Anti-Leishmanial Activity (In Vitro and In Vivo) of Allicin and Allicin Cream Using Leishmania major (Sub-strain Zymowme LON4) and Balb/c Mice

Current studies and potential future research directions on biological effects and related mechanisms of allicin

Allicin, a thiosulfonate extract from freshly minced garlic, has been reported to have various biological effects on different organs and systems of animals and human. It can reduce oxidative stress, inhibit inflammatory response, resist pathogen infection and regulate intestinal flora. In addition, dozens of studies also demonstrated allicin could reduce blood glucose level, protect cardiovascular system and nervous system, and fight against cancers. Allicin was widely used in disease prevention and health care. However, more investigations on human cohort study are needed to verify the biological or clinical effects of allicin in the future. In this review, we summarized the biological effects of allicin from previous outstanding and valuable studies and provided useful information for future studies on the health effects of allicin.

Green Approach: ''A Forwarding Step for Curing Leishmaniasis-A Neglected Tropical Disease''

The present review focuses on a dreaded vector-mediated leishmaniasis, with the existing therapeutic approaches including a variety of drugs along with their limitations, the treatment with natural compounds, and different types of metal/metal oxide nanoparticles (NPs). As evidenced, various metallic NPs, comprising silver, silver oxide, gold, zinc oxide, titanium, lead oxide, etc., played a curative role to treat leishmaniasis, are also presented. Keeping in view the advance success of vaccines against the prevalent dreaded diseases in the past and the present scenario, efforts are also being made to develop vaccines based on these NP formulations.

Antileishmanial Activity and Synergistic Effects of Amphotericin B Deoxycholate with Allicin and Andrographolide against Leishmania martiniquensis In Vitro

Leishmania (Mundinia) martiniquensis is a causative agent of visceral leishmaniasis, but in HIV-infected patients both visceral and disseminated cutaneous leishmaniasis are presented. Recurrence of the disease after treatment has been reported in some cases indicating that improved chemotherapy is required. In this study, the susceptibility of L. martiniquensis to Amphotericin B deoxycholate (AmB), allicin, and andrographolide was evaluated and the synergistic effects of allicin or andrographolide combined with AmB against L. martiniquensis intracellular amastigotes in mouse peritoneal exudate macrophages (PEMs) were investigated in vitro for the first time. The results showed that L. martiniquensis was highly susceptible to AmB as expected, but allicin and andrographolide had selectivity index (SI) values greater than 10, indicating promise in both compounds for treatment of host cells infected with L. martiniquensis. Four AmB/allicin combinations presented combination index (CI) values less than 1 (0.58–0.68) for intracellular amastigotes indicating synergistic effects. The combination with the highest dose reduction index (DRI) allowed an approximately four-fold reduction of AmB use in that combination. No synergistic effects were observed in AmB/andrographolide combinations. The data provided in this study leads for further study to develop novel therapeutic agents and improve the treatment outcome for leishmaniasis caused by this Leishmania species.

Clinical Efficacy Associated with Enhanced Antioxidant Enzyme Activities of Silver Nanoparticles Biosynthesized Using Moringa oleifera Leaf Extract, Against Cutaneous Leishmaniasis in a Murine Model of Leishmania major

Leishmaniasis is one of the most significant vector-borne syndromes of individuals. This parasitic infection can be affected by many species of Leishmania, most of which are zoonotic. Natural products have made and are continuing to make important contributions to the search for new antileishmanial agents. The use of plants in the production assembly of silver nanoparticles has drawn attention because of its rapid, eco-friendly, non-pathogenic, economical protocol and provides a single step technique for the biosynthetic process. Hence, we aimed to biosynthesize silver nanoparticles (Ag-NPs) using Moringa oleifera leaf extract and investigated the antileishmanial activity of these nanoparticles in a murine model of Leishmania major infection. A total of 50 mice were used and divided into five groups-healthy control, infected, infected mice treated with pentostam, infected mice treated with Ag-NPs and infected mice pretreated with Ag-NPs. In the present study, the leaf extract of the plant species Moringa oleifera was found to be a good source for the synthesis of silver nanoparticles, their formation being confirmed by color change and stability in solution. In the present murine model of Leishmania major infection, we found that oral treatment with silver nanoparticles biosynthesized using Moringa oleifera extract resulted in a significant reduction in the average size of leishmaniasis cutaneous lesions compared with untreated mice. Furthermore, the clinical efficacy of Moringa oleifera extract was associated with enhanced antioxidant enzyme activities. In conclusion, treatment with silver nanoparticles biosynthesized using Moringa oleifera extract has higher and faster clinical efficacy than standard pentavalent antimonial treatment, probably by boosting the endogenous antioxidant activity.

Pomegranate (Punica granatum) Juice Shows Antioxidant Activity against Cutaneous Leishmaniasis-Induced Oxidative Stress in Female BALB/c Mice

Leishmania species are parasites that multiply within phagocytes and cause several clinical diseases characterized by single or multiple ulcerations. One of the complications that can induce tissue damage and the resulting scars is caused by secondary bacterial infections. Studies to find new, effective, and safe oral drugs for treating leishmaniasis are being conducted since several decades, owing to the problems associated with the use of antimonials available. Previously, the antiparasitic and antioxidant properties of Punica granatum (pomegranate, P. granatum) have been reported. Therefore, in the present study, we aimed to investigate the antileishmanial activity of pomegranate aqueous juice in vitro and in female BALB/c mice. A 3-(4.5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in Leishmania major promastigotes and alterations in the antioxidant status, liver function, and skin histological changes in L. major-infected mice orally treated with pomegranate juice alone and in combination with the antibiotic ciprofloxacin, were used to investigate the in vitro and in vivo antileishmanial activity of pomegranate juice, respectively. Oral P. granatum juice treatment significantly reduced the average size of cutaneous leishmaniasis lesions compared with that of the untreated mice. This antileishmanial activity of P. granatum was associated with enhanced antioxidant enzyme activities. Histopathological evaluation proved the antileishmanial activity of P. granatum, but did not reveal changes in the treated animals, compared to the positive control. In conclusion, P. granatum shows high and fast antileishmanial activity probably by boosting the endogenous antioxidant activity.

In Vitro and In Vivo Control of Secondary Bacterial Infection Caused by Leishmania major

Bacterial infections of cutaneous leishmaniasis cause skin ulcers on mice, resulting in increased tissue deterioration, and these infections can be controlled with liquid allicin. To isolate and identify the incidences of real secondary bacterial infections in mice, we performed the current study by injecting mice (n = 50) with Leishmania major. L. major infections were initiated by an intramuscular injection of 0.1 mL Roswell Park Memorial Institute (RPMI 1640 media/mouse (107 promastigote/mL)). Scarring appeared 2-6 weeks after injection, and the bacteria were isolated from the skin ulcer tissues. Allicin (50 µL/mL) and ciprofloxacin (5 μg; Cip 5) were used for controlling L. major and bacteria. One hundred samples from skin ulcers of mice were examined, and 200 bacterial colonies were isolated. Forty-eight different genera and species were obtained and identified by Gram staining and physiological and biochemical characterization using identification kits. All samples were positive for secondary bacterial infections. Of the isolates, 79.16% were identified as Gram-negative bacteria, and 28.84% were identified as Gram-positive bacteria; only one yeast species was found. Interestingly, pure allicin liquid at a concentration 50 µL/mL exhibited antibacterial activity against a wide range of Gram-negative and some Gram-positive bacteria, in addition to yeast, and was 71.43% effective. Antimicrobial resistance patterns of all genera and species were determined using 15 different antibiotics. Allicin (50 µL/mL) and Cip 5 were the most effective against L. major and 92.30% of isolated bacteria. Stenotrophomonas maltophilia was the most resistant bacterium to the tested antibiotics with a survival rate of 73.33%, and it exhibited resistance to allicin.