ABSTRACT
Piperine (amide alkaloid) derived from pepper is globally utilized in diverse conventional and traditional systems of medicine. The co-administration of piperine has been observed to induce subtle modifications in the absorption, membrane transport, and drug metabolism of several high-efficacy medicines. The occurrence of medication interactions might have a notable impact on the pharmacokinetic parameters, resulting in either a favorable or unfavorable pharmacological effect. This comprehensive pharmacokinetic drug interaction evaluation of piperine encompasses a total of 34 scholarly articles (specific for pharmacokinetic interactions), consisting of 62 studies (56 preclinical studies and 6 clinical investigations). In this study, we propose that piperine has the ability to increase the bioavailability and bioactive molecules of a natural origin of a variety of medications, making it an effective bioenhancer. By enhancing bioavailability, piperine can reduce the required dosage, lower drug costs, minimize the occurrence of drug resistance, and mitigate dose-dependent side effects associated with various medications such as ciprofloxacin, ampicillin, metronidazole carbamazepine, curcumin, and oxytetracycline. However, a limited number of published studies have indicated a reduction in bioavailability following oral administration of isoniazid, puerarin, diltiazem, desacetyldiltiazem, and magnolol in combination with piperine or pepper/Trikatu (containing piperine majorly). Several other critical studies have demonstrated that there is no significant variation in pharmacokinetic characteristics along with piperine. The medications containing piperine have led to significant modifications in their pharmacokinetic properties, finally yielding advantageous outcomes for drugs with low bioavailability. Additionally, these alterations have resulted in reduced side effects and extended half-life (T1/2) for specific drugs.
ABSTRACT
Evidence indicates that anxiety disorders arise from an imbalance in the functioning of brain circuits that govern the modulation of emotional responses to possibly threatening stimuli. The circuits under consideration in this context include the amygdala's bottom-up activity, which signifies the existence of stimuli that may be seen as dangerous. Moreover, these circuits encompass top-down regulatory processes that originate in the prefrontal cortex, facilitating the communication of the emotional significance associated with the inputs. Diverse databases (e.g., Pubmed, ScienceDirect, Web of Science, Google Scholar) were searched for literature using a combination of different terms e.g., "anxiety", "stress", "neuroanatomy", and "neural circuits", etc. A decrease in GABAergic activity is present in both anxiety disorders and severe depression. Research on cerebral functional imaging in depressive individuals has shown reduced levels of GABA within the cortical regions. Additionally, animal studies demonstrated that a reduction in the expression of GABAA/B receptors results in a behavioral pattern resembling anxiety. The amygdala consists of inhibitory networks composed of GABAergic interneurons, responsible for modulating anxiety responses in both normal and pathological conditions. The GABAA receptor has allosteric sites (e.g., α/γ, γ/ß, and α/ß) which enable regulation of neuronal inhibition in the amygdala. These sites serve as molecular targets for anxiolytic medications such as benzodiazepine and barbiturates. Alterations in the levels of naturally occurring regulators of these allosteric sites, along with alterations to the composition of the GABAA receptor subunits, could potentially act as mechanisms via which the extent of neuronal inhibition is diminished in pathological anxiety disorders.
