Berberine Nanoparticles with Enhanced in vitro Bioavailability: Characterization and Antimicrobial Activity [Retraction]

[This retracts the article DOI: 10.2147/DDDT.S156123.].

Statement of Removal: Role and Impact of Engaging Private Pharmacies in TB Care and Control in Selected Districts of Pakistan

Tuberculosis (TB) constitutes a major public health challenge and is one of the top 10 causes of death worldwide. In 2015, over 10.4 million people fell ill with TB and 1.8 million died from the disease; an estimated 480,000 people developed multidrug-resistant TB (MDR-TB); and an estimated 1 million children became ill with TB, and 170,000 children died due to TB. According to the WHO, the incidence of TB cases in Pakistan for all types are 270/100,000. A cross-sectional study was designed, and a potential 2,000 registered pharmacies from different rural and urban/peri-urban areas of 12 districts across Pakistan were selected. Supervisors, pharmacy focal persons, students and faculty coordinators from seven universities were trained on TB case identification, a referral mechanism, and collaboration with the program, followed by signing MOU. In phase 1 an entire (100%) pharmacy staff was trained; followed by the second phase, in which 96% of focal persons were trained from private pharmacies nation-wide. A total of 4,085 referrals were sent to the trained doctors, out of which 622 cases were identified. The percentage of case registration was 14.5% of total referrals. The highest number of TB presumptives (527) were referred from private pharmacies of district Muzafargarh, and 136 TB cases were registered out of these referrals. For a significant impact on case detection, it is important to acknowledge a number of concerns expressed by pharmacists and attempt to change both client's and provider's expectations with regard to the pharmacist's role.

Antimicrobial, Cytotoxic, and Antioxidant Potential of a Novel Flavone "6,7,4'-Trimethyl Flavone" Isolated from Wulfenia amherstiana

Wulfenia amherstiana belongs to the Scrophulariaceae family and various plants of this family are known for their biological activities. The present study was focused on the isolation of bioactive compounds including a novel flavone 6,7,4'-trimethyl flavone (TMF) along with three known flavonoids such as quercetin, rutin, and a steroid β-sitosterol which were isolated from the ethanolic extract of W. amherstiana (Himalayan Wulfenia) through column chromatography and purified by using HPLC. Their structures were identified and elucidated through electron ionization mass spectroscopy (EIMS), 1DNMR (1H-NMR and 13C-NMR), and 2DNMR (COSY, HMQC, and HMBC) spectroscopy. The antimicrobial activities of this novel compound were evaluated through agar well diffusion method, while antioxidant and cytotoxic activities were assessed through 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging assay and brine shrimp lethality assay, respectively. The NMR data revealed that TMF is a novel compound. TMF showed potential antibacterial and antifungal activities against Staphylococcus aureus (MIC = 128 μg/ml) and Candida albicans (MIC = 128 μg/ml). The cytotoxic potential of TMF was determined from brine shrimp lethality assay with LD50 of 127.01 μg/ml. The free-radical scavenging potential of TMF at various concentrations implicated its strong antioxidant activity in vitro. The results revealed that TMF demonstrated substantial antimicrobial activity against S. aureus and C. albicans, strong antioxidant activity, and moderately cytotoxic activity.

Berberine nanoparticles with enhanced in vitro bioavailability: characterization and antimicrobial activity

BACKGROUND

Berberine is an isoquinoline alkaloid widely used in Ayurveda and traditional Chinese medicine to treat illnesses such as hypertension and inflammatory conditions, and as an anticancer and hepato-protective agent. Berberine has low oral bioavailability due to poor aqueous solubility and insufficient dissolution rate, which can reduce the efficacy of drugs taken orally. In this study, evaporative precipitation of nanosuspension (EPN) and anti-solvent precipitation with a syringe pump (APSP) were used to address the problems of solubility, dissolution rate and bioavailability of berberine.

METHODS

Semi-crystalline nanoparticles (NPs) of 90-110 nm diameter for APSP and 65-75 nm diameter for EPN were prepared and then characterized using differential scanning calorimetry (DSC) and X-ray powder diffractometry (XRD). Thereafter, drug content solubility and dissolution studies were undertaken. Berberine and its NPs were evaluated for their antibacterial activity.

RESULTS

The results indicate that the NPs have significantly increased solubility and dissolution rate due to conversion of the crystalline structure to a semi-crystalline form.

CONCLUSION

Berberine NPs produced by both APSP and EPN methods have shown promising activities against Gram-positive and Gram-negative bacteria, and yeasts, with NPs prepared through the EPN method showing superior results compared to those made with the APSP method and the unprocessed drug.

Toxicity of ultraviolet radiation exposure to the lens expressed by maximum tolerable dose

The maximum tolerable dose (MTD2.3:16) for avoidance of cataract on exposure to ultraviolet radiation (UVR)-300 nm in the rat was here estimated at 3.65 kJ/m2. Sprague-Dawley rats were unilaterally exposed to UVR in the 300 nm wavelength region. One week after the exposure, the intensity of forward light scattering was measured. Toxicity for continuous response events can be estimated with MTD. Current safety standards for avoidance of cataract after exposure to UVR are based on a binary response event. It has, however, recently been shown that UVR-induced cataract is a continuous dose-dependent event. MTD provides a statistically well-defined criterion of toxicity for continuous response events.