Bee venom (BV) or apitoxin is a complex mixture of substances with reported biological activity. In the present work, five bee venom samples obtained from Apis mellifera iberiensis from the Northeast Portugal (two different apiaries) were chemically characterized and evaluated for their antioxidant, anti-inflammatory and cytotoxic properties. The LC/DAD/ESI-MS n analysis of the samples showed that melittin was the most abundant compound, followed by phospholipase A2 and apamin. All the samples revealed antioxidant and anti-inflammatory activity but without a direct relation with any of the individual chemical components identified.The results highlight that there are specific concentrations (present in BV5) in which these compounds are more active. The BV samples showed similar cytotoxicity for all the tested tumour cell lines (MCF-7, NCI-H460, HeLa and HepG2), being MCF-7 and HeLa the most susceptible ones. Nevertheless, the studied samples seem to be suitable to treat breast, hepatocellular and cervical carcinoma because at the active concentrations, the samples were not toxic for non-tumour cells (PLP2). Regarding the non-small cell lung carcinoma, BV should be used under the toxic concentration for non-tumour cells. Overall, the present study corroborates the enormous bioactive potential of BV being the first report on samples from Portugal.
PurposeThe purpose of this paper is to analyse whether a social exchange relationship between temporary workers and organizations is possible. The authors aim to consider whether, when training is perceived by an employee as an organizational practice that promotes his or her employability, this entails a social exchange relationship.Design/methodology/approachSurveys from 240 call centre workers were analyzed using correlation and multiple regression to explore relationships between training to promote employability, perceived organizational support (POS) and affective commitment.FindingsThe data support the idea that social exchange theories are useful frameworks in explaining temporary workers' affective commitment towards organisations. Organisational investment in training was positively related to the affective commitment of these temporary workers. However, employees attributed greater importance to the fact that training increased their employability than to the number of training hours received. The relationship between this human resource management practice and affective commitment partly occurred through the perceived organisational support. Such perception partially mediates the relationship between training as a promoter of employability and this positive attitude.Research limitations/implicationsThe study is limited due to sample nature and the lack of longitudinal design. It does not provide implications for other types of commitment that may be relevant for temporary workers (continuance commitment, for example).Practical implicationsAn important implication from this research is that employers should not assume that training is an investment without return from temporary workers. Developmental opportunities, while important to all employees, did make temporary workers more committed to organizations.Originality/valueThe paper is the first, to the authors' knowledge, to assess training as promoting employability with a specific measure. While the results are simple, they refute many stereotypes of temporary workers and add an important perspective to the human resource management literature.
Bee bread (BB) is a fermented mixture of plant pollen, honey, and bee saliva that worker bees use as food for larvae, and for young bees to produce royal jelly. In the present study, five BB samples, collected from Apis mellifera iberiensis hives located in different apiaries near Bragança, in the northeast region of Portugal, and one BB commercial sample were characterized by high-performance liquid chromatography coupled to a diode array detector and electrospray mass spectrometry (HPLC-DAD-ESI/MS) in terms of phenolic compounds, such as flavonoid glycoside derivatives. Furthermore, the samples were screened, using in vitro assays, against different human tumor cell lines, MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer), HeLa (cervical carcinoma) and HepG2 (hepatocellular carcinoma), and also against non-tumor liver cells (porcine liver cells, PLP2). The main phenolic compounds found were flavonol derivatives, mainly quercetin, kaempferol, myricetin, isorhamnetin and herbacetrin glycoside derivatives. Thirty-two compounds were identified in the six BB samples, presenting BB1 and BB3 with the highest contents (6802 and 6480 µg/g extract, respectively) and the highest number of identified compounds. Two isorhamnetin glycoside derivatives, isrohamnetin-O-hexosyl-O-rutinoside and isorhamnetin-O-pentosyl-hexoside, were the most abundant compounds present in BB1; on the other hand, quercetin-3-O-rhamnoside was the most abundant flavonol in BB3. However, it was not possible to establish a correlation between the flavonoids and the observed low to moderate cytotoxicity (ranging from >400 to 68 µg/mL), in which HeLa and NCI-H460 cell lines were the most susceptible to the inhibition. To the authors’ knowledge, this is the first report characterizing glycosidic flavonoids in BB samples, contributing to the chemical knowledge of this less explored bee product.
The aim of this study was to analyse whether the social exchange between temporary agency workers (TAWs) and the client organization is associated with a perception of training. In this study, we developed and tested a moderated mediation model that accounts for TAWs' exhaustion and desire to obtain a direct contract with the client company in the relationship between the perception of training and affective commitment. Our hypotheses were tested on a sample of 425 blue-collar workers from four Portuguese companies with temporary agency work contracts. Our findings support a conditional indirect relationship between the perception of TAWs that the training provided by the client company facilitates their internal employability and their commitment towards this company via exhaustion for those TAWs who have a low desire to have a direct contract with this company. In addition, our findings show that TAWs do not reciprocally respond to the training that promotes external employability, as this factor is not associated with the affective commitment of these individuals, although exhaustion is associated with this perception. Moreover, we discuss the implications of these findings for the human resource management of TAWs.
The aim of this study is to compare the employment relationship of temporary agency and permanent workers in two different sectors analyzing the relationship between human resource practices systems and workers’ affective commitment and the mediating role of work engagement. The hypotheses were tested with multiple group analysis on two samples: from a call center and from two industrial companies. Results confirm that in both the temporary agency and the permanent subsamples in the two sectors workers’ perception of the human resource practices system relates positively with affective commitment toward the organization, and work engagement partially mediates this relationship. Moreover, the study confirms that the relationship between workers’ perception of the human resource practices system and affective commitment was stronger for temporary agency than for permanent workers. However, this moderation occurred only in the manufacturing sector. Contrarily, the relationship between workers’ perception of the human resource practices system and engagement was stronger for permanent workers than for temporary agency workers (TAWs) in this sector and the relationship between this psychological state and affective commitment was also stronger for permanent than for TAWs, in both sectors (call center and manufacturing).
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