A quantification of the relationship between neuronal responses in the rat rostral ventromedial medulla and noxious stimulation-evoked withdrawal reflexes

The rostral ventromedial medulla (RVM) regulates a range of involuntary behaviours but is most often associated with nociception via the action of pronociceptive ON cells and antinociceptive OFF cells. The phasic responses of ON and OFF cells determine whether or not incoming noxious signals provoke a withdrawal reflex, and previous studies have suggested that reflex RVM activity patterns actively shape motor output. Here we challenged the model by using juvenile rats, which are known to exhibit markedly different reflex responses compared with adults. By recording single-cell activity in the RVM and the electromyography responses of hindlimb flexor muscles to noxious thermal stimulation we found that the juvenile reflex had a shorter onset latency, was larger in amplitude and exhibited a decreased rise time compared with the adult reflex. The responses of ON and OFF cells faithfully tracked the shorter onset latency of the reflex by also responding earlier and, thus, still preceded the reflex. However, neither the reflex amplitude nor the ongoing response profile was predicted by the firing rate of RVM cells in either age group. Instead we found a close correspondence between RVM activity and the reflex only during the initiation of the response. Furthermore, the short rise time of the juvenile reflex was reflected in higher rates of change of both ON and OFF cell firing. Our data suggest that the RVM is associated only with the initiation of reflexes and does not shape ongoing muscle activity, which is more likely to be subserved by downstream spinal processes

Sub-acute toxicity of black seed (Nigella sativa) and honey mixture

Consumption of black seed (Nigella sativa) and honey mixture (BSH) has been reported to provide multiple health advantages. However, the toxicity effect of black seed and honey mixture (BSH) consumption has not been reported, although it has been consumed for centuries. Thus, this toxicity study was conducted, including determination of 50% lethal dose (LD50), changes in body and relative organ weights, differential leukocytes count, liver function test and histopathology analysis of liver and kidney. Thirty male Sprague Dawley rats (120-300 g) were used in the study and treated with varying dosages of BSH (100, 500, 1000 and 2000 mg/kg, respectively) for 14 days. Half of the rats from each group (n=3) were euthanized on day 14 for a sub-acute toxicity study to obtain relative organ weight, haematology, liver function test and histopathology analysis. Another half of animals from each group (n=3) were kept for another 14 days without any treatment for delayed toxicity study. No lethality was observed in all dosage groups, while the LD50 value was evaluated to be more than 2000 mg/kg. No significant alterations (p>0.05) were observed in animal body weight, differential leukocytes count and relative organ weight in all treatment groups as compared to control for both sub-acute and delayed toxicity studies. However, AST enzymes drop significantly at dosage 500 and 2000 mg/kg in recovery period, which suggested delayed hepatoprotective effect of the mixture. Histopathology analysis of the liver and kidney confirmed no abnormalities in cell morphology. This study clearly demonstrates that consumption of BSH is safe and do not provide any adverse or delayed toxicity effect

Positive and negative effects of COVID-19 pandemic on aquatic environment: a review

In December 2019, a novel coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak was reported for the first time in Wuhan, Hubei province, China. This coronavirus has been referred as Coronavirus Disease 2019 or COVID-19 by World Health Organization (WHO). The spread of COVID-19 has become unstoppable, infecting around 93.5 million people worldwide, with the infections and deaths still increasing. Today, the entire planet has changed due to the greatest threat on the planet since the introduction of this lethal disease. This pandemic has left the world in turmoil and various measures have been taken by many countries including movement control order or lockdown, to slow down or mitigate the infection. Since the lockdown has been implemented almost in all affected countries, there has been a significant reduction in anthropogenic activity, including a reduction in industrial operations, vehicle numbers, and marine-related activities. All of these changes have also led to some unexpected environmental consequences. As a result of this lockdown, it had a positive and negative impact on the environment including the aquatic environment. Hence this review will therefore focus on the good and bad perspectives of the lockdown toward the aquatic environment

Antibacterial properties of selected mangrove plants against vibrio species and its cytotoxicity against artemia salina

Emerging antibiotic resistance among the pathogenic microorganism has triggered the discovery of various antimicrobial compounds from marine source. Secondary metabolites from plants especially mangroves is traditionally being used widely as antimicrobials. Hence, present study was aimed to determine the antibacterial and cytotoxic properties of the selected mangrove plant leaves (Bruguiera cyclindrica, Sonneratia caseolaris, Luminitzera racemosa, Rhizophora apiculata, Avicennia alba, Acrostichum aureum, Nypa fruticans, Pandanus odoratissimus, Hibiscus tiliaceous and Derris trifoliate) against aquaculture pathogenic strains of genus. Methanol and aqueous extracts of leaves samples were prepared. The antibacterial activity was determined by using disc diffusion method against six pathogenic Gram-negative Vibrio species, such as Vibrio alginolyticus and V. parahaemolyticus (isolated from Scylla serrata, mangrove crab), V. alginolyticus and V. parahaemolyticus (from Giant prawn), V. alginolyticus (from Tiger prawn) and also V. parahaemolyticus (from Reference strain ATCC 17802). Methanolic extracts of S. caseolaris produced significant inhibition zone against all the pathogenic Vibrio spp. except for V. parahaemolyticus (from Giant prawn). Minimum inhibitory concentration test (MIC) and cytotoxicity (LC50) test using Artemia salina as a test animal in sterile ELISA (Enzyme-Linked Immunosorbent Assay) microplates showed the significant antimicrobial properties of methanolic extract of S. caesolaris. Overall, present study proved the active antimicrobial compounds in methanolic extract of S. caesolaris which could be used against Vibrio pathogens in aquaculture

Eco-friendly photocatalysts for degradation of dyes

In the current era of globalization, synthetic dyes are one of the key factors of water pollution. Photocatalysis constitutes a promising technology for the treatment of wastewater, especially to those containing hard-to-remove organic compounds. Zinc oxide nanoparticles (ZnONPs) play a vital role as a photocatalyst material. This research highlights the synthesized ZnONPs with roselle flower and oil palm leaf extract. The extracts and sodium hydroxide (NaOH) act as reducing agents during the synthesis process. Synthesis without the addition of plant extract is used as blank control for the experiment. Structural and optical studies of the three variants of ZnONPs were performed. High purity of ZnONPs with element Zn and O was obtained. The size of the three variants of ZnONPs was from 10–15 nm and found in agglomerated spherical shape. Large band gap, 3.2 eV was obtained by UV-Vis and high thermal stability was proven by TGA. Oxygen vacancies that assist in the degradation phenomenon were found in ZnONPs. Five percent of ZnONPs with the presence of 10 W UV light could effectively degrade 10 ppm MO in 5 h and MB in 3 h. Besides, high antioxidant properties and low toxicity demonstrated the ability of ZnONPs to be used as photocatalysts. In conclusion, ZnONPs can be further developed for pharmaceutical and industrial use

Aqueous extract emulsifying ointment of Marphysa moribidii (Annelida: Polychaeta) increases collagen deposition in wound healing model at low concentration

Acute wound cases are increasing every year. Meanwhile, current treatments have many adverse impacts; thus, alternative treatment is required. Marphysa moribidii; a local polychaete is found to has a promising potential as a wound-healing agent due to its regenerative capability. However, no prior study has been conducted to prove this notion. Hence, this study is aimed to determine the effectiveness of aqueous extract of M. moribidii in wound healing treatment. The polychaete was finely pulverized and lyophilized by freeze-dryer to form a powdery-form extract before preparing in three different concentrations: 0.3% (w/w), 1.0% (w/w), and 2.0% (w/w) in ointment form. The treatments including Gamat oil 0.4% (w/w) as control were applied to the rat model once daily for 14 days. Gamat oil (0.4%) demonstrated the most rapid wound healing, followed by polychaete ointment (0.3%). However, based on Masson’s trichrome staining, the polychaete ointment exhibited the most collagen deposition compared to other treatments. The staining indicates a more effective healing process of the wound after treated with the polychaete ointment. Based on the findings, polychaete extract has great potential in wound healing; more detailed studies are needed to gain more evidences

Acute Wound Healing Potential of Marine Worm, Diopatra claparedii Grube, 1878 Aqueous Extract on Sprague Dawley Rats

Diopatra claparedii which is colloquially known as Ruat Sarung can be found along the west coast of Peninsular Malaysia. The species has a unique ability to regenerate anterior and posterior segments upon self-amputation or injury, thus having potential as a wound healing promoter. In this study, the wound healing potential of D. claparedii aqueous extract on acute wound model in rats was revealed for the first time. Various concentrations (0.1%, 0.5%, and 1.0% w/w) of D. claparedii ointment were formulated and tested on Sprague Dawley rats through topical application on full-thickness skin wounds for 14 days. The wound healing effects were investigated via behaviour observation, wound contraction, and histopathological analysis. Quality assessment was performed via skin irritation test, microbial contamination test (MCT), and heavy metal detection. The study also included test for antibacterial activities and detection of bioactive compounds in D. claparedii. One percent of D. claparedii ointment showed rapid wound healing potential with good soothing effects and more collagen deposition in comparison to the commercial wound healing ointments such as acriflavine (0.1% w/v) and traditional ointment gamat (sea cucumber extract) (15.0% w/v). No local skin irritation, microbial contamination, and insignificant concentration of heavy metals were observed, which indicate its safe application. Moreover, the aqueous extract of D. claparedii exhibited antibacterial activities against Escherichia coli and Pseudomonas aeruginosa with minimum inhibitory concentration (MIC) value at 0.4 g/ml. 1H NMR analysis of the aqueous extract of D. claparedii revealed some metabolites that might be responsible for its wound healing properties such as amino acids, halogenated aromatics, organic acids, vitamins, and others. Altogether, these results suggested that the aqueous extract of D. claparedii could be utilised as an alternative natural wound healing promoter

Effectiveness of Aqueous Extract of Marine Baitworm Marphysa moribidii Idris, Hutchings and Arshad, 2014 (Annelida, Polychaeta), on Acute Wound Healing Using Sprague Dawley Rats

Wound healing is a well-coordinated process that restores skin integrity upon injury. However, some wound treatment poses harmful effects on the skin, which delay the normal wound healing process. Marphysa moribidii, a marine baitworm or polychaete, represents unique ability to regenerate posterior segment after injury, which may be beneficial in the wound healing treatment. The effectiveness of the polychaete as wound healing treatment was discovered through skin irritation, microbial testing, animal wound model, and chemical identifications. Three polychaete extracts (PE) emulsifying ointment (0.1%, 0.5%, and 1.0%) were topically applied to the full thickness wound model once daily for 14 days. Interestingly, PE 1.0% revealed the most rapid wound healing effects as compared to other treatments, including gamat (sea cucumber) oil (15% w/v) and acriflavine (0.1% w/v). Histopathological analysis using Masson’s trichrome staining further confirms that PE treated wound exhibited minimal scar, high collagen deposition, and the emergence of neovascularisation. The extract also displayed a minimum inhibitory concentration (MIC) of 0.4 g/ml against Escherichia coli and absence of skin irritation, infectious bacteria, and heavy metals from the extract. Moreover, chemical compounds such as alkaloid, flavonoid, amino acids, and organic acid were detected in M. moribidii extracts, which could contribute to wound healing activity. In conclusion, this study further justifies the beneficial use of polychaete in treating wound healing and could be developed as a novel bioactive agent in nutraceuticals and pharmaceutical drugs

Traditional medicinal uses, phytochemistry, biological properties, and health applications of Vitex sp

The genus Vitex is also known as a chaste tree, in which it is a large shrub native to the tropical and subtropical regions of the world. A diverse range of species is distributed throughout Southern Europe, the Mediterranean, and Central Asia. The Vitex tree, including its leaves and fruits, has been used for herbal remedies in the form of pastes, decoctions, and dried fruits since ancient times. This article aimed to prepare a comprehensive review of traditional uses and secondary metabolites derived from Vitex sp., including the chemical compounds, biological activities, application of Vitex in human clinical trials, toxicology and safety, marketed products, and patents. The scientific findings were obtained using a number of search engines and databases, including Google Scholar, PMC, and ScienceDirect. Vitex species are well known in pharmacology to have medicinal values, such as anti-inflammatory, antibacterial, antifungal, antimicrobial, antioxidant, and anticancer properties. Previous studies reported that some species are proven to be effective in treating diseases, such as diabetes, and improving female health. A total of 161 compounds from different Vitex species are reported, covering the literature from 1982 to 2022. A chemical analysis report of various studies identified that Vitex exhibited a wide range of phytoconstituents, such as iridoid, diterpenoid, ecdysteroid, and flavonoid and phenolic compounds. Apart from that, the review will also discuss the application of Vitex in human clinical trials, toxicology and safety, marketed products, and patents of the genus. While the extracts of the genus have been made into many commercial products, including supplements and essential oils, most of them are made to be used by women to improve menstrual conditions and relieve premenstrual syndrome. Among the species, Vitex agnus-castus L. is the only one that has been reported to undergo clinical trials, mainly related to the use of the genus for the treatment of mastalgia, menstrual bleeding problems, amenorrhea, menorrhagia, luteal insufficiency, and premenstrual syndrome. Overall, the review addresses recent therapeutic breakthroughs and identifies research gaps that should be explored for prospective research work