Plants have played an important role over the centuries in providing products that have been used to help combat ailments and diseases. Many products originating from fresh, dried-plant materials, or extracts are utilized as community remedies in traditional practices or even in modern medicine. The Annonaceae family contains different types of bioactive chemical properties, such as alkaloids, acetogenins, flavonoids, terpenes, and essential oil, meaning the plants in this family are potential therapeutic agents. Belonging to the Annonaceae family, Annona muricata Linn. has recently attracted the attention of scientists for its medicinal value. It has been utilized as a medicinal remedy since ancient times to treat and improve various diseases, for example, diabetes mellitus, hypertension, cancer, and bacterial infections. This review, therefore, highlights the important characteristic and therapeutic effect of A. muricata along with future perspectives on its hypoglycemic effect. The most-common name is soursop, referring to its sour and sweet flavors, while in Malaysia, this tree is commonly called ‘durian belanda’. Furthermore, A. muricata contains a high content of phenolic compounds in the roots and leaves. In vitro and in vivo studies have shown that A. muricata has the pharmacological effects of anti-cancer, anti-microbial, antioxidant, anti-ulcer, anti-diabetic, anti-hypertensive, and wound healing. With regard to its anti-diabetic effect, mechanisms of inhibiting glucose absorption via α-glucosidase and α-amylase activity inhibition, increasing glucose tolerance and glucose uptake by peripheral tissues, and stimulating insulin release or acting like insulin were deeply discussed. There is still a significant research gap, and future studies are required to conduct detailed investigations and gain a better molecular understanding of A. muricata’s anti-diabetic potential, especially by using the metabolomics approach.

The subchronic toxicity effect of the leaf extract of Carica papaya Linn. in Sprague Dawley (SD) rats was investigated in this study. The extract was prepared by dissolving the freeze dried extract of the leaves in distilled water and was administered orally to SD rats (consisted of 10 rats/sex/group) at 0 (control), 0.01, 0.14, and 2 g/kg body weight (BW) for 13 weeks. General observation, mortality, and food and water intake were monitored throughout the experimental period. Hematological and biochemical parameters, relative organ weights, and histopathological changes were evaluated. The study showed that leaf extract when administered for 13 weeks did not cause any mortality and abnormalities of behavior or changes in body weight as well as food and water intake. There were no significant differences observed in hematology parameters between treatment and control groups; however significant differences were seen in biochemistry values, for example, LDH, creatinine, total protein, and albumin. However, these changes were not associated with histopathological changes. In conclusion, the results suggested that daily oral administration of rats with C. papaya leaf extract for 13 weeks at a dose up to fourteen times the levels employed in traditional medicine practice did not cause any significant toxic effect.

Huge quantities of oil palm (Elaeis guineensis Jacq.) leaves (OPL) are generated as agricultural biomass from oil palm plantations. OPL are known to contain significant amounts of flavonoids. For maximal exploitation of these valuable antioxidant compounds, an innovative and sustainable extraction method employing natural deep eutectic solvents (NaDES) combined with ultrasonic assisted extraction was developed. Various NaDES composed of choline chloride as the hydrogen bond donor (HBD) and 1,2 propanediol (PD), 1,4 butanediol (BD), glycerol (GLY), glucose (GLU), maltose (MAL), and lactic acid (LA) as the hydrogen bond acceptor (HBA) were synthesized. The influence of these compositions, the methods of their synthesis, molar ratios, and water contents on their capacity to extract flavonoids from OPL was evaluated. Based on the results, it was found that methods which incorporate a heating step produced NaDES with the best capacity to extract OPL flavonoids. These thermal methods combined with molar ratios of 1:3 or 1:4 and water contents of 17 to 50% were found to be the optimal conditions for preparing NaDES, specifically when applied to the PD, BD, and GLY NaDES. Subsequently, UHPLC-UV/PDA-MS/MS analysis revealed NaDES extracts recovered by macroporous adsorption resin XAD7HP were able to optimally extract at least twelve luteolin and apigenin derivatives in OPL NaDES extracts prepared from glycerol and 1,4-butanediol demonstrated better and comparable efficiency as aqueous methanol in extracting flavonoids from OPL. The in vitro studies of antioxidant and wound healing properties supported these findings by exhibiting good free radical scavenging, cell proliferation, and migration activities. Additionally, the NaDES extracts also showed non-cytotoxicity effects at 1000 µg/mL and below on 3T3 fibroblast cells. Results of the study showed that NaDES could be a promising eco-friendly green solvent to extract bioactive OPL flavonoids that have great potential for applications as wound healing agents.

The potential therapeutic effect of Carica papaya leaf juice has attracted wide interest from the public and scientists in relieving dengue related manifestations. Currently, there is a lack of evaluated evidence on its juice form. Therefore, this scoping review aims to critically appraise the available scientific evidence related to the efficacy of C. papaya leaf juice in dengue. A systematic search was performed using predetermined keywords on two electronic databases (PubMed and Google Scholar). Searched results were identified, screened and appraised to establish the association between C. papaya and alleviating dengue associated conditions. A total of 28 articles (ethnobotanical information: three, in vitro studies: three, ex vivo studies: one, in vivo study: 13, clinical studies: 10) were included for descriptive analysis, which covered study characteristics, juice preparation/formulations, study outcomes, and toxicity findings. Other than larvicidal activity, this review also reveals two medicinal potentials of C. papaya leaf juice on dengue infection, namely anti-thrombocytopenic and immunomodulatory effects. C. papaya leaf juice has the potential to be a new drug candidate against dengue disease safely and effectively.

Systems biology is an interdisciplinary study that involves a combination of expertise in biology, chemistry, mathematics, physics, and engineering to unravel the biology of complex living systems by incorporating multiple kinds of quantitative molecular computations by using sophisticated mathematical models. This interdisciplinary study can be applied to identify and understand molecular and metabolic changes in recalcitrant plant species. Many tropical plants with recalcitrant seeds have difficulty with long-term seed storage and preservation due to their intolerance to desiccation and low temperatures. The aim of this review was to explore and discuss how omics analyses can assist in elucidating molecular responses and metabolic changes of recalcitrant seed species. Genomics and transcriptomics analyses identified genes, such as late embryogenesis abundant (LEA), that were highly expressed after exposure to desiccation and low temperatures. Meanwhile, proteomic analysis using 2D gel electrophoresis, MALDI-TOF MS, or MS/MS analysis revealed dehydrins induced from recalcitrant seeds upon exposure to desiccation and low temperatures. Metabolomic analysis using liquid chromatography–mass spectrometry (LC–MS) and gas chromatography–mass spectrometry (GC–MS) profiling of recalcitrant seeds has discovered metabolites such as sugar and organic acid changes in recalcitrant seeds at different developmental stages. This information may contribute to comprehending the behaviour of recalcitrant seeds and provide insight into how crop management can be improved in terms of seed storage for conservation in order to maintain plant biodiversity.

The role of Carica papaya L. leaf juice in immune dysregulation caused by dengue virus infection remains unclear. This study aimed to investigate the immunomodulatory activities of the freeze-dried C. papaya leaf juice (FCPLJ) on AG129 mice infected with a clinical DENV-2 (DMOF015) isolate. The infected AG129 mice were orally treated with 500 and 1000 mg/kg/day of FCPLJ, for three days. Platelet, leukocyte, lymphocyte and neutrophil counts were microscopically determined. The level of plasma proinflammatory cytokines was measured by multiplex immunoassay. The levels of intracellular cytokines and viral RNA were determined by RT-qPCR technique. The results showed that the FCPLJ treatment increased the total white blood cell and neutrophil counts in the infected mice. The FCPLJ treatment decreased the level of GM-CSF, GRO-alpha, IL-1 beta, IL-6, MCP-1 and MIP-1 beta in the plasma of the infected mice. The intracellular IL-6 and viral RNA levels in the liver of infected mice were decreased by the FCPLJ treatment. In conclusion, this study supports the potential immunomodulatory role of the FCPLJ in a non-lethal, symptomatic dengue mouse model. Further studies on the action mechanism of the C. papaya leaf juice and its possible use as adjunctive dengue immunotherapy are warranted.