Herbal remedies in the management of hyperuricemia and gout: A review of in vitro, in vivo and clinical evidences

Gout, or hyperuricemia is a multifactorial and multi-faceted metabolic disease that is quite difficult to manage and/or treat. Conventional therapies such as non-steroidal anti-inflammatory drugs (NSAIDs) such as allopurinol, corticosteroids and colchicine amongst others, have helped in its management and treatment to some extent. This study aimed to compile and analyze the different herbal remedies used in the management of hyperuricemia and gout. A literature search was conducted from key databases (PubMed, ScienceDirect, Cochrane Library, Google Scholar) using relevant keywords via the PRISMA model. Smilax riparia A.DC. from Traditional Chinese Medicine is used in many countries for its therapeutic effect on lowering serum urate levels. No single study was able to establish the efficacy of a specific traditionally used herb via in vitro, in vivo, and clinical studies. Patients were found to use a panoply of natural remedies, mainly plants to treat hyperuricemia and gout, which have been validated to some extent by in vitro, in vivo, and clinical studies. Nonetheless, further research is needed to better understand the ethnopharmacological relationship of such herbal remedies.

Evaluating the factors influencing sun protection factors (SPF): Pooling data from multiple studies involving two reference ISO 24444:2019 sunscreen products (P2 and P8)

BACKGROUND

Standardized methods for sun protection factor (SPF) testing are still beset with endpoint and method-driven issues, and can be influenced by multiple factors. The purpose of this analysis is to explore the factors influencing the results of sun protection factor (SPF) testing in human subjects according to the ISO 24444:2019 standard. Intrinsic factors, such as baseline skin color, age and gender, the minimal erythemal dose on an unprotected area (MEDu), as well as environmental factors such as season/weather influences, are considered for analysis.

METHODS

Datasets generated for two reference products (P2 and P8) during the conduct of 50 such studies using the ISO standard 24444:2019 for the testing of SPF products, from a single testing center located in Bucharest, Romania between April 2021 and December 2022, were retrieved and compiled. Overall, the data for 334 subjects was available, with 276 observations for the reference P8, and 171 for P2.

RESULTS

No effects due to gender or age were detected. Seasonal changes, the individual typology angle (ITA°) and MEDu were found to have an influence on the outcome of the SPF values.

CONCLUSIONS

This study adds new original data about the impact of intrinsic and extrinsic factors on SPF variations pertaining to ISO reference sunscreen P8 (SPF 50+). The findings suggest that some factors will inevitably impact the results between two SPF experiments for the same product and SPF testing laboratory. The interconnections between the sources of this variation are discussed. The findings of this research help to identify and characterize factors that contribute to SPF testing variability.

Outdoor clinical testing with reference sunscreens to determine differences in skin response between populations of different ethnicity: A combined data analysis from 128 subjects

BACKGROUND

Two previously published clinical studies by our group assessed erythema and pigmentation responses in outdoor conditions with three reference sunscreens, comparing their effectiveness under the full spectrum of natural sunlight. These studies followed an almost identical protocol but were conducted in two different locations and in two ethnic groups: broadly, Chinese (Singapore) and White European (Mauritius). We analysed the data from these two study populations to compare differences in skin response according to ethnicity.

METHODS

The analysis included 128 subjects (53 were Chinese from Singapore and 75 were White European from Mauritius and Singapore). Products used were the reference sunscreens P3 (sun protection factor [SPF] 15), P5 (SPF 30) and P8 (SPF 50+) from ISO norm 24444:2019. Participants were exposed to outdoor sunlight for 2-3 h, depending on baseline ITA. Endpoints were erythema at 24 h: clinical score and colorimetry (Δa*) and pigmentation at 1 week based on colorimetry (ΔL* and ΔITA).

RESULTS

Among those with baseline ITA > 41, there were differences in erythemal response between the Chinese and White European groups, the White European group being more erythematous and also having a higher rate of photoprotection failure particularly at SPFs 15 and 30.

CONCLUSION

Differences in skin response to sun influenced by ethnicity should be taken into account when making recommendations on sun safety.

Nutritional, medicinal and functional properties of different parts of the date palm and its fruit (Phoenix dactylifera L.) - A systematic review

Appraised for being one of the oldest staple nutritive foods mainly in the Arabian Peninsula, the date palm tree (Phoenix dactylifera L.), is a crop native to the subtropical and tropical regions of Southern Asia and Africa. Different parts of the date tree have been extensively studied for their nutritional and therapeutic properties. Despite an array of publications on the date tree, there has been no attempt to compile in a single study the traditional uses, nutritive value, phytochemical profile, the medicinal properties as well as the potential of the different plant parts as a functional food. Therefore, this review endeavors to systematically review the scientific literature to highlight the traditional uses of date fruit and parts around the world, the nutritional profile of several parts and the medicinal properties. A total of 215 studies was retrieved (traditional uses (n = 26), nutritional (n = 52), and medicinal (n = 84)). Scientific articles were further categorized as in vitro (n = 33), in vivo (n = 35), and clinical (n = 16) evidences. Date seeds were found to be effective against E. coli and Staphylococcus aureus. Aqueous date pollen was used to manage hormonal problems and boost fertility. Palm leaves showed anti-hyperglycemic effects via inhibition of α-amylase and α-glucosidase. Unlike previous studies, this study highlighted the functional roles of all the plant parts of the palm tree and provided insights into the various mechanism of action of their bioactive compounds. Although scientific shreds of evidence have been growing over the years, there is still a dearth of studies concerning the clinical validation of the date fruit and other plant parts to provide strong evidence on their medicinal uses. In conclusion, P. dactylifera can be regarded as a potent medicinal plant with prophylactic potential and should be further explored to alleviate the burden of both communicable and non-communicable diseases.

Prevalence, Genomic Characterization, and Risk Assessment of Human Pathogenic Vibrio Species in Seafood

ABSTRACT

Pathogenic Vibrio species are largely responsible for human diseases associated with consumption of contaminated seafood. The aim of this study was to determine the prevalence, population densities, species diversity, and molecular characteristics of pathogenic Vibrio in various seafood commodities and the health risks associated with consumption of these contaminated commodities. Samples of finfish and shellfish (oysters and sea urchins) were collected from various regions and analyzed for Vibrio with the most-probable-number (MPN) technique. Genomic DNA of putative Vibrio isolates was analyzed by whole genome sequencing for taxonomic identification and identification of virulence and antimicrobial resistance genes. The risk of Vibrio-related illnesses due to the consumption of contaminated seafood was assessed with Risk Ranger. Populations of presumptive Vibrio were 2.6 to 4.4 log MPN/g and correlated with season; Vibrio levels were significantly higher (P < 0.05) in the summer. Fifteen Vibrio isolates were identified as Vibrio alginolyticus (five isolates), Vibrio parahaemolyticus (six isolates), Vibrio harveyi (two isolates), and Vibrio diabolicus (two isolates). Two of the six V. parahaemolyticus isolates (ST 2504 and ST 2505) from oysters harbored either the tdh gene for thermostable direct hemolysin or the trh gene for thermostable direct hemolysin-related hemolysin. In addition to virulence genes, the shellfish isolates also harbored genes encoding resistance to multiple antibiotics, including tetracycline, penicillin, quinolone, and β-lactams, thus arousing concern. The risk assessment predicted that an estimated 21 cases of V. parahaemolyticus-associated gastroenteritis could occur in the general population annually due to consumption of contaminated oysters. This study highlights both the wide prevalence and diversity of Vibrio in seafood and the potential for certain strains to threaten public health.

HIGHLIGHTS

Evaluation of a Sunscreen Product Compared with Reference Standards P3, P5 and P8 in Outdoor Conditions: a Randomized, Double-Blinded, Intra-individual Study in Healthy Subjects

INTRODUCTION

The shortcomings of standardized sunscreen testing have been discussed in recent years, noting differences between how sunscreens perform in indoor clinical (in vivo) laboratory testing compared with real-life conditions. We previously developed an outdoor clinical method for ranking sunscreens by performance level. We used this method to test the performance of a new broad-spectrum sunscreen against International Organization for Standardization (ISO) reference products P3, P5 and P8.

METHODS

Sixty-five healthy volunteers with individual typology angle (ITA) ≥ 28° (light to intermediate skin colour) participated in an outdoor study in Mauritius. Test areas were marked on their backs, which were treated with the different products: one commercially available broad-spectrum sun protection factor (SPF) 50 sunscreen [investigational product (IP)] and the three reference products P3 (SPF 15), P5 (SPF 30) and P8 (SPF 50+) from ISO norm 24444:2019 for SPF testing. The test areas were exposed for 2-3 h, depending on the baseline skin colour. They were also compared with an unprotected positive control area and a non-exposed negative control area. Clinical and colorimetry assessment of erythema and pigmentation were performed at 24 h and 8 days, respectively.

RESULTS

Overall, according to this outdoor clinical testing method, the sunscreens' efficacy was ranked in an appropriate order given their established SPF levels, with higher SPFs giving greater protection against erythema and pigmentation. Between the different levels of SPF, the differences were statistically significant, for both clinical and colorimetry assessments. The new broad-spectrum SPF 50 IP performed similarly to the SPF 50+ (P8) reference product. Even the highest SPF products, SPF 50 and SPF 50+, had some instances of photoprotection failure.

CONCLUSION

These findings confirm the feasibility of this outdoor clinical testing method in ranking sunscreens and provide further evidence, in addition to standardized SPF and UVA protection factor (UVAPF) testing, on how this new broad-spectrum SPF 50 sunscreen performs in extreme outdoor solar exposure: in line with reference product P8 (SPF 50+).

TRIAL REGISTRATION NO

ISRCTN95394014.

The protective effect of a novel sunscreen against blue light

BACKGROUND AND OBJECTIVE

Premature skin ageing, and skin hyperpigmentation are influenced by exogenous factors, such as ultraviolet radiation and blue light. In this study, we assess the protective effect of a sunscreen (TDF^® Blu Voile Sunscreen) in protecting the skin against the harmful effects of blue light irradiation in vivo and through the in situ quantitative and qualitative evaluation of protein carbonylation in human skin explants.

METHODOLOGY

The protective effect of the test product against blue light was first evaluated ex vivo on human skin explants. The treated and non-treated explants were exposed to 14 J/cm² of blue light 460 nm following which the protein carbonylation was evaluated by in situ epifluorescence imaging and separation by high-resolution gel electrophoresis. To determine whether the test product could also protect against the immediate and persistent pigmenting effect of blue light, two randomized in vivo studies were conducted, which included respectively 17 subjects with a skin phototype of IV and V (Fitzpatrick classification) and 22 subjects with a skin phototype of IV, V, and VI (Fitzpatrick classification). The duration of the study for each subject was 2 days (D1 and D2) for immediate observations and 5 days (D1-D5) for persistent observations. Specific zones on the subjects' back were either left non-treated or treated with the test product and were then exposed to a unique dose of blue light 415 nm. The onset of pigmentation between the treated and exposed zones was then assessed relative to the non-exposed treated zone through colorimetric measurements of the Individual Typology Angle (ITA^o ).

RESULTS

Human skin explants treated with test product showed significantly lower levels of accumulated carbonylated proteins, with a protection of 82%, following exposure to blue light 460 nm. Findings of the in vivo studies also indicated that the test product presented significantly better protective efficacy against immediate and persistent pigmentation induced by blue light 415 nm.

CONCLUSION

Hence, it can be concluded that the test product can protect against the oxidative stress as well as the immediate and persistent pigmentation induced by blue light.

Outdoor sunscreen testing with high-intensity solar exposure in a Chinese and Caucasian population

BACKGROUND

Currently, sunscreens' sun protection factor (SPF) and ultraviolet (UV) A protection are tested separately under indoor conditions, without considering external conditions that may affect performance. Studies are often conducted in Caucasian individuals; other racial groups may respond differently.

METHODS

An outdoor, double-blind, intra-individual study was performed in 63 healthy Chinese and Caucasian volunteers in Singapore. Subjects underwent one outdoor sun exposure lasting 2-3 hours. ISO reference products P3 (SPF 15), P5 (SPF 30), and P8 (SPF 50+) applied at 2 mg/cm² were compared against each other and against an untreated exposed area (positive control) and an unexposed area (negative control). Endpoints were investigator global assessment (IGA) of erythema at 24 hours, IGA of pigmentation at 1 week, and colorimetry (a*, L*, and ITA) at 24 hours and 1 week.

RESULTS

Clinical erythema and pigmentation scores were statistically significantly different among the three sunscreens, with the highest SPF product providing the highest protection, confirming the discriminatory capacity of the model used. Colorimetric assessment correlated well with clinical evaluation.

CONCLUSION

This study confirmed the feasibility of ranking sunscreens (at 2 mg/cm² ) based on clinical effects of high-intensity outdoor solar radiation. Larger studies are needed to look at differences in erythema and pigmentation reactions between Chinese and Caucasian individuals, which could be relevant for photoprotection.

New Methodology to Evaluate Sunscreens Under Outdoor Conditions: A Double-Blind, Randomized Intra-Individual Clinical Study of a Water-Based Broad-Spectrum SPF50+ Versus SPF15 (P3) and SPF50

Introduction

This study explored a new method to test sunscreens in outdoor conditions (very high to extreme ultraviolet [UV] radiation) approximating real-life solar exposure while maintaining scientific standards and acceptable conditions, and assessed the efficacy of a water-based sun-protection factor (SPF) 50+ versus a reference SPF15 and two comparator SPF50+ products.

Methods

Thirty-five subjects underwent testing in summertime Mauritius. In each subject, five test areas were marked on the back. One area was left unprotected, and four sunscreens were applied to the others: investigational product (IP), SPF15 (ISO 24444:2010 reference standard P3), and two marketed SPF50+ controls. Subjects spent 1–2 h (depending on skin type) in the sun. After 24 h, erythema was assessed by clinical scoring (0–5) and colorimetry (a*, L*, and ITA). Secondary endpoints were correlation between clinical and colorimetry assessment, product tolerability, and total UV radiation received.

Results

All subjects were exposed to a very high UV index (≥ 8) and 30/35 were exposed to an extreme UV index (≥ 11). The IP showed statistically significant differences in clinical erythema scoring compared with unprotected skin and SPF15, but not with SPF50+ controls. On colorimetry, differences in a* (redness) and L* (lightness) reached statistical significance for the IP vs SPF15 but not vs SPF50+ controls. Clinical and instrumental erythema assessment correlated strongly (Spearman’s rho 0.663). No tolerability issues were reported.

Conclusion

This exploratory study confirmed the ability of this outdoor model to discriminate sunscreens with different SPF using clinical evaluation as an objective measure. The water-based sunscreen maintained its efficacy in outdoor conditions of very high to extreme UV radiation: it was superior to SPF15 and comparable to SPF50+ controls in preventing erythema. The method used represents an option for sunscreen efficacy comparison outside of the laboratory.

Funding

Isdin.

Electronic supplementary material

The online version of this article (10.1007/s13555-019-00315-4) contains supplementary material, which is available to authorized users.

Selected essential oils inhibit key physiological enzymes and possess intracellular and extracellular antimelanogenic properties in vitro

Essential oils (EOs) extracted from six medicinal herbs and food plants [Cinnamomum zeylanicum (CZ), Psiadia arguta (PA), Psiadia terebinthina (PT), Citrus grandis (CGp), Citrus hystrix (CH), and Citrus reticulata (CR)] were studied for any inhibitory potential against key physiological enzymes involved in diabetes (α-glucosidase), skin aging (collagenase and elastase), and neurodegenerative disorders (acetylcholinesterase). Kinetic studies of the active EOs on the aforementioned enzymes were determined using Lineweaver–Burk plots. The intracellular and extracellular antimelanogenic potential of the EOs were evaluated on B16F10 mouse melanocytes. CH and CR were found to significantly inhibit (2.476 ± 0.13 μg/mL and 3.636 ± 0.10 μg/mL, respectively) acetylcholinesterase, compared with galantamine (3.989 ± 0.16 μg/mL). CH inhibited collagenase (50% inhibitory concentration 28.71 ± 0.16 μg/mL) compared with the control (24.45 ± 0.19 μg/mL). The percentage inhibition in the elastase assay of CH was 63.21% compared to the positive control (75.09%). In addition, CH, CR, CGp, CZ, and PT were found to significantly inhibit α-glucosidase (276.70 ± 0.73 μg/mL, 169.90 ± 0.58 μg/mL, 240.60 ± 6.50 μg/mL, 64.52 ± 0.69 μg/mL, and 313.0 ± 5.0 μg/mL, respectively), compared to acarbose (448.80 ± 0.81 μg/mL). Active EOs showed both uncompetitive and competitive types of inhibition. The EOs also inhibited intracellular (50% inhibitory concentration 15.92 ± 1.06 μg/mL, 23.75 ± 4.47 μg/mL, and 28.99 ± 5.70 μg/mL for CH, CR, and CGp, respectively) and extracellular (< 15.625 μg/mL for CH, CR, CGp, and PT) melanin production when tested against B16F10 mouse melanocytes. Results from the present study tend to show that EOs extracted from these medicinal plants can inhibit key enzymes and may be potential candidates for cosmetic and pharmaceutical industries.