Background and Objective: Muna local tomato (Solanum lycopersicum L.) is a valuable local genetic resource with potential as a functional food due to its bioactive compounds and antioxidant activity. However, the use of endophytic-rhizosphere bacterial consortia to improve the phytochemical quality and antioxidant capacity of local tomatoes remains limited. This study aimed to evaluate the effects of single isolates and consortia of endophytic-rhizosphere bacteria on the antioxidant activity and phytochemical profile of Muna local tomato fruits. Materials and Methods: The experiment was arranged in a randomized block design with eight treatments, consisting of a control, Pseudomonas sp. SWRII B02, Bacillus sp. CKD061, Pseudomonas sp. Ke03 and combinations of two and three bacterial isolates. Antioxidant activity was determined using the DPPH assay, while phytochemical profiling was performed using LC-MS/MS. Quantitative data, including DPPH inhibition and IC50 values, were analyzed by ANOVA followed by DMRT at α = 0.05. Results: All isolate combinations were compatible in vitro. Biological agent treatments enhanced antioxidant activity compared with the control. Bacillus sp. CKD061 exhibited the strongest antioxidant activity, with the lowest IC50 value of 41.15 ppm, while the consortium of Pseudomonas sp. SWRII B02 and Bacillus sp. CKD061 was the most effective bacterial combination, with an IC50 value of 47.14 ppm. The LC-MS/MS analysis revealed differences in phytochemical compounds among treatments. Fucosylthreonine, hupeheninoside and triacetoxypiperidinone were detected in all treatments. Solasodine glycoside was detected in the control and Bacillus sp. The CKD061 treatments, whereas tomatidine was detected only in the consortium of Pseudomonas sp. SWRII B02 and Bacillus sp. CKD061. After one week of storage, the metabolite profile changed, as indicated by the presence of N-fructosylvaline, N-succinyl-2-amino-6-oxo-L-pimelic acid, tetrodamine and epivolkenin. Conclusion: Bacillus sp. CKD061 and its consortium with Pseudomonas sp. SWRII B02 have potential as bioinoculants to improve the functional quality of Muna local tomato fruits.

Background and Objective: Improving fertilizer-use efficiency and soil water retention is essential for sustaining crop production under increasing water scarcity. This study aimed to valorize starch extracted from Thai purple yam (Dioscorea alata L.) into a biodegradable hydrogel-based nitrogen fertilizer with slow-release and water-retention functionalities. Materials and Methods: Yam starch hydrogels were synthesized through citric acid crosslinking and loaded with calcium nitrate to produce a starch-hydrogel slow-release fertilizer (SH-SRF). The swelling behavior, soil water-retention capacity, nitrate-release characteristics, biodegradability and plant-growth performance under water-deficit conditions were evaluated using lettuce and tomato as model crops. Results: The optimized hydrogel exhibited a swelling ratio of 5.94 g/g and significantly improved soil water retention, maintaining 9.87% residual moisture after 7 days compared with 0.44% in unamended soil. In a soil-column system, conventional Ca(NO3)2·4H2O released nearly all nitrate within 10 days, whereas SH-SRF extended nutrient release to 30 days, with cumulative NO3[-] release of 1.68%, 91.23% and 100% after 1, 20 and 30 days, respectively. The hydrogel showed partial biodegradability with 17.3% mass loss after 20 days. Under water-deficit conditions, SH-SRF markedly enhanced seedling performance. Lettuce treated with SH-SRF showed improved growth and biomass, whereas plants in the control and conventional fertilizer treatments failed to survive. A similar trend was observed in tomato, where SH-SRF produced superior growth compared with other treatments. Conclusion: These results demonstrate that Thai purple yam starch can be converted into a biodegradable hydrogel fertilizer that simultaneously regulates nutrient release and improves soil moisture retention, offering a sustainable strategy for crop production in water-limited agricultural systems.

Background and Objective: Microalgae represent an important biological resource with significant potential for applications in aquaculture, biotechnology and sustainable bioresource development. However, information regarding the genetic diversity of indigenous Vietnamese microalgal accessions remains limited. This study aimed to assess the genetic diversity and genetic relationships among 18 indigenous microalgal accessions using 15 RAPD and 15 ISSR molecular markers. Materials and Methods: Amplified loci were scored as binary data and analyzed using Jaccard similarity coefficients. We inferred genetic relationships through UPGMA clustering and principal coordinate analysis (PCoA). The consistency among marker systems was evaluated using Mantel tests and cophenetic correlation coefficients (CCC). Results: RAPD and ISSR markers generated 140 and 188 loci, respectively, with high polymorphism levels of 87.86 and 91.49%. The combined RAPD-ISSR dataset revealed substantial genetic variation among the analyzed accessions, with Jaccard similarity coefficients ranging from 0.263 to 0.938. The UPGMA analysis separated the 18 accessions into three genetic groups, while PCoA produced a congruent distribution pattern. The LC11 and G6 exhibited pronounced genetic divergence from the remaining accessions. Mantel tests revealed strong correlations among RAPD, ISSR and combined datasets (r = 0.865-0.971, p = 0.001). High CCC values (0.963-0.978) further confirmed the reliability of the inferred genetic relationships. Conclusion: The studied microalgal collection possesses substantial genetic diversity and includes highly differentiated genetic lineages. The combined RAPD-ISSR approach provides a reliable framework for genetic characterization and offers valuable information for germplasm conservation, accession selection and future biotechnological exploitation of indigenous microalgae.

Background and Objective: The stem of Arcangelisia flava Merr., a medicinal plant from Southeast Sulawesi, has shown potential as a natural source of antidiabetic agents, but its activity requires further validation through in vitro and in vivo approaches. This study aimed to evaluate the antidiabetic activity of the stem extract and fractions of A. flava using in vitro and in vivo approaches. Materials and Methods: The in vitro assay was performed using a colorimetric α-glucosidase inhibition method with p-nitrophenyl-D-glucopyranoside (pNPG) as the substrate. The in vivo study was conducted using streptozotocin/nicotinamide-induced diabetic mice divided into 15 groups (n = 4), including normal control, negative control, positive control, ethanol extract groups, n-hexane fraction groups, ethyl acetate fraction groups and butanol fraction groups. The extract was administered at doses of 250, 500 and 750 mg/kg bw, while each fraction was administered at doses of 28, 56 and 112 mg/kg bw. Data was analyzed using two-way repeated measures ANOVA. Result: The extract and fractions of A. flava stem exhibited α-glucosidase inhibitory activity and reduced fasting blood glucose levels in diabetic mice. Among the samples, the ethyl acetate fraction showed the strongest in vitro activity, with an IC50 value of 95.35 μg/mL. In vivo evaluation also showed that the ethyl acetate fraction at 112 mg/kg bw produced the highest reduction in fasting blood glucose levels. The effects of the ethanol extract and ethyl acetate fractions at 56 and 112 mg/kg bw were comparable statistically (p>0.05) to glibenclamide. Conclusion: These findings suggest that Southeast Sulawesi yellow wood has promising antidiabetic potential and warrants further investigation for active compound identification and mechanism elucidation.

Background and Objective: Marine algal endophytes remain a highly promising yet underexplored frontier for discovering unique bioactive scaffolds. This study aimed to isolate endophytic actinomycetes from the tissues of the green macroalga Caulerpa lentillifera in Phetchaburi Province, Thailand and evaluate their antibacterial and selective anticancer properties. Materials and Methods: Actinomycetes were isolated from surface-sterilized C. lentillifera tissues using humic acid-vitamins agar. The most antagonistic strain, ARR153, was identified via morphological and 16S rDNA phylogenetic analysis. Following large-scale cultivation on ISP-2 agar, the secondary metabolites were extracted using ethyl acetate and purified via column and thin-layer chromatography. Purified compounds were evaluated using MIC microdilution assays, in vitro MTT cytotoxicity tests against human cancer lines (HeLa, HepG2, MDA-MB-231) and normal Vero cells and in silico molecular docking/ADMET simulations targeting the EGFR kinase domain. Results: Isolate ARR153 was identified as Streptomyces sanyensis. Chromatographic purification yielded four L-cyclic dipeptides (diketopiperazines): Cyclo-(L-Leu-L-Val), Cyclo-(L-Leu-L-Thr), Cyclo-(L-Leu-L-Ile) and Cyclo-(L-Leu-L-Leu). These molecules exhibited broad-spectrum bactericidal activity against Gram-positive pathogens, including clinical MRSA (MICs: 16-128 μg/mL). In cytotoxicity assays, the dipeptides induced strong, dose-dependent growth inhibition against MDA-MB-231 and HeLa cells, while showing no toxicity toward normal Vero cells (IC50>400 μg/mL). Notably, Cyclo-(L-Leu-L-Leu) demonstrated a higher selectivity index for breast cancer cells than doxorubicin. In silico modeling confirmed that the compounds effectively bind the EGFR active site via essential hydrogen bonds at residue Thr830 with favorable predictive pharmacokinetic profiles. Conclusion: This study demonstrates that C. lentillifera-associated S. sanyensis ARR153 is a valuable source of bioactive L-cyclic dipeptides. These natural products offer potent structural platforms for the design of targeted biopharmaceuticals to counter multidrug-resistant bacterial infections and specific human cancers.

Background and Objective: Early-onset neonatal sepsis (EONS) is a major cause of neonatal morbidity and mortality globally, yet its early diagnosis remains challenging due to the limited availability of rapid, reliable biomarkers at the time of birth. This study aimed to analyze procalcitonin (PCT) and Interleukin-18 (IL-18) levels measured from umbilical cord blood as early diagnostic biomarkers for EONS. Materials and Methods: An observational case-control study was conducted on 66 neonates born with at least one EONS risk factor at four hospitals in Riau Province, Indonesia. Subjects were classified into an EONS group (n = 33) and a non-EONS group (n = 33). Umbilical cord blood PCT and IL-18 were measured using an enzyme-linked immunosorbent assay. Normality was assessed using the Shapiro-Wilk test. Between-group differences were analyzed using the Mann-Whitney U test (α = 0.05). Results: The PCT levels in umbilical cord blood were significantly higher in the EONS group compared to the non-EONS group [median 322.77 (range: 66.70-2599.57) pg/mL vs. 45.9 (4.90-321.97) pg/mL; p<0.001]. The IL-18 levels were similarly elevated [median 564.00 (216.40-1979.00) pg/mL vs. 107.60 (-19.60-773.38) pg/mL; p<0.001]. Maternal fever history was significantly more frequent in the EONS group (36.4% vs. 6.1%; p = 0.005), as was colored amniotic fluid (93.9% vs. 45.5%; p<0.001). Conclusion: Umbilical cord blood PCT and IL-18 levels are significantly elevated in neonates with EONS and may serve as early diagnostic biomarkers for EONS when measured at the time of birth. Their combined use may improve early risk stratification and clinical decision-making in at-risk neonates.

Background and Objective: Fagraea fragrans Roxb. is a medicinal plant traditionally used in herbal medicine; however, information regarding the phytochemical composition and antibacterial activity of its flower extract against antibiotic-resistant bacteria remains limited. This study aimed to investigate the phytochemical constituents, antioxidant capacity and antibacterial activity of F. fragrans Roxb. flower ethanol extract against selected antibiotic-resistant bacterial strains. Materials and Methods: Qualitative phytochemical screening was performed to identify major bioactive compounds in the ethanol extract. Antioxidant activity was assessed using the DPPH radical scavenging assay, while antibacterial activity against clinically important antibiotic-resistant bacteria was evaluated by agar disc diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. Data (mean±SD, n = 3) were analyzed by one-way ANOVA with Duncan's test using SPSS v20 (p<0.05). Results: Phytochemical analysis revealed the presence of phenolics, flavonoids, alkaloids and terpenoids in the ethanol extract. The extract demonstrated considerable antioxidant activity with strong DPPH radical scavenging capacity. Antibacterial assays showed inhibitory activity against Acinetobacter baumannii, Burkholderia pseudomallei, carbapenem-resistant Enterobacteriaceae (CRE), multidrug-resistant Klebsiella pneumoniae (MDR-K) and Proteus mirabilis, with inhibition zone diameters ranging from 7 to 11 mm. The lowest MIC value was observed against A. baumannii (1.95 mg/mL), while the lowest MBC value was detected against B. pseudomallei (31.25 mg/mL). No detectable antibacterial activity was observed against Enterococcus faecalis and colistin-resistant Pseudomonas aeruginosa. Conclusion: The new findings demonstrated that F. fragrans Roxb. flower extract possesses promising phytochemical constituents with antioxidant and antibacterial properties. The extract may serve as a potential natural source of bioactive compounds for herbal medicine and future antimicrobial applications against antibiotic-resistant bacteria.

Background and Objective: Silybum marianum (milk thistle) is a valuable medicinal plant that produces silymarin, a complex of flavonolignans with well-documented hepatoprotective, antioxidant and anti-inflammatory properties. However, silymarin production from field-grown plants is limited by low yield, environmental variability and inconsistent metabolite accumulation. This study aimed to evaluate the effects of biotic and abiotic elicitors on biomass growth, silymarin biosynthesis and the expression of key biosynthetic genes in S. marianum callus cultures. Materials and Methods: Callus cultures were established from sterile explants and treated with biotic elicitors (yeast extract and chitosan) and abiotic elicitors (methyl jasmonate and silver nanoparticles) at different concentrations under optimized in vitro conditions. Biomass accumulation, total flavonolignan content and the expression of the phenylpropanoid pathway genes PAL, CHS and TAT were analyzed. High-Performance Liquid Chromatography (HPLC) was employed to quantify the major silymarin constituents, including silybin A, silybin B, silychristin, silydianin and isosilybin. Results: Elicitor treatments significantly enhanced silymarin biosynthesis compared with the untreated control. The combined treatment of methyl jasmonate (100 μM) and chitosan (50 mg/L) produced the highest response, resulting in a 10.4-fold increase in total silymarin content (14.08 mg/g DW) and an 18.42-fold upregulation of CHS expression. The HPLC analysis confirmed increased accumulation of the major silymarin flavonolignans, demonstrating a synergistic effect of combined biotic and abiotic elicitation on secondary metabolite production. Conclusion: Combined biotic and abiotic elicitation effectively enhanced silymarin biosynthesis in S. marianum callus cultures, with increased expression of selected phenylpropanoid-associated genes and higher flavonolignan accumulation. The findings support combined elicitation as a promising controlled in vitro approach, but validation at larger culture scales and across broader molecular targets is required before industrial application.

&lt;b&gt;Background and Objective:&lt;/b&gt; Chenopodium quinoa Willd. is a strategic crop for food security in salt-affected regions; however, genotype-specific physiological responses to salinity during early germination remain insufficiently characterized. Understanding variation among geographically distinct accessions is essential for identifying salt-tolerant genotypes. This study aimed to evaluate germination performance and antioxidant defense responses of three quinoa accessions of contrasting geographic origins under salinity stress. &lt;b&gt;Materials and Methods:&lt;/b&gt; Three quinoa accessions 18GR (Ames 13724, USA), R-132 (PI 478418, Bolivia) and DE-1 (PI 674266, Ecuador) obtained from the USDA National Plant Germplasm System were evaluated under four NaCl concentrations (0, 100, 200 and 300 mM) under controlled laboratory conditions. Germination percentage, mean germination time (MGT), radicle length and germination kinetics were recorded. Reversibility assays were conducted to differentiate osmotic and ionic effects of salinity. Oxidative stress markers, including Hydrogen Peroxide (H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt;) and malondialdehyde (MDA), were quantified along with antioxidant enzyme activities such as peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX). Proline accumulation was also assessed as an indicator of osmotic adjustment. &lt;b&gt;Results:&lt;/b&gt; Salinity significantly affected germination traits in an accession-dependent manner. At 300 mM NaCl, germination rates were 90, 60 and 33.33% for 18GR, R-132 and DE-1, respectively. Reversibility assays indicated osmotic stress predominance at 200 mM, while ionic toxicity dominated at higher concentrations. NaCl stress increased H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; and MDA accumulation in all accessions. POD activity increased consistently across treatments. CAT and APX activities in 18GR showed a biphasic response, being stimulated up to 200 mM and inhibited at 300 mM, indicating stress threshold regulation. Proline accumulation increased with salinity, with 18GR showing the highest osmotic adjustment capacity. &lt;b&gt;Conclusion:&lt;/b&gt; Geographic origin significantly influences salt tolerance during germination in quinoa. Accession 18GR exhibited superior stress tolerance and antioxidant regulation, making it a promising candidate for saline agriculture. The contrasting biochemical responses provide a physiological basis for selecting salt-tolerant quinoa genotypes adapted to arid and semi-arid environments.

Background and Objective: Keratinases are gaining traction in green technology and the bio-economy due to their ability to convert keratinous biomass into valuable products, such as animal feed. However, improving their output remains challenging. This study investigated genetic engineering approaches to increase keratinase production. Materials and Methods: The genome of the keratinolytic bacterium, C. proteolyticum, was sequenced using the Ion GeneStudio[™] S5 Prime System, covering 2,484,843 reads, and sequence reads generated were assembled using SPAdes 3.13.0. The quality of the reads was assessed with QUAST V4.1, and the obtained sequences were annotated with Prokka 1.14.6, which revealed that trxA is associated with keratinolytic activity. The nucleotide sequence obtained was uploaded to the NCBI database and was assigned the accession number JBJLWK000000000. The trxA gene was amplified with primers from NCBI Primer-BLAST, cloned into a p-GEM[®]-T Easy vector, and transformed into E. coli JM109, and expressed using IPTG and SDS-PAGE analysis. The effects of pH and temperature on enzyme production were studied, and the recombinant strain's thermostability and tolerance to commercial laundry detergents were assessed. Results: The gene was successfully cloned and expressed, with SDS-PAGE showing a clear band at 11 kDa, matching trxA's molecular weight. The pGEM-trxA construct demonstrated high keratinase activity across various pH and temperature conditions. Additionally, the recombinant strain showed excellent thermostability and detergent tolerance. Conclusion: These findings highlight the potential of recombinant technology to boost keratinase yields and support the sustainable recycling of keratinous waste.

Background and Objective: The high cost and limited availability of commercial live feeds have encouraged the use of locally available Tubifex sp. as an alternative. This study evaluated the effects of enriching Tubifex sp. with different fish oil sources on the fatty acid profile, growth performance and survival of Thai mahseer (Tor tambroides) larvae. Materials and Methods: Tubifex sp. were enriched for 18 hrs with squid oil emulsion (TSO), sardinella fish oil (TLO), or striped catfish oil (TCO), while unenriched Tubifex sp. served as the control (TNC). Larvae were reared from 7 to 25 days post-hatch and fed ad libitum. Fatty acid composition was analyzed by gas chromatography and growth performance was assessed based on length growth, weight gain, condition factor and survival. Results: Enrichment significantly increased lipid, polyunsaturated fatty acid and n-3 fatty acid contents in Tubifex sp. (p<0.05), which were subsequently reflected in larval tissues. Larvae fed TCO-enriched Tubifex sp. exhibited significantly greater growth and higher condition factors than those in other treatments (p<0.05). Survival remained high (97-99%) and did not differ significantly among treatments (p>0.05). Conclusion: Striped catfish oil is a promising, cost-effective local lipid source for enriching Tubifex sp. to improve the culture performance of Thai mahseer larvae.

Background and Objective: Ovarian cancer is a highly lethal gynecologic malignancy, often diagnosed at advanced stages due to nonspecific symptoms. The IL-6/STAT3 pathway promotes tumor progression, chemoresistance and poor prognosis. Therefore, this study aimed to evaluate the histologic patterns of ovarian tumors based on the WHO 2020 classification and investigate the role of the IL-6/STAT3 pathway in ovarian cancer progression. Materials and Methods: A retrospective observational study was conducted using 2,309 ovarian biopsy specimens collected between 2016 and 2025 and classified according to the 2020 WHO Classification of Female Genital Tumours. Histopathological data were analyzed using descriptive statistics and the chi-square test (p<0.05). Bioinformatic analyses of TCGA gene expression data were performed using DESeq2 for differential expression analysis and Kaplan-Meier and Cox regression analyses to evaluate the prognostic significance of the IL-6/STAT3 signaling pathway. Results: Surface epithelial tumors were the most common ovarian neoplasms (74.08%), followed by germ cell tumors (12.56%). Mucinous ovarian tumors were the predominant epithelial subtype. A significant association between age and malignancy was observed (p<0.001). STAT3 expression was significantly increased in the low-grade group (p = 0.022), while IL-6 expression was not statistically significant. Conclusion: Ovarian tumors showed diverse histopathological features and STAT3 dysregulation may contribute to ovarian carcinoma prognosis. Integrating histopathological and molecular analysis may improve diagnostic and prognostic assessment.

Background and Objective: Azithromycin is a widely used macrolide antibiotic with broad-spectrum antimicrobial activity; however, its clinical acceptability is limited by poor patient compliance due to its bitter taste. Additionally, the growing threat of antimicrobial resistance necessitates the development of novel derivatives with improved therapeutic performance. This study aimed to synthesize and evaluate novel azithromycin derivatives with dual potential for taste masking and enhanced antibacterial activity. Materials and Methods: Five novel azithromycin derivatives were synthesized by reacting azithromycin with different functional linkers, including N-acetyl benzenesulfonyl chloride, p-nitrobenzoyl chloride, p-toluenesulfonyl chloride, 3,5-dinitrobenzoyl chloride and p-nitrobenzenesulfonyl chloride. The synthesized compounds were characterized using Fourier-Transform Infrared Spectroscopy (FT-IR), nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). Prodrug properties were assessed through kinetic stability studies at physiological pH values (2.2, 5.5 and 7.4). Antibacterial activity was evaluated in-vitro using minimum inhibitory concentration (MIC) and Half-Maximal Inhibitory Concentration (IC50) assays against clinically relevant bacterial strains, including Escherichia coli, Pseudomonas aeruginosa, Streptococcus pneumoniae and Staphylococcus aureus. The bacterial strains used in this study were standard ATCC reference strains and were not derived from human or animal subjects. Therefore, ethical approval was not required. All experiments were conducted following standard microbiological laboratory practices. Results: All five azithromycin derivatives were successfully synthesized with satisfactory yields and confirmed structural characteristics. <strong>Compounds 2, 4 and 5</strong> demonstrated favorable prodrug behavior by undergoing pH-dependent hydrolysis and regenerating the parent drug, indicating promising taste-masking potential. Furthermore, <strong>compounds 1 and 3</strong> exhibited superior antibacterial activity against Pseudomonas aeruginosa compared to the parent azithromycin. Conclusion: The synthesized azithromycin derivatives demonstrated promising potential as next-generation therapeutic agents with improved palatability and retained or enhanced antimicrobial efficacy. These findings support their prospective application in overcoming taste-related compliance issues while addressing antimicrobial resistance challenges.

Background and Objective: The seagrass Enhalus acoroides is a marine plant species widely distributed in the waters of Southeast Sulawesi. It is considered a potential source of bioactive compounds with pharmaceutical relevance. This study aimed to characterize the chemical constituents of E. acoroides rhizomes and evaluate their antimicrobial and anti-inflammatory activities. Materials and Methods: Phytochemical profiling of the extract and ethyl acetate fraction was performed using Liquid Chromatography-Mass Spectrometry/Mass Spectrometry (LC-MS/MS). Antimicrobial activity was assessed using the microdilution method against Staphylococcus aureus, Escherichia coli, and Candida albicans. Anti-inflammatory activity was evaluated using a protein denaturation assay. The statistical analysis was conducted using SPSS, with a one-way ANOVA at a significance level of p<0.05 (95% CI). Results: LC-MS/MS analysis identified twelve compounds in the extract and ethyl acetate fraction, including hecogenone, periploca side N, blumenol C glucoside, α-D-glucopyranose-1-hexadecanoate, kushenol R, procyanidin A2, physalin L, Δ5-pregnene-3β,17α,20α-diol, verticiol, quercimeritrin, pterodontoside F, and vitamin K1. Fractions D and E exhibited strong antibacterial activity against S. aureus, with minimum inhibitory concentrations (MICs) of 2 and 1 μg/mL, respectively, and both showed activity against E. coli (MIC = 2 μg/mL). Fraction E also demonstrated antifungal activity against C. albicans (MIC = 4 μg/mL). In the anti-inflammatory assay, fraction E exhibited the highest activity, with an IC50 of 29.48 μg/mL. Conclusion: The findings indicate that E. acoroides rhizomes are a promising source of bioactive compounds with significant antimicrobial and anti-inflammatory potential.

Background and Objective: Avicennia marina is the dominant mangrove species along the Saudi Arabian coasts of the Red Sea and the Arabian Gulf, where extreme environmental conditions frequently result in dwarf growth forms. This study evaluated regional variation in mangrove growth form and the distribution of dwarf stands across contrasting coastal environments. Materials and Methods: Field surveys were conducted during the first half of 2026 at 121 sampling sites distributed across the Northern Red Sea (27), Central Red Sea (37), Southern Red Sea (20) and the Arabian Gulf (37). Tree height was measured to classify mangrove growth forms and regional differences were analyzed using one-way analysis of variance (ANOVA) followed by Tukey's honestly significant difference (HSD) test. Results: Tree height differed significantly among regions (p<0.001). The Northern Red Sea exhibited the lowest mean tree height (2.49±0.77 m) and the greatest prevalence of dwarf mangroves, whereas significantly taller trees were recorded in the Central Red Sea (3.67±1.22 m), Southern Red Sea (3.63±1.44 m) and the Arabian Gulf (3.68±1.31 m). These results demonstrate pronounced spatial variation in the structural development of A. marina along the Saudi Arabian coastline. Conclusion: Avicennia marina exhibits marked regional differences in growth form, with dwarf mangroves predominating in the Northern Red Sea. The findings establish a regional baseline for evaluating structural variability in A. marina and advance current understanding of mangrove dwarfism in arid coastal ecosystems.