Effect of Carum carvi, a herbal bioenhancer on pharmacokinetics of antitubercular drugs: A study in healthy human volunteers

Robust anti-tubercular profile of Solanum virginianum extract in enhancing isoniazid bioavailability and curtailing stress tolerance in Mycobacterium smegmatis

Introduction

The formidable survival mechanisms employed by Mycobacterium tuberculosis (Mtb), combined with the low bioavailability of anti-tubercular drugs and their associated hepatotoxicity, worsen tuberculosis management. Traditional medicinal plants offer potential solutions to these challenges. This study focuses on exploring the anti-tubercular potential of Solanum virginianum against Mycobacterium smegmatis, mc2155.

Methods and results

HPTLC and UHPLC phytochemically characterized the hydro-methanolic extract of Solanum virginianum (SVE). SVE curtails the growth and viability of mc2155 under normal and in vitro stress conditions. The compromised cell wall integrity of mc2155 with SVE is depicted through scanning electron microscopy (SEM) while EtBr permeability assays and TLC-based comparative changes in lipids extraction addressed the integrity of the cell wall. Furthermore, SVE augmented the susceptibility of mc2155 towards Isoniazid (INH) through enhanced bioavailability. Adjunct treatment of SVE with INH demonstrated a markedly reduced survival of the intracellular bacilli. The study also uncovered the hepatoprotective potential of SVE in HepG2 cells.

Conclusion

This research paves the way for deeper exploration into the potential of Solanum virginianum against virulent Mtb strains, emphasizing over the significance of traditional medicinal plants in tuberculosis treatment. Collectively, the findings suggest SVE as a potent candidate for independent or adjunct anti-tubercular therapy.

PLANT BASED BIOAVAILABILITY ENHANCERS

Many of the synthetic as well as herbal drugs despite of their notable in vitro finding demonstrate insignificant in vivo activity majority of times due to poor bioavailability. As per Biopharmaceutical Classification System (BCS) one of the main concern is low solubility and/or permeation of drugs resulting in reduced absorption and poor bioavailability. To overcome these issues the various strategies have been adopted including use of permeation enhancers which are also known as bioenhancers. Bioenhancers are synthetic or natural compounds that increases the bioavailability of drugs and nutrients such as vitamins, amino acids, minerals, etc. into the systemic circulation and at the site of action for exhibiting improved therapeutic action. By improving bioavailability, bioenhancers can lead to reduction in drug dose, decrease in the treatment period and can circumvent the problem of drug resistance. Numerous studies have reported application of synthetic bioenhancers. On the other hand, owing to the natural origin, plant based bioenhancer can serve as better alternative. Literature review have revealed that the plant-based bioenhancers have been used in with a wide varieties of drugs including antibiotics, antiviral and anti-cancer. These can be categorized based on their sources and the mechanism of activity. This review will provide a systematic and detailed overview of the various plant based bioenhancers and applications.

Herb-drug interactions: a mechanistic approach

In India, traditional herbal medicines have been an essential part of therapy for the last centuries. However, a large portion of the general populace is using these therapies in combination with allopathy lacking a proper understanding of possible interactions (synergistic or antagonistic) between the herbal product and the allopathic drug. This is based on the assumption that herbal drugs are relatively safe, i.e. without side effects. We have established a comprehensive understanding of the possible herb-drug interactions and identified interaction patterns between the most common herbs and drugs currently in use in the Indian market. For this purpose, we listed common interactors (herbs and allopathic drugs) using available scientific literature. Drugs were then categorized into therapeutic classes and aligned to produce a recognizable pattern present only if interactions were observed between a drug class and herb in the scientific literature. Interestingly, the top three categories (with highest interactors), antibiotics, oral hypoglycemics, and anticonvulsants, displayed synergistic interactions only. Another major interactor category was CYP450 enzymes, a natural component of our metabolism. Both activation and inhibition of CYP450 enzymes were observed. As many allopathic drugs are known CYP substrates, inhibitors or inducers, ingestion of an interacting herb could result in interaction with the co-administered drug. This information is largely unavailable for the Indian population and should be studied in greater detail to avoid such interactions. Although this information is not absolute, the systematic literature review proves the existence of herb-drug interactions in the literature and studies where no interaction was detected are equally important.

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.

Matryoshka-type gastro-resistant microparticles for the oral treatment of Mycobacterium tuberculosis

AIM

Production of Matryoshka-type gastroresistant microparticles containing antibiotic-loaded poly lactic-co-glycolic acid (PLGA) nanoparticles (NP) against Mycobacterium tuberculosis.

MATERIALS & METHODS

The emulsification and evaporation methods were followed for the synthesis of PLGA-NPs and methacrylic acid-ethyl acrylate-based coatings to protect rifampicin from degradation under simulated gastric conditions.

RESULTS & CONCLUSION

The inner antibiotic-loaded NPs here reported can be released under simulated intestinal conditions whereas their coating protects them from degradation under simulated gastric conditions. The encapsulation does not hinder the antituberculosis action of the encapsulated antibiotic rifampicin. A sustained antibiotic release could be obtained when using the drug-loaded encapsulated NPs. Compared with the administration of the free drug, a more effective elimination of M. tuberculosis was observed when applying the NPs against infected macrophages. The antibiotic-loaded PLGA-NPs were also able to cross an in vitro model of intestinal barrier.

Drug Bioavailability Enhancing Agents of Natural Origin (Bioenhancers) that Modulate Drug Membrane Permeation and Pre-Systemic Metabolism

Many new chemical entities are discovered with high therapeutic potential, however, many of these compounds exhibit unfavorable pharmacokinetic properties due to poor solubility and/or poor membrane permeation characteristics. The latter is mainly due to the lipid-like barrier imposed by epithelial mucosal layers, which have to be crossed by drug molecules in order to exert a therapeutic effect. Another barrier is the pre-systemic metabolic degradation of drug molecules, mainly by cytochrome P450 enzymes located in the intestinal enterocytes and liver hepatocytes. Although the nasal, buccal and pulmonary routes of administration avoid the first-pass effect, they are still dependent on absorption of drug molecules across the mucosal surfaces to achieve systemic drug delivery. Bioenhancers (drug absorption enhancers of natural origin) have been identified that can increase the quantity of unchanged drug that appears in the systemic blood circulation by means of modulating membrane permeation and/or pre-systemic metabolism. The aim of this paper is to provide an overview of natural bioenhancers and their main mechanisms of action for the nasal, buccal, pulmonary and oral routes of drug administration. Poorly bioavailable drugs such as large, hydrophilic therapeutics are often administered by injections. Bioenhancers may potentially be used to benefit patients by making systemic delivery of these poorly bioavailable drugs possible via alternative routes of administration (i.e., oral, nasal, buccal or pulmonary routes of administration) and may also reduce dosages of small molecular drugs and thereby reduce treatment costs.

Caraway as Important Medicinal Plants in Management of Diseases

Carum carvi or caraway is traditionally used for treatment of indigestion, pneumonia, and as appetizer, galactagogue, and carminative. Essential oil, fixed oil and many other valuable extractive compounds with industrial applications are prepared from caraway. This review article has new deep research on caraway as medicinal plant. For preparing the manuscript, the information was extracted from accessible international databases (Google scholar, PubMed, Science direct, Springer, and Wiley), electronic resources and traditional books by key word of caraway or Carum carvi. The results of traditional studies exhibited that the galactagogue and carminative effects of caraway fruits are superior to other effects. Although, the traditional scholars used it as appetizer, while caraway was the main ingredient of anti-obesity drugs in traditional medicine, which has been confirmed in two modern clinical trials of human studies. Caraway oil in combination with peppermint oil or menthol is used for treatment of functional dyspepsia in clinical studies. Caraway oil topically on abdomen relieves the IBS symptoms in patient. Although, the use of caraway oil is not recommended in adults under 18 years due to insufficient data, but it can topically use as anti-colic and carminative agent in children or infants. The anti-aflatoxigenic, antioxidant and antimicrobial effects of caraway oil along with its reputation as spice help the industries to use it as natural preservatives and antioxidant agents.

Spices: Potential Therapeutics for Alzheimer's Disease

India has traditionally been known to all over the world for spices and medicinal plants. Spices exhibit a wide range of pharmacological activities. In contemporary, Indian spices are used to rustle up delicious delicacies. However, the Indian spices are more than just adjuvant which adds aroma and fragrance to foods. A few spices are very widely used and grown commercially in many countries, contain many important chemical constituents in the form of essential oil, oleoresin, oleogum, and resins, which impart flavor, pungency, and color to the prepared dishes, simultaneously exerts diverse therapeutic benefits. Ayurveda, the traditional systems of medicine in India has many evidences for the utilization of spices to cure various diseases. Some of the activities have been scientifically proven. Among various indications central nervous system disorders are of prime importance and it has been evident in traditional books and published reports that spices in fact protect and cure neuronal ailments. Likewise there are many spices found in India used for culinary purpose and have been found to have reported specific activities against brain disorders. About 400 B.C., Hippocrates rightly said "Let food be thy medicine and medicine thy food." This review focuses on the importance of spices in therapeutics and the till date scientific findings of Indian spices in CNS pharmacology and explores the potential of Indian spices to cure CNS disorders.

Population Pharmacokinetics of Rifampicin in Chinese Patients With Pulmonary Tuberculosis

Rifampicin (RIF) induces cytochrome P450, which in turn catalyzes drug metabolism; however, pharmacokinetic studies on this phenomenon in the Chinese population, especially in the context of disease, are limited. Therefore, we sought to establish population-based pharmacokinetic models of RIF in a Chinese population with pulmonary tuberculosis (TB). Clinical data were retrospectively collected from 54 patients with pulmonary TB and analyzed alongside RIF blood levels from 95 samples collected prior to RIF administration and between 2 and 12 hours after treatment. HPLC was used to measure serum RIF concentrations. A nonlinear mixed model used to characterize RIF pharmacokinetics and the data generated from the present study were validated using a bootstrap method. Covariates, including demographics, as well as hematological and biological indicators were analyzed. We observed a 1-compartment model with first-order absorption. Typical population values of apparent clearance (CL/F) and apparent volume of distribution (VD /F) were 4.02 L/h and 57.8 L, respectively. No covariate significantly changed the parameters of CL/F and VD . The present study may serve as a foundation for individualized therapy and offer a basis for pharmacokinetic-pharmacodynamic (PK-PD) analysis.

Role of therapeutic drug monitoring in pulmonary infections: use and potential for expanded use of dried blood spot samples

Respiratory tract infections are among the most common infections in men. We reviewed literature to document their pharmacological treatments, and the extent to which therapeutic drug monitoring (TDM) is needed during treatment. We subsequently examined potential use of dried blood spots as sample procedure for TDM. TDM was found to be an important component of clinical care for many (but not all) pulmonary infections. For gentamicin, linezolid, voriconazole and posaconazole dried blood spot methods and their use in TDM were already evident in literature. For glycopeptides, β-lactam antibiotics and fluoroquinolones it was determined that development of a dried blood spot (DBS) method could be useful. This review identifies specific antibiotics for which development of DBS methods could support the optimization of treatment of pulmonary infections.