Screening of microorganisms for hydrolyases with commercial potential

Advancement in green chemistry has increased the use of microbial hydrolyases in various industries and chemical processes because of high catalytic efficiency, specificity, cost-effectiveness and eco-friendly nature. Bioconversion of tannins such as tannic acid is achieved by tannin acyl hydrolase, also known as tannase. It converts tannic acid into glucose and gallic acid by catalyzing the hydrolysis of ester and depside linkages in tannic acid. Tyrosinase is monophenol and O-diphenol oxidase a copper containing enzyme catalyzes the oxidation of tyrosine and generates different types of pigment such as melanin. Xylanases hydrolyze xylan into its constituent sugar with the help of several debranching enzymes. Microbial strains isolated from various sources were screened for these hydrolyases: Bhavnagar marine salterns (Bacillus megaterium BVUC_01 and Bacillus licheniformis BVUCh_02); Okhamadhi marine salterns Aspergillus versicolor; Spoiled/infected pomegranate (Xenoacremonium falcatum, two strains PGF1 and PGF4, Bacillus velezensisPGF2 and Candida freyschussiiPGF3. The other laboratory maintained bacterial cultures namely, Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi were also used in this study. Asp. versicolor and Xen. falcatum (PGF1) produced all the three enzymes (tannase, tyrosinase and xylanase). B. licheniformis, B. megaterium, B. subtilis, B. velezensis produced tyrosinase and xylanase. Xen. falcatum (PGF4) and PGF2 produced tannase and xylanase. PGF3 produced tannase and tyrosinase. While, Bacillus megaterium and Salmonella typhi showed only tyrosinase activity. Candida freyschussii showed tannase activity. Staphylococcus aureus did not produce any of these enzymes.

The Effects of Polyphenol, Tannic Acid, or Tannic Acid in Combination with Pamidronate on Human Osteoblast Cell Line Metabolism

Background: This study investigates the effect of tannic acid (TA) combined with pamidronate (PAM) on a human osteoblast cell line. Methods: EC50 for TA, PAM, and different combination ratios of TA and PAM (25:75, 50:50, 75:25) were measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The combination index value was utilized to analyze the degree of drug interaction, while trypan blue assay was applied to analyze the cells proliferation effect. The mineralization and detection of bone BSP and Osx genes were determined via histochemical staining and PCR test, respectively. Results: The EC50 of osteoblasts treated with TA and a 75:25 ratio of TA and PAM were more potent with lower EC50 at 0.56 µg/mL and 0.48 µg/mL, respectively. The combination of TA and PAM (75:25) was shown to have synergistic interaction. On Day 7, both TA and PAM groups showed significantly increased proliferation compared with control and combination groups. On Day 7, both the TA and combination-treated groups demonstrated a higher production of calcium deposits than the control and PAM-treated groups. Moreover, on Day 7, the combination-treated group showed a significantly higher expression of BSP and Osx genes than both the TA and PAM groups. Conclusion: Combination treatment of TA and PAM at 75:25 ameliorated the highest enhancement of osteoblast proliferation and mineralization as well as caused a high expression of BSP and Osx genes.

The Application of Tannic Acid in Orthopedics

Tannic acid (TA) is a naturally occurring polyphenol compound commonly found in tea, wine, and fruits. Because of the excellent structural and functional properties afforded by TA, materials based on the structure of polyhydroxyphenols have great value, particularly for orthopedic transplantation. This compound, for example, can form a strong interaction with metals and can form a stable coating on their surfaces, thus, improving the physical and chemical properties of bone–implant surfaces and boosting implantation success rates. TA can also inhibit the activity of osteoclasts, thus, playing a potential role in the treatment of osteoporosis. Furthermore, if the body becomes polluted with heavy metals, TA can chelate the ions to protect bone morphology and structure. It also has a significant antibacterial effect and can reduce infections caused by surgical implantation and inhibit a variety of tumor cells, thereby promoting its potential application in spinal metastasis surgery. Furthermore, it can also slow the corrosion caused by magnesium alloys, thereby greatly improving the development of degradable orthopedic metal fixatives. Importantly, TA is cheap and easy to obtain, making it extremely valuable for use in orthopedics. This review focuses on the research status and practical applications of TA, and prospects for its future application for orthopedics (Figure 1).

Two-step screening method to identify α-synuclein aggregation inhibitors for Parkinson’s disease

Parkinson’s disease is a neurodegenerative disease characterized by the formation of neuronal inclusions of α-synuclein in patient brains. As the disease progresses, toxic α-synuclein aggregates transmit throughout the nervous system. No effective disease-modifying therapy has been established, and preventing α-synuclein aggregation is thought to be one of the most promising approaches to ameliorate the disease. In this study, we performed a two-step screening using the thioflavin T assay and a cell-based assay to identify α-synuclein aggregation inhibitors. The first screening, thioflavin T assay, allowed the identification of 30 molecules, among a total of 1262 FDA-approved small compounds, which showed inhibitory effects on α-synuclein fibrilization. In the second screening, a cell-based aggregation assay, seven out of these 30 candidates were found to prevent α-synuclein aggregation without causing substantial toxicity. Of the seven final candidates, tannic acid was the most promising compound. The robustness of our screening method was validated by a primary neuronal cell model and a Caenorhabditis elegans model, which demonstrated the effect of tannic acid against α-synuclein aggregation. In conclusion, our two-step screening system is a powerful method for the identification of α-synuclein aggregation inhibitors, and tannic acid is a promising candidate as a disease-modifying drug for Parkinson’s disease.

Biomedical applications of tannic acid

Tannic Acid (TA) is a naturally occurring antioxidant polyphenol that has gained popularity over the past decade in the field of biomedical research for its unique biochemical properties. Tannic acid, typically extracted from oak tree galls, has been used in many important historical applications. TA is a key component in vegetable tanning of leather, iron gall ink, red wines, and as a traditional medicine to treat a variety of maladies. The basis of TA utility is derived from its many hydroxyl groups and its affinity for forming hydrogen bonds with proteins and other biomolecules. Today, the study of TA has led to the development of many new pharmaceutical and biomedical applications. TA has been shown to reduce inflammation as an antioxidant, act as an antibiotic in common pathogenic bacterium, and induce apoptosis in several cancer types. TA has also displayed antiviral and antifungal activity. At certain concentrations, TA can be used to treat gastrointestinal disorders such as hemorrhoids and diarrhea, severe burns, and protect against neurodegenerative diseases. TA has also been utilized in biomaterials research as a natural crosslinking agent to improve mechanical properties of natural and synthetic hydrogels and polymers, while also imparting anti-inflammatory, antibacterial, and anticancer activity to the materials. TA has also been used to develop thin film coatings and nanoparticles for drug delivery. In all, TA is fascinating molecule with a wide variety of potential uses in pharmaceuticals, biomaterials applications, and drug delivery strategies.