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Seagrasses, one of the most threatened yet overlooked ecosystems on Earth, are the only flowering plants to recolonising the seabed. Apart from their critical ecological prominence on the life of many marine organisms, seagrasses are also used as an alternative or complementary medicine to manage an array of pathological disorders such as muscle aches, wounds, abdominal pain, indigestion, hangover, and mental disorders. However, a compilation of existing work on their ethnopharmacological uses, nutritional values, pharmacological propensities and bioactive compounds is lacking. Thus, this review aims at elaborating on the biochemical composition, phytochemical analysis, and biological properties including antioxidant, antimicrobial activities of various species of seagrasses. Seagrasses harbour several metabolites with multiple bioactivities. The phytochemical compounds isolated from Zostera marina L., Thalassia testudinum K. D. Koenig. and Thalassodendron ciliatum (Forssk.) exhibit a plethora of biological activities, including cytotoxicity against cancer cell lines, anti-human immunodeficiency virus (HIV), antimicrobial, and skin regenerating properties. This review also identifies vital lacuna in seagrass research. For instance, the mechanism and site of action of compounds displaying potent biological activities has not been adequately addressed together with optimisation of extraction methods to isolate minor metabolites and applying technological advancements in biological assays. In conclusion, this review provides a synthesis of current knowledge and highlights future work that needs to be undertaken for the biomedical application of such natural resources.

Secondary metabolites, derivatives of primary metabolites, are known for their biological activities. Marine organisms, especially marine invertebrates such as sponges, tunicates, soft corals, bryozoans, and nudibranchs are important source of secondary metabolites with diverse biological properties. Approximately 40,000 marine natural products have been identified from various marine resources. Soft corals are a group of invertebrates known for their production of a vast range of metabolites with great structural diversity. Among 39 genera of soft coral Alcyonacean, a total of eighteen different species of Lobophytum soft corals have been identified. Isolation of secondary metabolites from the genus Lobophytum is tremendously explored by researchers worldwide. This review compiles several secondary metabolites that have been isolated and published on the soft coral L. pauciflorum, including the compound structures and some notable bioactivity.

Mangrove forests are salt-tolerant intertidal vegetation in tropical and subtropical areas. Mangrove ecosystems provide commercial products, valuable fisheries, and aquaculture resources, protect and stabilize coastlines, and are important carbon sinks. However, they are threatened globally by human activities such as deforestation, pollution, and development causing fragmentation between the well-preserved, restored, and disturbed mangrove forests. Despite this, mangroves can adapt and strive well and are notable well associated with microbial diversity. Here, we investigate the diversity of microbes in different environmental settings using preferred reporting items for systematic and meta-analyses (PRISMA) analysis for publications from Scopus and the Web of Science databases. We report publications since 1987, and observed an exponential increase in publications beginning in the year 2000, which may be associated with the development of molecular and sequencing technologies. Differences in bacterial diversity was observed across the well-preserved, restored, and disturbed mangrove environments. Disturbed mangrove forests had a higher diversity (70 unique taxon orders reported) compared to well-preserved (33 unique taxon orders reported) and restored forests (38 unique taxon orders reported). Based on our analysis, we found that the microbial community plays an important role in the survival and adaptability of mangroves under varying environmental conditions. Thus, there is a need and a lot of potential for research in the area of mangrove microbiology with reference to ecology, biogeochemistry, and geomorphology.

Seaweeds are an important ingredient of functional foods recommended for daily food, due to their unique compositions and nutritional value. Padina tetrastromatica is a brown edible seaweed that is commonly found along the coastal regions of Peninsular Malaysia and consumed as food by some coastal communities. This study investigates the nutritional and antihyperglycaemic potential of P. tetrastromatica extracts, which is generally accepted as an important functional food. In our methodology, we induced diabetes intraperitoneally in experimental animals with a dose of 65 mg kg−1 body weight of streptozotocin. Oral treatment with 200 and 400 mg kg−1 of P. tetrastromatica ethanolic and ethyl acetate extracts were initiated, respectively, to experimental rats once daily for 18 days. Metformin was used as the positive control. Biochemical estimations and histopathological analysis were included in this study. Treatment with P. tetrastromatica extracts significantly lowered the plasma glucose levels in Streptozotocin-induced diabetic rats. In addition, P. tetrastromatica extract treatment also showed a significant reduction in serum alanine transaminase levels. However, no significant changes were observed in serum aspartate transaminase levels. The ethyl acetate extract of P. tetrastromatica at 400 mg kg−1 dose shows some nephroprotective effect, which is observed from the significant increase in the plasma albumin levels. Histopathological evaluation revealed no marked morphological changes in tissues of the isolated organs of the ethyl acetate extract-treated group, revealing the safe nature of P. tetrastromatica.

Diabetes is an endocrinological disorder with a rapidly increasing number of patients globally. Over the last few years, the alarming status of diabetes has become a pivotal factor pertaining to morbidity and mortality among the youth as well as middle-aged people. Current developments in our understanding related to autoimmune responses leading to diabetes have developed a cause for concern in the prospective usage of immunomodulatory agents to prevent diabetes. The mechanism of action of vaccines varies greatly, such as removing autoreactive T cells and inhibiting the interactions between immune cells. Currently, most developed diabetes vaccines have been tested in animal models, while only a few human trials have been completed with positive outcomes. In this review, we investigate the undergoing clinical trial studies for the development of a prototype diabetes vaccine.

Middle East respiratory syndrome (MERS) is a lethal respiratory disease with its first case reported back in 2012 (Jeddah, Saudi Arabia). It is a novel, single-stranded, positive-sense RNA beta coronavirus (MERS-CoV) that was isolated from a patient who died from a severe respiratory illness. Later, it was found that this patient was infected with MERS. MERS is endemic to countries in the Middle East regions, such as Saudi Arabia, Jordan, Qatar, Oman, Kuwait and the United Arab Emirates. It has been reported that the MERS virus originated from bats and dromedary camels, the natural hosts of MERS-CoV. The transmission of the virus to humans has been thought to be either direct or indirect. Few camel-to-human transmissions were reported earlier. However, the mode of transmission of how the virus affects humans remains unanswered. Moreover, outbreaks in either family-based or hospital-based settings were observed with high mortality rates, especially in individuals who did not receive proper management or those with underlying comorbidities, such as diabetes and renal failure. Since then, there have been numerous reports hypothesising complications in fatal cases of MERS. Over the years, various diagnostic methods, treatment strategies and preventive measures have been strategised in containing the MERS infection. Evidence from multiple sources implicated that no treatment options and vaccines have been developed in specific, for the direct management of MERS-CoV infection. Nevertheless, there are supportive measures outlined in response to symptom-related management. Health authorities should stress more on infection and prevention control measures, to ensure that MERS remains as a low-level threat to public health.

Seaweeds have an important place in the ancient systems of medicine. In addition, they also find significant mention in farming and in nutritional diet due to their benefits such as, availability, cheaper price, renewable potential and the advantage of being easily accessible. There are over 10,000 species of seaweeds that reflect their immense diversity. They are further used for both, their flavour and nutritional properties. Edible seaweeds are rich sources of bioactive compounds. In the last three decades, the discovery of metabolites with biological activities from macroalgae has increased significantly. Padina australis has been reported to possess several therapeutic activities including, antioxidant, anti-inflammatory, antibacterial and larvicidal effects. In addition, studies have also reported on the antidiabetic and antihypertensive potential of Padina australis. Till date, there are limited or no scientific reviews that have been published on the pharmacological and therapeutical activities of Padina australis in specific. Thus, there is a need for such a review to appreciate the various biological actions of this potent seaweed. This review, in this direction, attempts to explore the various therapeutic activities of the brown marine seaweed Padina australis, from the current published literature along with their pharmacological and molecular mechanisms, underlying its therapeutic activities. The main limitation of this review is that ancient texts, leisure magazines and traditional manuscripts were not searched.

Caulerpa racemosa (Forsskal) J. Agardh is a green seaweed used as food and folk medicine since ancient times in the Indo-Pacific region, particularly in southeast Asia. In this study, the proximate nutrient composition, phytochemical, anti-oxidant and anti-diabetic properties of sea grape C. racemosa collected from culture fishponds in Johor, Malaysia were analysed. The contents (dry weight basis) of carbohydrate, crude protein, crude lipids, ash and caloric value obtained were 33.42 ± 1.34%, 20.27 ± 0.14%, 4.20 ± 0.32%, 28.25 ± 0.27% and 2544.67 ± 7.04 cal g−1, respectively. The amino acid score (AAs) and biological protein value (213.43 mg g−1) indicated that C. racemosa presented a better protein quality. The most abundant fatty acids were C16:0 (palmitic acid: 63.27%), followed by C18:1 (oleic acid: 5.80%), and C18:2 ῳ6 (linoleic acid: 5.33%). The analysis of the ash content indicated that essential minerals and trace elements, such as Ca, Fe, and Mn, were present in the seaweed. The total phenolic content (TPC) and total flavonoid content (TFC) observed in the ethyl acetate extract were 17.88 ± 0.78 mg GAE g−1 and 59.43 ± 2.45 mg QE g−1, respectively. The ethyl acetate extract of C. racemosa demonstrated notable anti-diabetic activity in diabetic induced rats. The low (100 mg kg−1) and high (200 mg kg−1) doses of cultivated C. racemosa extract exhibited a significant decrease (p < 0.05) in blood glucose levels while preventing weight loss, reducing plasma AST, ALT levels as a sign of hepatoprotective effect and recording albumin levels similar to positive control in diabetic induced rats. The results support the usefulness of cultivated C. racemosa as a potential functional food.

Over the last decade, food waste has been one of the major issues globally as it brings a negative impact on the environment and health. Rotting discharges methane, causing greenhouse effect and adverse health effects due to pathogenic microorganisms or toxic leachates that reach agricultural land and water system. As a solution, composting is implemented to manage and reduce food waste in line with global sustainable development goals (SDGs). This review compiles input on the types of organic composting, its characteristics, physico-chemical properties involved, role of microbes and tools available in determining the microbial community structure. Composting types: vermi-composting, windrow composting, aerated static pile composting and in-vessel composting are discussed. The diversity of microorganisms in each of the three stages in composting is highlighted and the techniques used to determine the microbial community structure during composting such as biochemical identification, polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE), terminal restriction fragment length polymorphism (T-RFLP) and single strand-conformation polymorphism (SSCP), microarray analysis and next-generation sequencing (NGS) are discussed. Overall, a good compost, not only reduces waste issues, but also contributes substantially to the economic and social sectors of a nation.

Seaweeds have been exploited as both food products and therapeutics to manage human ailments for centuries. This study investigated the metabolite profile of five seaweeds (Halimeda spp., Spyridia hypnoides (Bory de Saint-Vincent) Papenfuss, Valoniopsis pachynema (G. Martens) B&oslash, rgesen, Gracilaria fergusonii J. Agardh and Amphiroa anceps (Lamarck) Decaisne using ultra-high-performance liquid chromatography coupled with electrospray ionization mass spectrometry (UHPLC-ESI-MS/MS). Furthermore, these seaweeds were assessed for antioxidant and inhibitory effects against &alpha, amylase, &alpha, glucosidase, acetyl-cholinesterase (AChE), butyryl-cholinesterase (BChE) and tyrosinase. Valoniopsis pachynema and A. anceps yielded the highest flavonoid (4.30 &plusmn, 0.29 mg RE/g) and phenolic content (7.83 &plusmn, 0.08 mg RE/g), respectively. Additionally, A. anceps exhibited significant antioxidant properties with all assays and significantly depressed BChE (IC50 = 6.68 &plusmn, 0.83 mg/mL) and &alpha, amylase activities (IC50 = 5.34 &plusmn, 0.14 mg/mL). Interestingly, the five seaweeds revealed potent inhibitory effects against tyrosinase activity. In conclusion, A. anceps might be considered as a key source of phytoantioxidants and a potential candidate to develop nutritional supplements. Besides, the five tested seaweeds warrant further study and may be exploited as promising natural sources for managing hyperpigmentation.

The agricultural sector generates approximately 1300 million tonnes of waste annually, where up to 50% comprising of raw material are discarded without treatment. Economic development and rising living standards have increased the quantity and complexity of waste generated resulting in environmental, health and economic issues. This calls for a greener waste management system such as valorization or recovery of waste into products. For successful implementation, social acceptance is an essential component with involvement of all local stakeholders including community to learn and understand the process and objective of the implementation. The agricultural waste product manufacturing industry is expected to increase with the growing demand for organic food. Thus, proper livestock and crop waste management is vital for environmental protection. It will be essential to successfully convert waste into a sustainable product that is reusable and circulated in the system in line with the green concept of circular economy. This review identifies the commercially produced crops by-product that have been considered for valorization and implemented green extraction for recovery. We highlight the importance of social acceptance and the economic value to agricultural waste recycling. Successful implementation of these technologies will overcome current waste management problems, reduce environmental impacts of landfills, and sustainability issue for farm owners.

Decline in forest productivity due to forest conversion is defining the Bornean landscape. Responses of bacterial communities due to land-use changes are vital and could define our understanding of ecosystem functions. This study reports the changes in bacterial community structure in organic soil (0-5 cm; O-Horizon) and organic-mineral soil (5-15 cm; A-Horizon) across Maliau Basin Conservation Area old growth forest (MBOG), Fragment E logged forest (FELF) located in Kalabakan Forest Reserve to Benta Wawasan oil palm plantation (BWOP) using two-step PCR amplicon analysis of bacteria DNA on Illumina Miseq next generation sequencing. A total of 30 soil samples yielded 893,752-OTU reads at ≥97% similarity from 5,446,512 good quality sequences. Soil from BWOP plantation showed highest unshared OTUs for organic (49.2%) and organic-mineral (50.9%) soil. MBOG soil showed a drop in unshared OTUs between organic (48.6%) and organic-mineral (33.9%). At phylum level, Proteobacteria dominated MBOG but shifted to Actinobacteria in logged and plantation soil. Present findings also indicated that only FELF exhibited change in bacterial communities along the soil depth, moving from the organic to the organic-mineral layer. Both layers of BWOP plantation soils deviated from other forests' soil in β-diversity analysis. To our knowledge, this is the first report on transitions of bacterial community structures with different soil horizons in the tropical rainforest including Borneo, Sabah. Borneo tropical soils form a large reservoir for soil bacteria and future exploration is needed for fully understanding the diversity structure and their bacterial functional properties.

Invertebrates are an important source of structurally-diverse and biologically-active halogenated metabolites. The sea hare Aplysia dactylomela Rang has long been known to possess halogenated metabolites of dietary origin that are used as a self-defense mechanism. The compounds from Aplysia dactylomela Rang are comprised mainly of terpenoids and small percentages of C-15 acetogenins, indoles, macrolides, sterols and alkaloids with potent cytotoxic, anti-microbial and anti-inflammatory properties. For decades the metabolites discovered have been investigated for their medical and pharmaceutical applications, so much so that the ecological role of the metabolites has been overlooked. The interaction between Aplysia dactylomela Rang and its diet that is comprised of seaweed can provide information into the distribution and diversity of the seaweed, the application of bioaccumulated secondary metabolites as part of its defense mechanism and the potential roles of these metabolites for adaptation in the marine environment. This paper compiles the diversity of halogenated secondary metabolites documented from Aplysia dactylomela Rang.

This study evaluated the effect of seasonal variation on the physicochemical, biochemical, and nutritional composition of Gracilaria manilaensis. Sampling was designed during the main monsoon seasons in Malaysia—the Southwest monsoon (SWM) and Northeast monsoon (NEM)—to understand the intraspecific variation (p &lt, 0.05). Carbohydrates, protein, and dietary fiber were found to be higher in NEM–G. manilaensis, whereas a higher ash content was quantified in SWM–G. manilaensis. No significant differences were found in crude lipid and moisture content (p &gt, 0.05). Vitamin B2 was calculated as (0.29 ± 0.06 mg 100 g−1) and (0.38 ± 0.06 mg 100 g−1) for the NEM and SWM samples, respectively (p &lt, 0.05). The fatty acid profile showed the dominance of saturated fatty acids (SFAs)—palmitic acids, stearic acid, and myristic acid—while the mineral contents were found to be good sources of calcium (1750.97–4047.74 mg 100 g−1) and iron (1512.55–1346.05 mg 100 g−1). Tryptophan and lysine were recorded as the limiting essential amino acids (EAAs) in NEM G. manilaensis, while leucine and phenylalanine were found to be the limiting EAAs in the SWM samples. None of the extracts exhibited antibacterial properties against the screened strains. The study concluded that seasonal changes have a great effect on the biochemical composition of G. manilaensis.

Soft corals are widely distributed across the globe, especially in the Indo-Pacific region, with Sarcophyton being one of the most abundant genera. To date, there have been 50 species of identified Sarcophyton. These soft corals host a diverse range of marine fungi, which produce chemically diverse, bioactive secondary metabolites as part of their symbiotic nature with the soft coral hosts. The most prolific groups of compounds are terpenoids and indole alkaloids. Annually, there are more bio-active compounds being isolated and characterised. Thus, the importance of the metabolite compilation is very much important for future reference. This paper compiles the diversity of Sarcophyton species and metabolites produced by their associated marine fungi, as well as the bioactivity of these identified compounds. A total of 88 metabolites of structural diversity are highlighted, indicating the huge potential these symbiotic relationships hold for future research.

Red algae genus Laurencia is an interesting alga with the ability to produce halogenated secondary metabolites that exhibits ecological and pharmaceutical potential. In nature, Laurencia is selectively grazed by sea hares (Aplysia dactylomela). In this study, Laurencia populations in three islands (Mantanani, Sulug, and Dinawan Islands) in the coastal waters of North Borneo were investigated and their chemical relationship with sea hare determined. Four species of Laurencia were found to grow abundantly in these waters, Laurencia snackeyi, Laurencia majuscula, Laurencia nangii, and Laurencia similis. Sea hares, Aplysia dactylomela, found grazing on Laurencia were collected and their chemical composition determined. A total of 20 halogenated metabolites were isolated and identified via spectroscopic data. Isolated compounds could be grouped into syndrean (5), chamigrane (6), non-chamigrane sesquiterpene (3), cuparane (1), bromoindole (2), and C15 acetogenin (acetylene type) (3). Sea hares from Mantanani, Sulug, and Dinawan Islands contained a total of 9, 10, and 10 compounds, respectively. In addition, 12-acetoxypalisadin B (1), which was isolated from sea hares of Sulug Island is a first record of its existence in nature.

A new manoalide-related sesterterpene, (4E,6E)-dehydro-25-O-methylmanoalide (1), was isolated from the organic extracts of the Bornean marine sponge Luffariella variabilis, together with the known compound (4E,6E)-dehydromanoalide (2). The structure of compound 1 was elucidated by interpretation of its spectroscopic data.

A new briarane-type diterpenoid, named 2-acetoxyverecynarmin C, was isolated from the methanolic extract of an octocoral, Pennatula aculeata, that exhibited cyclooxygenase (COX) inhibitory activity. The structure of the compound was elucidated by ESI-HRMS, 1D and 2D NMR spectroscopy and comparison of the measured spectral data with those reported in the literature. The relative stereochemistry at chiral carbons was established from 2D NOESY experiments. 2-Acetoxyverecynarmin C is a tricyclic compound containing a furan ring at C-7,8 of a briarane skeleton. 2-Acetoxyverecynarmin C showed moderate inhibitory activity in in vitro COX-1 and COX-2 assays.

A new manoalide-related sesterterpene, (4 E,6 E)-dehydro-25- O-methylmanoalide (1), was isolated from the organic extracts of the Bornean marine sponge Luffariella variabilis, together with the known compound (4 E,6 E)-dehydromanoalide (2). The structure of compound 1 was elucidated by interpretation of its spectroscopic data.

A new briarane-type diterpenoid, named 2-acetoxyverecynarmin C, was isolated from the methanolic extract of an octocoral, Pennatula aculeata, that exhibited cyclooxygenase (COX) inhibitory activity. The structure of the compound was elucidated by ESI-HRMS, 1D and 2D NMR spectroscopy and comparison of the measured spectral data with those reported in the literature. The relative stereochemistry at chiral carbons was established from 2D NOESY experiments. 2-Acetoxyverecynarmin C is a tricyclic compound containing a furan ring at C-7,8 of a briarane skeleton. 2-Acetoxyverecynarmin C showed moderate inhibitory activity in in vitro COX-1 and COX-2 assays.