Pakistan Journal of Biological Sciences最新文献

<b>Background and Objective:</b> Cellulose degradation is essential in biomass conversion, but limited access to efficient cellulase-producing microbes constrains industrial applications. Herbivorous insect guts are potential sources of novel cellulolytic bacteria. This study aimed to purify and characterize cellulase enzymes from bacteria isolated from the gut of <i>Oryctes rhinoceros</i>, to evaluate their potential for biotechnological use. <b>Materials and Methods:</b> Bacterial strains were isolated from the gut of <i>O. rhinoceros</i> and cultured in carboxymethyl cellulose (CMC) medium. Cellulase enzymes were purified using Sephadex G-100 gel filtration followed by Diethylaminoethyl (DEAE)-cellulose ion-exchange chromatography. Protein concentrations and enzyme activities were measured to calculate specific activities. The SDS-PAGE was used to determine the molecular weight. Enzymatic activity was assessed under different pH, temperature and metal ion conditions. <b>Results:</b> Two strains, <i>Bacillus tequilensis</i> B01L and <i>Bacillus cereus</i> B19L, were identified as potent cellulase producers. The cellulase from B01L was purified 11.46-fold (specific activity: 8.529 U/mg), while the enzyme from B19L showed a 12.28-fold increase (specific activity: 9.221 U/mg). Both enzymes had a molecular weight of approximately 52.23 kDa. Optimal activity occurred at pH 6.0, with temperature of 50°C for B01L and 60°C for B19L. Enzyme activity was unaffected by Ca²⁺ and Mg²⁺, but inhibited by 35-40% in the presence of K⁺ and Fe²⁺. <b>Conclusion:</b> The gut of <i>O. rhinoceros</i> harbors cellulolytic bacteria with significant enzymatic potential. These findings highlight a promising source of industrially relevant cellulases. Further studies are warranted to optimize production conditions and evaluate their application in biomass degradation.

<i>Terminalia spinosa</i> Engl. is a shrub or small tree widely used as a source of traditional medicines in tropical Africa. This study was aimed at reviewing the medicinal uses, phytochemical and pharmacological properties of <i>T. spinosa</i>. A search for available information on the medicinal uses, phytochemical and pharmacological properties of <i>T. spinosa </i>was conducted by searching the electronic databases which included SciELO, ScienceDirect^®, Web of Science, PubMed^®, SpringerLink^®, Scopus^® and Google Scholar, as well as pre-electronic literature sources such as books, book chapters and other scientific publications obtained from the university library. This research revealed that the bark, fibres, leaves, roots or stem bark of <i>T. spinosa</i> are used as traditional medicines for wounds, fever, jaundice, malaria, sore throat and stomach ailments. The phytochemical evaluation of the plant species revealed that it contains flavonoids, fatty acids, anthocyanins, coumarins, ellagic acid, polyphenols, anthraquinone, tannins, polysaccharides, steroids and triterpenoids. The pharmacological evaluations showed that the crude extracts of <i>T. spinosa</i> have antibacterial, anti-Neisseria gonorrhoeae, antimycobacterial, antifungal, antiplasmodial and antiproliferative activities. To realize the full potential of <i>T. spinosa</i> as traditional medicine, future studies should focus on conducting detailed phytochemical, pharmacological and toxicological evaluations, <i>in vivo</i> and clinical research.

<b>Background and Objective:</b> <i>Diaphorina citri </i>is the primary vector of <i>Candidatus Liberibacter asiaticus </i>(<i>CLas</i>), the bacterial pathogen responsible for Huanglongbing (HLB) disease in citrus. This psyllid also harbors endosymbionts such as <i>Wolbachia</i>, which may competitively interact with <i>CLas </i>within the insect's body. This study aimed to evaluate the effect of doxycycline treatment on the titers of <i>Wolbachia </i>and <i>CLas </i>in <i>D. citri.</i> <b>Materials and Methods:</b> This study analyzes the quantitative relationship between these microorganisms. Four treatment groups were used: Control, 2.5, 5 and 10 mg/mL doxycycline. Absolute quantification was performed using qPCR targeting the <i>wsp </i>and <i>CLas </i>genes. These results reflect the effect of doxycycline antibiotic treatment up to a concentration of 10 mg/mL; therefore, interpretation is limited to this concentration range. Doxycycline effects on <i>Wolbachia</i> and <i>CLas </i>abundance were analyzed using ANOVA or Kruskal-Wallis tests, with pairwise t-tests in RStudio at α<0.05. <b>Results:</b> It showed that doxycycline concentrations did not significantly affect the titers of either bacterium based on Kruskal-Wallis tests (p>0.05). Nevertheless, biological trends were observed: <i>Wolbachia</i> titers increased with higher antibiotic concentrations, while <i>CLas </i>titers decreased. A polynomial non-linear regression model revealed a downward-opening parabolic relationship between <i>Wolbachia</i> and <i>CLas </i>titers, with the equation y = -0.0407x²+4,6881x-70,116 and R² = 0.8303, indicating that approximately 83% of the variation in <i>CLas </i>titers could be explained by <i>Wolbachia</i> abundance. <b>Conclusion:</b> These findings support the hypothesis that <i>Wolbachia</i> may suppress <i>CLas </i>proliferation through intracellular competition or microbiota modulation. This study provides a foundational insight into the potential of symbiont-based management strategies for HLB vector control.

<b>Background and Objective:</b> Carvacrol, a naturally occurring phenolic monoterpenoid compound found in various essential oils, exhibits outstanding pharmacological characteristics, essentially anticancer, antiproliferative and pro-apoptotic effects. This study evaluates the therapeutic potential of carvacrol as a topical agent in preventing and treating DMBA-induced oral cancer in rats through <i>in vivo</i> assessment of its anticancer efficacy and histopathological effects. <b>Materials and Methods:</b> This study was designed to investigate the chemopreventive and therapeutic potential of topically applied carvacrol in a rat model of Oral Squamous Cell Carcinoma (OSCC) induced by 7,12-dimethylbenz[a]anthracene (DMBA). The expression of Proliferating Cell Nuclear Antigen (PCNA) and B-cell lymphoma/leukemia-2 (Bcl-2), markers of proliferation and apoptosis, respectively, was estimated by immunohistochemical staining. Data were analyzed using one-way ANOVA with Tukey's <i>post hoc</i> test and Pearson's correlation, following normality confirmation (p>0.05), with results summarized using descriptive statistics. <b>Results:</b> Noteworthy declines in both PCNA and Bcl-2 expression were noticed in groups treated with carvacrol, either concurrently with DMBA or following its application. The group receiving carvacrol alternately with DMBA showed the most noticeable suppression in both markers. <b>Conclusion:</b> These results highlight carvacrol's dual character in quashing carcinogenesis and stimulating apoptotic cell death, supporting its potential as a safe, natural therapeutic agent for OSCC intervention.

<b>Background and Objective:</b> The persistent global threats of antimicrobial resistance and cancer necessitate the discovery of novel chemical entities, a search where actinomycetes from unique environments are critical. To discover new therapeutics, this study investigated actinomycetes from the <i>Apis florea</i> beehive environment, aiming to identify a promising strain and structurally characterize its antibacterial and anticancer metabolites. <b>Materials and Methods:</b> Actinomycetes were isolated from five <i>Apis florea</i> beehives. Strain identification was performed using morphological, chemotaxonomic and dual-gene sequencing (16S rRNA and <i>gyr</i>B). Metabolites were purified and biological activity was assessed using MIC/MBC (antibacterial) and MTT cytotoxicity assays. The mechanism was explored via molecular docking against Topoisomerase II, complemented by ADMET prediction. <b>Results:</b> The most active isolate, BH111, was identified as <i>Streptomyces kunmingensis</i>. It produced two anthraquinone derivatives: Resistomycin (Compound <b>1</b>) and tetracenomycin D (Compound <b>2</b>). These compounds demonstrated selective, potent antibacterial activity against Gram-positive strains (MIC and MBC values ranged from 16 to 32 and 128 to 256 μg/mL, respectively) and significant cytotoxicity against tested cancer lines (IC₅₀ values ranged from 10.72 to 27.57 μg/mL). Docking results supported Topoisomerase II inhibition. However, low selectivity indices and ADMET flags (CYP450, hepatotoxicity) were noted. <b>Conclusion:</b> <i>Streptomyces kunmingensis</i> BH111 is the first strain of this species reported to produce resistomycin and tetracenomycin D from a beehive source. While these anthraquinone derivatives are promising drug scaffolds due to their potent antibacterial and topoisomerase-inhibiting anticancer activities, significant therapeutic optimization is required to enhance selectivity and mitigate predicted toxicological risks.

<b>Background and Objective:</b> The rising global challenge of drug resistance and cancer demands the discovery of novel therapeutic agents. Endophytic microorganisms, particularly those from medicinal plants like <i>Ocimum basilicum</i>, represent a promising, yet underexplored, source of natural products. This study aimed to isolate and screen bioactive endophytic actinomycetes from <i>O. basilicum</i> roots. The research focused on characterizing the most active isolate, purifying its secondary metabolites and evaluating their antibacterial and anticancer properties. <b>Materials and Methods:</b> The potent strain SB03 was isolated from basil roots and identified as <i>Streptomyces griseoincarnatus</i> using 16S rDNA sequencing. Two compounds were purified from its crude extract and structurally characterized by spectroscopy. Their bioactivities were assessed by determining MIC/MBC against pathogenic bacteria (including MRSA) and IC₅₀ against human cancer cells (HeLa, HepG2 and MDA-MB-231). Molecular docking investigated their interaction with topoisomerase II, complemented by <i>in silico</i> ADMET analysis. <b>Results:</b> A potent actinomycete strain, <i>S. griseoincarnatus</i> SB03, was successfully isolated from sweet basil roots. Two known anthraquinone compounds, 2-butyryl-1,8-dihydroxy-3-methyl-anthraquinone (Compound <b>1</b>) and 2-butyryl-1,4,8-trihydroxy-3-methyl-anthraquinone (Compound <b>2</b>), were isolated from the culture extract. Both exhibited strong antibacterial activity (MIC 64-128 μg/mL against Gram-positive strains) and significant cytotoxicity (IC₅₀ 35.01-97.68 μg/mL) against all tested cancer lines. Importantly, they showed a higher selectivity index against the HepG2 line than the control, doxorubicin. Docking studies indicated favorable binding to topoisomerase II. <b>Conclusion:</b> <i>Streptomyces griseoincarnatus</i> SB03 from sweet basil is a promising source of therapeutic agents. Its anthraquinone metabolites possess valuable dual antibacterial and selective anticancer properties. These compounds are excellent lead candidates for future drug development against infectious diseases and hepatocellular carcinoma.

<b>Background and Objective:</b> Diabetic cardiomyopathy (DCM) is a serious complication of type 2 diabetes, characterized by metabolic imbalance, oxidative stress, inflammation and apoptosis, leading to impaired cardiac function. Despite available treatments, safer and more effective natural alternatives remain underexplored. This study investigated the active composition of <i>Stevia rebaudiana</i> leaf extract (SLE) and evaluated its prophylactic effects against diabetic cardiomyopathy in an experimental rat model. <b>Materials and Methods:</b> Twenty-four male rats were randomly divided into four groups: Control, SLE-treated (400 mg/kg Stevia glycosides for 30 days), STZ-induced diabetic (110 mg/kg Nicotinamide followed by 60 mg/kg Streptozotocin) and SLE+STZ co-treated. Biochemical assays were performed to assess glucose metabolism, insulin sensitivity, serum electrolytes, protein and cardiac enzymes (LDH, CK-MB). Oxidative stress markers, antioxidant levels, inflammatory cytokines, apoptotic markers and cardiac histopathology were evaluated. Data were analyzed using One-way ANOVA followed by <i>post hoc</i> tests, with p<0.05 considered significant. <b>Results:</b> The SLE significantly reduced serum glucose and insulin resistance while improving QUICKI and regulating electrolytes, total protein, LDH and CK-MB compared to diabetic rats. It restored redox balance by lowering PCO, NO and MDA, while enhancing SOD, CAT, GSH and TAC. Inflammatory cytokines (TNF-α, IL-6, IL-1β, VCAM-1 and ICAM-1) and apoptotic markers (Bax, P53, Cytochrome C, Caspase-9 and Caspase-3) were markedly downregulated, whereas anti-apoptotic Bcl-2 was upregulated. Histological analysis confirmed preserved cardiac structure, reduced fibrosis and diminished DNA fragmentation, further supported by decreased PARP levels. <b>Conclusion:</b> <i>Stevia</i> <i>rebaudiana</i> leaf extract exerts potent cardioprotective effects in diabetic rats by improving metabolic indices, attenuating oxidative stress, inflammation and apoptosis and preserving cardiac architecture. These findings highlight its therapeutic potential as a natural prophylactic agent against diabetic cardiomyopathy, warranting further clinical validation.

<b>Background and Objective:</b> Endophytic actinomycetes associated with medicinal plants constitute a valuable yet underinvestigated source of bioactive secondary metabolites. <i>Tinospora cordifolia</i>, a widely respected ethnomedicinal plant, harbors diverse microbial endophytes with strong therapeutic potential. This study aimed to isolate and characterize endophytic actinomycetes from <i>T. cordifolia</i>, identify their major metabolites and evaluate the antibacterial, anticancer and molecular inhibitory properties of the purified compounds. <b>Materials and Methods:</b> Actinomycetes were isolated from surface-sterilized root, stem and leaf tissues using selective media. The most potent isolate, TTCF1, was identified through morphological characteristics, chemotaxonomic profiling and 16S rRNA gene sequencing. Bioactive metabolites were extracted and purified via column chromatography, followed by structural characterization using advanced spectroscopic techniques. Antibacterial activity was assessed by determining MIC and MBC values against human pathogens, including MRSA. Cytotoxicity was evaluated using the MTT assay on HeLa, HepG2 and MDA-MB-231 cancer cell lines, along with Vero cells as the non-cancerous control. Molecular docking was performed against EGFR, accompanied by ADMET property prediction. Statistical significance was determined using one-way ANOVA with Tukey's <i>post hoc</i> test (p<0.05). <b>Results:</b> Ten actinomycete isolates were obtained, all exclusively from root tissues. The strongest producer, TTCF1, showed 99.54% 16S rRNA similarity to <i>Streptomyces triticiradicis</i>. Chemical analysis yielded two diketopiperazines: Cyclo-(D-Pro-L-Tyr) and Cyclo-(D-Pro-L-Leu). Both compounds demonstrated potent antibacterial activity against Gram-positive pathogens (MIC 32-64 μg/mL) and cytotoxicity toward cancer cell lines (IC₅₀ 58.16-362.71 μg/mL). Compound 1 showed selective toxicity toward HepG2 cells and exhibited stronger predicted EGFR binding affinity (-7.188 kcal/mol) than the reference inhibitor AQ4 (-6.703 kcal/mol). The ADMET profiles indicated good oral absorption. <b>Conclusion:</b> <i>Streptomyces triticiradicis</i> TTCF1 is a promising source of pharmacologically relevant diketopiperazines. Cyclo-(D-Pro-L-Tyr) emerges as a potential lead molecule with notable antimicrobial and selective anticancer activity, supported by strong EGFR-binding predictions.

<b>Background and Objective:</b> Up to now, evidence remains inconclusive about how vitamin D (VD) status relates to the severity of COVID-19 among hospitalized patients. The present study aims to explore the impact of VD status on the severity of COVID-19 among hospitalized patients in Qatar and examine its effects on health factors related to the disease. <b>Materials and Methods:</b> A retrospective, cross-sectional, multicenter study was conducted at Hamad Medical Corporation in Qatar from March, 2020 to May, 2021. Demographics, laboratory values, comorbidities, clinical outcomes and some inflammatory markers were retrieved from the hospital's system. The severity of COVID-19 disease was determined by an elevated neutrophil-lymphocyte ratio (NLR). A patient with VD levels less than 20 ng/mL was considered deficient. Data were analyzed using SPSS v22, with significance set at p<0.05, employing Mann-Whitney, Chi-squared and correlation tests as appropriate. <b>Results:</b> The VD deficiency was common (68.6%), with longer ICU stays observed in deficient patients compared to those with normal VD status (19.7 vs. 11.2; p = 0.04). There was a trend of higher NLR with lower VD levels. No significant difference in interleukin-6 levels was found between the deficient and sufficient VD groups (60.6±64.1 vs. 41.2±45.2 pg/mL; p = 0.472). <b>Conclusion:</b> This study highlights the link between VD status and COVID-19 disease severity. The findings suggest that suboptimal levels of VD in COVID-19 patients may be potentially associated with increased length of stay in the ICU and have a minor impact on the pro-inflammatory state.

A comprehensive review of published information on ethnomedicinal uses, phytochemical and pharmacological properties of <i>Terminalia mollis</i> M.A. Lawson, a medium-sized to large deciduous tree, is presented. This study revealed that <i>T. mollis</i> is used as ethnoveterinary medicine and traditional medicine against sexually transmitted infections, respiratory infections, gastrointestinal problems, bilharzia, malaria, haemorrhoids, abdominal pains, measles, jaundice, cryptococcal meningitis and back pain. Phytochemical research identified flavonoids, polyphenols, ellagitannin, pentacyclic triterpenoids, trihydroxybenzoic acid, tannins, steroids, saponins, anthraquinones, cardiac glycosides and anthocyanins from leaves and root bark of <i>T. mollis</i>. Ethnopharmacological research revealed that the phytochemical compounds isolated from <i>T. mollis</i> and crude extracts of the species showed antibacterial, antimycobacterial, antimycoplasmal, antifungal, antiviral, anticonvulsant, antileishmanial, antioxidant, antiplasmodial, antitrypanosomal and cytotoxicity activities. Since <i>T. mollis</i> extracts are widely used as sources of traditional medicines, there is a need for extensive phytochemical, pharmacological, toxicological evaluations, <i>in vivo</i> and clinical studies.