Mithun Rudrapal

Topical ethosomal capsaicin attenuates edema and nociception in arthritic rats.

Abstract In this study, topical ethosomal formulation of capsaicin was prepared and evaluated for bio-efficacy in arthritic rats. Physical and biological characterizations of prepared capsaicin-loaded nano vesicular systems were also carried out. Ethosomal capsaicin showed significant reduction of rat paw edema along with promising antinociceptive action. The topical antiarthritic efficacy of prepared formulation of capsaicin was found more than that of Thermagel, a marketed gel of capsaicin. From toxicological study, no predictable signs of toxicity such as skin irritation (of experimental rats) were observed. Based on this finding, ethosomal capsaicin could be proposed as an effective as well as a safe topical delivery system for the long-term treatment of arthritis and associated inflammo-musculoskeletal disorders. Such exciting result would eventually enlighten the analgesic and anti-inflammatory potential of capsaicin for topical remedy.

Potential of capsaicin-loaded transfersomes in arthritic rats

Abstract In the present study, the biopotential of capsaicin (an active principle of capsicum) as a topical antiarthritic agent was studied in arthritic rats. Transfersomal vesicular system was employed for the topical administration of capsaicin in experimental rats. The characterization of prepared capsaicin-loaded transfersomes reveals their nano size (94 nm) with negative surface charge (−14.5 mV) and sufficient structural flexibility, which resulted in 60.34% entrapment efficacy, penetration across the biomembrane (220 µm) and 76.76% of drug release from vesicular system in 24 h in their intact form as evident from confocal laser scanning micrographic study. Results of transfersomal nanoformulation (capsaicin loaded, test) were compared with that of conventional gel formulation available in the market (Thermagel, standard), with an aim to assess the antiarthritic efficacy of our prepared capsaicin-loaded transfersomal formulation. In vivo antiarthritic activity study shows that our formulation possesses superior inhibitory activity than the marketed Thermagel formulation at the same dosage level, which could probably be due to the lesser permeability of Thermagel across the dermal barriers compared to our specially designed transfersomal delivery system. Moreover, the better tolerance of prepared vesicular formulation in biological system further enlightens the suitability of the transfersomal vesicle to be used as a novel carrier system for the topical administration of such highly irritant substance.

Penetration of Tamoxifen Citrate Loaded Ethosomes and Liposomes Across Human Skin: A Comparative Study with Confocal Laser Scanning Microscopy

In the present study, ethosomal and liposomal formulations containing tamoxifen citrate were prepared and evaluated for their penetration properties in human cadaver skin using Franz diffusion cell and confocal laser scanning microscope (CLSM). The results clearly revealed that ethosomal vesicles showed a better drug permeation profile than that of liposomal vesicles. In addition, low fluorescence intensity in CLSM was recorded with liposomes as compared to ethosomes, indicating lower cumulative amount of drug permeation from liposomal vesicles. Furthermore, CLSM showed uniform fluorescence intensity across the entire depth of skin in ethosomal treatment, indicating high penetrability of ethosomal vesicles through human cadaver skin. In contrast, low penetrability of conventional liposomal vesicles was recorded as penetration was limited to the 7(th) section (i.e. upper epidermis layer) of skin as evident from visualization of intact liposomal vesicles in CLSM.

Synthesis, antimalarial-, and antibacterial activity evaluation of some new 4-aminoquinoline derivatives

Some new 4-aminoquinoline derivatives were synthesized, characterized by their analytical and spectral data (IR, 1HNMR, 13CNMR and MS), and screened for in vitro antimalarial activity against a chloroquine-sensitive strain of Plasmodium falciparum (3D7). Results clearly reveal that all the synthesized compounds possess in vitro antimalarial activity at the tested dose which, however, was considerably less than that of the standard reference drug, chloroquine. From results, it could be assumed that the presence of an aromatic bulky group with optimal lipophilicity at 1,3-thiazinan-4-one ring system might be an important requirement for the antimalarial activity of synthesized compounds, 6a–g. In addition to the evaluation of antimalarial activity, the synthesized compounds were also screened for antibacterial activity against six different strains of Gram-positive (Bacillus subtilis, Bacillus cereus, and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae). All the compounds at the tested doses were found to be active against all the tested organisms, but were less active as compared to the standard drug, ofloxacin. Results of antibacterial study indicate that aromatic bulky substituents have greater contributing effect than the aliphatic non-bulky group toward the antibacterial activity of the prepared 4-aminoquinoline derivatives.

Novel series of 1,2,4-trioxane derivatives as antimalarial agents

Abstract Among three series of 1,2,4-trioxane derivatives, five compounds showed good in vitro antimalarial activity, three compounds of which exhibited better activity against P. falciparum resistant (RKL9) strain than the sensitive (3D7) one. Two best compounds were one from aryl series and the other from heteroaryl series with IC50 values of 1.24 µM and 1.24 µM and 1.06 µM and 1.17 µM, against sensitive and resistant strains, respectively. Further, trioxane derivatives exhibited good binding affinity for the P. falciparum cysteine protease falcipain 2 receptor (PDB id: 3BPF) with well defined drug-like and pharmacokinetic properties based on Lipinski’s rule of five with additional physicochemical and ADMET parameters. In view of having antimalarial potential, 1,2,4-trioxane derivative(s) reported herein may be useful as novel antimalarial lead(s) in the discovery and development of future antimalarial drug candidates as P. falciparum falcipain 2 inhibitors against resistant malaria.

Newer series of trioxane derivatives as potent antimalarial agents

Among synthesized 1,2,4-trioxane derivatives, six compounds were found to be considerably potent, with better activity against resistant strain of P. falciparum than the sensitive strain. The IC50 values of the best compound with 4-hydroxyphenyl substitution were found to be 0.391 and 0.837 µg/mL against sensitive and resistant strain of P. falciparum, respectively. Results of the tested compounds were comparable with that of the standard drug, chloroquine (IC50 = 0.044 and 0.205 µg/mL against sensitive and resistant strain of P. falciparum, respectively). Docking simulation, in silico drug-likeness and ADMET studies further validated the results of in vitro antimalarial activity. Trioxane derivatives exhibited good binding affinity for the P. falciparum cysteine protease falcipain 2 receptor (PDB id: 3BPF) with well defined drug-like and pharmacokinetic properties based on Lipinski’s rule of five with additional physicochemical and ADMET parameters. In view of having antimalarial potential, newly reported 1,2,4-trioxane derivative(s) may be useful as novel antimalarial lead(s) in the discovery and development of future antimalarial drug candidates as P. falciparum falcipain 2 inhibitors against resistant malaria.

Endoperoxide antimalarials: development, structural diversity and pharmacodynamic aspects with reference to 1,2,4-trioxane-based structural scaffold

Malaria disease continues to be a major health problem worldwide due to the emergence of multidrug-resistant strains of Plasmodium falciparum. In recent days, artemisinin (ART)-based drugs and combination therapies remain the drugs of choice for resistant P. falciparum malaria. However, resistance to ART-based drugs has begun to appear in some parts of the world. Endoperoxide compounds (natural/semisynthetic/synthetic) representing a huge number of antimalarial agents possess a wide structural diversity with a desired antimalarial effectiveness against resistant P. falciparum malaria. The 1,2,4-trioxane ring system lacking the lactone ring that constitutes the most important endoperoxide structural scaffold is believed to be the key pharmacophoric moiety and is primarily responsible for the pharmacodynamic potential of endoperoxide-based antimalarials. Due to this reason, research into endoperoxide, particularly 1,2,4-trioxane-, 1,2,4-trioxolane- and 1,2,4,5-teraoxane-based scaffolds, has gained significant interest in recent years for developing antimalarial drugs against resistant malaria. In this paper, a comprehensive effort has been made to review the development of endoperoxide antimalarials from traditional antimalarial leads (natural/semisynthetic) and structural diversity of endoperoxide molecules derived from 1,2,4-trioxane-, 1,2,4-trioxolane- and 1,2,4,5-teraoxane-based structural scaffolds, including their chimeric (hybrid) molecules, which are newer and potent antimalarial agents.

Phytochemical and biological potential of Cassia tora Linn.

Cassia tora Linn. (Caesalpinaceae) is a semi-wild annual herb grown widely in different places of south-east Asia including India, Northern Australia and Americas. This plant species is well known for having potential in traditional medicine practices for the treatment of a variety of disorders and ailments ranging from simple cough, hypertension to diabetes. Recent scientific investigation reveals its phytochemical as well as biological potential. C. tora has been proven to be medicinally effective for having antimicrobial, antiantioxidant, antihypertensive, antidiabetic and antimutagenic activities, just to name a few. This paper encompasses a comprehensive review on phytochemical and biological aspects of Cassia tora L.

Antidiabetic activity of hydro-alcoholic stem bark extract of Callicarpa arborea Roxb. with antioxidant potential in diabetic rats

BACKGROUND Despite the availability of synthetic antidiabetic drugs, diabetes mellitus is still affecting millions of people with increasing rate of disease incidence and mortality throughout the world. Ethnomedicinal survey documents the traditional usefulness of Callicarpa arborea Roxb. stem bark in the management of diabetes mellitus. MATERIALS AND METHODS In our study, hydro-alcoholic extract (HAE) of Callicarpa arborea stem bark was prepared according to WHO guidelines for herbal drugs, and screened for antidiabetic activity in streptozotocin (STZ)-induced diabetic rats. Acute oral toxicity and in vitro antioxidant activity studies along with phytochemical analyses of HAE were also carried out. RESULTS Acute oral toxicity study indicated that HAE was safe up to a dose of 2000mg/kg body weight of rats. Results of antidiabetic activity study revealed that HAE of C. arborea stem bark possesses significant (p<0.05) hypoglycemic activity compared to normal control group in experimental rats. Histological observations of treated pancreas and liver tissues confirmed the antidiabetic efficacy of HAE. In antioxidant activity, HAE exhibited significant radical scavenging activity. CONCLUSION From results, it can be concluded that HAE of C. arborea stem bark may have possible role as herbal antioxidants in the prevention and/or treatment of oxidative stress-induced diabetes mellitus. The antioxidant property of plant phenolic and flavonoid contents present in HAE might be responsible for the antidiabetic efficacy of C. arborea stem bark.