Effects of Nigella sativa and Lepidium sativum on Cyclosporine Pharmacokinetics

The present study was conducted to investigate the effects of Nigella sativa and Lepidium sativum on the pharmacokinetics of cyclosporine in rabbits. Two groups of animals were treated separately with Nigella sativa (200 mg/kg p.o.) or Lepidium sativum (150 mg/kg p.o.) for eight consecutive days. On the 8th day, cyclosporine (30 mg/kg p.o.) was administered to each group one hour after herbal treatment. Blood samples were withdrawn at different time intervals (0.0, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, 8.0, 12, and 24 hrs) from marginal ear vein. Cyclosporine was analyzed using UPLC/MS method. The coadministration of Nigella sativa significantly decreased the max and AUC 0−∞ of cyclosporine; the change was observed by 35.5% and 55.9%, respectively ( ≤ 0.05). Lepidium sativum did not produce any significant change in max of cyclosporine, although its absorption was significantly delayed compared with control group. A remarkable change was observed in max and AUC 0− of Lepidium sativum treated group. Our findings suggest that concurrent consumption of Nigella sativa and Lepidium sativum could alter the pharmacokinetics of cyclosporine at various levels

Identification of Doxorubicin as Repurposing Inhibitory Drug for MERS-CoV PLpro

Middle East respiratory syndrome coronavirus (MERS-CoV), belonging to the betacoronavirus genus can cause severe respiratory illnesses, accompanied by pneumonia, multiorgan failure, and ultimately death. CoVs have the ability to transgress species barriers and spread swiftly into new host species, with human-to-human transmission causing epidemic diseases. Despite the severe public health threat of MERS-CoV, there are currently no vaccines or drugs available for its treatment. MERS-CoV papain-like protease (PLpro) is a key enzyme that plays an important role in its replication. In the present study, we evaluated the inhibitory activities of doxorubicin (DOX) against the recombinant MERS-CoV PLpro by employing protease inhibition assays. Hydrolysis of fluorogenic peptide from the Z-RLRGG-AMC–peptide bond in the presence of DOX showed an IC50 value of 1.67 μM at 30 min. Subsequently, we confirmed the interaction between DOX and MERS-CoV PLpro by thermal shift assay (TSA), and DOX increased ΔTm by ~20 °C, clearly indicating a coherent interaction between the MERS-CoV PL protease and DOX. The binding site of DOX on MERS-CoV PLpro was assessed using docking techniques and molecular dynamic (MD) simulations. DOX bound to the thumb region of the catalytic domain of the MERS-CoV PLpro. MD simulation results showed flexible BL2 loops, as well as other potential residues, such as R231, R233, and G276 of MERS-CoV PLpro. Development of drug repurposing is a remarkable opportunity to quickly examine the efficacy of different aspects of treating various diseases. Protease inhibitors have been found to be effective against MERS-CoV to date, and numerous candidates are currently undergoing clinical trials to prove this. Our effort follows a in similar direction

Employing a PLGA-TPGS based nanoparticle to improve the ocular delivery of Acyclovir

Delivering drugs via the ocular route has always been a challenge for poorly soluble drugs. The various anatomical and physiological barriers in the eye cavity hinder the residence of drugs within the corneal and precorneal regions. In this study, the nanosystem that could sufficiently deliver the poorly soluble Acyclovir topically via ocular route. Our nanosystem is composed of the biocompatible PLGA polymer stabilized with TPGS which possess a high emulsifying capacity and is also known as P-gp inhibitor. The optimized nanoparticles were prepared with 0.3% TPGS and had particle-size of 262.3 nm, zeta-potential of +15.14 mV. The physicochemical-characterization, ex vivo transcorneal permeation, ocular-irritation and Acyclovir ocular-availability, following topical ocular application of PLGA-NPs in rabbit eyes, were performed. The tested parameters and irritation by Draize’s test suggested the suitability and safety of PLGA-NPs for ocular use. An ultrahigh performance liquid chromatographic method was developed, validated, and applied to quantify Acyclovir in aqueous humor which was shown to be significantly higher (p < 0.05) using the developed nanoparticles as compared to Acyclovir-aqueous suspension following their single topical ocular administration. Noticeable 2.78-, 1.71- and 2.2-times increased values of AUC0–24h, t1/2 (h) and MRT0–24h were found, respectively, with the PLGA-TPGS-NPs as compared to ACY-AqS. These results demonstrate the superiority of delivering Acyclovir using a nanosystem compared to conventional methods. Keywords: Acyclovir, PLGA, TPGS, Corneal permeation, Ocular pharmacokinetic

Cinnamon modulates the pharmacodynamic &amp; pharmacokinetic of amlodipine in hypertensive rats

The objective of this study was to investigate the effects of cinnamon on the pharmacodynamic (PD) &amp; pharmacokinetic (PK) of amlodipine in hypertensive rats. The hypertensive control group of Wistar rats received L-NAME (40 mg/kg, daily, orally) only. The cinnamon group of rats was treated with cinnamon (200 mg/kg, daily, orally) along with L-NAME. Following 14 days treatment period, blood pressures of rats were monitored at designated intervals over 24 h utilizing a tail-cuff system for measuring blood pressure. To assess the oral PK; amlodipine was administered as a single oral dose of 1 mg/kg to rats and blood samples were collected at specified intervals over 24 h and analysed by UPLC-LC MS/MS.Synergistic decreased in rat’s blood pressure was observed in presence of cinnamon + amlodipine. Simultaneous administration of cinnamon ameliorates the Cmax and AUC0-t of amlodipine, the Cmax and AUC0-t was 11.04 ± 1.01 ng/ml and 113.76 ± 5.62 ng h/ml for the cinnamon + amlodipine group as compared to 4.12 ± 0.49 ng/ml and 48.59 ± 4.28 ng h/ml for the amlodipine alone group. The study demonstrates that the use of cinnamon considerably decreases the blood pressure levels and enhances the PK parameters of amlodipine in hypertensive rats

Perspectives of Positively Charged Nanocrystals of Tedizolid Phosphate as a Topical Ocular Application in Rabbits

The aim of this study was the successful utilization of the positively charged nanocrystals (NCs) of Tedizolid Phosphate (TZP) (0.1% w/v) for topical ocular applications. TZP belongs to the 1, 3-oxazolidine-2-one class of antibiotics and has therapeutic potential for the treatment of many drug-resistant bacterial infections, including eye infections caused by MRSA, penicillin-resistant Streptococcus pneumonia and vancomycin-resistant Enterococcus faecium. However, its therapeutic usage is restricted due to its poor aqueous solubility and limited ocular availability. It is a prodrug and gets converted to Tedizolid (TDZ) by phosphatases in vivo. The sterilized NC1 was subjected to antimicrobial testing on Gram-positive bacteria. Ocular irritation and pharmacokinetics were performed in rabbits. Around a 1.29 to 1.53-fold increase in antibacterial activity was noted for NC1 against the B. subtilis, S. pneumonia, S. aureus and MRSA (SA-6538) as compared to the TZP-pure. The NC1-AqS was “practically non-irritating” to rabbit eyes. There was around a 1.67- and 1.43 fold increase in t1/2 (h) and Cmax (ngmL−1) while there were 1.96-, 1.91-, 2.69- and 1.41-times increases in AUC0–24h,AUC0–∞,AUMC0–∞ and MRT0–∞, respectively, which were found by NC1 as compared to TZP-AqS in the ocular pharmacokinetic study. The clearance of TDZ was faster (11.43 mLh−1) from TZP-AqS as compared to NC1 (5.88 mLh−1). Relatively, an extended half-life (t1/2; 4.45 h) of TDZ and the prolonged ocular retention (MRT0–∞; 7.13 h) of NC1 was found, while a shorter half-life (t1/2; 2.66 h) of TDZ and MRT0–∞(t1/2; 5.05 h)was noted for TZP-AqS, respectively. Cationic TZP-NC1 could offer increased transcorneal permeation, which could mimic the improved ocular bioavailability of the drug in vivo. Conclusively, NC1 of TZP was identified as a promising substitute for the ocular delivery of TZP, with better performance as compared to its conventional AqS

Role of Oxidative Stress and Inflammatory Cytokines (TNF-α and IL-6) in Acetic Acid-Induced Ulcerative Colitis in Rats: Ameliorated by Otostegia fruticosa

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) that causes irritation, inflammation, and ulceration in the linings of the colon and rectum. Otostegia fruticosa is traditionally used to treat various disorders in different parts of the Middle East and sub-Saharan Africa. In the present study, we evaluated the ameliorative effects of crude leaves extract of O. fruticosa (OF.Cr) on acetic acid (AA)-induced UC model in Wistar albino rats. Wistar rats were administered orally with either vehicle (10 mL/kg), OF.Cr (200 and 400 mg/kg), or prednisolone (2 mg/kg) once a day for 6 days. On day 6, UC was induced in rats by intrarectal administration of a single dose of 5% AA (1.0 mL). Disease activity index (DAI) was recorded after one day of colitis induction by assessing the symptoms of colitis and then the rats were euthanized by cervical dislocation, and colon tissues were isolated for the histopathological examination and biochemical analysis of oxidative stress parameters and cytokines (Interleukin-6 and Tumor Necrosis Factor-α). OF.Cr pretreatment exhibits significant prevention against UC, as confirmed by a significant decrease of DAI, colonic ulceration, and reduced inflammatory score as compared to the AA-induced colitis rats. Depletion of total glutathione (GSH) levels and catalase (CAT) activities in the colitis group was significantly restored in the OF.Cr treated groups, while increased lipid peroxidation in the colon tissues was significantly reduced. OF.Cr prevented the activation of the IL-6 and TNF-α pathways in the colonic tissues, which were clearly observed by the decreased levels of IL-6 and TNF-α in the OF.Cr treated animals. Hence, OF.Cr could be developed in the future for the treatment of UC

Role of Oxidative Stress and Inflammatory Cytokines (TNF-α and IL-6) in Acetic Acid-Induced Ulcerative Colitis in Rats: Ameliorated by <i>Otostegia fruticosa</i>

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) that causes irritation, inflammation, and ulceration in the linings of the colon and rectum. Otostegia fruticosa is traditionally used to treat various disorders in different parts of the Middle East and sub-Saharan Africa. In the present study, we evaluated the ameliorative effects of crude leaves extract of O. fruticosa (OF.Cr) on acetic acid (AA)-induced UC model in Wistar albino rats. Wistar rats were administered orally with either vehicle (10 mL/kg), OF.Cr (200 and 400 mg/kg), or prednisolone (2 mg/kg) once a day for 6 days. On day 6, UC was induced in rats by intrarectal administration of a single dose of 5% AA (1.0 mL). Disease activity index (DAI) was recorded after one day of colitis induction by assessing the symptoms of colitis and then the rats were euthanized by cervical dislocation, and colon tissues were isolated for the histopathological examination and biochemical analysis of oxidative stress parameters and cytokines (Interleukin-6 and Tumor Necrosis Factor-α). OF.Cr pretreatment exhibits significant prevention against UC, as confirmed by a significant decrease of DAI, colonic ulceration, and reduced inflammatory score as compared to the AA-induced colitis rats. Depletion of total glutathione (GSH) levels and catalase (CAT) activities in the colitis group was significantly restored in the OF.Cr treated groups, while increased lipid peroxidation in the colon tissues was significantly reduced. OF.Cr prevented the activation of the IL-6 and TNF-α pathways in the colonic tissues, which were clearly observed by the decreased levels of IL-6 and TNF-α in the OF.Cr treated animals. Hence, OF.Cr could be developed in the future for the treatment of UC

Topical Application of Linezolid–Loaded Chitosan Nanoparticles for the Treatment of Eye Infections

Linezolid (LZ) loaded chitosan–nanoparticles (CSNPs) was developed by the ionic–gelation method using Tripolyphosphate–sodium as a crosslinker for topical application for the treatment of bacterial eye infections. Particles were characterized by Zeta–Sizer (Malvern Nano–series). TEM was used for structural morphology. Encapsulation and drug loading were estimated by measuring the unencapsulated drug. In-vitro drug release in STF (pH 7) was performed through a dialysis membrane. Storage stability of LZ–CSNPs was checked at 25 °C and 40 °C for six months. The antimicrobial potency of NPs was evaluated on different Gram–positive strains. Ocular irritation and pharmacokinetic studies were completed in rabbits. Ex-vivo transcorneal permeation of the drug was determined through the rabbit cornea. Ionic interaction among the oppositely charged functional groups of CS and TPP generated the CSNPs. The weight ratio at 3:1, wt/wt (CS/TPP) with 21.7 mg of LZ produced optimal NPs (213.7 nm with 0.387 of PDI and +23.1 mV of ZP) with 71% and 11.2% encapsulation and drug loading, respectively. Around 76.7% of LZ was released from LZ–AqS within 1 h, while 79.8% of LZ was released from CSNPs at 12 h and 90% at 24 h. The sustained drug release property of CSNPS was evaluated by applying kinetic models. The linearity in the release profile suggested that the release of LZ from CSNPs followed the Higuchi–Matrix model. LZ–CSNPs have shown 1.4 to 1.6-times improved antibacterial activity against the used bacterial strains. The LZ–CSNPs were “minimally–irritating” to rabbit eyes and exhibited 4.4-times increased transcorneal permeation of LZ than from LZ–AqS. Around 3-, 1.2- and 3.1-times improved Tmax, Cmax, and AUC0–24 h, respectively were found for LZ–CSNPs during the ocular pharmacokinetic study. AqS has shown 3.1-times faster clearance of LZ. Conclusively, LZ–CSNPs could offer a better alternative for the prolonged delivery of LZ for the treatment of bacterial infections in the eyes

Mesoporous Silica Nanoparticles Coated with Carboxymethyl Chitosan for 5-Fluorouracil Ocular Delivery: Characterization, In Vitro and In Vivo Studies

This study investigates the development of topically applied non-invasive amino-functionalized silica nanoparticles (AMSN) and O-Carboxymethyl chitosan-coated AMSN (AMSN-CMC) for ocular delivery of 5-Fluorouracil (5-FU). Particle characterization was performed by the DLS technique (Zeta-Sizer), and structural morphology was examined by SEM and TEM. The drug encapsulation and loading were determined by the indirect method using HPLC. Physicochemical characterizations were performed by NMR, TGA, FTIR, and PXRD. In vitro release was conducted through a dialysis membrane in PBS (pH 7.4) using modified Vertical Franz diffusion cells. The mucoadhesion ability of the prepared nanoparticles was tested using the particle method by evaluating the change in zeta potential. The transcorneal permeabilities of 5-FU from AMNS-FU and AMSN-CMC-FU gel formulations were estimated through excised goat cornea and compared to that of 5-FU gel formulation. Eye irritation and ocular pharmacokinetic studies from gel formulations were evaluated in rabbit eyes. The optimum formulation of AMSN-CMC-FU was found to be nanoparticles with a particle size of 249.4 nm with a polydispersity of 0.429, encapsulation efficiency of 25.8 ± 5.8%, and drug loading capacity of 5.2 ± 1.2%. NMR spectra confirmed the coating of AMSN with the CMC layer. In addition, TGA, FTIR, and PXRD confirmed the drug loading inside the AMSN-CMC. Release profiles showed 100% of the drug was released from the 5-FU gel within 4 h, while AMSN-FU gel released 20.8% of the drug and AMSN-CMC-FU gel released around 55.6% after 4 h. AMSN-CMC-FU initially exhibited a 2.45-fold increase in transcorneal flux and apparent permeation of 5-FU compared to 5-FU gel, indicating a better corneal permeation. Higher bioavailability of AMSN-FU and AMSN-CMC-FU gel formulations was found compared to 5-FU gel in the ocular pharmacokinetic study with superior pharmacokinetics parameters of AMSN-CMC-FU gel. AMSN-CMC-FU showed 1.52- and 6.14-fold higher AUC0-inf in comparison to AMSN-FU and 5-FU gel, respectively. AMSN-CMC-FU gel and AMSN-FU gel were “minimally irritating” to rabbit eyes but showed minimal eye irritation potency in comparison to the 5 FU gel. Thus, the 5-FU loaded in AMSN-CMC gel could be used as a topical formulation for the treatment of ocular cancer

Changes in Pharmacokinetics and Pharmacodynamics of Losartan in Experimental Diseased Rats Treated with <i>Curcuma longa</i> and <i>Lepidium sativum</i>

The current study investigated “pharmacodynamics and pharmacokinetics interactions” of losartan with Curcuma longa (CUR) and Lepidium sativum (LS) in hypertensive rats. Hypertension was induced by oral administration of L-NAME (40 mg/kg) for two weeks. Oral administration of CUR or LS shows some substantial antihypertensive activity. The systolic blood pressure (SBP) of hypertensive rats was decreased by 7.04% and 8.78% 12 h after treatment with CUR and LS, respectively, as compared to rats treated with L-NAME alone. LS and CUR display the ability to potentiate the blood pressure-lowering effects of losartan in hypertensive rats. A greater decrease in SBP, by 11.66% and 13.74%, was observed in hypertensive rats treated with CUR + losartan and LS + losartan, respectively. Further, both the investigated herbs, CUR and LS, caused an increase in plasma concentrations of losartan in hypertensive rats. The AUC0-t, AUC0-inf and AUMC0-inf of losartan were increased by 1.25-fold, 1.28-fold and 1.09-fold in hypertensive rats treated with CUR + losartan. A significant (p 0-t (2.41-fold), AUC0-inf (3.86-fold) and AUMC0-inf (8.35-fold) of losartan was observed in hypertensive rats treated with LS + losartan. The present study affirms that interactions between CUR or LS with losartan alter both “pharmacokinetics and pharmacodynamics” of the drug. Concurrent administration of losartan with either CUR or LS would require dose adjustment and intermittent blood pressure monitoring for clinical use in hypertensive patients. Additional investigation is necessary to determine the importance of these interactions in humans and to elucidate the mechanisms of action behind these interactions