Swietenia macrophylla extract promotes the ability of Caenorhabditis elegans to survive Pseudomonas aeruginosa infection

Ethnopharmacological relevance

Swietenia macrophylla or commonly known as big leaf mahogany, has been traditionally used as an antibacterial and antifungal agent.

Aim of the study

The unwanted problem of antibiotic resistance in many bacterial species advocates the need for the discovery of the new anti-infective drugs. Here, we investigated the anti-infective properties of Swietenia macrophylla with an assay involving lethal infection of Caenorhabditis elegans with the opportunistic human pathogen Pseudomonas aeruginosa.

Materials and methods

Using a slow killing assay, Caenorhabditis elegans was challenged with an infective strain of Pseudomonas aeruginosa (PA14). The ability of Swietenia macrophylla seed ethyl acetate extract to promote the survival of infected worms was assessed by comparing the percentage of survival between extract treated and non-treated worm populations. The effect of Swietenia macrophylla towards PA14 growth, Caenorhabditis elegans feeding rate and degree of PA14 colonization in the worm gut was also evaluated. Lastly, using a fluorescent transgenic Caenorhabditis elegans strain and real time PCR, the effect of Swietenia macrophylla on the expression of lys-7, an immune response gene was also investigated.

Results

Our results demonstrate the ability of Swietenia macrophylla seed ethyl acetate extract in rescuing Caenorhabditis elegans from fatal PA14 infection. Consequently, we showed that the extract promotes the survival without exhibiting any bactericidal effect or perturbation of Caenorhabditis elegans feeding rate. We also showed that Swietenia macrophylla was able to restore the initially repressed lys-7 level in PA14 infected Caenorhabditis elegans.

Conclusion

Swietenia macrophylla extract is able to enhance the ability of Caenorhabditis elegans to survive PA14 infection without directly killing the pathogen. We further showed that the extract boosted the expression of a gene pivotal for innate immunity in Caenorhabditis elegans. Collectively, these findings strongly suggest the presence of compounds within Swietenia macrophylla seed that either reduces Pseudomonas aeruginosa virulence and/or enhance host resistance.     

Physalin F from Physalis minima L. triggers apoptosis-based cytotoxic mechanism in T-47D cells through the activation caspase-3- and c-myc-dependent pathways

Ethnopharmacological relevance

Physalin F (a secosteroid derivative), is well recognized as a potent anticancer compound from Physalis minima L., a plant that is traditionally used to treat cancer. However, the exact molecular anticancer mechanism remains to be elucidated.

Aim of the study

We have recently reported the apoptosis-based cytotoxic effect of the chloroform extract of this plant. Here, we investigated the cytotoxicity and possible cell death mechanism elicited by the active constituent, physalin F on human breast T-47D carcinoma.

Materials and methods

Cytotoxic-guided fractionation of the chloroform extract of Physalis minima has led to the isolation of physalin F. The cytotoxicity activity was assayed using MTS assay. The effect of the compound to induce apoptosis was determined by biochemical and morphological observations through DeadEnd Colorimetric and annexin V assays, respectively, and RT-PCR analysis of mRNA expression of the apoptotic-associated genes.

Results

Cytotoxicity screening of physalin F displayed a remarkable dose-dependant inhibitory effect on T-47D cells with lower EC₅₀ value (3.60 μg/ml) than the crude extract. mRNA expression analysis revealed the co-regulation of c-myc- and caspase-3-apoptotic genes in the treated cells with the peak expression at 9 and 12 h of treatment, respectively. This apoptotic mechanism is reconfirmed by DNA fragmentation and phosphatidylserine externalization.

Conclusion

These findings indicate that physalin F may potentially act as a chemopreventive and/or chemotherapeutic agent by triggering apoptosis mechanism via the activation of caspase-3 and c-myc pathways in T-47D cells.     

Severe leptospirosis with unusual manifestation

We report a case of an 8-year-old aborigine boy referred to our hospital for respiratory insufficiency with skin eruptions over the trunk and limbs. The skin condition was diagnosed as acquired ichthyosis. He also had a non-bleeding form of disseminated intravascular coagulopathy. Radiograph of the lungs showed bilateral perihilar opacities with bilateral pleural effusion. The diagnosis of leptospirosis was confirmed by a 4-fold rise in microagglutinating titre and polymerase chain reaction assay.     

Evaluation of NMU-Induced Breast Cancer Treated with Sirolimus and Sunitinib on Breast Cancer Growth

Objective: To analyze the effect of sirolimus and sunitinib in blocking the tumor growth and to evaluate the expressions of estrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth factor receptor-2 (HER2/neu) after treated with sirolimus and sunitinib. Methods: Thirty-two female Sprague Dawley rats at age 21-days old were administered intraperitoneally with N-Methyl-N-Nitroso Urea (NMU), dosed at 70mg/kg body weight. The rats were divided into 4 groups; Group 1 (Control, n=8), Group 2 (Sirolimus, n=8), Group 3 (Sunitinib, n=8) and Group 4 (Sirolimus+Sunitinib, n=8), being treated twice when the tumor reached the size of 14.5±0.5 mm and subsequently sacrificed after 5 days. The protein expressions of ER, PgR and HER2/neu of the tumor tissues were evaluated by using immunohistochemistry analysis. Results: Treatment with sirolimus alone lowered expressions of ER and PgR of breast cancer and reduced tumor size. There was no significant difference of ER and PgR expressions between control and sunitinib treated tumor. Sunitinib treated tumors reduce in diameter after the first treatment, however the diameter increases after the second treatment. Histologically, sunitinib treated tumor did not show any aggressive invasive carcinoma of no special type (NST) histological subtypes. In addition, all NMU-induced tumors are HER2/neu-negative scoring. Conclusion: Sirolimus is neither synergistic nor additive with sunitinib for breast cancer treatment.     

Isolation and characterisation of microsatellite loci in the tire track eel,Mastacembelus favus and cross-species amplification

Nine microsatellite loci were isolated and characterized in the tire track eel, Mastacembelus favus by using library enriched for microsatellite region. Among 47 specimens collected from Mekong River, the number of alleles ranged from 2 to 17 while levels of observed and expected heterozygosities ranged from 0.021 to 0.873 and from 0.021 to 0.893, respectively. The primers were successfully tested in six closely related species, hence valuable for investigating population genetics and other related aspects of M. favus and its congener species.     

Recurrent radiation recall dermatitis 40 years after radiation therapy for breast cancer

Radiation recall dermatitis is an inflammatory reaction of the skin, which occurs at previously irradiated areas, usually following a subsequent exposure to an aggravating factor. Recall dermatitis can occur weeks to months after radiation, and the longest duration between radiation and dermatitis has been reported to be about 25 years. Here, we report a case of recurrent radiation recall dermatitis that developed spontaneously after 40 years following radiation for breast cancer. This case suggests that radiation recall dermatitis can occur much later than previously reported. In spite of this late presentation, topical anti-inflammatory agents managed the condition well.     

Factors related to urinary incontinence among the Malaysian elderly

Background

Urinary incontinence is a prevalent condition in the elderly that is the spontaneous leakage of urine. It is an age-related problem and increases especially in people aged above 65 years. It can cause many psychological, behavioral, biological, economic and social effects. The treatment of urinary incontinence can reduce morbidity and mortality. Thus, this study aimed to determine the effects of variables including age, ethnicity, gender, education, marital status, body weight, blood elements and nutritional parameters on urinary incontinence among the Malaysian elderly.

Methods

The study was on 2322 non-institutionalized Malaysian elderly. The hierarchy logistic regression analysis was applied to estimate the risk of independent variables for urinary incontinence among respondents.

Results

The findings indicated that approximately 3.80% of subjects had urinary incontinence. In addition, constipation was found a significant factor that increased the risk of urinary incontinence in samples (p=0.006; OR=3.77). The increase in dietary monounsaturated fat (p=0.038; OR=0.59) and plasma triglyceride levels (p=0.029; OR=0.56) significantly reduced the risk of incontinence in subjects. Many of suspected variables including socio-demographic factors, diseases, nutritional minerals, blood components and body weight were non-relevant factors to urinary incontinence in respondents.

Conclusions

Constipation increased the risk of urinary incontinence in subjects, and increase in dietary monounsaturated fat and plasma triglyceride levels decreased the risk.