Antioxidant and antimicrobial activities of various solvent extracts, piperine and piperic acid from Piper nigrum

The critical role of piperamide derivative D4 in the regulation of inflammatory response by the microglia and astrocytic glial cells

Acute and chronic inflammation in the central nervous system plays a critical role in the development of neurodegenerative disorders. Various pro-inflammatory cytokines, chemokines, and enzymes such as TNF-α, IL1-β, IL-6, COX-1, COX-2, iNOS, IKK, and inducible nitric oxide are expressed in several signalling pathways, and mediate the neuroinflammatory process. ROS and NF-kB nuclear translocation are the two fundamental pathways involved in neuroinflammatory pathogenesis in neuronal and glial cells. In recent years several compoundswere designed to affect the neuroinflammation and suppress neurodegenerative process. Derivatives of natural products (NPs) attract the most attention of drug developers and industries due to their safety and lesser side effects in comparison with generic drugs. One of the most well-known NP is piperine, which is a yellow crystalline alkaloid extracted from black and white pepper. Recently, we developed a novel piperine derivative (((2E,4E)-5-(benzo[d][1,3]dioxol-5-yl)-N-(4-(hydroxymethyl)phenyl)penta-2,4-dienamide, D4) to enhance the specificity and efficacy of the base molecule. Next, we evaluated the potential anti-inflammatory properities of D4 in CHME3 and SVG cell-lines corresponding to human microglia and astrocytes, respectively. Our results indicated that D4 inhibited NF-kB translocation pathway, and significantly reduced transcript and protein levels of pro-inflammatory cytokines in comparison with Aspirin, as a well-known non-selective NSAID. Furthermore, in silico study showed excellent D4 bioavailability in oral administration. The results of the present study suggest a novel molecule with high anti-neuroinflammatory potency for further pre-clinical tests and pharmacological drug investigation.

Experimental Characterization of the Drying of Kampot Red Pepper (Piper nigrum L.)

The objective of this work is to provide new insights into the mechanisms taking place during the drying of the mature grains of Kampot pepper, a cultivar of pepper (Piper nigrum L.), which is produced in the Kampot Province, Cambodia. Indeed, even if the Kampot pepper is recognized for its organoleptic qualities, no research works were dedicated to the drying of its mature grains, in order to yield red pepper. Experiments with different pretreatment and drying conditions were performed. The results of these experiments were analyzed, regarding the drying kinetics, the color of the dry product, and the degradation of the bioactive compounds during the drying. Regarding these bioactive compounds, several parameters were considered: the total phenolic content, the total flavonoid content, and the piperine content. The results show that the Kampot mature pepper is prone to alterations when dried at a temperature of 55∘C or 65∘C: the color, the total phenolic content, and the flavonoid content are significantly altered, while the piperine content, important for the pungency of this spice, seems unaltered. Raising the temperature leads to more important degradations. However, performing a pretreatment by dipping the pepper grains into boiling water appears to significantly reduce these alterations and, concomitantly, to accelerate the drying. As a conclusion of the analysis of the results, it can be stated that, to increase the product quality, it is recommended to pretreat the pepper by dipping it into boiling water during 5 min., before drying at 55∘C.

Formulation and Evaluation of Supramolecular Food-Grade Piperine HP β CD and TPGS Complex: Dissolution, Physicochemical Characterization, Molecular Docking, In Vitro Antioxidant Activity, and Antimicrobial Assessment

The purpose of the present study was to improve the aqueous solubility, dissolution, and antioxidant activity of the water-insoluble drug piperine (PIP). The study was performed by preparing PIP binary inclusion complex (PIP BIC) and piperine ternary inclusion complex (PIP TIC) by different methods. The effect of a hydrophilic auxiliary substance (TPGS) was assessed with addition to PIP and hydroxypropyl beta cyclodextrin (HP β CD) complex. The phase solubility study was performed to evaluate the complexation efficiency and stability constant. The aqueous solubility, dissolution, physicochemical assessment, antioxidant activity, antimicrobial activity, and molecular docking were further evaluated to check the effect of the complexation of PIP. The stability constant (Ks) value was found to be 238 and 461 M⁻¹ for the binary and ternary inclusion complex. The dissolution study results showed a marked enhancement of release in comparison to pure drug. XRD and SEM studies revealed the presence of more agglomerated and amorphous structures of PIP, which confirmed the formation of complexes. The results of DPPH radical scavenging and antimicrobial activity showed a significant (p < 0.05) enhancement in scavenging activity for PIP TIC (microwave irradiation (MI)). The docking studies have revealed that the binding affinity of TPGS at the PIP-HP β CD complex was −5.2 kcal/mol.

Degree of crosslinking in β-cyclodextrin-based nanosponges and their effect on piperine encapsulation

Piperine (PIP) is an alkaloid which is potent as a therapeutic agent. However, its applications are restricted by its poor water solubility. Nanosponges (NS) derived from polymers are versatile carriers for poor water-soluble substances. The aim of this work was to synthesize β-cyclodextrin NS, by microwave-assisted fusion, for the encapsulation of PIP. Different formulations of NS were synthesized by varying the molar ratio of β-cyclodextrin:diphenyl carbonate (β-CD:DPC; 1:2, 1:6 and 1:10). NS specimens derived from 1:2, 1:6 and 1:10 β-CD:DPC molar ratios exhibited degree of substitution values of 0.345, 0.629 and 0.878, respectively. The crystallinity of NS was enhanced by increasing diphenyl carbonate concentration. A high degree of crosslinking in the NS increased the loading efficiency due to increased surface area available for bioactive inclusion. This study demonstrated the feasibility of synthesizing NS derived from β-cyclodextrin of high crystallinity for the encapsulation of PIP at high loading capacity.

Feasibility of rapid piperine quantification in whole and black pepper using near infrared spectroscopy and chemometrics

Piperine is a bioactive alkaloid that possesses various health benefits and is responsible for the pungent aroma of pepper. Piperine content in whole and ground black pepper (n = 132) was analyzed by near-infrared spectroscopy (NIRS) in the 950 to 1650 nm wavelength window. Chemometric modeling using partial least square regression was performed, and outliers were checked and removed during the preparation of the calibration curve by considering sample residual variance and sample leverage. Model accuracy was evaluated with a low root-mean-square error of cross-validation (RMSECV) and a high ratio performance to deviation (RPD). The optimal model had a coefficient of determination (R² ) of 0.726, RMSECV of 0.289 g/100 g, and RPD of 1.744 for the whole black pepper. The results of R² , RMSECV, and RPD for the ground black pepper were 0.850, 0.231 g/100 g, and 2.424, respectively. Therefore, based on the perspective of onsite process, the proposed NIRS method can be employed for selecting abnormal samples during the inspection of black pepper raw material and for quantifying piperine contents of final black pepper product. PRACTICAL APPLICATION: Generally, the quality indicators of black pepper are graded solely based on their external appearance, quality, and size. This study discloses the development of a near-infrared spectroscopy-based fast and accurate nondestructive analytical method for the detection of piperine, a bioactive constituent of pepper, as a tool for the quality control of whole and ground black pepper.

Piperine ameliorated memory impairment and myelin damage in lysolecethin induced hippocampal demyelination

AIMS

We still do not have effective treatment for hippocampal demyelination and memory deficit, the two common comorbidities in multiple sclerosis (MS). This study aimed to assess the therapeutic effect of Piperine (the main alkaloid of black pepper) in an experimental model of demyelination.

MAIN METHODS

Demyelination was induced in male Wistar rats by bilateral injection of lysolecithin (LPC) into the CA1 region of the hippocampus. Piperine (5, 10, 20 mg/kg) was daily injected intraperitoneally three days post LPC injection for ten days. The spatial memory was examined by the Morris water maze task. Demyelination and astrocyte activation were assessed by an immunohistological study. The gene expression analysis of TNF-α, IL1-β, NF-κB, IL-10, Foxp3, iNOS, Nrf2, HO1, MBP, and BDNF was done using qPCR. The total antioxidant capacity of hippocampal tissue was measured using FRAP assay.

KEY FINDINGS

Our results showed that piperine improved the memory performance and myelin repair in the hippocampal demyelination model. Piperine inhibited iNOS expression concomitant with enhanced expression levels of Nrf2, HO1 and the total antioxidant capacity in the hippocampal tissue. Piperine treatment significantly reduced the gene expression level of TNF-α, IL1-β, NF-κB, and glial activation in the injured area; however, the mRNA level of IL-10, Foxp3, BDNF and MBP were significantly increased.

SIGNIFICANCE

We found piperine to be an effective treatment for spatial memory impairment and myelin repair in the hippocampal demyelination model. However, further experimental evidence is needed to investigate the precise mechanisms underlying piperine as a promising therapeutic target in MS patients.

Improved Solubility and Dissolution Rates in Novel Multicomponent Crystals of Piperine with Succinic Acid

The objectives of this study were to prepare and characterize a novel piperine–succinic acid multicomponent crystal phase and to evaluate the improvement in the solubility and dissolution rate of piperine when prepared in the multicomponent crystal formation. The solid-state characterization of the novel multicomponent crystal was performed by powder X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier transform-infrared (FT-IR) spectroscopy. Solubility and dissolution rate profiles were evaluated in distilled water. The physical stability was evaluated under high relative humidity (75% and 100% RH). The determination of the single crystal X-ray diffraction structure revealed that this novel multicomponent crystal was a cocrystalline phase of piperine–succinic acid (2:1 molar ratio). The differential scanning calorimetry thermogram of the cocrystal showed a single and sharp endothermic peak at 110.49 °C. The cocrystal resulted in greater solubility and a faster dissolution rate of piperine than intact piperine. This improvement was a result of the formation of a channel structure in the cocrystal. In addition, the cocrystal was stable under a humid condition.

Synthesis, Radical-Scavenging Activities, and Protective Effects against AAPH-Induced Oxidative Damage in DNA and Erythrocytes of Piperine Derivatives

Piperine amino acid derivatives containing phenolic hydroxyl groups were synthesized using piperine as the raw material by amide hydrolysis, amidation, ester hydrolysis, and deacetalization. The obtained products were characterized by mass spectrometry and nuclear magnetic resonance. The antioxidant activity of the piperine derivatives was evaluated by the DPPH and ABTS scavenging rates and the total antioxidant capacity. The results showed that the piperine amino acid (4a–4d) had relatively weak radical-scavenging ability, while the piperine amino acid derivatives (5a–5d) containing phenolic hydroxyl groups had significant radical-scavenging effects. In addition, the total reducing ability of 5a–5d was better than that of piperine. The study also found that piperine derivatives containing phenolic hydroxyl groups played an important role in inhibiting oxidative damage in DNA and erythrocytes.

Comparative Therapeutic Effects of Natural Compounds Against Saprolegnia spp. (Oomycota) and Amyloodinium ocellatum (Dinophyceae)

The fish parasites Saprolegnia spp. (Oomycota) and Amyloodinium ocellatum (Dinophyceae) cause important losses in freshwater and marine aquaculture industry, respectively. The possible adverse effects of compounds used to control these parasites in aquaculture resulted in increased interest on the search for natural products with antiparasitic activity. In this work, eighteen plant-derived compounds (2′,4′-Dihydroxychalcone; 7-Hydroxyflavone; Artemisinin; Camphor (1R); Diallyl sulfide; Esculetin; Eucalyptol; Garlicin 80%; Harmalol hydrochloride dihydrate; Palmatine chloride; Piperine; Plumbagin; Resveratrol; Rosmarinic acid; Sclareolide; Tomatine, Umbelliferone, and Usnic Acid) have been tested in vitro. Sixteen of these were used to determine their effects on the gill cell line G1B (ATCC®CRL-2536™) and on the motility of viable dinospores of Amyloodinium ocellatum, and thirteen were screened for inhibitory activity against Saprolegnia spp. The cytotoxicity results on G1B cells determined that only two compounds (2′,4′-Dihydroxychalcone and Tomatine) exhibited dose-dependent toxic effects. The highest surveyed concentrations (0.1 and 0.01 mM) reduced cell viability by 80%. Upon lowering the compound concentration the percentage of dead cells was lower than 20%. The same two compounds revealed to be potential antiparasitics by reducing in a dose-dependent manner the motility of A. ocellatum dinospores up to 100%. With respect to Saprolegnia, a Minimum Inhibitory Concentration was found for Tomatine (0.1 mM), Piperine and Plumbagin (0.25 mM), while 2′,4′-Dihydroxychalcone considerably slowed down mycelial growth for 24 h at a concentration of 0.1 mM. Therefore, this research allowed to identify two compounds, Tomatine and 2′,4′-Dihydroxychalcone, effective against both parasites. These compounds could represent promising candidates for the treatment of amyloodiniosis and saprolegniosis in aquaculture. Nevertheless, further in vitro and in vivo tests are required in order to determine concentrations that are effective against the considered pathogens but at the same time safe for hosts, environment and consumers.

Plants: A natural solution to enhance raw milk cheese preservation?

Plants have been traditionnally used for centuries in cheese manufacturing, either for their aromatic properties or as technological auxiliaries (e.g. milk-clotting enzyme preparations, cheese wrappers). Some of these plants are known to have antimicrobial and/or antioxidant properties and could also act as natural preservatives for raw milk and derived dairy products. This review examined the traditional uses of plants in dairy processing, and then focuses on known antimicrobial and antioxidant properties of their extracts (e.g. maceration, decoction, essential oil). Known effects of theses plants on technological flora (starter cultures and microorganisms implicated in cheese ripening) were also summarized, and the potential for plant extracts used in combination with hurdle technologies was explored. Then, legal restriction and bioactivity variations from a culture media to a food matrix was reviewed: non-toxic bioactive molecules found in plants, extract preparation modes suitable with foodgrade processing restrictions, the role of the food matrix as a hindrance to the efficiency of bioactive compounds, and a review of food legislation. Finally, some commercial plant extracts for milk preservation were discussed.

Discovery of γ-lactam derivatives containing 1,3-benzodioxole unit as potential anti-phytopathogenic fungus agents

A series of γ-lactam analogs containing 1,3-benzodioxole moiety were designed, and these derivatives were synthesized from the lead compound of lactam via a structural diversity-oriented synthesis, their structures were confirmed by ¹HNMR,¹³CNMR, ESI-MS spectrum. Their antifungal activities were evaluated against four serious and typically crop-threatening agricultural fungi, including Rhizoctonia solani, Alternaria tenuis Nees, Gloeosporium theae-sinensis, and Fusarium graminearum. Some of these derivatives exhibited activity against Alternaria tenuis Nees higher than that of commercial fungicides carbendazim, such as compounds 7a, 7b, and 7i, compared with the blank control, some of these derivatives showed good antifungal activities against Gloeosporium theae-sinensis and Fusarium graminearum. The systematic study provides evidences for further structural modification and application of lactam analogues as antifungal agents for agriculture.

Piperine Is a Mechanism-Based Inactivator of CYP3A

Piperine (PPR) is the representative alkaloid component of the piper species (family: Piperaceae). Our rapid screening study found PPR caused time-dependent inhibition of cytochrome P450s (CYP) 3A and 2D6, and CYP3A was inactivated the most. Further study demonstrated that PPR is a time-, concentration-, and NADPH-dependent inhibitor of CYP3A, and significant loss (49.5% ± 3.9%) of CYP3A activity was observed after 20minute incubations with 80 μM PPR at 37°C. The values of K _I and k _inact were 30.7 μM and 0.041 minutes^-1, respectively. CYP3A competitive inhibitor ketoconazole showed protective effect against the enzyme inactivation. Superoxide dismutase/catalase and GSH displayed minor protection against the PPR-caused enzyme inactivation. Ferricyanide partially reduced the enzyme inhibition by PPR. Additionally, NADPH-dependent formation of reactive metabolites from PPR were found in human liver microsomal incubation mixtures. An ortho-quinone intermediate was trapped by NAC in microsomal incubations with PPR. DM-PPR, demethylene metabolite of PPR, showed weak enzyme inactivation relative to that caused by PPR. It appears that both carbene and ortho-quinone intermediates were involved in the inactivation of CYP3A caused by PPR. SIGNIFICANCE STATEMENT: CYP3A subfamily members (mainly CYP3A4 and CYP3A5) play a critical role in drug metabolism. Piperine (PPR), a methylenedioxyphenyl derivative combined with an unsaturated ketone, is the major active ingredient of pepper. PPR revealed time-, concentration-, and NADPH-dependent inhibitory effect on CYP3A. Carbene and quinone metabolites were both involved in the observed CYP3A inactivation by PPR. Apparently, the unsaturated ketone moiety did not participate in the enzyme inactivation. The present study sounds an alert of potential risk for food-drug interactions.

Neuroprotective Effect of Quercetin in Combination with Piperine Against Rotenone- and Iron Supplement-Induced Parkinson's Disease in Experimental Rats

Parkinson's disease (PD) is a neurodegenerative disorder caused by selective dopaminergic neuronal loss. Rotenone is a neurotoxin that selectively destroys dopaminergic neurons, leading to PD-like symptoms. Quercetin possesses antioxidant, anti-inflammatory, and neuroprotective properties but a major drawback is its low bioavailability. Therefore, the present study was designed to evaluate the neuroprotective effect of quercetin in combination with piperine against rotenone- and iron supplement-induced model of PD. Rotenone was administered at a dose of 1.5 mg/kg through an intraperitoneal route with iron supplement at a dose of 120 μg/g in diet from day 1 to day 28. Pre-treatment with quercetin (25 and 50 mg/kg, p.o.), piperine (2.5 mg/kg, p.o.) alone, quercetin (25 mg/kg, p.o.) in combination with piperine (2.5 mg/kg), and ropinirole (0.5 mg/kg, i.p.) was administered for 28 days 1 h prior to rotenone and iron supplement administration. All behavioral parameters were assessed on weekly basis. On the 29th day, all animals were sacrificed and striatum was isolated for biochemical (LPO, nitrite, GSH, mitochondrial complexes I and IV), neuroinflammatory (TNF-α, IL-1β, and IL-6), and neurotransmitter (dopamine, norepinephrine, serotonin, GABA, glutamate) estimation. Quercetin treatment attenuated rotenone- and iron supplement-induced motor deficits and biochemical and neurotransmitter alterations in experimental rats. However, combination of quercetin (25 mg/kg) with piperine (2.5 mg/kg) significantly enhanced its neuroprotective effect as compared with treatment with quercetin alone. The study concluded that combination of quercetin with piperine contributed to superior antioxidant, anti-inflammatory, and neuroprotective effect against rotenone- and iron supplement-induced PD in experimental rats.

Electrochemical quantification of piperine in black pepper

A simple, rapid method of the detection of piperine in black pepper is reported using a voltammetric sensor based on a glassy carbon (GC) electrode with analysis following a short one-step extraction using ethanol. The method is based on a novel potential sweep designed to maximise signal sizes and shown with context of the present analytical challenge to be essential for gathering data allowing the construction of a linear calibration curve for the analysis in the relevant range namely 0.25-5.0 mM.

Discovery of Antibacterial Dietary Spices That Target Antibiotic-Resistant Bacteria

Although spice extracts are well known to exhibit antibacterial properties, there is lack of a comprehensive evaluation of the antibacterial effect of spices against antibiotic-resistant bacteria. In the present study, ethanolic extracts from a total of 67 spices were comprehensively investigated for their in vitro antibacterial activities by agar well diffusion against two common food-borne bacteria, Staphylococcus aureus and Salmonella enteritidis, with multi-drug resistance. Results showed that S. aureus was generally more sensitive to spice extracts than S. enteritidis. Of the 67 spice extracts, 38 exhibited antibacterial activity against drug-resistant S. aureus, while only four samples were effective on drug-resistant S. enteritidis. In addition, 11 spice extracts with inhibition zones greater than 15 mm were further verified for their broad-spectrum antibacterial properties using another 10 drug-resistant S. aureus strains. It was found that five spice extracts, including galangal, fructus galangae, cinnamon, yellow mustard seed, and rosemary, exhibited the highest antibacterial capacity. Further cytotoxicity of these 11 spices was determined and LC₅₀ values were found to be more than 100 μg/mL except for galangal, rosemary, and sage, whose LC₅₀ values were 9.32 ± 0.83, 19.77 ± 2.17, and 50.54 ± 2.57, respectively. Moreover, the antioxidant activities (ferric-reducing antioxidant power (FRAP) and trolox equivalent antioxidant capacity (TEAC) values) and total phenolic content (TPC) of spice extracts were determined to establish possible correlations with the antibacterial activity. Although the antibacterial effect was positively correlated with the antioxidant activities and TPC, the correlation was weak (r < 0.5), indicating that the antibacterial activity could also be attributed to other components besides antioxidant polyphenols in the tested spice extracts. In conclusion, dietary spices are good natural sources of antibacterial agents to fight against antibiotic-resistant bacteria, with potential applications as natural food preservatives and natural alternatives to antibiotics in animal feeding.

A systematic review on black pepper (Piper nigrum L.): from folk uses to pharmacological applications

Considered as the "King of spices", black pepper (Piper nigrum L.) is a widely used spice which adds flavor of its own to dishes, and also enhances the taste of other ingredients. Piper nigrum has also been extensively explored for its biological properties and its bioactive phyto-compounds. There is, however, no updated compilation of these available data to provide a complete profile of the medicinal aspects of P. nigrum. This study endeavors to systematically review scientific data on the traditional uses, phytochemical composition, and pharmacological properties of P. nigrum. Information was obtained using a combination of keywords via recognized electronic databases (e.g., Science Direct and Google Scholar). Google search was also used. Books and online materials were also considered, and the literature search was restricted to the English language. The country with the highest number of traditional reports of P. nigrum for both human and veterinary medicine was India, mostly for menstrual and ear-nose-throat disorders in human and gastrointestinal disorders in livestock. The seeds and fruits were mostly used, and the preferred mode of preparation was in powdered form, pills or tablets, and paste. Piper nigrum and its bioactive compounds were also found to possess important pharmacological properties. Antimicrobial activity was recorded against a wide range of pathogens via inhibition of biofilm, bacterial efflux pumps, bacterial swarming, and swimming motilities. Studies also reported its antioxidant effects against a series of reactive oxygen and nitrogen species including the scavenging of superoxide anion, hydrogen peroxide, nitric oxide, DPPH, ABTS, and reducing effect against ferric and molybdenum (VI). Improvement of antioxidant enzymes in vivo has also been reported. Piper nigrum also exhibited anticancer effect against a number of cell lines from breast, colon, cervical, and prostate through different mechanisms including cytotoxicity, apoptosis, autophagy, and interference with signaling pathways. Its antidiabetic property has also been confirmed in vivo as well as hypolipidemic activity as evidenced by decrease in the level of cholesterol, triglycerides, and low-density lipoprotein and increase in high-density lipoprotein. Piper nigrum also has anti-inflammatory, analgesic, anticonvulsant, and neuroprotective effects. The major bioactive compound identified in P. nigrum is piperine although other compounds are also present including piperic acid, piperlonguminine, pellitorine, piperolein B, piperamide, piperettine, and (-)-kusunokinin, which also showed biological potency. Most pharmacological studies were conducted in vitro (n = 60) while only 21 in vivo and 1 clinical trial were performed. Hence, more in vivo experiments using a pharmacokinetic and pharmacokinetic approach would be beneficial. As a conclusive remark, P. nigrum should not only be regarded as "King of spices" but can also be considered as part of the kingdom of medicinal agents, comprising a panoply of bioactive compounds with potential nutraceutical and pharmaceutical applications.

Efecto bioplaguicida de extractos vegetales para el control de Spodoptera frugiperda en el cultivo de maíz (Zea mays)

El maíz es el segundo cereal de mayor producción en Colombia con un 21,9 % de la superficie total. La plaga Spodoptera frugiperda ataca la planta desde las primeras semanas de crecimiento, devorando sus hojas, tallo y granos; disminuyendo el rendimiento de los cultivos. Esta plaga se controla con el uso indiscriminado de plaguicidas sintéticos como: carbofurano, clorpirifos y atrazina. En esta investigación, los extractos de Azadirachta indica, Piper nigrum, Petiveria alliacea y sus mezclas; y los extractos de Nicotiana tabacum, Lippia alba, Allium sativum y sus mezclas se aplicaron como bioplaguicidas en plantas de maíz amarillo tradicional. Después de la tercera semana de crecimiento, los tratamientos se aplicaron dos veces al día cada tres días durante siete semanas. Las variables estudiadas fueron número de larvas muertas, altura de las plantas y daño en hojas y tallos. Las plantas tratadas crecieron dos veces más y su grado de afectación, según la escala de Mihm, fue menor que las plantas del grupo testigo. Los porcentajes de eficacia de las seis especies vegetales y sus mezclas fueron representativos (>80 %), de acuerdo con Henderson y Tilton, demostrando que estos extractos vegetales son una alternativa viable para el control de S. frugiperda.

Evaluation of the antinociceptive and anti-inflammatory activities of piperic acid: Involvement of the cholinergic and vanilloid systems

Piperin is the active compound of black pepper (Piper nigrum). From the piperine was obtained the molecule of the piperic acid (PAC). The objective of this study was to evaluate the antinociceptive and anti-inflammatory of the compound. The antinociceptive effects of PAC were evaluated by abdominal writhing, formalin, capsaicin and tail-flick tests; while the anti-inflammatory effects were evaluated by paw oedema and air pouch tests, and in vitro COX inhibition assay. The possible action mechanism of PAC was evaluated using naloxone, L-NAME, glibenclamide and atropine in tail flick test and by Cholinesterase activity assay and production of TNF-α and IL-1β. PAC significantly reduced the nociceptive effects induced by acetic acid or formalin in mice. PAC also demonstrated an antinociceptive effect in the tail-flick model. The muscarinic receptor antagonist, atropine reduced the antinociceptive effect of PAC in the tail-flick model. PAC was able to inhibit capsaicin-induced nociception, showing involvement of TRPV1. The compound did not alter the motor capacity of the animals, not interfering in the nociceptive response. PAC also showed anti- inflammatory activity by inhibiting the formation of carrageenan-induced paw oedema, leukocyte migration, and cytokine production / release. Atropine reduced the activity of PAC on leukocyte migration, and cytokine production. The compound showed to be able to reduce the cytokine production stimulated by capsaicin. PAC inhibited the COX activity. The results presented suggest that the possible cholinomimetic action and vanilloid agonist of the piperic acid may be responsible by antinociceptive and anti- inflammatory effects; these effects are devoid of toxicity.

Pulverizing processes affect the chemical quality and thermal property of black, white, and green pepper (Piper nigrum L.)

In this study, the effects of different pulverizing methods on the chemical attributes and thermal properties of black, white and green pepper were evaluated. Cryogenic grinding minimally damaged the lipid, moisture, crude protein, starch, non-volatile ether extract, piperine, essential oil and the typical pepper essential oil compounds of the spices. The pulverizing methods and storage significantly affected the compositions of the fatty acid in the peppers, except for palmitic acid and lignoceric acid. The amino acid contents and the thermo-gravimetric analysis curve were hardly influenced by the grinding techniques. The use of cryogenic grinding to prepare pepper ensured the highest quality of pepper products. Regardless of grinding technique, the values of moisture, piperine, unsaturated fatty acids, essential oil, monoterpenes, and the absolute concentrations of typical pepper essential oil constituents (except caryophyllene oxide) decreased, whereas the amino acid, lipid, protein, starch, and non-volatile ether extract content as well as the thermal properties were insignificantly changed after storage at 4 °C for 6 months.

Comparative Study between Ethanolic and β-Cyclodextrin Assisted Extraction of Polyphenols from Peach Pomace

Peach byproducts are often regarded as food waste despite their high content in health-promoting components. Amongst the latter, polyphenols are bioactive molecules with significant health benefits. The present study investigated an eco-friendly and cost-effective method using a GRAS food additive, β-cyclodextrin (β-CD), for the recovery of polyphenols from peach pomace. β-CD assisted extraction of polyphenols was compared to that of conventional solvent (ethanol) extraction at the same concentrations (10 mg/mL, 20 mg/mL, 30 mg/mL, 40 mg/mL, and 50 mg/mL) in terms of quality (antiradical activity) and quantity. The extract obtained by 50 mg/mL β-CD assisted extraction showed the highest polyphenol (0.72 mg GAE/g DM) and flavonoid (0.35 mg catechin/g of DM) concentrations as maximal antiradical activity (6.82%) and a noted antibacterial activity. Our results showed the competitiveness of β-CD assisted extraction to recover a high quantity and quality of polyphenols from peach pomace suggesting β-CD as a green alternative method for phenolic extraction.

Piperine-loaded chitosan-STPP nanoparticles reduce neuronal loss and astrocytes activation in chemical kindling model of epilepsy

Recent evidence suggests that encapsulation of hydrophobic drugs in biodegradable polymers opens a new horizon in nanomedicine filed. Piperine, a main alkaloid form of black pepper possesses potent anticonvulsant activity. However, the low water solubility of piperine has limited its clinical application. In this study, piperine was loaded on chitosan-sodium tripolyphosphate nanoparticles (CS-STPP NPs) and the effect of piperine NPs on seizures behavior and astrocytes activation was assessed in pentylentetrazol (PTZ)-induced kindling model. Animals have received the daily injection of free piperine or piperine NPs at doses of 5 or 10mg/kg, 10days before PTZ injections and their intraperitoneally (i.p) administration continued until the last PTZ injection. The neuroprotective effects of piperine NPs were evaluated using nissl staining and immunostaining against NeuN. Astrocytes activation was examined by GFAP immunostaining. Behavioral data showed that piperine NPs have inhibited the development of seizure parameters compared to the free piperine groups. In addition, the levels of cell loss and astrocytes activation were reduced in piperine NPs groups. In conclusion, these data suggest that piperine NPs enhance the neuroprotection and ameliorate the astrocytes activation in chemical kindling model of epilepsy. This may provide an effective therapeutic strategy for the treatment of epilepsy disorder.

[Ru(pipe)(dppb)(bipy)]PF6: A novel ruthenium complex that effectively inhibits ERK activation and cyclin D1 expression in A549 cells

Lung cancer is the most frequent type of cancer worldwide. In Brazil, only 14% of the patients diagnosed with lung cancer survived 5years in the last decades. Although improvements in the therapeutic approach, it is relevant to identify new chemotherapeutic agents. In this framework, ruthenium metal compounds emerge as a promising alternative to platinum-based compounds once they displayed lower cytotoxicity and more selectivity for tumor cells. The present study aimed to evaluate the antitumor potential of innovative ruthenium(II) complex, [Ru(pipe)(dppb)(bipy)]PF₆ (PIPE) on A549 cells, which is derived from non-small cell lung cancer. Results demonstrated that PIPE effectively reduced the viability and proliferation rate of A549 cells. When PIPE was used at 9μM there was increase in G0/G1 cell population with concomitant reduction in frequency of cells in S-phase, indicating cell cycle arrest in G1/S transition. Antiproliferative activity of PIPE was associated to its ability of reducing cyclin D1 expression and ERK phosphorylation levels. Cytotoxic activity of PIPE on A549 cells was observed when PIPE was used at 18μM, which was associated to its ability of inducing apoptosis by intrinsic pathway. Taken together, the data demonstrated that PIPE is a promising antitumor agent and further in vivo studies should be performed.

Antibacterial and Antifungal Activities of Spices

Infectious diseases caused by pathogens and food poisoning caused by spoilage microorganisms are threatening human health all over the world. The efficacies of some antimicrobial agents, which are currently used to extend shelf-life and increase the safety of food products in food industry and to inhibit disease-causing microorganisms in medicine, have been weakened by microbial resistance. Therefore, new antimicrobial agents that could overcome this resistance need to be discovered. Many spices-such as clove, oregano, thyme, cinnamon, and cumin-possessed significant antibacterial and antifungal activities against food spoilage bacteria like Bacillus subtilis and Pseudomonas fluorescens, pathogens like Staphylococcus aureus and Vibrio parahaemolyticus, harmful fungi like Aspergillus flavus, even antibiotic resistant microorganisms such as methicillin resistant Staphylococcus aureus. Therefore, spices have a great potential to be developed as new and safe antimicrobial agents. This review summarizes scientific studies on the antibacterial and antifungal activities of several spices and their derivatives.

Characterization of piperine metabolites in rats by ultra-high-performance liquid chromatography with electrospray ionization quadruple time-of-flight tandem mass spectrometry

RATIONALE

Piperine is a major constituent of Piper nigrum L. and is a naturally bioactive alkaloid. Structural changes in piperine have been shown to result in different biological effects. The present study aims to investigate piperine metabolites in rat plasma, bile, urine, and feces after oral administration.

METHODS

The metabolic pathway of piperine in vivo was investigated using ultra-high-performance liquid chromatography (UHLPC) combined with electrospray ionization quadruple time-of-flight tandem mass spectrometry (QTOF-MS). Piperine metabolites were found and identified by fragmentation patterns and accurate mass measurements.

RESULTS

The 12 metabolites detected and identified were divided into three groups: methylenedioxycyclic ring-opening metabolites (M01-M08), methylenedioxycyclic ring-oxidizing metabolites (M09-M11), and piperidine ring-cleavage metabolites (M12). Seven piperine metabolites, including M02, M03, M04, M05, M09, M10 and M11, were reported for the first time in the literature.

CONCLUSIONS

Results showed that the principal metabolism pathways of piperine in rat were reduction and demethylation after ring-opening, and that UHPLC/QTOF-MS can serve as an important analytical platform to gather the piperine metabolism profile. Copyright © 2017 John Wiley & Sons, Ltd.

Antimicrobial effect of black pepper petroleum ether extract for the morphology of Listeria monocytogenes and Salmonella typhimurium

This study aimed to evaluate the effects of black pepper petroleum extract (BPPE) on pathogenic bacteria. The extraction from black pepper showed intense antimicrobial activity against the Gram-positive Listeria monocytogenes ATCC 19115 and the Gram-negative bacteria Salmonella typhimurium ATCC 14028. The minimum inhibitory concentrations of BPPE against L. monocytogenes and S. typhimurium were 0.625 and 1.25 mg/ml, respectively. Detection of Alkaline phosphatase outside the cell revealed that BPPE treatment destroyed the cell wall integrity. BPPE also altered the membrane integrity, thereby causing leaching of 260 and 280 nm UV-absorbing materials into the medium, particularly, nucleic acids and proteins. Propidium iodide infiltration experiments also indicated that BPPE treatment altered the permeability of bacterial cell membrane. Moreover, Na+/K+-ATPase activity was inhibited by BPPE. And the results of scanning electron microscopy showed that BPPE treatment damaged the morphology of the tested bacteria. These results indicated that BPPE could destroy cell wall integrity, alter the permeability of cell membrane, and inhibit the activity of intracellular enzyme, which could kill bacteria.

Evidences for Piperine inhibiting cancer by targeting human G-quadruplex DNA sequences

Piperine, a naturally occurring alkaloid, is well known as anti-oxidant, anti-mutagenic, anti-tumor and anti-proliferative agent. Piperine exerts such pharmacological activities by binding or interacting with various cellular targets. Recently, the first report for Piperine interaction with duplex DNA has been published last year but its interaction with G-quadruplex structures has not been studied yet. Herein, we report for the first time the interaction of Piperine with various DNA G-quadruplex structures. Comprehensive biophysical techniques were employed to determine the basis of interaction for the complex formed between Piperine and G-quadruplex DNA sequences. Piperine showed specificity for G-quadruplex DNA over double stranded DNA, with highest affinity for G-quadruplex structure formed at c-myc promoter region. Further, in-vitro studies show that Piperine causes apoptosis-mediated cell death that further emphasizes the potential of this natural product, Piperine, as a promising candidate for targeting G-quadruplex structure and thus, acts as a potent anti-cancer agent.

Antitumor, Antioxidant, and Nitrite Scavenging Effects of Chinese Water Chestnut (Eleocharis dulcis) Peel Flavonoids

The preparation, quantification, and characterization of flavonoid compounds from Chinese water chestnut peel (CWCP) flavonoid extract and ethyl acetate fraction (EF), n-butanol fraction, and water fraction were studied. Among these, EF showed the maximum free radical levels (IC₅₀ values of 0.36, 0.40, and 0.37 mg/mL for DPPH•, ABTS•⁺ , and •OH, respectively), nitrite scavenging effects (IC₅₀ = 1.89 mg/mL), and A549 cell inhibitory activities (IC₅₀ = 776.12 μg/mL) with the highest value of total flavonoid content (TFC, 421.32 mg/g). Moreover, the contents of 8 flavonoids in this fraction were quantified using high-performance liquid chromatography, and fisetin, diosmetin, luteolin, and tectorigenin were the 4 major flavonoids with levels of 31.66, 29.91, 13.69, and 12.41 mg/g, respectively. Luteolin produced a greater inhibition of human lung cancer A549 cells (IC₅₀ = 59.60 μg/mL) than did fisetin, diosmetin, and tectorigenin. Flow cytometry revealed that the cellular mechanisms of luteolin inhibition of A549 cells were achieved via the induction of cell proliferation arrest at G₁ phase and apoptosis/necrosis. Our findings suggest that flavonoids are closely associated with antitumor, antioxidant, and nitrite scavenging effects of CWCP.

De Novo Assembly and Characterization of Fruit Transcriptome in Black Pepper (Piper nigrum)

Black pepper is one of the most popular and oldest spices in the world and valued for its pungent constituent alkaloids. Pinerine is the main bioactive compound in pepper alkaloids, which perform unique physiological functions. However, the mechanisms of piperine synthesis are poorly understood. This study is the first to describe the fruit transcriptome of black pepper by sequencing on Illumina HiSeq 2000 platform. A total of 56,281,710 raw reads were obtained and assembled. From these raw reads, 44,061 unigenes with an average length of 1,345 nt were generated. During functional annotation, 40,537 unigenes were annotated in Gene Ontology categories, Kyoto Encyclopedia of Genes and Genomes pathways, Swiss-Prot database, and Nucleotide Collection (NR/NT) database. In addition, 8,196 simple sequence repeats (SSRs) were detected. In a detailed analysis of the transcriptome, housekeeping genes for quantitative polymerase chain reaction internal control, polymorphic SSRs, and lysine/ornithine metabolism-related genes were identified. These results validated the availability of our database. Our study could provide useful data for further research on piperine synthesis in black pepper.

Development of piperic acid derivatives from Piper nigrum as UV protection agents

CONTEXT

There is a need for the discovery of novel natural and semi-synthetic sunscreen that is safe and effective. Piperine has a UV absorption band of 230-400 nm with high molar absorptivity. This compound has a high potential to be developed to sunscreen.

OBJECTIVE

This study develops new UV protection compounds from piperine by using chemical synthesis.

MATERIALS AND METHODS

Piperine was isolated from Piper nigrum L. (Piperaceae) fruits, converted to piperic acid by alkaline hydrolysis, and prepared as ester derivatives by chemical synthesis. The piperate derivatives were prepared as 5% o/w emulsion, and the SPF values were evaluated. The best compound was submitted to cytotoxicity test using MTT assay.

RESULTS

Piperic acid was prepared in 86.96% yield. Next, piperic acid was reacted with alcohols using Steglich reaction to obtain methyl piperate, ethyl piperate, propyl piperate, isopropyl piperate, and isobutyl piperate in 62.39-92.79% yield. All compounds were prepared as 5% oil in water emulsion and measured its SPF and UVA/UVB values using an SPF-290S analyzer. The SPF values (n = 6) of the piperate derivatives were 2.68 ± 0.17, 8.89 ± 0.46, 6.86 ± 0.91, 16.37 ± 1.8, and 9.68 ± 1.71. The UVA/UVB ratios of all compounds ranged from 0.860 to 0.967. Cytotoxicity of isopropyl piperate was evaluated using human skin fibroblast cells and the IC50 was equal to 120.2 μM.

DISCUSSION AND CONCLUSION

From the results, isopropyl piperate is an outstanding compound that can be developed into a UV protection agent.