Antibacterial and biofilm disruptive nonribosomal lipopeptides from Streptomyces parvulus against multidrug-resistant bacterial infections

BACKGROUND

In recent years, new drugs for the treatment of various diseases, thereby the emergence of antimicrobial resistance tremendously increased because of the increased consumption rate of various drugs. However, the irrational use of antibiotics increases the microbial resistance along with that the frequency of mortality associated with infections is higher. Broad-spectrum antibiotics were effectively against various bacteria and the unrestricted application of antibiotics lead to the emergence of drug resistance. The present study was aimed to detect the antibacterial properties of lipopeptide novel drug producing Streptomyces parvulus.

METHODS

A lipopeptide-producing S. parvulus was isolated from the soil sample. The inhibitory effect of lipopeptide was detected against Gram-positive and Gram-negative bacteria. Bactericidal activity and minimum inhibitory concentration (MIC) were assayed. The IC50 value was analysed against ovarian and human melanoma cell lines. The experimental mouse model was infected withKlebsiella pneumoniae and treated with lipopeptide and bactericidal activity was determined.

RESULTS

The results indicated that the antibacterial activity of lipopeptide ranges from 13 ± 1 mm to 32 ± 2 mm against Gram-positive and Gram-negative strains. The lowest MIC value was noted as 1.5 ± 0.1 µg/mL against K. pneumoniae and the highest against E. aerogenes (7.5 ± 0.2 µg/mL). The IC50 value was considerably high for the ovarian cell lines and human melanoma cell lines (426 µg/mL and 503 µg/mL). At 25 µg/mL concentration of lipopeptide, only 16.4% inhibition was observed in the ovarian cell line whereas 20.2% inhibition was achieved at this concentration in the human melanoma cell line. Lipopeptide inhibited bacterial growth and was completely inhibited at a concentration of 20 µg/mL. Lipopeptide reduced bacterial load in experimental mice compared to control (p < 0.05).

CONCLUSION

Lipopeptide activity and its non-toxic nature reveal that it may serve as a lead molecule in the development of a novel drug.

Molecular docking of monkeypox (mpox) virus proteinase with FDA approved lead molecules

BACKGROUND

Monkeypox virus (mpox) disease is caused by a double-stranded DNA virus from the Poxviridae family. The mpox virus showed structural similarity with smallpox virus disease. The recent outbreak of mpox infection in the rest of African countries causes public health issues of increased pandemic potential. Mpox virus is involved in the viral replication cycle through the biocatalytic reaction of precursor polyproteins cleavage.

OBJECTIVES

The main objective of the study was to analyze the molecular interactions between mpox and FDA-approved drugs.

METHODS

The primary and secondary structure of the protein was retrieved and FDA approved drug was screened using AutoDock. The best hit was analyzed and the molecular interactions were studied. Model validation analyzes the peptide, energy of hydrogen bonds, steric conflicts and bond planarity. Z-score was calculated using ProSA-web tool and the score tested the native fold from other alternative folds.

RESULTS

The confidence level of the submitted amino acids was> 80 % and the maximum confidence score for a single template was 98.2 %. The generated proteinase model was subjected to analyze the distribution of atoms and the using ERRAT server. The overall quality score was 88.535 and this value represents the amino acid percentage with anticipated error value and the value falling below the rejection limit. The Z-score of this study result was within the Z-score range (-4.17) validated for native enzymes. The binding pockets of the enzyme were determined in this study and two binding pockets were predicted using the automatic online tool using the web server. The selected FDA-approved drugs were ordered based on their minimum binding energy to the proteinase.

CONCLUSIONS

Molecular docking studies revealed the involvement of various hydrophobic interactions between FDA-approved drugs and amino acid residues of monkeypox virus proteinase.

Prevalence of genetic variants associated with cardiovascular disease risk and drug response in the Southern Indian population of Kerala

BACKGROUND AND AIM:

This study reports the prevalence of five clinically significant variants associated with increased risk of cardiovascular disorders, and variable responses of individuals to commonly prescribed cardiovascular drugs in a South Indian population from the state of Kerala.

MATERIALS AND METHODS:

Genomic DNA isolated from 100 out-patient samples from Kerala were sequenced to examine the frequency of clinically relevant polymorphisms in the genes MYBPC3 (cardiomyopathy), SLCO1B1 (statin-induced myopathy), CYP2C9, VKORC1 (response to warfarin) and CYP2C19 (response to clopidogrel).

RESULTS:

Our analyses revealed the frequency of a 25 bp deletion variant of MYBPC3 associated with risk of cardiomyopathy was 7%, and the SLCO1B1 “C” allele associated with risk for statin-induced myopathy was 15% in this sample group. Among the other variants associated with dose-induced toxicity of warfarin, VKORC1 (c.1639G>A), was detected at 22%, while CYP2C9*3 and CYP2C9*2 alleles were present at a frequency of 15% and 3% respectively. Significantly, the tested sample population showed high prevalence (66%) of CYP2C19*2 variant, which determines response to clopidogrel therapy.

CONCLUSIONS:

We have identified that certain variants associated with cardiovascular disease and related drug response in the five genes, especially those in VKORC1, CYP2C19 and MYBPC3, are highly prevalent in the Kerala population, with almost 2 times higher prevalence of CYP2C19*2 variant compared with other regions in the country. Since the variants chosen in this study have relevance in disease phenotype and/or drug response, and are detected at a higher frequency, this study is likely to encourage clinicians to perform genetic testing before prescribing therapy.

Chemopreventive effect and HPTLC fingerprinting analysis of Jasminum sambac (L.) Ait. Extract against DLA-induced lymphoma in experimental animals

The anticancer activity of the ethanolic extract of Jasminum sambac against Dalton's lymphoma ascites-induced lymphatic cancer in Swiss albino mice was investigated. The anticancer activity of J. sambac was studied against lymphoma using lipid profiles, biochemical parameters, and membrane-bound marker enzymes by standard procedures. A high-performance thin-layer chromatography fingerprinting analysis showed the presence of terpenoids and flavonoids. The levels of cholesterol, triglyceride, VLDL cholesterol, and LDL cholesterol were significantly decreased in tumor-induced mice, while HDL cholesterol showed increased levels compared with those profiles. On treatment with J. sambac, the levels were brought back to near normal. The albumin, creatinine, total protein, urea, and uric acid contents were also approaching normal values. There was s significant increase in the levels of ATPase in group II. These levels were brought back to normal upon plant extract treatment of mice. DNA fragmentation occurred in the tumor-induced group of tissue, and treatment with ethanolic extract reduced the DNA damage caused by lymphoma. Expression of lactate dehydrogenase (LDH) isoenzymes shows an increase in the levels of LDH-4 and LDH-5 in cancer-bearing animals which is brought back to near normal. Histopathological investigation showed normal sections of liver tissues in the treatment group. The results found in mice treated with ethanolic extract 100 mg kg(-1) body weight quite promising and were comparable with the standard drug 5-fluorouracil. The statistically processed results support the conclusion that the ethanolic extract of J. sambac flower (100 mg kg(-1)) possesses a dose-dependent significant anticancer activity against lymphoma.

Effect of Aqueous Extract of Passiflora edulis on Biochemical and Hematological Parameters of Wistar Albino Rats

Passiflora edulis is traditionally used in folk lore medicine for the treatment of various ailments. To validate its use in traditional medicine, it is important to evaluate its toxicity in the animal system. Therefore, this study aimed to evaluate the toxicological effects of oral administration of aqueous leaf extract of P. edulis in Wistar albino rats. Acute toxicity tests were conducted by the oral administration of 200, 500, 1000 and 2000 mg/kg body weight of the animal. In subacute study, they were administered with various doses of aqueous extract of P. edulis (100, 200, 300, and 400 mg/kg body weight) to evaluate its toxicity for a period of 7 days. The effect of aqueous extract of P. edulis on organ weight, hematological, renal, and hepatic markers were analyzed. In acute toxicity study, no mortality was seen with in 24 h of the administration of P. edulis extract. No signs of neurological and behavioral changes were noticed with in 72 h. In the subacute study, the extract intake has not changed the hematological parameters such as RBC, WBC, and platelets and it was also found that the plasma level of amino transferases, ALP, urea, uric acid and, creatinine were also not altered by the administration of P. edulis extract throughout the study. The weight of organ was found to be unaltered in all the doses selected. The acute toxicity study reveals that the oral administration of the extract was found to be safe up to the dose level of 2000 mg/kg. The subacute study indicates that the extract is safe on the bone marrow function and it is neither hepatotoxic nor nephrotoxic. This supports the safety use of the aqueous extract of P. edulis in pharmacological studies.

Amelioration of nitrobenzene-induced nephrotoxicity by the ethanol extract of the herb Euphorbia hirta

BACKGROUND

Euphorbia hirta (L.) (Euphorbiaceae) is a very popular herb amongst practitioners of traditional medicine and used in the treatment of female disorders, respiratory ailments, tumors, jaundice, digestive problems, wounds, etc. We aimed to evaluate the protective effect of E. hirta against nitrobenzene-induced nephrotoxicity in albino rats.

MATERIALS AND METHODS

The nephroprotective activity of the ethanol extract of E. hirta (400 mg/kg body weight) was studied in nitrobenzene-induced albino rats (1000 mg/kg body weight). The activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and the levels of reduced glutathione (GSH), total thiols and vitamin C in the kidney tissues were determined. Histopathologic investigation was performed in the kidney tissue samples.

RESULTS

Nitrobenzene administration significantly (P < 0.01) enhanced the lipid peroxidation and significantly (P < 0.05) depleted the levels of SOD, CAT, GPx, GST, GSH, total thiols and vitamin C. Treatment with the ethanol extract of E. hirta significantly normalized the antioxidant levels. The nephroprotective activity was also supported by histopathologic studies of kidney tissue.

CONCLUSION

The results indicate that the ethanol extract of E. hirta ameliorates renal dysfunction and could be used as an effective protector against nitrobenzene-induced nephrotoxicity, primarily through its antioxidant capacity.

Androgen signaling and post-transcriptional downregulation of Bcl-2 in androgen-unresponsive prostate cancer

We previously characterized the LNCaP prostate cancer progression model and showed that despite loss of Bcl-2 protein in the androgen-unresponsive LNCaP-unresponsive (UR) cells, these cells maintained an increased resistance to the induction of apoptosis. Since the loss of Bcl-2 protein coincided with the progression to androgen-unresponsiveness, we sought to determine if Bcl-2 expression was regulated through androgen signaling pathways. LNCaP-responsive (R) and -UR cells grown in charcoal-stripped serum conditions for 3 months differentiated to a neuroendocrine (NE)-like morphology. Under these conditions, LNCaP-UR cells regained Bcl-2 protein expression, and LNCaP-R cells overexpressed Bcl-2. Chronic exposure to casodex resulted in differentiation of both LNCaP-R and -UR cells to the NE-type morphology accompanied by a marked downregulation of Bcl-2 protein, while Bax protein levels were unchanged. Downregulation of Bcl-2 was post-transcriptional since Bcl-2 message levels were unchanged in LNCaP cells treated with casodex. These data suggest that Bcl-2 is post-transcriptionally modulated by androgen signaling pathways in LNCaP cells.

Cisplatin induced nephrotoxicity and the modulating effect of glutathione ester

The objective of this study was to assess the therapeutic advantage of glutathione ester along with cisplatin. Comparisons were made with renal reduced glutathione, enzymatic antioxidants, and lipid peroxidation levels. Cisplatin caused differential toxic effects on renal antioxidants and lipid peroxidation. However administration of glutathione ester modulates the toxic effects of cisplatin observed in renal antioxidants and lipid peroxidation. The finding that glutathione ester co-administration along with cisplatin is more effective and advantageous in protecting against the nephrotoxicity of cisplatin when it was given alone.

Effect of patulin on albumin fraction of plasma proteins studied in rats

The toxic nature of the secondary metabolite of Penicillium patulum has been studied in rats. Plasma of the experimental animals showed a decrease in protein concentration. Detailed electrophoretic studies have been carried out, to find which fraction of the plasma protein is affected. It shows clearly that albumin fraction is very much affected, while in the tissues of the liver, kidney and intestine the DNA and RNA levels are found to be increased.