In vitro and in vivo antifungal activities of the eight steroid saponins from Tribulus terrestris L. with potent activity against fluconazole-resistant fungal pathogens

Antifungal activity of natural products is being studied widely. Saponins are known to be antifungal and antibacterial. We have isolated eight steroid saponins from Tribulus terrestris L. , namely TTS-8, TTS-9, TTS-10, TTS-11, TTS-12, TTS-13, TTS-14 and TTS-15. TTS-12 and TTS-15 were identified as tigogenin-3-O-β-D-xylopyranosyl（1→ 2）-[-β-D-xylopyranosyl（ 1 → 3 ） 3-β- D-glucopyranosyl （ 1 → 4 ）- 1- α-L-rhamnopyranosyl （ 1 → 2 ） 3-β-D-galactopyranoside and tigogenin-3-O-β-D-glucopyranpyranosyl（1→2）-[-β-D-xylopyranosyl（1→ 3）3-β-D-glucopyranosyl（1→4）-β-D-galactopyranoside, respectively. The in vitro antifungal activities of the eight saponins against six fluconazole-resistant yeasts, Candida albicans, Candida glabrata, Candida para psilosis , Candida tropicalis , Candida krusei , and Cryptococcus neo f ormans were studied using microbroth dilution assay. The results showed that TTS-12 and TTS-15 were very effective against several pathogenic candidal species and C. neoformans in vitro. It is noteworthy that TTS-12 and TTS-15 were very active against fluconazole-resistant C. albicans （MIC80 = 4.4, 9.4 mg/ml）, C. neoformans （MIC80 =10.7, 18.7 mg/ml） and inherently resistant C. krusei （MIC80 =8.8, 18.4 mg/ml）. So in vivo activity of TTS-12 in a vaginal infection model with fluconazole-resistant C. albicans was studied in particular. Our studies revealed TTS-12 also showed in vivo activities against fluconazole-resistant yeasts. In conclusion, steroid saponins TTS-12 and TTS-15 from Tribulus terrestris L. have significant in vitro antifungal activity against fluconazole-resistant fungi, especially TTS-12 also showed in vivo activity against fluconazole-resistant C. albicans.     

Fisetin for COVID-19 in skilled nursing facilities: Senolytic trials in the COVID era

The burden of senescent cells (SnCs), which do not divide but are metabolically active and resistant to death by apoptosis, is increased in older adults and those with chronic diseases. These individuals are also at the greatest risk for morbidity and mortality from SARS-CoV-2 infection. SARS-CoV-2 complications include cytokine storm and multiorgan failure mediated by the same factors as often produced by SnCs through their senescence-associated secretory phenotype (SASP). The SASP can be amplified by infection-related pathogen-associated molecular profile factors. Senolytic agents, such as Fisetin, selectively eliminate SnCs and delay, prevent, or alleviate multiple disorders in aged experimental animals and animal models of human chronic diseases, including obesity, diabetes, and respiratory diseases. Senolytics are now in clinical trials for multiple conditions linked to SnCs, including frailty; obesity/diabetes; osteoporosis; and cardiovascular, kidney, and lung diseases, which are also risk factors for SARS-CoV-2 morbidity and mortality. A clinical trial is underway to test if senolytics decrease SARS-CoV-2 progression and morbidity in hospitalized older adults. We describe here a National Institutes of Health-funded, multicenter, placebo-controlled clinical trial of Fisetin for older adult skilled nursing facility (SNF) residents who have been, or become, SARS-CoV-2 rtPCR-positive, including the rationale for targeting fundamental aging mechanisms in such patients. We consider logistic challenges of conducting trials in long-term care settings in the SARS-CoV-2 era, including restricted access, consent procedures, methods for obtaining biospecimens and clinical data, staffing, investigational product administration issues, and potential solutions for these challenges. We propose developing a national network of SNFs engaged in interventional clinical trials.     

Guardianship: A medicolegal review for clinicians

Guardianship may pose an ethical dilemma for physicians, who must balance protecting vulnerable patients from potential safety concerns with respecting their autonomy. Older adults with dementia are particularly susceptible to loss of independence and the ability to participate in medical decision making. To have the capacity for medical decision making, individuals must understand relevant information, appreciate their circumstances, demonstrate reasoning, and express a consistent choice free from coercion. Although capacity assessments are usually task-specific, geriatricians and other specialists may be asked to comment on capacity more globally. These determinations may be used to support a Petition for the Appointment of a Guardian of a Legally Incapacitated Adult, the legal process of pursuing guardianship in probate court. Assigned guardians may be known to the incapacitated individual (e.g., a family member or friend) or may be professional guardians with no prior relationship to the ward. Guardians are encouraged to use substituted decision-making, taking into account the ward's previously expressed values and preferences. Although a number of viable alternatives to guardianship exist, numerous systemic barriers may prevent these from being fully explored. The ongoing need for guardianship should be periodically revisited and reassessed. Data about guardians and wards is shockingly sparse, as there are no centralized databases. Laws and regulations for guardianships vary significantly between states. Physicians can serve as important allies and advocates for patients with cognitive impairment at risk of incapacity, can help preserve their autonomy for as long as possible, and ensure appropriate protections are in place if the patient does lose their decision-making ability.     

Detection of genomic deletions of PKP2 in arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited myocardial disease that predominantly affects the right ventricle and is associated with ventricular arrhythmias that may lead to sudden cardiac death. Mutations within at least seven separate genes have been identified to cause ARVC, however a genetic culprit remains elusive in approximately 50% of cases. Although negative genetic testing may be secondary to pathogenic mutations within undiscovered genes, an alternative explanation may be the presence of large deletions or duplications involving known genes. These large copy number variants may not be detected with standard clinical genetic testing which is presently limited to direct DNA sequencing. We describe two cases of ARVC possessing large deletions involving plakophilin‐2 (PKP2) identified with microarray analysis and/or multiplex ligation‐dependent probe amplification (MLPA) that would have been classified as genotype negative with standard clinical genetic testing. A deletion of the entire coding region of PKP2 excluding exon 1 was identified in patient 1 and his son. In patient 2, MLPA analysis of PKP2 revealed deletion of the entire gene with subsequent microarray analysis demonstrating a de novo 7.9 Mb deletion of chromosome 12p12.1p11.1. These findings support screening for large copy number variants in clinically suspected ARVC cases without clear disease causing mutations following initial sequencing analysis.