Control of ticks and tick-borne pathogens is a priority for human and animal health. Livestock-holders extensively rely on acaricide applications for tick control. Different groups of acaricides including cypermethrin and amitraz have been consistently used in Pakistan. There has been a gap in understanding the susceptibility or resistance of Rhipicephalus microplus, the most prevalent tick in Pakistan, to acaricides. The present study aimed to molecularly characterize cypermethrin and amitraz targeted genes such as voltage-gated sodium channel (VGSC) and octopamine tyramine (OCT/Tyr) of R. microplus ticks in Khyber Pakhtunkhwa (KP), Pakistan to monitor the acaricides resistance. Tick specimens were collected from cattle and buffaloes in northern (Chitral, Shangla, Swat, Dir, and Buner), central (Peshawar, Mardan, Charsadda, Swabi, and Nowshera), and southern districts (Kohat, Karak, Lakki Marwat, Tank, and Dera Ismail Khan) of KP, Pakistan. Different concentrations of commercially available cypermethrin (10%) and amitraz (12.5%) were prepared for in vitro larval immersion tests (LIT). In LIT, the average mortality rate of immersed larvae was recorded that was increased gradually with an increase in the concentration of specific acaricide. The larvae's highest mortality rates (94.5% and 79.5%) were observed at 100-ppm of cypermethrin and amitraz, respectively. A subset of 82 R. microplus ticks was subjected to extract genomic DNA, followed by PCR to amplify partial fragments of VGSC (domain-II) and OCT/Tyr genes. The BLAST results of the consensus sequence of VGSC gene (domain-II) showed 100% identity with the acaricides susceptible tick sequence from the United States (reference sequence). Obtained identical sequences of OCT/Tyr genes showed maximum identity (94-100%) with the identical sequences reported from Australia (reference sequence), India, Brazil, Philippines, USA, South Africa, and China. Thirteen single nucleotide polymorphisms (10 synonymous and three non-synonymous) were observed at various positions of partial OCT/Tyr gene fragments. The SNP at position A-22-C (T-8-P) in OCT/Tyr gene has been linked to amitraz resistance in R. microplus ticks. Molecular analysis and LIT bioassay's findings indicate the availability of resistant R. microplus ticks in the KP region. To our understanding, this is the first preliminary study to monitor cypermethrin and amitraz resistance via molecular profiling of cypermethrin and amitraz targeted genes (VGSC and OCT/Tyr) in combination with in vitro bioassays (LIT) in R. microplus ticks from Pakistan.
In the present work, the biogenic amines tryptamine (TRP), putrescine (PUT), histamine (HIS), tyramine (TYR) and spermidine (SPD) were determined in 32 various types of tofu that were obtained from different states in Malaysia. Three main types of tofu; soft tofu, firm tofu and processed tofu, were analysed in the present work. The biogenic amine contents in the respective types of tofu were analysed by a reversed-phase HPLC with a DAD detector after the aqueous extraction and derivatisation with dansyl chloride. The LOD values ranged from 0.019 mg/L for PUT to 0.028 mg/L for TYR. While, the LOQ values ranged from 0.063 mg/L (PUT) to 0.096 mg/L (TYR). The recovery values for all the five amines ranged from 80.3% to 120.5% with RSD ≤ 3.1%. The total levels of biogenic amines found varied, ranging from 1.5 mg/kg to 687.9 mg/kg, with mean values (p < 0.05) in descending order of 44.6, 12.6, 9.1, 4.8 and 4.7 mg/kg for PUT, TYR, SPD, HIS and TRP, respectively. PUT and TRP were the most prevailing biogenic amines and they were found respectively in 90.62% of the tofu analysed. Significant positive correlations (r = 0.266 to 0.874, p < 0.05) were found between some individual biogenic amines and protein content in all the three types of tofu. However, negative correlations (r = -0.246 to -0.832, p < 0.05) were observed between biogenic amines and moisture content, and between biogenic amines and water activity in all the three types of tofu. Significant and strong correlations (r = 0.525 to 0.999, p < 0.05) were found between most of the individual biogenic amines and the total biogenic amines. Those tofu exceeding the legal limits may affect the health of sensitive individuals.
Alcohol consumption is a widespread behaviour that may eventually result in the development of alcohol use disorder (AUD). Alcohol, however, is rarely consumed in pure form but in fruit- or corn-derived preparations, like beer. These preparations add other compounds to the consumption, which may critically modify alcohol intake and AUD risk. We investigated the effects of hordenine, a barley-derived beer compound on alcohol use-related behaviours. We found that the dopamine D2 receptor agonist hordenine (50 mg/kg) limited ongoing alcohol consumption and prophylactically diminished relapse drinking after withdrawal in mice. Although not having reinforcing effects on its own, hordenine blocked the establishment of alcohol-induced conditioned place preference (CPP). However, it independently enhanced alcohol CPP retrieval. Hordenine had a dose-dependent inhibitory effect on locomotor activity. Chronic hordenine exposure enhanced monoamine tissue levels in many brain regions. Further characterization revealed monoaminergic binding sites of hordenine and found a strong binding on the serotonin and dopamine transporters, and dopamine D3 , and adrenergic α1A and α2A receptor activation but no effects on GABAA receptor or glycinergic signalling. These findings suggest that natural ingredients of beer, like hordenine, may work as an inhibitory and use-regulating factor by their modulation of monoaminergic signalling in the brain.
Biological amines are nitrogenous compounds that occur naturally in wide variety of food. Histamine, putrescine, cadavarine, tyramine, spermine, spermidine, tryptamine and β-phenylethylamine are the biogenic amines that are normally present in foods. Although the biogenic amines play some important physiological functions but high level of amines can cause toxicological effects. High amount of amines can be produced by bacteria during amino acids decarboxylation and have been identified as one of the important agent causing seafood intoxication. Temperature is the major factor for controlling the biogenic amines formation in food. The effects of other alternatives are also discussed including salting, packaging, irradiation, high pressure processing and the use of starter culture. A variety of techniques can be combined together to control the microbial growth and enzyme activity during processing and storage for better shelf life extension and food safety.
Increasing animal evidence support an important facilitatory interaction between angiotensin II and norepinephrine within the kidney. This angiotensin II/norepinephrine interaction was investigated in man by examining the effect of enalapril pretreatment (5 mg for 5 days) on the renal response to a low non-pressor dose of intravenous tyramine 4 micrograms/kg/min for 120 min in 8 healthy subjects undergoing water diuresis. Tyramine is an indirect sympathomimetic agent which causes neuronal release of norepinephrine. Enalapril and tyramine, alone and in combination, had no effect on glomerular filtration, effective renal plasma flow or sodium excretion. Tyramine caused a significant increase in urinary flow rate (p < 0.05) but this was not influenced by enalapril pretreatment. The lack of effect of enalapril on the renal response to tyramine contrasts with a previous study which examined the effect of enalapril on the renal response to circulating norepinephrine. This may suggest that enalapril affect renal function only when there is renal vasoconstriction (as with norepinephrine) and not when renal blood flow is unchanged (as with tyramine).