Effect of piperine on pharmacokinetics of sodium valproate in plasma samples of rats using gas chromatography-mass spectrometry method

Molecular and pharmacological aspects of piperine as a potential molecule for disease prevention and management: evidence from clinical trials

BACKGROUND

Piperine is a type of amide alkaloid that exhibits pleiotropic properties like antioxidant, anticancer, anti-inflammatory, antihypertensive, hepatoprotective, neuroprotective and enhancing bioavailability and fertility-related activities. Piperine has the ability to alter gastrointestinal disorders, drug-metabolizing enzymes, and bioavailability of several drugs. The present review explores the available clinical and preclinical data, nanoformulations, extraction process, structure-activity relationships, molecular docking, bioavailability enhancement of phytochemicals and drugs, and brain penetration properties of piperine in the prevention, management, and treatment of various diseases and disorders.

MAIN BODY

Piperine provides therapeutic benefits in patients suffering from diabetes, obesity, arthritis, oral cancer, breast cancer, multiple myeloma, metabolic syndrome, hypertension, Parkinson's disease, Alzheimer's disease, cerebral stroke, cardiovascular diseases, kidney diseases, inflammatory diseases, and rhinopharyngitis. The molecular basis for the pleiotropic activities of piperine is based on its ability to regulate multiple signaling molecules such as cell cycle proteins, anti-apoptotic proteins, P-glycoprotein, cytochrome P450 3A4, multidrug resistance protein 1, breast cancer resistance protein, transient receptor potential vanilloid 1 proinflammatory cytokine, nuclear factor-κB, c-Fos, cAMP response element-binding protein, activation transcription factor-2, peroxisome proliferator-activated receptor-gamma, Human G-quadruplex DNA, Cyclooxygenase-2, Nitric oxide synthases-2, MicroRNA, and coronaviruses. Piperine also regulates multiple signaling pathways such as Akt/mTOR/MMP-9, 5'-AMP-activated protein kinase-activated NLR family pyrin domain containing-3 inflammasome, voltage-gated K+ current, PKCα/ERK1/2, NF-κB/AP-1/MMP-9, Wnt/β-catenin, JNK/P38 MAPK, and gut microbiota.

SHORT CONCLUSION

Based on the current evidence, piperine can be the potential molecule for treatment of disease, and its significance of this molecule in the clinic is discussed.

GRAPHICAL ABSTRACT

Metabolomic Profiling and Immunomodulatory Activity of a Polyherbal Combination in Cyclophosphamide-Induced Immunosuppressed Mice

The study was aimed to develop a characterized polyherbal combination as an immunomodulator containing Phyllanthus emblica L., Piper nigrum L., Withania somnifera (L.) Dunal, and Tinospora cordifolia (Willd.) Miers. Through response surface methodology (RSM), the ratio of aqueous extracts of four plant materials was optimized and comprised 49.76% of P. emblica, 1.35% of P. nigrum, 5.41% of W. somnifera, and 43.43% of T. cordifolia for optimum immunomodulatory activity. The optimized combination showed antioxidant potential and contains more than 180 metabolites, out of which gallic acid, quercetin, ellagic acid, caffeic acid, kaempferitrin, and p-coumaric acid are some common and significant metabolites found in plant extracts and in polyherbal combination. Treatment with the polyherbal combination of different doses in cyclophosphamide-induced immunosuppressed mice significantly (p < 0.01) enhanced the subsets of immune cells such as natural killer (NK) cells (60%), B cells (18%), CD4 cells (14%), and CD8 cells (7%). The characterized polyherbal combination exhibited potent immunomodulatory activity, which can be further explored clinically for its therapeutic applicability.

Safety Aspects of the Use of Isolated Piperine Ingested as a Bolus

Piperine is a natural ingredient of Piper nigrum (black pepper) and some other Piper species. Compared to the use of pepper for food seasoning, piperine is used in food supplements in an isolated, concentrated form and ingested as a bolus. The present review focuses on the assessment of the possible critical health effects regarding the use of isolated piperine as a single ingredient in food supplements. In human and animal studies with single or short-term bolus application of isolated piperine, interactions with several drugs, in most cases resulting in increased drug bioavailability, were observed. Depending on the drug and extent of the interaction, such interactions may carry the risk of unintended deleteriously increased or adverse drug effects. Animal studies with higher daily piperine bolus doses than in human interaction studies provide indications of disturbance of spermatogenesis and of maternal reproductive and embryotoxic effects. Although the available human studies rarely reported effects that were regarded as being adverse, their suitability for detailed risk assessment is limited due to an insufficient focus on safety parameters apart from drug interactions, as well as due to the lack of investigation of the potentially adverse effects observed in animal studies and/or combined administration of piperine with other substances. Taken together, it appears advisable to consider the potential health risks related to intake of isolated piperine in bolus form, e.g., when using certain food supplements.

Bioavailability Enhancement of Poorly Soluble Drugs: The Holy Grail in Pharma Industry

Background:

Bioavailability, one of the prime pharmacokinetic properties of a drug, is defined as the fraction of an administered dose of unchanged drug that reaches the systemic circulation and is used to describe the systemic availability of a drug. Bioavailability assessment is imperative in order to demonstrate whether the drug attains the desirable systemic exposure for effective therapy. In recent years, bioavailability has become the subject of importance in drug discovery and development studies.

Methods:

A systematic literature review in the field of bioavailability and the approaches towards its enhancement have been comprehensively done, purely focusing upon recent papers. The data mining was performed using databases like PubMed, Science Direct and general Google searches and the collected data was exhaustively studied and summarized in a generalized manner.

Results:

The main prospect of this review was to generate a comprehensive one-stop summary of the numerous available approaches and their pharmaceutical applications in improving the stability concerns, physicochemical and mechanical properties of the poorly water-soluble drugs which directly or indirectly augment their bioavailability.

Conclusion:

The use of novel methods, including but not limited to, nano-based formulations, bio-enhancers, solid dispersions, lipid-and polymer-based formulations which provide a wide range of applications not only increases the solubility and permeability of the poorly bioavailable drugs but also improves their stability, and targeting efficacy. Although, these methods have drastically changed the pharmaceutical industry demand for the newer potential methods with better outcomes in the field of pharmaceutical science to formulate various dosage forms with adequate systemic availability and improved patient compliance, further research is required.

Pharmacokinetic and pharmacodynamic interaction of hydroalcoholic extract of Ocimum sanctum with valproate

For effective control of seizures, antiepileptic drugs (AEDs) are administered at higher dose which is associated with several adverse effects. This study envisaged antiepileptic and neuroprotective potential of Tulsi, a commonly used herb for its immunomodulatory property. The optimal dose of Ocimum sanctum hydroalcoholic extract (OSHE) was determined using maximal electroshock seizure (MES)- and pentylenetetrazol (PTZ)-induced seizure models in Wistar rats (200-250g) after administering OSHE (200-1000mg/kg) orally for 14days. For interaction study, OSHE optimal dose in combination with maximum and submaximal therapeutic doses of valproate was administered for 14days. Serum levels of valproate were estimated using HPLC for pharmacokinetic study. For pharmacodynamic interaction, antiepileptic effect on above seizure models, neurobehavioral effect using Morris water maze, passive avoidance and elevated plus maze tests, and antioxidant capacity were assessed. Ocimum sanctum hydroalcoholic extract 1000mg/kg was found to be optimal providing 50% protection against both MES- and PTZ-induced seizures. Combination of OSHE with valproate did not alter antiepileptic efficacy of valproate significantly. However, the combination showed better memory retention potential in neurobehavioral tests and protection against oxidative stress compared with valproate-alone-treated groups. Pharmacokinetic parameters did not reveal any significant change in combination group compared with valproate alone. Ocimum, although having per se antiepileptic action, did not affect antiepileptic action of valproate in combination. However, combination treatment has an edge over valproate alone-better neurobehavioral function and reduced oxidative stress-predicting adjuvant potential of Ocimum in epilepsy treatment.

Efficacy of anticonvulsant substances in the 6Hz seizure test: Comparison of two rodent species

Usually performed in the mouse, the 6Hz seizure test is used for screening potential new anticonvulsant substances against complex partial seizures. Nevertheless, advanced models of temporal lobe epilepsy (TLE) are more often performed in rats, so that possible species-related differences may complicate the development of anticonvulsant substances. The aim of the present study was to evaluate the feasibility of adapting the 6Hz test in the rat. We first compared the effects of increasing current intensities for inducing seizures in the mouse and in the rat. This step was followed by the evaluation of the activity of anticonvulsant substances. Animals received an electrical stimulation with a constant current via corneal electrodes. The seizure was characterized by the presence of forelimb clonus immediately after stimulation. Spontaneous locomotion was evaluated following the 6Hz test. In the rat, the forelimb seizure score was intensity-dependently increased and seizures were observed in all animals tested at 44mA. In the mouse, the seizures were of lower magnitude and they were not observed in all mice stimulated at 44mA. In both species, levetiracetam (LEV) clearly decreased the forelimb seizure score over the dose-range 100-300mg/kg without affecting locomotion. Valproate (VPA) displayed anticonvulsant activity at 200mg/kg and fully protected both species at 300mg/kg, a dose producing sedative effects in the mouse. Phenytoin (PHT) showed slight to moderate anticonvulsant activity at 100mg/kg in the mouse and at 60 and 100mg/kg in the rat without modifying locomotor activity. Lamotrigine (LTG) partially antagonized forelimb seizure at 60mg/kg in the mouse and at 30-60mg/kg in the rat, but it induced clear motor impairments at high dose in both species. Our data suggest that in the 6Hz test, the magnitude and the nature of seizures differed between the mouse and the rat for a given current intensity. Nevertheless, the pharmacological profile of anticonvulsant substances was similar in both species for the 4 substances tested. Dose-dependent efficacy of LEV and VPA was observed and LTG and PHT also showed anticonvulsant activity, even though the magnitude of the effects remained moderate for these two last substances. The 6Hz test in the rat therefore appears as a useful model which may be performed prior to follow-up models of partial seizures performed in the same species.

Piperine regulates UCP1 through the AMPK pathway by generating intracellular lactate production in muscle cells

This study characterizes the human metabolic response to piperine, a curcumin extract, and the details of its underlying molecular mechanism. Using ¹H-NMR-based metabolome analysis, we showed the metabolic effect of piperine on skeletal muscle and found that piperine increased the level of intracellular lactate, an important metabolic intermediate that controls expression of several genes involved in mitochondrial activity. Piperine also induced the phosphorylation of AMP-activated protein kinase (AMPK) and its downstream target, acetyl-CoA carboxylase (ACC), while additionally stimulating glucose uptake in an AMPK dependent manner. Piperine also stimulates the p38 mitogen-activated protein kinase (p38 MAPK), an effect that was reversed by pretreatment with compound C, an AMPK inhibitor. Inhibition of p38 MAPK resulted in no piperine-induced glucose uptake. Increased level of lactate resulted in increased expression of mitochondrial uncoupling protein 1 (UCP1), which regulates energy expenditure, thermogenesis, and fat browning. Knock-down of AMPK blocked piperine-induced UCP1 up-regulation, demonstrating the required role of AMPK in this effect. Taken together, these results suggest that piperine leads to benign metabolic effects by activating the AMPK-p38 MAPK signaling pathway and UCP1 expression by activating intracellular lactate production in skeletal muscle.