A Systematic Literature Review of Curcumin with Promising Antileishmanial Activity

Nanoemulgel mediated enhanced skin curcumin penetration/retention for local treatment of cutaneous leishmaniasis: in vitro and in vivo assessment

BACKGROUND

Skin delivery of a therapeutically effective drug is imperative for local cutaneous leishmaniasis (CL) treatment.

OBJECTIVE

This study aimed to formulate, optimize, and characterize curcumin-loaded nanoemulgel for enhanced skin drug retention to treat CL locally.

METHODS

Nanoemulsions were prepared by high-speed homogenization, characterized, and optimized for size, PDI, zeta potential, stability, morphology, drug contents, encapsulation efficiency, in vitro drug release, antileishmanial activity, and cell viability. The optimized nanoemulsion (C3) was then incorporated into a carbopol-based gel and evaluated for pH, viscosity, spreadability, and in vitro drug release. Both formulations were then assessed for ex-vivo and in vivo skin permeation/retention, and pharmacokinetic analysis.

RESULTS

All nanoemulsion formulations had size in nano range with negative surface charge, homogeneously distributed, with spherical droplet geometries, where C3 being highly stable, had good encapsulation efficiency and drug contents (85 ± 5.4 and 68 ± 3.2%), released 90% of drug within 4 h, while C3 gel released the drug significantly sustained up to 46% in 24 h. The C3 formulation demonstrated significant in vitro antileishmanial activity across all tested concentrations, while the IC50 value against NIH3T3 fibroblasts was 0.6202 mM (Log IC50: 2.7, R2: 0.98). The C3 gel showed significantly low skin permeation (341.7 ± 43.6 and 52.6 ± 8.9 µg) with significantly higher skin drug retention (129.5 ± 16.7 and 190.2 ± 33.4 µg) ex-vivo and in vivo, with significantly lower Cmax, AUC0-t, and AUC0-∞.

CONCLUSION

These results suggested that curcumin nanoemulgel could be an effective alternative strategy for treating CL locally.

Anti-leishmanial activity of Hypericum Scabrum extract against Leishmania major

Leishmaniasis is a vector-borne disease and one of the most significant neglected tropical diseases. Current anti-leishmanial treatments are often ineffective over extended periods and are associated with toxic side effects, highlighting the urgent need for new, effective, and safe alternative treatments for this infectious disease. The objective of this study was to evaluate the anti-leishmanial effects of a hydroalcoholic extract of Hypericum scabrum (H. scabrum), comparing its efficacy to that of the control drug glucantime against the standard strain of Leishmania major. The H. scabrum plants were collected from the western regions of Iran. A hydroalcoholic extract was prepared from the flower and stem of the plant using a maceration method. High-performance liquid chromatography analysis was conducted to identify the chemical compounds present in the extract. Promastigotes of L. major were cultured, and the anti-leishmanial activity of the extracts was assessed at concentrations ranging from 12.5 to 800 µg/ml using the MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide] assay. The half-maximal inhibitory concentration (IC50) values for the H. scabrum plant extract at 24, 48, and 72 h were 245.47, 141.25 and 85.11 μg/ml, respectively. The IC50 values for glucantime (the control drug) at 24 h, 48 h, and 72 h were 30.19, 21.37, and 12.58 μg/ml, respectively. While the H. scabrum extract exhibited a lower effect compared to the control drug, it still demonstrated a significant inhibitory effect on the promastigote form of L. major. Given that the plant extract of H. scabrum has demonstrated promising anti-leishmanial effects against L. major promastigotes, further studies are warranted to evaluate the efficacy of these extracts in animal models of leishmaniasis.

Piperine, quercetin, and curcumin identified as promising natural products for topical treatment of cutaneous leishmaniasis

Leishmania braziliensis (L. braziliensis) causes cutaneous leishmaniasis (CL) in the New World. The costs and the side effects of current treatments render imperative the development of new therapies that are affordable and easy to administer. Topical treatment would be the ideal option for the treatment of CL. This underscores the urgent need for affordable and effective treatments, with natural compounds being explored as potential solutions. The alkaloid piperine (PIP), the polyphenol curcumin (CUR), and the flavonoid quercetin (QUE), known for their diverse biological properties, are promising candidates to address these parasitic diseases. Initially, the in vitro cytotoxicity activity of the compounds was evaluated using U-937 cells, followed by the assessment of the leishmanicidal activity of these compounds against amastigotes of L. braziliensis. Subsequently, a golden hamster model with stationary-phase L. braziliensis promastigote infections was employed. Once the ulcer appeared, hamsters were treated with QUE, PIP, or CUR formulations and compared to the control group treated with meglumine antimoniate administered intralesionally. We observed that the three organic compounds showed high in vitro leishmanicidal activity with effective concentrations of less than 50 mM, with PIP having the highest activity at a concentration of 8 mM. None of the compounds showed cytotoxic activity for U937 macrophages with values between 500 and 700 mM. In vivo, topical treatment with QUE daily for 15 days produced cured in 100% of hamsters while the effectiveness of CUR and PIP was 83% and 67%, respectively. No failures were observed with QUE. Collectively, our data suggest that topical formulations mainly for QUE but also for CUR and PIP could be a promising topical treatment for CL. Not only the ease of obtaining or synthesizing the organic compounds evaluated in this work but also their commercial availability eliminates one of the most important barriers or bottlenecks in drug development, thus facilitating the roadmap for the development of a topical drug for the management of CL caused by L. braziliensis.

The Effect of Curcumin on the Expression of INFγ, TNF-α, and iNOS Genes in PBMCs Infected with Leishmania major [MRHO/IR/75/ER]

BACKGROUND

Leishmaniasis, caused by the Leishmania parasite, is one of the most important tropical neglected diseases. The urgent search for effective, inexpensive, and preferably herbal anti-leishmanial agents, is needed.

OBJECTIVE

Curcumin is a natural polyphenolic compound derived from turmeric that is well known for its antioxidant, anti-inflammatory, anti-tumor, and anti-cancer activity.

METHODS

The present work evaluates the anti-leishmanial [Leishmania major] activity of curcumin. The infected PBMCs were treated with curcumin. The ROS level at 6, 12, 24 h and gene expression levels at 24, 48, and 72 h of PBMCs after treatment with curcumin were determined.

RESULTS

Based on the results, the curcumin concentrations of 268 μM [24 h] and 181.2 μM [72 h] were defined as IC50 against L. major promastigotes. Treatment of L. major infected-peripheral blood mononuclear cells [PBMCs] with IC50 concentrations of curcumin, depending on exposure time, significantly induced the reactive oxygen species [ROS] generation and increased the expression levels of interferongamma [IFN-γ], tumor necrosis factor-alpha [TNF-α], and nitric oxide synthase [iNOS] genes.

CONCLUSION

These findings suggest the potential of curcumin against Leishmaniasis.