Potential Antibacterial Activity of Ethanolic Curcuma longa L. Rhizome Extract Against Antibiotic-Resistant Bacteria.

<b>Background and Objective:</b> <i> Curcuma longa</i> L. rhizomes are the source of many bioactive compounds such as antitumor, antidepressant, antibacterial, anti-aging and antidiabetic. Due to the growing problem of antibiotic-resistant bacteria, it is necessary to find new sources of antibiotics. This research aimed to investigate the antibacterial activity of ethanolic <i>Curcuma longa</i> L. rhizomes extract against <i>Proteus mirabilis, Acinetobacter baumannii</i> and Multidrug-Resistant <i>Klebsiella pneumoniae</i> (MDR-K). <b>Materials and Methods:</b> Dry <i>Curcuma longa</i> L. rhizomes were extracted with ethanol. The agar diffusion method was used as the primary screening of antibacterial activity determination. The broth dilution method was used to measure the MIC and MIC of the extract. <b>Results:</b> It presented the largest diameter of the inhibition zone at 0.9 mm against <i>Proteus mirabilis</i>, followed by 0.8 mm against MDR-K. The lowest MIC and MBC values were at 0.048 and 0.39 mg mL¹ against <i>Proteus mirabilis</i>, followed by 0.195 and 6.25 mg mL¹ against MDR-K. The ethanolic <i>Curcuma longa</i> L. rhizomes extract did not affect <i>Acinetobacter baumannii</i>. <b>Conclusion:</b> The new finding of this research was that the ethanolic extract from <i>Curcuma longa</i> L. rhizomes can eliminate <i>Proteus mirabilis</i> and MDR-K that can be applied to treating antibiotic-resistant bacterial infectious diseases in the hospital.

Bacterial cellulose production from Komagataeibacter xylinus TISTR 1011 and Komagataeibacter nataicola TISTR 975 using yam bean juice as a nutrient source.

The present study investigated the efficacy of bacterial cellulose production by K. xylinus TISTR 1011 and K. nataicola TISTR 975 using yam bean juice as a nutrient source, and the physicochemical and sensory characteristics of bacterial cellulose were examined. Bacterial cellulose content, production yield, and production rate were significantly higher when K. xylinus TISTR 1011 rather than K. nataicola TISTR 975 was used as the bacterial strain. The analysis of physicochemical characteristics revealed that bacterial cellulose produced by K. xylinus TISTR 1011 using yam bean juice medium had higher scores for CIE L*, a*, and b* values, wet weight, moisture content, firmness, and gel strength than bacterial cellulose produced by K. nataicola TISTR 975. In contrast, sensory evaluation showed that the acceptability scores and preference of all attributes of bacterial cellulose produced by K. nataicola TISTR 975 using yam bean juice medium were higher than those of bacterial cellulose produced by K. xylinus TISTR 1011. The results of this study indicate that yam bean juice from yam bean tubers, an alternative raw material agricultural product, can be used as a nutrient source for producing bacterial cellulose or nata by Komagataeibacter strains.

Gonadotropin releasing hormone and brooding behavior in the native Thai hen.

Changes in the number of hypothalamic gonadotropin releasing hormone-I (GnRH-I) neurons within the Nucleus commissurae pallii (nCPa) were associated with the reproductive cycle of native Thai chickens. In order to further understand the association of GnRH-I in the regulation of brooding behavior in this bird, the native Thai chickens were divided into two groups; chick-rearing (R) and non-chick-rearing (NR) hens. Numbers of visible of GnRH-I-immunoreactive (GnRH-I-ir) neurons in the hypothalamus of R and NR hens were compared utilizing immunohistochemistry. Numbers of visible GnRH-I-ir neurons within the Nucleus anterior medialis hypothalami, Nucleus suprachaiasmaticus, pars medialis, Nucleus septalis lateralis, Nucleus paraventricularis magnocellularis, and Regio lateralis hypothalami areas were observed in both groups, but no differences were seen between R and NR hens. The number of visible GnRH-I neurons in the nCPa was higher (P<0.05) in the NR than in R hens, and increased in NR hens by day 14 after chick removal. These findings suggest, for the first time, an association of the GnRH system with brooding behavior in continuously breeding birds. Furthermore, the expression of brooding behavior of native Thai chickens might be regulated, in part, by GnRH-I neurons in the nCPa.

Neuroendocrine regulation of rearing behavior in the native Thai hen.

Vasoactive intestinal peptide (VIP) is the avian prolactin releasing factor and changes in the concentrations of plasma prolactin (PRL) are found during the avian reproductive cycle. This study investigated the changes in the VIP/PRL system of native Thai hens rearing their young as compared to hens deprived of rearing their chicks. The number of VIP-immunoreactive (VIP-ir) neurons in the Nucleus inferioris hypothalami (IH) and Nucleus infundibuli hypothalami (IN) of hens rearing chicks (R) were compared with those of non-rearing chicks (NR). Plasma PRL levels were determined by enzyme-linked immunosorbent assay. The localization and number of VIP-ir neurons were determined by immunohistochemistry. The numbers of VIP-ir neurons in the IH-IN areas were high in the R hens, whereas the number of VIP-ir neurons decreased in the NR hens as compared to their respective R hens. During the rearing period, changes in the VIP-ir neurons within the IH-IN were correlated with plasma PRL levels. The results of the present study indicate for the first time that the VIP/PRL system plays a role in neuroendocrine reorganization to establish maternal behavior in native Thai chickens. The VIP/PRL system functions not only as a well established key regulator of incubation behavior, but is also involved in the regulation of rearing behavior. It is possible that VIP and the decline in the number of VIP-ir neurons and in turn VIPergic activity and the decrease in PRL levels are related to their contribution to rearing behavior of this non-seasonal breeding, equatorial precocial species.

Plasma leptin concentrations during the reproductive cycle in the native Thai chicken (Gallus domesticus).

Plasma leptin concentrations were investigated during the reproductive cycle in the native Thai chicken. The plasma leptin concentration was high during non-laying (0.69±0.15ng/ml), lowered to a minimum concentration during egg laying (0.07±0.02ng/ml), and gradually increased during egg incubation and rearing of the chicks (0.53±0.22 and 0.74±0.29ng/ml, respectively). However, the differences were not significant. Incubating chickens that were deprived of their nests for 3 weeks showed a significant decrease in plasma leptin concentrations (0.29±0.04ng/ml, P<0.05) compared to those of their corresponding incubating controls (0.77±0.08ng/ml). Similarly, plasma leptin concentration of chickens that were deprived of their chicks for 4 weeks was significantly lower (0.09±0.11ng/ml, P<0.05), when compared to those of chickens that rearing their chicks (0.71±0.18ng/ml). These findings taken together with the results that the low plasma leptin concentrations were observed in chickens having relatively greater ovary and oviduct weights led to the suggestion that circulating leptin concentrations are associated with the reproductive states of the birds, especially the ovarian activity (i.e. ovarian steroid hormone concentrations) in the native Thai chicken, a tropical and continuous breeding species.

Distribution and variation in gonadotropin releasing hormone-I (GnRH-I) immunoreactive neurons in the brain of the native Thai chicken during the reproductive cycle.

Gonadotropin releasing hormone-I (GnRH-I) is known to regulate the avian reproductive system. We investigated the roles of GnRH-I in the regulation of the reproductive system of the native Thai chicken. The distribution of GnRH-I neurons and changes in GnRH-I-immunoreactive (-ir) neurons throughout the reproductive stages and between incubating and nest-deprived hens were analyzed utilizing immunohistochemical techniques. The results revealed that GnRH-I-ir neurons were distributed in a discrete region lying close to the third ventricle from the level of preoptic area through the anterior hypothalamus, with the greatest abundance found within the nucleus commissurae pallii (nCPa). The number of GnRH-I-ir neurons in the nCPa was highest in laying hens when compared with that in the other reproductive stages. Nest deprivation caused an increase in the number of GnRH-I-ir neurons in the nCPa of nest-deprived hens when compared with incubating hens. These results indicate that GnRH-I expression is correlated with the reproductive state in the native Thai chicken and may be, in part, regulated by it. This study also confirms a pivotal role of GnRH-I in controlling avian reproduction of this non-seasonal breeding, equatorial species.

Changes in vasoactive intestinal peptide and tyrosine hydroxylase immunoreactivity in the brain of nest-deprived native Thai hen.

Hyperprolactinemia is associated with incubation behavior and ovarian regression in birds. To investigate the association of prolactin (PRL), vasoactive intestinal peptide (VIP), and dopamine (DA) with the neuroendocrine regulation of incubation behavior, changes in the number of visible VIP-immunoreactive (VIP-ir) neurons in the nucleus inferioris hypothalami (IH) and nucleus infundibuli hypothalami (IN) and tyrosine hydroxylase-immunoreactive (TH-ir) neurons in the nucleus intramedialis (nI) and nucleus mamillaris lateralis (ML) of incubating native Thai hens were compared with those of nest-deprived hens. TH was used as a marker for dopaminergic (DAergic) neurons. Blood samples were collected to determine PRL levels. The localization and the number of visible VIP-ir and TH-ir neurons were determined by immunohistochemistry. Disruption of incubation behavior was accompanied by a precipitous decline in plasma PRL levels. The number of visible VIP-ir neurons in the IH-IN and TH-ir neurons in the nI and ML were high during incubation and decreased when hens were deprived of their nests. This study indicated an association between VIP neurons in the IH-IN and DA neurons in the nI and ML with the degree of hyperprolactinemia, suggesting that the expression of incubation behavior in birds might be, in part, regulated by the DAergic input from the nI and ML to VIP neurons in the IH-IN and subsequent PRL release.

Vasoactive intestinal peptide and its role in continuous and seasonal reproduction in birds.

Native Thai chicken, an equatorial species breeds throughout the year, whereas turkeys are seasonal temperate zone breeder whose reproductive cycle is terminated by the onset of photorefractoriness. This study investigated VIPergic activity throughout a reproductive cycle in both species, hypothesizing that the differential expression of vasoactive intestinal peptide (VIP) would provide an insight into the differing reproductive strategies of the two species. Distribution of VIP neurons in the native Thai chicken and a comparison of VIPergic activity in the nucleus inferioris hypothalami (IH) and nucleus infundibuli hypothalami (IN) were investigated. VIP immunoreactivity was found throughout the native Thai chicken brain, predominantly located within the IH-IN. The pattern of VIP distribution in the native Thai chicken supports the findings reported in temperate zone species. Unlike the turkey, where there is a dissociation between VIPergic activity and prolactin levels during photorefractoriness, in the native Thai chicken, which do not express photorefractoriness, changes in VIP immunoreactive (VIP-ir) neurons within the IH-IN were directly correlated with prolactin throughout the reproductive cycle. VIPergic activity reached its lowest level after hatching of the chicks in the native Thai chicken, while in the turkey VIPergic activity was lowest only after exposure to a short day photoperiod and the acquisition of photosensitivity. This suggests that VIP neurons in the IH-IN may play a pivotal role in regulating the reproductive cycle and its differential expression following hatching of the young may, in part, account for the difference in reproductive mode between equatorial, continually breeding, non-photoperiodic birds and seasonally breeding, photoperiodic birds.