This study presents a bibliometric analysis of the publications on melatonin research from the Scopus database during the period 2015–2019. Based on the keywords used, which are related to melatonin in the article title, the study retrieved 4411 documents for further analysis using various tools. We used Microsoft Excel to conduct the frequency analysis, VOSviewer for data visualization, and Harzing’s Publish or Perish for citation metrics and analysis. This study reports the results using standard bibliometric indicators such as the growth of publications, authorship patterns, collaboration, and prolific authors, country contribution, most active institutions, preferred journals, and top-cited articles. Based on our findings, there is a continuous growth of publications on melatonin research for 5 years since 2015. China was the largest contributor to melatonin research, followed by the United States. The Journal of Pineal Research published the most number of publications related to melatonin research. Our findings suggest that the role of melatonin in plant and food sciences, as well as in cancer, may in later years take over the clusters that earlier dominated melatonin research.

Alzheimer’s disease (AD) is a primary cause of dementia in the middle-aged and elderly worldwide. Animal models for AD are widely used to study the disease mechanisms as well as to test potential therapeutic agents for disease modification. Among the non-genetically manipulated neuroinflammation models for AD, lipopolysaccharide (LPS)-induced animal model is commonly used. This review paper aims to discuss the possible factors that influence rats’ response following LPS injection. Factors such as dose of LPS, route of administration, nature and duration of exposure as well as age and gender of animal used should be taken into account when designing a study using LPS-induced memory impairment as model for AD.

Scientific research on honey has grown substantially over the past decades, accumulating more evidence on its role in complementary and alternative medicine. We conducted a bibliometric analysis of honey research from 2011 to 2020 to see the trend of publications in this study area. Based on the keywords used, which are related to honey in the article title, the study retrieved 4,433 documents for further analysis. VOSviewer software was used to create maps based on network data of scientific publications displaying relationships among researchers, countries, and scientific journals. Author keywords were used to explore the co-occurrence of different terms connected to honey research. Results reveal close and strong interconnections between the top authors suggesting a considerable strong research link. The top country researching on honey was the United States, while the top journal was Food Chemistry. In terms of co-occurrence, the top author keywords were “honey”, “antioxidant”, “chemometric”, “Manuka honey” and “antibacterial”. These analyses of the existing work provide a valuable and important reference for researchers and practitioners in honey research communities.

Disruptions in sleep and sleep-wake cycle regulation have been identified as one of the main causes for the pathophysiology of depressive disorders. The search has been on for the identification of an ideal antidepressant that could improve both sleep disturbances and depressive symptomatology. Melatonin, the major hormone of the pineal gland, has been shown to improve sleep and is involved in the regulation of the sleep-wake cycle. Identification of high concentrations of MT1 and MT2 melatonergic receptors in the suprachiasmatic nucleus of the anterior hypothalamus, the structure concerned with regulation of circadian rhythms and sleep-wake cycles, has led to the development of melatonergic agonists with greater potency and longer durations of action. Agomelatine is one such melatonergic agonist that acts specifically on MT1/MT2 melatonergic receptors and at the same time exhibits 5-HT2C antagonism, a property that is utilized by current antidepressants that are in clinical use. Agomelatine has been shown to be effective in a number of animal models of depression. Clinical studies undertaken on patients with major depression, bipolar disorders, seasonal affective disorder, and generalized anxiety disorder have all shown that agomelatine is also very effective in ameliorating depressive symptoms and manifesting early onset of action with a good tolerability and safety profile. It improved sleep efficiency and also resynchronized the disrupted circadian rhythms. Hence, the melatonergic modulation by agomelatine is suggested as one of the mechanisms for its antidepressant effect. Agomelatine's action on dendritic neurogenesis in animal models of depression is also identified as yet another action.

The aim of this study was to evaluate the verbal learning and memory performance of postmenopausal women who received tualang honey (Agro Mas) in comparison with women receiving estrogen plus progestin therapy and untreated controls. A total of 102 postmenopausal women were recruited and randomly assigned to three groups: tualang honey (20 g/d)[corrected], estrogen plus progestin therapy (Femoston 1/5), and untreated control. Their verbal learning and memory performances were assessed using the Malay version of the Auditory Verbal Learning Test before and after 16 weeks of intervention. Data were analyzed using the repeated-measures analysis of variance, and a P value of less than 0.05 was considered significant. There were significant differences in the mean scores of total learning as well as the mean scores of trials A1, A5, A6, and A7 between the three groups. There were also significant differences in the overall mean scores of total learning and trials A1 and A5 between both estrogen plus progestin therapy and tualang honey groups when compared with the untreated control group. However, significant differences in the mean score for trials A6 and A7 were only observed between the estrogen plus progestin therapy and untreated control groups. Postmenopausal women who received tualang honey showed improvement in their immediate memory but not in immediate memory after the interference and delayed recall. This is comparable with the improvement seen in women receiving estrogen plus progestin therapy.