Enhanced oral bioavailability of metoprolol with gallic acid and ellagic acid in male Wistar rats: involvement of CYP2D6 inhibition

Dietary gallic acid as an antioxidant: A review of its food industry applications, health benefits, bioavailability, nano-delivery systems, and drug interactions

Gallic acid (GA), a dietary phenolic acid with potent antioxidant activity, is widely distributed in edible plants. GA has been applied in the food industry as an antimicrobial agent, food fresh-keeping agent, oil stabilizer, active food wrap material, and food processing stabilizer. GA is a potential dietary supplement due to its health benefits on various functional disorders associated with oxidative stress, including renal, neurological, hepatic, pulmonary, reproductive, and cardiovascular diseases. GA is rapidly absorbed and metabolized after oral administration, resulting in low bioavailability, which is susceptible to various factors, such as intestinal microbiota, transporters, and metabolism of galloyl derivatives. GA exhibits a tendency to distribute primarily to the kidney, liver, heart, and brain. A total of 37 metabolites of GA has been identified, and decarboxylation and dihydroxylation in phase I metabolism and sulfation, glucuronidation, and methylation in phase Ⅱ metabolism are considered the main in vivo biotransformation pathways of GA. Different types of nanocarriers, such as polymeric nanoparticles, dendrimers, and nanodots, have been successfully developed to enhance the health-promoting function of GA by increasing bioavailability. GA may induce drug interactions with conventional drugs, such as hydroxyurea, linagliptin, and diltiazem, due to its inhibitory effects on metabolic enzymes, including cytochrome P450 3A4 and 2D6, and transporters, including P-glycoprotein, breast cancer resistance protein, and organic anion-transporting polypeptide 1B3. In conclusion, in-depth studies of GA on food industry applications, health benefits, bioavailability, nano-delivery systems, and drug interactions have laid the foundation for its comprehensive application as a food additive and dietary supplement.

Prevention of aflatoxin B1 toxicity by pomegranate peel extract and its effects on growth, blood biochemical changes, oxidative stress and histopathological alterations

Contamination of animal feeds with mycotoxins is one of the most serious issues in the world of animal nutrition. The purpose of this study was to assess the efficacy of pomegranate peel extract (PPE) versus oxytetracycline (OXY) in reducing aflatoxin B1 (AFB1) toxicity in rabbits fed contaminated diets. This experiment was done on 48 weaned NZW, four groups (n = 12). The first (AF) served as the control group feed on an infected diet by AFB1 between 0.02 and 0.03 mg/kg BW; second (AF + OXY) received an infected diet by AFB1 and was treated with OXY 200 mg/kg BW/day; third (AF + PPE) received an infected diet by AFB1 and treated with PPE 130 mg/kg BW/day; fourth (AF + OXY + PPE) received an infected diet by AFB1 and treated with a daily oral dose of 100 mg/kg BW/day of OXY + PPE (65 mg/kg BW/day), the experiment lasted for 8 weeks experiment. The treated group with PPE and its combination with OXY concurrent with AF showed amelioration markedly for liver and kidney function. To summarise, adding PPE and combining it with OXY at a half dose to an AFB1-contaminated diet can help minimise the harmful effects of AFB1 on rabbit performance.

Pharmacokinetic Comparison of Nine Bioactive Compounds of Guanxinshutong Capsule in Normal and Acute Myocardial Infarction Rats

BACKGROUND AND OBJECTIVES

Guanxinshutong capsules (GXST) are usually used to treat acute myocardial infarction (AMI), and the clinical effect of GXST is significant. However, there have been only a few studies on the pharmacokinetics of GXST against AMI injury. The objective of this study was to investigate the pharmacokinetics of nine bioactive compounds of GXST in normal and AMI rats.

METHODS

In this work, a rat model of AMI was established by ligating the left anterior descending coronary artery. The pharmacokinetic parameters of nine bioactive compounds (gallic acid, danshensu, protocatechuic aldehyde, rosmarinic acid, salvianolic acid B and salvianolic acid A, dihydrotanshinone I, cryptotanshinone, and tanshinone IIA) in the plasma of AMI and normal rats were compared under the same dose of GXST by a LC-MS/MS method. Then, we selected P-glycoprotein (P-gp) and some representative cytochrome P450 enzymes (CYPs) for molecular docking to further analyze the interaction between these compounds.

RESULTS

The pharmacokinetic studies showed that the area under the concentration-time curve (AUC) and maximum concentration (C_max) of phenolic acids were relatively large, while the half-life (T_½) of tanshinones was longer. Among the nine components, salvianolic acid B in AMI rats had the maximum area under the concentration-time curve (AUC_0-∞ = 1961.8 ng·h/mL), which showed a significant difference compared with normal rats (P < 0.05). Tanshinone IIA in AMI rats had the longest half-life (T_½ = 10.1 h), and it was markedly longer than that in normal rats (P < 0.01). In addition, compared with the normal group, the AUC, C_max, T_½ , and time to reach C_max (T_max) of gallic acid increased significantly in AMI rats (P < 0.05 or P < 0.01). For the molecular docking results, it was found that gallic acid may interact with CYP1A2, CYP2D6, and CYP2C9, while danshensu may interact with CYP2C9. Tanshinones may interact with CYP1A2, CYP2D6, CYP2C9, and P-gp.

CONCLUSIONS

The results suggest that the pathological injury caused by AMI has a significant impact on the pharmacokinetic characteristics of some active compounds in GXST, which are conducive to providing a reference and promoting rational clinical drug use.

Coadministration of gallic acid abates zearalenone-mediated defects in male rat's reproductive function

As gallic acid (GA) role in zearalenone (ZEN); mediated reproductive dysfunction has not been studied, we report on GA's effect on reproductive dysfunction in rats treated with ZEN-100 µg/kg alone, or with GA-40 mg/kg; for 4 weeks. The mycotoxin ZEN contaminates crops, causing toxicity on ingestion, economic losses, and alters reproductive function. Relative to control, GA reversed ZEN-induced reduction of rats' testicular function enzymes and reproductive hormones and improved ZEN-impaired sperm quality. GA significantly (p < 0.05) increased rats antioxidant status, inhibited (p < 0.05) reactive oxygen and nitrogen species and lipid peroxidation levels, and abated (p < 0.05) proinflammatory biomarkers in the examined organs: hypothalamus, testis, and epididymis. Histopathology revealed that GA facilitated the preservation of testicular and epididymal cytoarchitecture significantly altered in rat cohorts treated with ZEN alone. Conclusively, GA protected against ZEN-induced toxicity in the rats' organs examined, enhanced endogenous antioxidative protective mechanism, and abated proinflammatory responses. GA further averted a decline in circulatory, reproductive enzymes, hormone levels. GA also protected against reproductive tissue damage and improved parameters of sperm functionality.

Potential Herb-Drug Interactions in the Management of Age-Related Cognitive Dysfunction

Late-life mild cognitive impairment and dementia represent a significant burden on healthcare systems and a unique challenge to medicine due to the currently limited treatment options. Plant phytochemicals have been considered in alternative, or complementary, prevention and treatment strategies. Herbals are consumed as such, or as food supplements, whose consumption has recently increased. However, these products are not exempt from adverse effects and pharmacological interactions, presenting a special risk in aged, polymedicated individuals. Understanding pharmacokinetic and pharmacodynamic interactions is warranted to avoid undesirable adverse drug reactions, which may result in unwanted side-effects or therapeutic failure. The present study reviews the potential interactions between selected bioactive compounds (170) used by seniors for cognitive enhancement and representative drugs of 10 pharmacotherapeutic classes commonly prescribed to the middle-aged adults, often multimorbid and polymedicated, to anticipate and prevent risks arising from their co-administration. A literature review was conducted to identify mutual targets affected (inhibition/induction/substrate), the frequency of which was taken as a measure of potential interaction. Although a limited number of drugs were studied, from this work, interaction with other drugs affecting the same targets may be anticipated and prevented, constituting a valuable tool for healthcare professionals in clinical practice.

Formulation development of linagliptin solid lipid nanoparticles for oral bioavailability enhancement: role of P-gp inhibition

Linagliptin (LGP), a novel anti-diabetic drug, is a DPP-4 inhibitor used in the treatment of type II diabetes. One of the major disadvantages of LGP is its low oral bioavailability (29.5%) due to first-pass metabolism and P-gp efflux. In an attempt to increase the oral bioavailability, LGP solid lipid nanoparticles (LGP-SLNs) were developed with poloxamer 188 and Tween 80 as P-gp inhibitors. LGP-SLNs were formulated using palmitic acid, poloxamer 188 and Tween 80 as lipid, surfactant and co-surfactant, respectively, by hot homogenization ultrasonication method and optimized using 3² full factorial designs. Particle size, entrapment efficiency (%EE) and drug release at 24 h were evaluated as responses. An optimized batch of LGP-SLNs (L12) was evaluated for intestinal transport of LGP by conducting in situ single-pass intestinal perfusion (SPIP), everted gut sac and Caco-2 permeability study. The pharmacokinetic and pharmacodynamic evaluation of L12 was carried out in albino Wistar rats. The mean particle size, polydispersity index, zeta potential and %EE of L12 were found to be 225.96 ± 2.8 nm, 0.180 ± 0.034, - 5.4 ± 1.07 mV and 73.8 ± 1.73%, respectively. %CDR of 80.96 ± 3.13% was observed in 24 h. The permeability values of LGP-SLNs in the absorptive direction were 1.82-, 1.76- and 1.74-folds higher than LGP-solution (LGP-SOL) in SPIP, everted gut sac and Caco-2 permeability studies, respectively. LGP-SLNs exhibited relative bioavailability of 300% and better reduction in glucose levels in comparison with LGP-SOL in rats. The enhanced oral bioavailability exhibited by LGP-SLNs bioavailability may be due to P-gp efflux inhibition and lymphatic targeting. Improved bioabsorption can cause reduction in dose, dose-related side effects and frequency of administration. Thus, LGP-SLNs can be considered promising carriers for oral delivery but clinical studies are required to confirm the proof of concept.Graphical abstract.

Gallic acid enhances reproductive function by modulating oxido-inflammatory and apoptosis mediators in rats exposed to aflatoxin-B1

IMPACT STATEMENT

Infertility resulting from reproductive deficiency can be stressful. Exposure to aflatoxin B1, a dietary mycotoxin prevalent in improperly stored grains, is reported to elicit reproductive insufficiencies and infertility. We, therefore, examined the likely beneficial effect of gallic acid (GA) a phytochemical, recognized to exhibit in vitro and in vivo pharmacological bioactivities against oxidative stress and related inflammatory damages in rats, since AFB1 toxicities are predicated on oxidative epoxide formation, in a bid to proffer new evidence to advance the field of nutriceutical application from plant-derived chemopreventive agents. Our findings will advance the field of chemoprevention by presenting data absent in the literature on GA. Our results demonstrate further evidence for GA conferred protection against AFB1-mediated histological lesions in testes, epididymis, and hypothalamus of treated rats; suppresses oxidative damages, relieved inflammatory and apoptotic responses, restored sperm functional characteristics, and hormonal levels relevant for reproductive integrity and function.

Gallic acid protects against Aflatoxin B1 -induced oxidative and inflammatory stress damage in rats kidneys and liver

The adverse effect of Aflatoxin B1 (AFB₁ ) exposure in both humans and rodents has been widely reported. The beneficial health effects of gallic acid (GA) against AFB₁ -induced toxicity in vitro have been published. Here, we present in vivo findings on AFB₁ and GA on hepatorenal function in rats, exposed to AFB₁ (75 µg/kg body weight) only or co-treated with GA (20 or 40 mg/kg) for 28 successive days. AFB₁ significantly increased pro-inflammatory biomarkers and suppressed IL-10 levels in rats' liver and kidney. AFB₁ caused increased (p < .05) oxidative stress by decreasing antioxidant enzymes levels and increasing levels of reactive oxygen and nitrogen species. Furthermore, reduction (p < .05) in cellular glutathione (GSH) levels and increased (p < .05) hepatorenal markers of toxicity were detected in rats treated with AFB₁ . These observed alterations were, however, reversed in GA co-treated rats. GA ameliorated AFB₁ -induced hepatorenal dysfunction by decreasing oxidative stress and inflammation in rats. PRACTICAL APPLICATIONS: GA can chemoprotect against the damaging effects of toxins contaminating food. GA is widely distributed in plants and in use in industries as antioxidant, immune-regulator, and natural defense agent against infections when consumed. Here, we disclosed that GA ameliorates AFB₁ -induced hepatorenal dysfunction by suppressing oxidative stress, inflammation, and enhanced apoptosis, thus improving hepatorenal functions in rats exposed to AFB_1.

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.