Synthesis and characterization of some new Schiff base derivatives of gabapentin, and assessment of their antibacterial, antioxidant and anticonvulsant activities

Purpose: To synthesize and characterize some new gabapentin Schiff base derivatives, and to assess their antibacterial, antioxidant and antiepileptic activities.Methods: Four Schiff base derivatives of gabapentin, termed G1, G2, G3 and G4, were synthesized by condensation with benzoin, vanillin, acetophenone, and benzophenone, respectively. Their chemical identities were established by FTIR, 1 H NMR and 13C NMR techniques. The new compounds were screened for antibacterial activity using agar well method, antioxidant activity by DPPH assay, and anticonvulsant activity against pentylenetetrazole (PTZ) induced seizures in mice.Results: All the compounds showed antibacterial activity against the test strains to variable degrees, while the parent drug did not exhibit antibacterial activity. The zones of inhibition of compound G2 against Micrococcus luteus (36.2 ± 1.0 mm) and Serratia marcescens (28.2 ± 1.0 mm), and of compound G4 against Stenotrophomonas maltophilia (36.8 ± 1.0 mm) were larger compared to thestandard drug, doxycycline, exhibiting zones of inhibition 28.2 ± 1.3, 28.2 ± 0.9 and 20.0 ± 0.9 mm, respectively. In addition, compounds G1 and G2 possessed significantly greater (p < 0.05) radical scavenging activity (82.3 ± 1.8 and 92.3 ± 2.2 %, respectively) than the precursor drug, gabapentin (63.2± 2.6 %). The seizure scores for compounds G1 (0.7 ± 0.06) and G2 (0.9 ± 0.07) were comparable(p ˃ 0.05) with gabapentin (0.8 ± 0.06), while compounds G3 and G4 were less active (p < 0.05) than gabapentin.Conclusion: Compounds G1 and G2 exhibit good antibacterial and antioxidant activities while retaining the anticonvulsant activity of the parent drug, gabapentin, thus making them suitable candidates for further development for the treatment of neurodegenerative pathologies associated with bacterial infections. Keywords: Gabapentin, Antibacterial, Seizures, Antioxidant, Anticonvulsan

Improving Phosphorous Uptake Efficiency and Quality of Maize Through Optimization of Basal Application

Phosphorous (P) dearth in alkaline calcareous soils of Pakistan renders P unavailable for plant uptake. Consequently,affects grain yield and is major constraint to achieve desired yield potential of field grown maize (Zea maysL.). The objectives of this study were to enhance phosphorus use efficiency (PUE) by determining thresholds ofbasal applied P. Treatments comprised of five rates of basal applied P viz. 0, 30, 60, 90, 120, and 150 kg ha-1. Theexperiment was laid out in randomized complete block design (RCBD) with a net plot size of 2.7 m × 5 m, duringautumn season 2013. Improved agronomic attributes; i.e., plant height, cob length, grains per cob, grain-pithratio, 1000-grain weight, biomass and grain yield were observed at 120 kg P ha-1. Likewise, higher agronomicuse efficiency of P, grain P content and total P uptake were recorded. Conclusively, application of P at 120 and150 kg ha-1 would improve grain yield and quality of maize over control. However, 120 kg P ha-1 manifested morepromising results than 150 kg P ha-1

Gas exchange and morpho-physiological response of soybean to straw mulching under drought conditions

A pot experiment was conducted to investigate the morphological, physiological and biochemical straw mulch-induced response of soybean under water-deficit conditions. Soybean (Glycine max L. Merrill) variety “Xidou 7” was treated with varying quantity of wheat straw mulch viz: (control (no straw mulch), 3750, 7500, 11000 and 14750 kg/ha) under water-deficit conditions. The experimental results indicate that the varying quantity of straw mulch significantly improved the plant growth in terms of plant height, leaf area, number of leaves/plant and stem diameter. Mulch treatment also significantly enhanced the photosynthesis (PN), intercellular CO2 concentration (Ci), transpiration rate (E) and stomatal conductance (gs) over the control. The gas exchange parameters were improved depending on the quantity of wheat straw mulch; significantly highPN and E was observed in the treatment where wheat straw was applied at the rate of 11000 kg/ha. Wheat straw mulch treatments led to noticeable reduction in malondialdehyde (MDA) contents, which protected the drought stressed soybean plants from membrane damage. Furthermore, the free proline contents linearly increased with increase in straw mulch quantity. It is evident that wheat straw mulch can considerably modulate growth, photosynthetic and physio-biochemical attributes of soybean under drought. The research will effectively solve seasonal drought problem and can provide technical assistance for sustainable agriculture development.Keywords: Soybean, growth, water-deficit, wheat straw mulchAfrican Journal of Biotechnology Vol. 12(18), pp. 2360-236

Protective role of glycinebetaine in maize against drought-induced lipid peroxidation by enhancing capacity of antioxidative system

Abstract A pot-culture study was performed to investigate the efficacy of glycinebetaine (GB) for drought tolerance in two contrasting maize cultivars. Progressive drought stress noticeably reduced the relative leaf water content (RLWC) but increased protein and proline concentrations in both cultivars. The reduction in RLWC in DD-60 was lower than ND-95, whereas, the accumulation of protein and proline was substantially higher in DD-60 over ND-95 during experimental period. Nonetheless, GB-treatment led to increase in RLWC, protein and proline accumulation in DD-60 than ND-95. Prolonged drought stress induced the membrane lipid peroxidation, which was more severe in ND-95 than DD-60. GB-treatment substantially ameliorated the lipid peroxidation in DD-60 over ND-95 under drought stress. The activity of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were substantially enhanced in DD-60 than ND-95 with the prolongation of drought stress at beginning and then declined subsequently. These results possibly suggest that the DD-60 showed a better protection mechanism against water-induced lipid peroxidation by maintaining higher constitutive activities of antioxidant enzymes than ND-95. Nevertheless, GB-treated plants maintained higher antioxidant enzymes activity during drought stress than non-GB treated plants, which ultimately enhanced the growth, yield and yield components. The foliar application of glycinebetaine only considered advantageous when applied under drought and exhibit pronounced effects when applied at flowering. Drought tolerance can be improved in maize by the foliar GB-treatment through enhancing the antioxidants capacity

Silver nanoparticles protect tillering in drought-stressed wheat by improving leaf water relations and physiological functioning

The tillering phase of wheat (Triticum aestivum) crops is extremely susceptible to drought. We explored the potential of silver nanoparticles (AgNPs) in protecting wheat genotypes from drought injury during this sensitive stage. After treating with AgNPs (60 ppm), the plants were submitted to different water levels; i.e. 100% field capacity (FC), 75% FC (mild drought), 50% FC (moderate drought) and 25% FC (severe drought) from 15 to 41 days after sowing (tillering phase). Leaf physiological data were collected at stress termination, while yield attributes were recorded at crop maturity. We found that increasing drought intensity significantly impaired leaf physiology and grain yield of both studied genotypes. Compared with control, moderately and severely drought-stressed plants produced 25% and 45% lesser grain yield per spike, respectively (averaged across genotypes and years of study). Likewise, moderate and severe drought reduced photosynthesis by 49% and 76%, respectively, compared with control. In contrast, AgNPs significantly restored leaf physiological functioning and grain yield formation at maturity. For example, under moderate and severe drought, AgNPs-treated plants produced 22% and 17% more grains per plant, respectively, than their respective water-treated plants. Our study suggests that exogenous AgNPs can protect wheat crops from drought during early development stages

Enhancing the catalytic activity of eggshell-derived CaO catalyst and its application in biodiesel production from waste chicken fat.

The comparatively greater cost of producing biodiesel in comparison to petroleum diesel is one of the key drawbacks. Eggshells and leftover chicken fat are examples of poultry wastes that can be used to produce biodiesel at a low cost as catalysts and oil, respectively. In this study, eggshell-derived CaO and its doping with sodium methoxide catalyst for enhancing catalytic activity was synthesized for the transesterification of waste chicken fat and characterized by FT-IR and XRD analyses. XRD studies confirmed the crystalline structure of the developed catalyst and doping of sodium with eggshell-derived CaO. The transesterification reaction was performed at different reaction parameters such as the catalyst loading, the methanol to oil ratio, the reaction temperature, and the reaction time. The biodiesel produced at the maximum yield was evaluated by gas chromatography mass spectrometry analysis. A maximum yield of 96% biodiesel was obtained with catalyst loading of 2 wt% of oil, as well as a methanol to oil ratio of 13:1 at 60 °C in 1 h. The output demonstrates that eggshell waste is a potentially accessible source of biomass-derived nano catalyst for the synthesis of biodiesel using chicken fat as a feedstock

Impact of duration of therapy on side effect profile of anti-HCV protocol: A retrospective cohort study from two tertiary health facilities in Pakistan

Purpose: To evaluate the plausible risks and adverse effects related to the duration of therapy in hepatitis C (HCV) patients in Lahore, Pakistan.Method: A retrospective observational study involving 250 HCV patients who received combination therapy with ribavirin and interferon was conducted. The patients were segregated into two groups on the basis of duration of therapy (≤ 6 months and > 6 months). Adverse effect profiles of patients under treatment were collected using a pre-validated questionnaire and compared using Pearson’s Chi- Square Test/Chi-Square Goodness-of-Fit tests and unpaired t-test.Results: Patients who underwent treatment for ≤ 6 months frequently encountered side-effects such as GIT disturbance (23.77 %) and joint pains (29.63 %). Additionally, diabetes mellitus (27.86 %) and frequent injections (74.59 %) were the most commonly observed co-morbid condition and disease risk, respectively. On the other hand, in patients who underwent therapy for > 6 months, skin disorders (30.46 %) and gastric acidity (10.15 %) were the most frequently observed side-effects with less frequent reporting on co-morbid conditions and disease risk factors. Moreover, there was a significant reduction in body weight (p = 0.03), serum bilirubin (p = 0.0005), albumin (p = 0.003) and triglycerides (p = 0.006) levels due to longer duration of treatment.Conclusion: The data suggest that treatment-related risks are higher among HCV patients on shorter treatment duration whereas adverse events subside in patients on longer duration of therapy (>6 months). Changes in biochemical profile were also more evident in those receiving treatment for periods >6 months.Keywords: Interferon, Ribavirin, Side effects, Duration of therapy, Outcomes of therap

Point prevalence survey of antimicrobial use during the COVID-19 pandemic among different hospitals in Pakistan : findings and implications

The COVID-19 pandemic has significantly influenced antimicrobial use in hospitals raising concerns regarding increased antimicrobial resistance (AMR) through their overuse. The objective of this study was to assess patterns of antimicrobial prescribing during the current COVID-19 pandemic among hospitals in Pakistan, including the prevalence of COVID-19. A point prevalence survey (PPS) was performed among 11 different hospitals from November 2020 to January 2021. The study included all hospitalized patients receiving an antibiotic on the day of the PPS. The Global-PPS web-based application was used for data entry and analysis. Out of 1024 hospitalized patients, 662 (64.64%) received antimicrobials. The top three most common indications for antimicrobial use were pneumonia (13.3%), central nervous system infections (10.4%) and gastrointestinal indications (10.4%). Ceftriaxone (26.6%), metronidazole (9.7%) and vancomycin (7.9%) were the top three most commonly prescribed antimicrobials among surveyed patients, with the majority of antibiotics administered empirically (97.9%). Most antimicrobials for surgical prophylaxis were given for more than one day, which is a concern. Overall, a high percentage of antimicrobial use, including broad-spectrums, was seen among the different hospitals in Pakistan during the current COVID-19 pandemic. Multifaceted interventions are needed to enhance rational antimicrobial prescribing including limiting their prescribing post-operatively for surgical prophylaxis

The Karachi intracranial stenosis study (KISS) Protocol: an urban multicenter case-control investigation reporting the clinical, radiologic and biochemical associations of intracranial stenosis in Pakistan.

Background: Intracranial stenosis is the most common cause of stroke among Asians. It has a poor prognosis with a high rate of recurrence. No effective medical or surgical treatment modality has been developed for the treatment of stroke due to intracranial stenosis. We aim to identify risk factors and biomarkers for intracranial stenosis and to develop techniques such as use of transcranial doppler to help diagnose intracranial stenosis in a cost-effective manner. Methods/Design: The Karachi Intracranial Stenosis Study (KISS) is a prospective, observational, case-control study to describe the clinical features and determine the risk factors of patients with stroke due to intracranial stenosis and compare them to those with stroke due to other etiologies as well as to unaffected individuals. We plan to recruit 200 patients with stroke due to intracranial stenosis and two control groups each of 150 matched individuals. The first set of controls will include patients with ischemic stroke that is due to other atherosclerotic mechanisms specifically lacunar and cardioembolic strokes. The second group will consist of stroke free individuals. Standardized interviews will be conducted to determine demographic, medical, social, and behavioral variables along with baseline medications. Mandatory procedures for inclusion in the study are clinical confirmation of stroke by a healthcare professional within 72 hours of onset, 12 lead electrocardiogram, and neuroimaging. In addition, lipid profile, serum glucose, creatinine and HbA1C will be measured in all participants. Ancillary tests will include carotid ultrasound, transcranial doppler and magnetic resonance or computed tomography angiogram to rule out concurrent carotid disease. Echocardiogram and other additional investigations will be performed at these centers at the discretion of the regional physicians. Discussion: The results of this study will help inform locally relevant clinical guidelines and effective public health and individual interventions