Herbal modulation of drug bioavailability: enhancement of rifampicin levels in plasma by herbal products and a flavonoid glycoside derived fromCuminum cyminum

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.

The potential of drug-herbal interaction among patients with chronic diseases in Saudi Arabia

AIMS

This study aimed to estimate the prevalence of the potential drug-herbal interaction among patients with chronic diseases in Al-Kharj, Saudi Arabia and to explore factors associated with the potential of drug-herbal interaction.

METHOD

A cross-sectional study was conducted through interview-based questionnaire at outpatient clinics in Al-Kharj. The study included patients with chronic diseases who used herbal products.

RESULTS

This study included 336 patients in total. The mean age of participants was 52.4 ± 12.0 years, and their most-used medications were metformin, atorvastatin, and aspirin, while their most-used herbs were ginger (74.7%), mint (72%), and cumin (66.7%). In 310 out of 336 (92.26%) cases, at least one potential drug-herbal interaction was found, and most of these interactions (84%) were moderate.

CONCLUSION

A substantial percentage of potential drug-herbal interactions were found among patients with chronic diseases. Healthcare providers are encouraged to discuss the safety and efficacy of herbal products with their patients.

Effect of rutin on pharmacokinetic modulation of diclofenac in rats

Diclofenac is an extensively used nonsteroidal anti-inflammatory drug, but gastrointestinal liabilities and cardiovascular complications take the shine away from such a widely prescribed drug. On the other hand, rutin, a dietary bioflavonoid, has quite a few pharmacological attributes to improve the efficacy and reduce the dose-related toxicities of diclofenac through the intended food-drug/herb-drug interaction. The aim of the present research work was to investigate the role of rutin on pharmacokinetic modulation and the consequent efficacy of diclofenac. At first, pharmacodynamics and pharmacokinetics of diclofenac as alone and in the presence of rutin were investigated orally in a rat model. Then, mechanistic studies were performed to explain the effect of rutin on improvement in oral exposure as well as the efficacy of diclofenac using a battery of in-vitro/in-situ/in-vivo studies. Results displayed that rutin enhanced efficacy as well as oral bioavailability of diclofenac in rats. A marked increase in permeability of diclofenac by rutin was displayed that is linked to inhibition of Breast Cancer Resistance Protein (BCRP) transporters. There was no significant effect of rutin on the modulation of intestinal transit, CYP2C9 inhibition in human liver microsomes, and CYP2C9/CYP2C11 expression in rat liver tissues to boost the oral exposure of diclofenac. Rutin is found to be an inhibitor for BCRP transporters and can act as an oral bioavailability enhancer for a drug like diclofenac.

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.

Effect of Natural Phenolics on Pharmacokinetic Modulation of Bedaquiline in Rat to Assess the Likelihood of Potential Food-Drug Interaction

Bedaquiline (TMC-207) is a recently approved drug for the treatment of multidrug-resistant tuberculosis (MDR-TB). Moreover, there is a present and growing concern for natural-product-mediated drug interaction, as these are inadvertently taken by patients as a dietary supplement, food additive, and medicine. In the present study, we investigated the impact of 20 plant-based natural products, typically phenolics, on in vivo oral bedaquiline pharmacokinetics, as previous studies are lacking. Three natural phenolics were identified that can significantly enhance the oral exposure of bedaquiline upon coadministration. We further investigated the possible role of all of the phytochemicals on in vitro P-glycoprotein (P-gp) induction and inhibition and CYP3A4 inhibition in a single platform as bedaquiline is the substrate for both P-gp and CYP3A4. In conclusion, curcumin, CC-I (3',5-dihydroxyflavone-7-O-β-d-galacturonide-4'-O-β-d-glucopyranoside), and 6-gingerol should not be coadministered with bedaquiline to avoid untoward drug interactions and, subsequently, its dose-dependent adverse effects.

Non-antibiotic adjunctive therapy: A promising approach to fight tuberculosis

Tuberculosis (TB) is currently a clinical and public health problem. There is a concern about the emergence and development of multidrug-resistant (MDR-TB) and extensively drug-resistant (XDR-TB) species. Additionally, the lack of effective vaccines is another limitation to control the related infections. To overcome these problems various approaches have been pursued such as finding novel drug candidates with a new mechanism of action or repurposing conventional antibiotics. However, these strategies are still far from clinical application. Hence, the use of adjunctive therapy has been suggested for TB. In this paper, we review non-antibiotic adjunctive treatment options for TB. Natural products, vitamins, micronutrients, and trace elementals, as well as non-antibiotic drugs, are examples of agents which have been used as adjunctive therapies. The use of these adjunctive therapies has been shown to improve disease outcomes and reduce the adverse effects of antibiotic drugs. Employing these agents, either alone or in combination with antibiotics, might be considered as a promising approach to control TB infections and achieve better clinical outcomes. However, supportive evidence from randomized controlled trials is still scant and merits further investigations.

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.

Intervention of curcumin on oral pharmacokinetics of daclatasvir in rat: A possible risk for long-term use

Curcumin, a natural diarylheptanoid, is extensively used as a food additive or dietary supplement on the regular basis. It is known to have potential to encumber the drug transporters and hepatic drug metabolizing enzymes that lead to pharmacokinetic interactions with drug or food. Daclatasvir is a new orally acting drug for the treatment of chronic Hepatitis C Virus infections. This is a substrate of P-glycoprotein and CYP3A4 that are involved in the major pharmacokinetic interaction. Hence, the studies' aim is to assess for any possible pharmacokinetic interactions. Pharmacokinetic studies of daclatasvir in presence or absence of curcumin were carried out in Wistar rats following oral administration. Parallelly, the oral pharmacokinetics of daclatasvir was also determined in the presence of ketoconazole or quinidine. Studies revealed that plasma level of daclatasvir was not altered significantly during concomitant single dose administration of curcumin, whereas significantly decreased upon pretreatment for 7 days with curcumin at high dose level. Ketoconazole and quinidine markedly increase daclatasvir exposure following concomitant administration with daclatasvir. It can be concluded that dose adjustment is unlikely to be required for intermittent use of curcumin at low dose but cautious for chronic and concomitant use of curcumin at a high dose.

Herbal Bioenhancers in Veterinary Phytomedicine

Herbal bioenhancers are active phytomolecules that increase the bioavailability, bioefficacy and biological activity of various drugs when coadministered at low concentrations. These valuable compounds reduce the dose, increase the treatment rate, decrease the treatment duration, drug resistance or related adverse reactions which have economical implications in livestock and pet medicine. Eventhough the concept of herbal bioenhancers are known for years through Ayurvedic medicine, the underlying mechanisms remains unclear. The main mechanisms involved are related to drug absorption (effect on solubility, drug efflux and transport proteins, increased permeability in gastrointestinal system) and drug metabolism (inhibition/induction of drug metabolysing enzymes, thermogenic effect). Due to species specific differences in these mechanisms, corresponding data on human and laboratory animal could not be attributed. As multidrug resistance is a major treat to both human and animal health, within "One Health" concept, efficient therapeutical strategies are encouraged by authorities, where focus on herbal supplements as a vast unexploited field remains to be researched within "Bioenhancement Concept." This review brings insight to mechanims involved in bioenhancing effect, examples of herbal extracts and phytoactive compounds and their potential in the veterinary medicine including different classes of drugs such as antibiotics, anticancerous, antiviral, and antituberculosis.

Effective antibiotics against 'Candidatus Liberibacter asiaticus' in HLB-affected citrus plants identified via the graft-based evaluation

Citrus huanglongbing (HLB), caused by three species of fastidious, phloem-limited 'Candidatus Liberibacter', is one of the most destructive diseases of citrus worldwide. To date, there is no established cure for this century-old and yet, newly emerging disease. As a potential control strategy for citrus HLB, 31 antibiotics were screened for effectiveness and phytotoxicity using the optimized graft-based screening system with 'Candidatus Liberibacter asiaticus' (Las)-infected citrus scions. Actidione and Oxytetracycline were the most phytotoxic to citrus with less than 10% of scions surviving and growing; therefore, this data was not used in additional analyses. Results of principal component (PCA) and hierarchical clustering analyses (HCA) demonstrated that 29 antibiotics were clustered into 3 groups: highly effective, partly effective, and not effective. In spite of different modes of actions, a number of antibiotics such as, Ampicillin, Carbenicillin, Penicillin, Cefalexin, Rifampicin and Sulfadimethoxine were all highly effective in eliminating or suppressing Candidatus Liberibacter asiaticus indicated by both the lowest Las infection rate and titers of the treated scions and inoculated rootstock. The non-effective group, including 11 antibiotics alone with three controls, such as Amikacin, Cinoxacin, Gentamicin, Kasugamycin, Lincomycin, Neomycin, Polymixin B and Tobramycin, did not eliminate or suppress Las in the tested concentrations, resulting in plants with increased titers of Las. The other 12 antibiotics partly eliminated or suppressed Las in the treated and graft-inoculated plants. The effective and non-phytotoxic antibiotics could be potential candidates for control of citrus HLB, either for the rescue of infected citrus germplasm or for restricted field application.

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

Aim and Objectives:

The present study was undertaken in 20 healthy human volunteers to evaluate the effect of a herbal bioenhancer, Carum carvi on pharmacokinetics of rifampicin, isoniazid, and pyrazinamide in fixed dose combination (FDC).

Materials and Methods:

It was a prospective, two-period, open-label, cross-over experiment on 20 healthy human male volunteers. The volunteers were administered a single dose of FDC containing rifampicin (450 mg), isoniazid (300 mg), and pyrazinamide (1000 mg) and after 10 days washout period the same FDC along with C. carvi extract (100 mg) was administered. Blood samples were collected at different time-points and analyzed by high-performance liquid chromatography (HPLC). Detailed pharmacokinetic parameters were calculated, which included C_max, area under curve (AUC), time to reach maximum plasma concentration (T_max), clearance (Cl), volume of distribution (V_d), and half-life (t_½).

Results:

Additions of C. carvi extract lead to increase in plasma levels of rifampicin, isoniazid, and pyrazinamide. The bioavailability indices C_max of rifampicin increased from 4.57 ± 0.19 to 5.95 ± 0.19 (P = 0.000) and AUC increased from 40.11 ± 1.69 to 53.01 ± 1.88 (P = 0.000). Similarly, C_max of isoniazid increased from 2.66 ± 0.16 to 3.62 ± 0.16 (P = 0.000) and AUC from 17.72 ± 0.78 to 22.87 ± 0.94 (P = 0.000). The bioavailability indices of pyrazinamide also revealed an increase in C_max from 18.81 ± 0.79 to 25.06 ± 1.14 (P = 0.000) and AUC from 107.65 ± 4.42 to 137.71 ± 5.92 (P = 0.000), respectively.

Conclusion:

C. carvi acts as a bioenhancer and modifies the kinetics of antitubercular treatment (ATT) favorably.

Consensus of local knowledge on medicinal plants among traditional healers in Mayiladumparai block of Theni District, Tamil Nadu, India

AIM OF THE STUDY

The role of ethnobotany in drug discovery is huge but there are criticisms over such studies due to their qualitative nature. The present study is aimed at quantitatively abstracting the medicinal plant knowledge of the healers trained in traditional ways, in Mayiladumparai block of Theni District, Tamil Nadu, India.

MATERIALS AND METHODS

The interviews and field observations were carried out in all the 18 village panchayaths from January to June 2010, consisting of 148 field days. The interviews were conducted with 80 traditional healers, after obtaining prior informed consent. Successive free listing was used to interview the informants. The informant consensus factor (F(ic)) was calculated to estimate the use variability of medicinal plants. Fidelity index and Cultural importance index were also calculated to analyze the data.

RESULTS

This study recorded the ethno-medicinal usage of 142 ethno-species belonging to 62 families that were used to prepare 504 formulations. Jaundice had the highest F(ic) value than all the illness categories studied. Phyllanthus spp. was the highly cited medicinal plant to treat jaundice and had high fidelity index value. This was followed by Senna angustifolia and Terminalia chebula as laxatives. The highly cited medicinal plants in each group with high F(ic) value were Pongamia pinnata (antiseptic), Aerva lanata (antidote and snakebite), Blepharis maderaspatensis (cuts and wounds), Abutilon indicum (hemorrhoids), Ruta graveolens (spiritual medicine), Ocimum tenuiflorum (cough), and Solanum trilobatum (pulmonary ailments). Phyllanthus spp., was the most culturally significant species according to this index, followed by Borassus flebellifer.

CONCLUSION

The process of drug discovery has become highly expensive and post-approval and post-marketing withdrawal of drugs is continuing. In such scenario, reverse pharmacology is considered an attractive option. The medicinal plants enumerated in this study with high number of citations and high F(ic) values for illness categories might give some useful leads for further biomedical research.

Cuminum cyminum and Carum carvi: An update

Cuminum cyminum and Carum carvi are the sources of cumin and caraway seeds respectively, which have been used since antiquity for the treatment of various indications in traditional healing systems in wide geographical areas. Cumin and caraway seeds are rich sources of essential oils and have been actively researched for their chemical composition and biological activities. In recent times (especially during the last 3 years) considerable progress has been made regarding validation of their acclaimed medicinal attributes by extensive experimental studies. In this attempt many novel bioactivities have been revealed. This review highlights the significance of cumin and caraway as potential source of diverse natural products and their medicinal applications.

RP-HPLC Analysis of Jirakadyarishta and Chemical Changes during Fermentation

Jirakadyarishta, an Ayurvedic formulation prepared by the fermentation of a decoction of Cuminum cyminum (seeds) is traditionally used for intestinal disorders. RP-HPLC analysis of the decoction and the final processed formulation revealed that apigenin-7- O-[galacturonide (1→4)- O-glucoside] and luteolin-4′- O-glucoside-7- O-galacturonide) were the two major constituents of the decoction of C. cyminum. Selective hydrolysis of 7 -O-glucosides of luteolin and apigenin during fermentation resulted in an increase in the amount of luteolin and apigenin. The 4′- O-glucoside-7- O-galacturonide of luteolin and galacturonide derivative of apigenin were not hydrolyzed during fermentation. Monomeric phenolics, together with 5-hydroxymethyl furfural (5-HMF), were also introduced into the formulation through the jaggery and other plant materials during fermentation. This communication highlights the importance of the ancient processing methods used in Ayurveda.

Synergy research: approaching a new generation of phytopharmaceuticals

The longstanding, successful use of herbal drug combinations in traditional medicine makes it necessary to find a rationale for the pharmacological and therapeutic superiority of many of them in comparison to isolated single constituents. This review describes many examples of how modern molecular-biological methods (including new genomic technologies) can enable us to understand the various synergistic mechanisms underlying these effects. Synergistic effects can be produced if the constituents of an extract affect different targets or interact with one another in order to improve the solubility and thereby enhance the bioavailability of one or several substances of an extract. A special synergy effect can occur when antibiotics are combined with an agent that antagonizes bacterial resistance mechanisms. The verification of real synergy effects can be achieved through detailed pharmacological investigations and by means of controlled clinical studies performed in comparison with synthetic reference drugs. All the new ongoing projects aim at the development of a new generation of phytopharmaceuticals which can be used alone or in combination with synthetic drugs or antibiotics. This new generation of phytopharmaceuticals could lend phytotherapy a new legitimacy and enable their use to treat diseases which have hitherto been treated using synthetic drugs alone.

Synergism between natural products and antibiotics against infectious diseases

Antibiotics have been effective in treating infectious diseases, but resistance to these drugs has led to the emergence of new and the reemergence of old infectious diseases. One strategy employed to overcome these resistance mechanisms is the use of combination of drugs, such as beta-lactams together with beta-lactamase inhibitors. Several plant extracts have exhibited synergistic activity against microorganisms. This review describes in detail, the observed synergy and mechanism of action between natural products including flavonoids and essential oils and synthetic drugs in effectively combating bacterial, fungal and mycobacterial infections. The mode of action of combination differs significantly than that of the same drugs acting individually; hence isolating a single component may lose its importance thereby simplifying the task of pharma industries.