GC-MS analysis and molecular docking of bioactive compounds of Camellia sinensis and Camellia assamica

Phytochemical characterization, anti-diarrhoeal, analgesic, anti-inflammatory activities and toxicity profile of Ananas comosus (L.) Merr (pineapple) leaf in albino rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ananas comosus (pineapple) leaf is used in ethnomedicine to treat diarrhoea, inflammation, pain, bacterial infections and oedema.

AIM OF THE STUDY

The aim of this study was to investigate the anti-diarrhoeal, anti-inflammatory and analgesic effects as well as the toxicity profile of the aqueous Ananas comosus leaf extract (AACLE) in rats.

METHODS

Methanol ACLE was subjected to gas chromatography-mass spectrometry (GC-MS) analysis. In the acute toxicity study, a single oral dose of up to 5000 mg/kg AACLE was administered. In the subacute toxicity study (28 days), rats in groups 2-4 received AACLE orally. The anti-diarrhoeal effect was studied using charcoal meal and castor oil-induced diarrhoea. Anti-inflammatory and analgesic tests were measured using egg albumin-induced paw oedema and acetic acid-induced writhing methods, respectively. For the subacute toxicity, anti-diarrhoeal, analgesic, and anti-inflammatory studies, AACLE was administered orally to rats at doses of 200, 400, and 600 mg/kg body weight.

RESULTS

Hexadecanoic acid methyl ester, 2-methoxy-4-vinylphenol, n-hexadecanoic acid and n-heptadecanol-1 were identified among other compounds with known pharmacological activities by GC-MS analysis. No deaths, behavioural changes, or signs of toxicity were observed in the acute toxicity study. Treatment with AACLE (28 days) decreased aspartate aminotransferase, alanine transaminase, total cholesterol, triglycerides, and low-density lipoprotein cholesterol, while high-density lipoprotein cholesterol, glutathione, and catalase increased when compared with control (P < 0.05). Treatment with AACLE did not cause significant changes in haematological or renal function parameters. Treatment with AACLE inhibited gastrointestinal motility and castor oil-induced diarrhoea in rats. Treatment with AACLE resulted in a dose-dependent (200-600 mg/kg) significant (P < 0.05) anti-diarrhoeal, analgesic, and anti-inflammatory effect compared to standard drugs.

CONCLUSION

Our study revealed that ACLE is not toxic but contains bioactive compounds with anti-diarrhoeal, anti-inflammatory, antimicrobial, and hepatoprotective activity. AACLE has antidiarrhoeal, analgesic and anti-inflammatory activity in rats, which justifies its therapeutic use in traditional medicine.

Epigenetic Induction of Secondary Metabolites Production in Endophytic Fungi Penicillium chrysogenum and GC-MS Analysis of Crude Metabolites with Anti-HIV-1 Activity

The continuous burden of human immunodeficiency virus-1 in Sub-Saharan Africa, coupled with the inability of antiretroviral agents to eradicate HIV-1 from viral reservoirs, the potential risks of drug resistance development, and the development of adverse effects, emphasizes the need to develop a new class of HIV-1 inhibitors. Here, we cultivated four endophytic fungal isolates from a medicinal plant, Albizia adianthifolia with the addition of small epigenetic modifiers, sodium butyrate, and valproic acid, to induce the expression of biosynthetic gene clusters encoding active secondary metabolites with probable anti-HIV activities. We identified a non-toxic crude extract of the endophytic fungus Penicillium chrysogenum treated with sodium butyrate to possess significantly greater anti-HIV activity than the untreated extracts. Penicillium chrysogenum P03MB2 showed anti-HIV activity with an IC₅₀ of 0.6024 µg/mL compared to untreated fungal crude extract (IC₅₀ 5.053 µg/mL) when treated with sodium butyrate. The profile of secondary metabolite compounds from the bioactive, partially purified extracts were identified by gas chromatography-mass spectrometry (GC-MS), and more bioactive compounds were detected in treated P. chrysogenum P03MB2 fractions than in untreated fractions. Pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro (13.64%), cyclotrisiloxane, hexamethyl (8.18%), cyclotetrasiloxane, octamethyl (7.23%), cyclopentasiloxane, decamethyl (6.36%), quinoline, 1,2-dihydro-2,24-trimethyl (5.45%), propanenitrile (4.55%), deca-6,9-diene (4.55%), dibutyl phthalate (4.55%), and silane[1,1-dimethyl-2-propenyl)oxy]dimethyl (2.73%) were the most abundant compounds. These results indicate that treatment of endophytic fungi with small epigenetic modifiers enhances the secretion of secondary metabolites with stronger anti-HIV-1 properties, acknowledging the feasibility of epigenetic modification as an innovative approach for the discovery of cryptic fungal metabolites which can be developed into therapeutic compounds.

Secondary metabolites produced by endophytic fungi, Alternaria alternata, as potential inhibitors of the human immunodeficiency virus

Antiretroviral treatment has significantly reduced human immunodeficiency virus infection and mortality. However, the current treatment regimen is limited by adverse side effects, the emergence of drug resistance, and the inability to eliminate viral reservoirs. Here, fifteen endophytic fungi were isolated from Sclerocarya birrea and Hypoxis plants. Crude extracts of Alternaria alternata (strain ID PO4PR1, PO4PR2, and PO2PL1) of the fifteen isolate's crude extracts showed anti-HIV-1 activity in TZM-bl cell line at inhibitory concentration (IC₅₀) values ranging from 0.017 to 1.170 μg/ml. The three crude extracts also maintained the virus replication inhibition profile on PBMCs and CD4⁺ T cells at concentrations ranging from 0.3 to 50.2 ng/ml. Partial purification using the solid phase extraction and analysis with Gas Chromatography-Mass spectrophotometry showed a diverse profile. The bioactive compounds were identified based on peak area, retention time, similarity index. The major compounds from GC-MS analysis of A. Alternata revealed the existence of cyclotrisiloxane octamethyl (22.92%); Propaninitrile (16,67%); Pyrrolol[1,2-a]pyrazine-1,4-dione, hexahydro-3-(2-methyl propyl) (10.42%); Silane, diethylethoxy(2-ethoxyethyloxy) (4.17%); Coumarin, 3,4-dihydro-4,5,7-trimethyl- 4,5,7-Trimethyl-2-chromanone (13.7%) and 1,2-Cyclobutanedicarbonitrile (2.08%) with previously reported biological activities such as antimicrobial, anti-inflammatory and antioxidant properties. Therefore, these bioactive compounds from A. alternata fungal endophytes could be repurposed as potential anti-HIV agents. This study showed the potential of endophytic fungi, Alternaria alternata from S. birrea, and Hypoxis species as producers of anti-HIV compounds.

Alteration of volatile compounds profile of brewers' spent grain by bath-ultrasonication and its combination with conventional water-bath and autoclave treatment

The study aimed to investigate the capability of bath-ultrasonication and its combination with conventional water-bath and autoclave treatment in modifying the volatile composition of brewers' spent grain (BSG). It was hypothesized that the treatments modified the volatile composition of BSG due to the sonochemical modification. The results demonstrated that the treatments intensified the desirable odor and removed the undesirable one which might allow the possibility of masking and renewing the odor perception of BSG. Besides the influence on odor perception related compounds, it is worth to highlight that the treatments eliminated herbicidal compounds such as (E,E)-2,4-heptadienal and (E)-2-hexenal which might be present from herbicidal treatment. Combination of bath-ultrasonication with autoclave treatment modified the volatile aldehydes while its combination with conventional water-bath generated the same profile as it was in untreated BSG. Time elevation on bath-ultrasonication had no significant impact on the amount of ketones and alkanes, while the fluctuation occurred as an impact of thermal exposures. Moreover, the treatment reduced the amount of alcohol and increased the fatty acids. In conclusion, bath-ultrasonication and its combination with thermal exposure modified the volatile compositions of BSG.

Variation in Volatile Compounds of Raw Pu-Erh Tea upon Steeping Process by Gas Chromatography-Ion Mobility Spectrometry and Characterization of the Aroma-Active Compounds in Tea Infusion Using Gas Chromatography-Olfactometry-Mass Spectrometry

Steeping process is an important factor for aroma release of tea, which has rarely been investigated for the aroma changes of raw Pu-erh tea (RAPT). In addition, the comprehensive aroma characteristics identification of RAPT infusion is necessary. In this study, GC-IMS coupled with principal component analysis (PCA) was used to clarify the difference of volatile profiles during the steeping process of RAPT. Furthermore, the volatiles contained in the RAPT infusion were extracted by three pretreatment methods (HS-SPME, SBSE, and SAFE) and identified using GC-O-MS. According to the odor activity value, 28 of 66 compounds were categorized as aroma-active compounds. Aroma recombination and omission experiments showed that "fatty", "green", "fruity", and "floral" are considered to be the main aroma attributes of RAPT infusion with a strong relationship with 1-octen-3-one, 1-octen-3-ol, (E)-2-octenal, β-ionone, linalool, etc. This study will contribute a better understanding of the mechanism of the RAPT steeping process and volatile generation.

Characterization of novel euryhaline microalgal cultures from Punjab, India for bioactive compounds

Microalgae have gained recognition due to the occurrence of nutraceuticals which are sustainable reservoir to substitute the organic chemical-based health supplements. The biomass of microalgae incorporates various functional biomolecules like chlorophyll, carotenoids and phenols that exhibit therapeutic properties and act as nutraceuticals. In spite of the higher production of the microalgal biomass, difference in their biochemical composition, and lack of characterization for nutraceutical properties are the prime hindrance in upscaling these bio-factories. Two euryhaline microalgal strains viz. BGLR8 and BGLR16, isolated from water-logged areas of Punjab, India were screened for biomass production and characterized for the nutraceutical properties using biochemical estimations. Results of the study indicated that BGLR8 retained maximum amount of lipids (86 mg/g), total chlorophyll (29.42 mg/g), carotenoids (28.82 mg/g), phenols (4.46 mg/g), phycocyanin (52 mg/g), astaxanthin (19.27 mg/g) and β-carotene (5.6 mg/g) and anti-oxidant activity (31.73%) as compared to BGLR 16. The results of gas chromatography-mass spectrometry (GC-MS) study revealed the presence of 8 therapeutic compounds like Dimethyl (E)-but-2-enedioate, Hexasilacyclododecane, Heptasilacyclotetradecane, Methyl (Z)-pentadec-8-enoate, Methyl octadec-13-enoate, Methyl hexadecanoate, Methyl octadecanoate, Methyl-octadeca-9,12-dienoate in BGLR8. Molecular identification through 18S rRNA gene sequencing confirmed BGLR8 to be a member of genus Coelastrella. (GenBank accession no. MW443083.1). Microalgae can be used as an alternate and feasible source of PUFAs; however, only a few species are employed for PUFA synthesis, necessitating additional in-depth research and the isolation of novel strains.

Antioxidant potential and molecular docking of bioactive compound of Camellia sinensis and Camellia assamica with cytochrome P450

Camellia sinensis and Camellia assamica are well known for their medicinal and therapeutic potential. The purpose of this work is to assess the flavonoid content and antioxidant potential of methanol extracts of C. sinensis (MES) and acetone extract of C. assamica (AEA) experimentally and computationally. Qualitative analysis was done to assess the presence of flavonoids. Further, the antioxidant potential of MES and AEA was done by ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)) and superoxide free radical-scavenging activity. The profiling of functional groups was analyzed by FT-IR analysis. The bioactive compounds n-heptadecanol-1 of MES and 2',6'-dihydroxyacetophenone, bis(trimethylsilyl) ether of AEA were procured from our previous study to analyze their antioxidant potential computationally (Auto-dock Vina). Both the extracts showed their potential to neutralize free radicals with variable potency. The study of the molecular interactions revealed that both the extracts MES and AEA interacted to the active site with higher binding energy. This work deduced that n-heptadecanol-1 and 2',6'-dihydroxyacetophenone, bis(trimethylsilyl) ether have good potential to inhibit and scavenge the free radicals.

Phylogenetic affiliation of endophytic actinobacteria associated with selected orchid species and their role in growth promotion and suppression of phytopathogens

Endophytic actinobacteria aid in plant development and disease resistance by boosting nutrient uptake or producing secondary metabolites. For the first time, we investigated the culturable endophytic actinobacteria associated with ten epiphytic orchid species of Assam, India. 51 morphologically distinct actinobacteria were recovered from surface sterilized roots and leaves of orchids and characterized based on different PGP and antifungal traits. According to the 16S rRNA gene sequence, these isolates were divided into six families and eight genera, where Streptomyces was most abundant (n=29, 56.86%), followed by Actinomadura, Nocardia, Nocardiopsis, Nocardioides, Pseudonocardia, Microbacterium, and Mycolicibacterium. Regarding PGP characteristics, 25 (49.01%) isolates demonstrated phosphate solubilization in the range of 61.1±4.4 - 289.7±11.9 µg/ml, whereas 27 (52.94%) isolates biosynthesized IAA in the range of 4.0 ± 0.08 - 43.8 ± 0.2 µg/ml, and 35 (68.62%) isolates generated ammonia in the range of 0.9 ± 0.1 - 5.9 ± 0.2 µmol/ml. These isolates also produced extracellular enzymes, viz. protease (43.13%), cellulase (23.52%), pectinase (21.56%), ACC deaminase (27.45%), and chitinase (37.25%). Out of 51 isolates, 27 (52.94%) showed antagonism against at least one test phytopathogen. In molecular screening, most isolates with antifungal and chitinase producing traits revealed the presence of 18 family chitinase genes. Two actinobacterial endophytes, Streptomyces sp. VCLA3 and Streptomyces sp. RVRA7 were ranked as the best strains based on PGP and antifungal activity on bonitur scale. GC-MS examination of ethyl acetate extract of these potent strains displayed antimicrobial compound phenol, 2,4-bis-(1,1-dimethylethyl) as the major metabolite along with other antifungal and plant growth beneficial bioactive chemicals. SEM analysis of fungal pathogen F. oxysporum (MTCC 4633) affected by Streptomyces sp. VCLA3 revealed significant destruction in the spore structure. An in vivo plant growth promotion experiment with VCLA3 and RVRA7 on chili plants exhibited statistically significant (p<0.05) improvements in all of the evaluated vegetative parameters compared to the control. Our research thus gives insight into the diversity, composition, and functional significance of endophytic actinobacteria associated with orchids. This research demonstrates that isolates with multiple plant development and broad-spectrum antifungal properties are beneficial for plant growth. They may provide a viable alternative to chemical fertilizers and pesticides and a sustainable solution for chemical inputs in agriculture.