Therapeutic potential of Aloe vera-A miracle gift of nature

Immunobiology and Application of Aloe Vera-Based Scaffolds in Tissue Engineering

Aloe vera (AV), a succulent plant belonging to the Liliaceae family, has been widely used for biomedical and pharmaceutical application. Its popularity stems from several of its bioactive components that have anti-oxidant, anti-microbial, anti-inflammatory and even immunomodulatory effects. Given such unique multi-modal biological impact, AV has been considered as a biomaterial for regenerative medicine and tissue engineering applications, where tissue repair and neo-angiogenesis are vital. This review outlines the growing scientific evidence that demonstrates the advantage of AV as tissue engineering scaffolds. We particularly highlight the recent advances in the application of AV-based scaffolds. From a tissue engineering perspective, it is pivotal that the implanted scaffolds strike an appropriate foreign body response to be well-accepted in the body without complications. Herein, we highlight the key cellular processes that regulate the foreign body response to implanted scaffolds and underline the immunomodulatory effects incurred by AV on the innate and adaptive system. Given that AV has several beneficial components, we discuss the importance of delving deeper into uncovering its action mechanism and thereby improving material design strategies for better tissue engineering constructs for biomedical applications.

Antimicrobial Efficiency of Aloe arborescens and Aloe barbadensis Natural and Commercial Products

Nowadays, there are many commercial products from natural resources on the market, but they still have many additives to increase their biological activities. On the other hand, there is particular interest in natural sources that would have antimicrobial properties themselves and would inhibit the growth and the reproduction of opportunistic microorganisms. Therefore, a comparative antimicrobial study of natural samples of aloe and its commercial products was performed. Qualitative and quantitative determination of antimicrobial efficiency of Aloe arborescens and Aloe barbadensis and its commercial products on fungi, Gram-negative, and Gram-positive bacteria was performed. Samples exhibited antimicrobial activity and slowed down the growth of all tested microorganisms. Research has shown that natural juices and gels of A. arborescens and A. barbadensis are at higher added concentrations comparable to commercial aloe products, especially against microbial cultures of Bacillus cereus, Candida albicans, and Pseudomonas aeruginosa, whose growths were completely inhibited at a microbial concentration of 600 μg/mL. Of particular importance are the findings of the good antimicrobial efficacy of fresh juice and gel of A. arborescens on tested microorganisms, which is less known and less researched. These results show great potential of A. arborescens for further use in medicine, cosmetics, food, and pharmaceutical industries.

Antioxidant, anti-inflammatory and hepatoprotective activities of Terminalia bellirica and its bioactive component ellagic acid against diclofenac induced oxidative stress and hepatotoxicity

Long term usage and overdose of diclofenac (DCF), an anti-inflammatory drug is known to cause oxidative stress and liver injury. The present study reports the antioxidant, anti-inflammatory and hepatoprotective activities of Terminalia bellirica (Tb) fruit aqueous and ethyl acetate extracts and its bioactive compound ellagic acid (EA) against DCF-induced toxicity. in vitro antioxidant activities were measured by ABTS and FRAP assays while anti‐inflammatory activity was assessed by the albumin denaturation method. The adverse effects of DCF and hepatoprotective potential of Tb extracts and EA were assessed in serum and liver tissue of rats after oral administration for 21 days. Silymarin was used as standard hepatoprptective agent for comparison. Hepatic markers analyzed in serum included ALP, GPT, GOT, LDH, γ-glutamyl transferase, total protein, creatinine, and uric acid while superoxide dismutase (SOD) and catalase (CAT) were analyzed in liver tissue. The EA exhibited superior ABTS radical scavenging, FRAP, and anti-inflammatory activities as compared to fruit extracts. DCF treatment led to rise in the levels of most of the serum hepatic markers with decline in total serum protein as well as SOD and CAT in liver tissue. The supplementation of extracts, EA and silymarin in DCF treated rats significantly reduced the adverse effects of DCF on serum and tissue markers. Histopathology of the liver indicated that extracts and EA significantly decreased the degree of liver fibrosis. The hepatoprotective ability of EA was comparable to the silymarin but activity of Tb fruit extracts was little lower. Among fruit extracts ethyl acetate extract exhibited better activity than aqueous extract. The results revealed that ellagic acid and T. bellirica fruit extracts have potential to mitigate oxidative stress and hepatotoxicity produced by long term use of diclofenac.

Differential inhibition of gelatinase activity in human colon adenocarcinoma cells by Aloe vera and Aloe arborescens extracts

BACKGROUND

Aloe's reported bioactivities (anticancer, anti-inflammatory and wound healing) suggest they might inhibit a subgroup of matrix metalloproteinases (MMPs) called gelatinases (MMP-2 and MMP-9). The goal of the present study was to compare the MMP inhibitory potential of two Aloe species, A. vera and A. arborescens.

METHODS

Different types of extraction were tested and specific bioactive compounds were quantified. Cancer cell invasion inhibitory activities were measured in vitro using the wound healing assay in human colon cancer cells (HT29). Effects on gelatinase activities were further assessed by dye-quenched gelatin and gelatin zymography.

RESULTS

Different types of extraction yielded significantly different levels of bioactivities and of bioactive compounds, which might be due to a greater amount of extractable bioactive compounds such as anthraquinones. Both A. arborescens and A. vera have potential as inhibitory agents in cancer cell proliferation via MMP-9 and MMP-2 enzymatic activity inhibition, being able to reduce colon cancer cell proliferation and migration but A. arborescens showed to be a more effective inhibitor of cancer cell migration than A. vera.

CONCLUSION

This work opens novel perspectives on the mode of action of Aloe species in cancer cell migration and may provide clues as to why there are so many conflicting results on Aloe's activities.

Aloe vera: A Medicinal Plant Used in Skin Wound Healing

Skin injury is a major problem threatening human physical and mental health, and how to promote wound healing has been the focus. Developing new wound dressings is an important strategy in skin regeneration. Aloe vera is a medicinal plant with a long history, complex constituents, and various pharmacological activities. Many studies have shown that A. vera plays an important role in promoting wound healing. Adding A. vera to wound dressing has become an ideal way. This review will describe the process of skin injury and wound healing and analyze the role of A. vera in wound healing. In addition, the types of wound dressing and the applications of A. vera in wound dressing will be discussed.

The therapeutic efficacy of Aloe vera gel ointment on staphylococcal pyoderma in dogs

BACKGROUND AND AIM

Staphylococcus pyoderma is a common problem in dogs that need a novel treatment rather than antibiotic therapy. The aim of this study was to investigate the therapeutic efficacy, anti-inflammatory, and antioxidative properties of Aloe vera (Aloe barbadensis) gel ointment on dogs' Staphylococcus pyoderma compared to gentamicin ointment.

MATERIALS AND METHODS

The inhibition zone of A. vera extract 20% and 40% and gentamicin 1% against Staphylococcus aureus was determined on well diffusion agar. Twenty Baladi local breed dogs were used as control negative group before intradermal inoculation with 105 CFU S. aureus. The animals were classified into four equal groups, control positive group without treatment (n=5), treated groups by 20% A. vera gel ointment (n=5), 40% A. vera gel ointment (n=5), and gentamicin ointment 1% (n=5). Topical application of A. vera and gentamicin ointments was carried out twice daily for 2 weeks until complete healing of dogs' pyoderma. Clinical evaluation was recorded. Inflammatory, oxidant, and antioxidant parameters were measured in serum.

RESULTS

The inhibition zone of A. vera extracts 20% and 40% was 19 mm and 23 mm, respectively, while gentamicin 1% was 18 mm. The half maximal inhibitory concentration (of A. vera 20% and 40% were 13.70 with R2=0.98. Dogs' pyoderma treated with A. vera gel ointment 20% and 40% were more likely to have low haptoglobin and tumor necrosis factor-α concentrations than gentamicin 1% ([odds ratio [OR]=4.6; 95% confidence interval [CI]=1.31-17.40; p<0.05]; [OR=5.2; 95% CI=1.04-22.30; p<0.05]), respectively.

CONCLUSION

It seems evident that A. vera has therapeutic effect, antibacterial, and anti-inflammatory effects against dogs' staphylococcal pyoderma than gentamicin that would support its further use rather than antibiotics in one health arena.

Aloe vera Flowers, a Byproduct with Great Potential and Wide Application, Depending on Maturity Stage

Flowers of Aloe vera are a byproduct providing a valuable source of bioactive compounds with different functions for health benefits. The characterization in amino acids, organic acids, sugars, trigonelline, volatiles compounds, fatty acids, total phenolic, carotenoids, vitamin C content, and antioxidant capacity of Aloe flowers (Aloe barbadensis Miller) has been studied at three maturity stages (I: immature; II: mature; III: mature, with flowers buds opened). Immature flowers presented the highest content in phenyl alanine, tyrosine, citric acid, trigonelline, carotenoids, retinol activity equivalent, vitamin C, and total phenolic and antioxidant capacity. As the flower develops, the content of these compounds decreases. Aloe vera flowers presented an important content in fatty acids, and the principal concentration was identified in polyunsaturated unsaturated fatty acids (PUFAs) as α-linolenic acid, and linoleic acid, with a ratio close to one. The main saturated fatty acid was palmitic acid, followed by stearic acid. Maturity stage III showed the lowest fatty acid content. The bioactive compounds found in Aloe vera flowers have potential applications in the cosmetic, pharmaceutical, nutraceutical, and food industries. Depending on the compound of interest, it could be worthwhile harvesting flowers at maturity stage I, thereby reducing the energy consumption of flowers from the plant and thus favoring plant development. This is an example of a circular economy for Aloe vera producers, generating economic and business opportunities and thus providing environmental and social benefits.

Advanced SA/PVA-based hydrogel matrices with prolonged release of Aloe vera as promising wound dressings

This work focuses on the influence of different amounts (5, 10, 15, 20 and 25%, v/v) of solution of Aloe vera on the chemical structure and properties of sodium alginate/poly(vinyl alcohol) hydrogel films. The polymeric matrix was prepared following the chemical cross-linking method using poly(ethylene glycol) diacrylate (PEGDA, Mn = 700 g/mol) as a cross-linking agent. First, the gel fractions of the modified hydrogels were determined and their swelling behavior in distilled water and phosphate-buffered saline (PBS) was tested. Subsequently, the following properties of the modified hydrogel materials were studied: structural (FT-IR spectra analysis), morphological (SEM analysis) and mechanical (tensile strength, elongation at break and hardness). Moreover, a thermal analysis (TG/DTG and DSC) confirmed that the SA/PVA hydrogels containing Aloe vera exhibited slightly higher thermal stability than the unmodified hydrogels, which allows concluding that a rigid and thermally stable three-dimensional structure had been obtained. Additionally, the release profile of polysaccharides from the hydrogel matrix was evaluated in PBS at 37 °C. The results show that the active substance was released in a prolonged manner, gradually, even for a week. It was found that the presence of Aloe vera inside the cross-linked polymeric network improved the active substance delivery properties of the hydrogel films. When greater amounts of Aloe vera were applied, the hydrogel had an irregular surface structure, as revealed by SEM images. The chemical structure was confirmed on the basis of an FT-IR spectral analysis. Concluding, SA/PVA/Aloe vera matrices are promising compounds and deserve further studies towards application in interactive wound dressings. Additionally, the cytotoxicity of the materials was studied and the results indicated good adhesion properties and no toxicity. In vitro experiments performed on normal human dermal fibroblasts proved excellent cell attachment on the Aloe vera hydrogel discs, which promoted cells spreading and proliferation.

Terminalia bellirica (Gaertn.) roxb. (Bahera) in health and disease: A systematic and comprehensive review

BACKGROUND

Terminalia bellirica (Gaertn.) Roxb. is one of the oldest medicinal herbs of India, Pakistan, Nepal, Bangladesh and Sri Lanka as well as South-East Asia. Its medicinal utility has been described in the different traditional medicinal systems, such as Ayurveda, Unani, Siddha, and traditional Chinese medicine.

PURPOSE

The present study is aimed at providing a comprehensive overview on the traditional medicinal use, major phytoconstituents, biological and pharmacological activities and related mechanisms of actions and clinical studies of T. bellirica. Another objective is to describe current limitations and future direction of T. bellirica-related research.

METHODS

PubMed, ScienceDirect, Scopus, Cochrane Library, and EBOSCO host databases were selected to explore literature published between 1980 and 2020 (till March). Keywords used in various combinations comprised of Terminalia bellirica, phytoconstituents, health effects, pharmacological activities, molecular targets, in vitro, in vivo, clinical studies, and disease prevention.

RESULTS

A broad spectrum in vitro and in vivo studies suggested various biological and pharmacological effects, including antioxidant, anti-inflammatory, immunomodulatory, antimicrobial, hepatoprotective, renoprotective, antidiabetic, anti-hyperlipidemic, and anticancer activities. Diverse bioactivities of T. bellirica have been ascribed to the presence of many bioactive phytochemicals, such as glucoside, tannins, gallic acid, corilagin, ellagic acid, ethyl gallate, galloyl glucose, chebulagic acid, and arjunolic acid.

CONCLUSION

Preclinical and clinical studies have suggested that T. bellirica plant and its phytoconstituents have immense potential for prevention and treatment of various diseases. Additional in vivo studies and clinical trials are warranted to realize the complete medicinal attributes of this plant.

Stellaria media (L.) Vill.- A plant with immense therapeutic potentials: phytochemistry and pharmacology

Stellaria media Vill. is a representative of Caryophyllaceae family. The plant is widely dispersed all over the world and has been used as therapeutic substance since time immemorial. This review is aimed at exploring the chemical constituents and pharmacological activities of S. media. The findings revealed important secondary metabolites such as flavonoid, oligosaccharide stellariose, anthraquinone derivatives, fatty acid, steroid saponins and phenolic compounds. These bioactive metabolites displayed diverse pharmacological activities such as anti-obesity, antifungal, antibacterial, antioxidant, anti-proliferative, anti-inflammatory, analgesic, antidiabetic and anxiolytic activities. All findings revealed that S. media is a major species of Caryophyllaceae family. However, bioactive constituents and pharmacological potential of are not well appraised. Hence, extracts with established pharmacological activities should be subjected to bioassay guided isolation so as to obtain compounds with novel structural moieties prior to toxicogenetic appraisals.

Effects of Aloe arborescens Whole Plant Homogenate on Lipid Metabolism, Inflammatory Conditions and Liver Function of Dairy Cows during the Transition Period

Simple Summary

This study highlights the positive effect of an Aloe arborescens Mill. whole plant homogenate on the liver and renal function of dairy cows during the peripartum period. Such positive effects could depend on both anti-hyperlipidemic and anti-inflammatory effects of Aloe that could have mitigated hepatic stresses that typically occur in early lactation. Our findings suggest Aloe arborescens supplementation to be an effective strategy to ameliorate adverse metabolic conditions in transition cows, indicating it as a preventive nutraceutical strategy against metabolic disorders.

Abstract

The anti-hyperlipidemic and anti-inflammatory effects exerted by Aloe on monogastric mammals suggest it as a potential strategy to address the tremendous metabolic alterations that affect dairy cows during their transition to calving. A group of 20 multiparous Italian Holstein dairy cows were housed in freestalls and allocated into two homogeneous groups to receive either 200 g/d of water (CTR) or 200 g/day of Aloe arborescens Mill. whole plant homogenate through a rumen tube (AAM) between −14 and 14 days from calving (DFC). From −14 to 35 DFC, the BCS, and milk yield were measured, and blood samples were collected to assess the hematochemical profile. Data underwent ANOVA testing using a mixed model for repeated measurements, including the treatment and time and their interactions as fixed effects. Compared to CTR cows, AAM cows had a less pronounced BCS loss in early lactation (p < 0.01), indicating less mobilization of body reserves. Compared to CTR cows, AAM cows had a lower plasma concentration of nonesterified fatty acids and beta hydroxybutyrate (p < 0.01 and = 0.01 respectively) that, paired with the lower butterfat content and fat/protein ratio in their milk (p = 0.03 and < 0.01 respectively), indicates that Aloe reduced the mobilization of body fats. AAM cows had a reduced concentration of myeloperoxidase in plasma and a lower SCC in milk compared to CTR cows (p = 0.02 for both), indicating an anti-inflammatory effect of Aloe. Furthermore, AAM cows had a lower plasma concentration of ceruloplasmin (p < 0.05) and higher plasma concentration of cholesterol, retinol, and paraoxonase compared to CTR cows (p < 0.01, < 0.01 and < 0.05 respectively), indicating Aloe was effective in mitigating the acute phase response in early lactation. Finally, AAM cows had lower plasma creatinine concentrations around calving (p < 0.05), a lower concentration of plasma bilirubin, and a higher concentration of plasma tocopherol compared to CTR cows (p = 0.01 for both). These data suggest Aloe has anti-hyperlipidemic and anti-inflammatory effects on transition dairy cows that could have ameliorated liver and kidney function disruption and increased the availability of body antioxidants in early lactation.

Efficacy of adjunctive therapy using Vizoovet in improving clinical signs of keratoconjunctivitis sicca in dogs: A pilot study

OBJECTIVE

To assess the clinical safety and efficacy of adjunctive therapy using Vizoovet to ameliorate clinical signs of keratoconjunctivitis sicca (KCS) in dogs.

ANIMALS STUDIED

Twenty client-owned dogs.

PROCEDURES

Canine patients diagnosed with KCS were enrolled in this prospective study. Patients were randomly selected to receive either Vizoovet or GenTeal drops twice daily in addition to twice daily tacrolimus 0.03% solution. Data were collected from only one eye of each patient and included STT-1, IOP, TFBUT, and results of objective clinical scoring performed by pet owners. Statistical significance was set at P ≤ .05.

RESULTS

In all, 20 dogs (20 eyes) were enrolled in this prospective randomized study. Females (n = 12; 60%) outnumbered males (n = 8; 40%) and all dogs were spayed/neutered. Mean age of all dogs was 10.6 ± 3.79 years. In both treatment groups, the improvement in STT-1 values over the course of the study was significant (P = .002). When comparing the STT-1 improvements between groups, no significance was found (P = .78). In both groups, the improvement in TFBUT was significant (P = .0018). When comparing the TFBUT improvements between groups, no significance was found (P = .14). Squinting, rubbing, ocular discharge, and medication administration scores all significantly improved throughout the course of the study; however, they did not differ significantly between groups. Throughout the study, no adverse side effects were noted clinically or by the pet owner in either group.

CONCLUSIONS AND CLINICAL RELEVANCE

Adjunctive treatment with Vizoovet was as safe and effective as GenTeal drops at improving clinical signs of dry eye in dogs.