molecular antioxidants are able to protect skin against UVA-generated oxidative stress. Therefore, new phenolic acid amides of phenolic benzylamines were synthesized as potential antioxidants by reaction of (if necessary protected) N-succinimidylesters of ferulic acid, sinapic acid, caffeic acid, 3-(4-hydroxy-3-methoxyphenyl)propanoic acid, 3-(3,4-dihydroxyphenyl)propanoic acid, 2-(4-hydroxy-3-methoxyphenyl)acetic acid and 2-(3,4-dihydroxyphenyl) acetic acid with different phenolic benzylamines in moderate to good yields. The radical scavenging activities of the compounds were determined by the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay and by a superoxide radical anion trapping assay. Antioxidant activities in bulk lipids were tested by accelerated peroxidation with or without test compounds performed in the Rancimat apparatus. Stripped soybean oil and the skin sebum component squalene were used as lipids. The synthesized compounds were found to be efficient radical scavengers and antioxidants, especially the hydroxyphenylacetic amides and the hydroxydihydrocinnamic acid amides of polyhydroxybenzylamines, which are superior to the standards alpha-tocopherol and l-ascorbic acid. A topically applied 0.1% 1,3-butyleneglycol solution of N-(3,4-dihydroxybenzyl)-2-(4-hydroxy-3-methoxyphenyl)acetic acid amide 19 inhibits the UVA-induced sebum peroxidation in human skin significantly, by 39%.

Synthesis and biological evaluation of piperamide analogues as HDAC inhibitors

Two natural piperamides (piperlonguminine and refrofractamide A) and their derivatives were synthesized and evaluated for inhibitory activity against histone deacetylases, as well as the HCT-116 human colon cancer cell line. The preliminary structure activity relationship was discussed. Compounds featuring a hydroxamic acid moiety exhibited moderate HDAC activity and in vitro cytotoxicity.

Muscle Thiobarbituric Acid Reactive Substance of the Atlantic Herring (Clupea harengus) in Marinades Collected in the Market Network

Fish fat belongs to highly specific nutritious elements especially due to its high content of polyunsaturated fatty acids. The aim of the present study was to determine the content of 2-thiobarbituric acid reactive substances in over-the-counter cold and warm marinades in which the base fish material consists of the Atlantic herring (Clupea harengus). Fifty six marinated fish products stored at refrigeration temperatures were analyzed before their expiration date. Their fat content was determined by means of the Soxhlet method and the TBARS validated fluorimetric micromethod. Lowest TBARS values were characteristic of warm baked marinades (1.17 ± 0.40 mg MDA/ kg muscle) and in case of cold marinades for the rolled herring fillets with pepper (5.03 ± 0.54 mg MDA/kg muscle) whereas the highest TBARS values were observed in warm cooked marinades (16.48 ± 4.22 mg MDA/kg muscle) and in roll mops sold over the counter (7.61 ± 3.87 mg MDA/kg muscle). The results showed that fat content is not always critical for herring TBARS determination in marinades. For the consumer safety it is essential to pay attention to cold marinades in brine sold over the counter and baked marinades in aspic before their expiration date.

Chemistry and in vitro antioxidant activity of volatile oil and oleoresins of black pepper (Piper nigrum)

Essential oil and oleoresins (ethanol and ethyl acetate) of Piper nigrum were extracted by using Clevenger and Soxhlet apparatus, respectively. GC-MS analysis of pepper essential oil showed the presence of 54 components representing about 96.6% of the total weight. beta-Caryophylline (29.9%) was found as the major component along with limonene (13.2%), beta-pinene (7.9%), sabinene (5.9%), and several other minor components. The major component of both ethanol and ethyl acetate oleoresins was found to contain piperine (63.9 and 39.0%), with many other components in lesser amounts. The antioxidant activities of essential oil and oleoresins were evaluated against mustard oil by peroxide, p-anisidine, and thiobarbituric acid. Both the oil and oleoresins showed strong antioxidant activity in comparison with butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) but lower than that of propyl gallate (PG). In addition, their inhibitory action by FTC method, scavenging capacity by DPPH (2,2'-diphenyl-1-picrylhydrazyl radical), and reducing power were also determined, proving the strong antioxidant capacity of both the essential oil and oleoresins of pepper.

Antioxidant capacity of some herbs/spices from cameroon: a comparative study of two methods

This study evaluates the antioxidant capacity of 14 herbs/spices from Cameroon. Freeze-dried samples extracted in methanol (free or unconjugated polyphenol) and in 1.2 M hydrochloric acid (HCl) in methanol (total antioxidant that is both unconjugated and conjugated) were analyzed using two different antioxidant assay methods [Folin-Ciocalteu reagent (Folin) and the ferric reducing antioxidant power (FRAP)]. The 1.2 M HCl in methanol extracts had significantly higher (P < 0.001) antioxidant capacities than the methanolic extract. Generally, the FRAP antioxidant values were significantly (P < 0.001) higher than the Folin antioxidant values. Although a significant correlation (P < 0.05) was obtained between the Folin phenol and the FRAP antioxidant, the trends of the antioxidant capacity of the samples were different for the Folin and FRAP methods. The leaves of the Piper species top the total antioxidant tables in both Folin and FRAP assay methods, respectively. Irvingia gabonensis tops the FRAP free antioxidant list, while Piper umbellatum leads the Folin free antioxidant followed by Thymus vulgaris. Thus, the antioxidant capacity of plant samples determined by different methods should be interpreted with caution. However, irrespective of the assay method used, the samples were rich in antioxidants.

Chemopreventive effects of coumaperine from pepper on the initiation stage of chemical hepatocarcinogenesis in the rat

This study was designed to investigate the chemopreventive action of three natural products, coumaperine, aurapten and an extract from rosemary, against the initiation stage of rat hepato-carcinogenesis. Coumaperine has been isolated from white pepper as a naturally occurring antioxidative agent, but its potential modifying effects on carcinogenesis remain unclear. In experiment 1, a modification of the model developed by Tsuda et al. was applied, with assessment of numbers and areas of induced glutathione S-transferase placental form (GST-P)-positive hepatocellular foci in male F344 rats. Coumaperine, aurapten and the extract from rosemary were administered i.g. at 100 mg / kg / day once daily for 5 days with initiation by diethylnitrosamine (DEN) on day 4 (20 mg / kg, i.p.). Numbers and areas of GST-P-positive foci in each group given test chemicals tended to be decreased as compared to the vehicle control group values, significance being achieved for number with coumaperine. Experiment 2 was planned to investigate the mechanism of the inhibitory effects of coumaperine. Livers at 8 h after initiation by DEN were examined with coumaperine administered at 100 mg / kg / day once daily for 3 days. Proliferating cell nuclear antigen (PCNA)-positive cells tended to be decreased as compared to the vehicle control, but no effects on apoptosis or cytochrome P-450 (CYP) 2E1 expression were apparent. Our results suggest that coumaperine provides protection against initiation of hepatocarcinogenesis, and that this is related to inhibition of cell proliferation.

"Hotness" stability of chicken hot-wing products as affected by preparation methods and storage

Chicken hot-drumettes containing 2% cayenne pepper were prepared using three different cooking methods and stored under two different temperatures for "hotness" evaluation. Results demonstrated that the hotness of the samples were highest when products were cooked in a microwave oven, followed by convection oven, and least hot by deep-fat frying. Regardless of the cooking method, the degree of hotness of the hot-drumette decreased drastically during refrigerated storage. Results also indicated that the loss of hotness was associated with the increase of 2-thiobarbituric acid (TBA) values in the product. The addition of antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), rosemary, and sodium nitrate during preparation or vacuum packaging retarded lipid oxidation of chicken hot-drumettes and retarded the loss of hotness of the products during refrigerated storage.

Prevention of cancer: vegetables and plants

1. Results of epidemiological studies indicate that a human diet rich in vegetables may lower the incidence of cancer. 2. This preventive effect of the vegetable diet against cancer could be ascribed to lowered intake of energy (joules) and its content of vitamins and carotene. 3. The consumption of vegetables means also less meat and fats as well as increased fiber content and specific chemopreventive compounds (indoles, plant phenols) present in such a diet. 4. The supposed mechanisms of prevention may include enhanced enzymatic detoxification of harmful compounds, and inhibition of their binding to cellular DNA, their adsorption on fiber, detoxification of radical forms of carcinogens by natural antioxidants in plants and probably many other ways too.