Asif Husain

A review on therapeutic potential of Nigella sativa: A miracle herb

Nigella sativa (N. sativa) (Family Ranunculaceae) is a widely used medicinal plant throughout the world. It is very popular in various traditional systems of medicine like Unani and Tibb, Ayurveda and Siddha. Seeds and oil have a long history of folklore usage in various systems of medicines and food. The seeds of N. sativa have been widely used in the treatment of different diseases and ailments. In Islamic literature, it is considered as one of the greatest forms of healing medicine. It has been recommended for using on regular basis in Tibb-e-Nabwi (Prophetic Medicine). It has been widely used as antihypertensive, liver tonics, diuretics, digestive, anti-diarrheal, appetite stimulant, analgesics, anti-bacterial and in skin disorders. Extensive studies on N. sativa have been carried out by various researchers and a wide spectrum of its pharmacological actions have been explored which may include antidiabetic, anticancer, immunomodulator, analgesic, antimicrobial, anti-inflammatory, spasmolytic, bronchodilator, hepato-protective, renal protective, gastro-protective, antioxidant properties, etc. Due to its miraculous power of healing, N. sativa has got the place among the top ranked evidence based herbal medicines. This is also revealed that most of the therapeutic properties of this plant are due to the presence of thymoquinone which is major bioactive component of the essential oil. The present review is an effort to provide a detailed survey of the literature on scientific researches of pharmacognostical characteristics, chemical composition and pharmacological activities of the seeds of this plant.

Aroylpropionic acid based 2,5-disubstituted-1,3,4-oxadiazoles: Synthesis and their anti-inflammatory and analgesic activities

Synthesis and biological evaluation of various aroylpropionic acid derivatives containing 1,3,4-Oxadiazole nucleus is reported here. The compounds (3a-w) were synthesized by cyclization of 3-aroylpropionic acids into 1,3,4-oxadiazole nucleus by treating with various aryl acid hydrazides in the presence of POCl(3). The structures of new compounds are supported by IR, (1)H NMR and MS data. These compounds were tested in vivo for their anti-inflammatory activity. All the compounds tested showed anti-inflammatory activity. The compounds which showed activity comparable to the standard drug ibuprofen were screened for their analgesic, ulcerogenic and lipid peroxidation activities. Seven (3c, g, i, j, m, o, p) out of 23 new compounds showed very good anti-inflammatory activity in the carrageenan-induced rat paw edema test with very less ulcerogenic action. The compounds, which showed less ulcerogenic action, also showed reduced malondialdehyde production (MDA), which is one of the byproducts of lipid peroxidation. Compound 3i and o showed 89.50 and 88.88% of inhibition in paw edema, 69.80 and 66.25% protection against acetic acid induced writhings and 0.7 and 0.65 of severity index respectively, compared to 90.12, 72.50 and 1.95 values of ibuprofen. The study showed that the cyclization of carboxylic group of aroylpropionic acids into an oxadiazole nucleus resulted in compounds having good anti-inflammatory and analgesic effects with reduced gastric irritation.

Synthesis of novel 1,3,4-oxadiazole derivatives and their biological properties

Synthesis of novel 1,3,4-oxadiazole derivatives and their biological properties A novel series of 2-[3-(4-bromophenyl)propan-3-one]-5-(substituted phenyl)-1,3,4-oxadiazoles (4a-n) have been synthesized from 3-(4-bromobenzoyl)propionic acid (3) with the aim to get better anti-inflammatory and analgesic agents with minimum or without side effects (ulcerogenicity). Compound 3 was reacted with several aryl acid hydrazides (2a-n) in phosphorous oxychloride to obtain the title compounds. Structures of the synthesized compounds were supported by means of IR, 1H NMR and mass spectroscopy. Title compounds were evaluated for their anti-inflammatory, analgesic, ulcerogenic and antibacterial activities. Antibacterial activity was expressed as the corresponding minimum inhibitory concentration (MIC). A fair number of compounds were found to have significant anti-inflammatory and analgesic activities, while a few compounds showed appreciable antibacterial activity. The newly synthesized compounds showed very low ulcerogenic action. The findings of the present study indicate that cyclization of the carboxylic group of 3 into novel 1,3,4-oxadiazole nucleus resulted in increased anti-inflammatory and analgesic activities with a significant decrease of ulcerogenic activity. Sinteza i djelovanje novih derivata 1,3,4-oksadiazola Reakcijom 3-(4-brombenzoil)propionske kiseline (3) i aril hidrazida (2a-n) u prisutnosti fosforovog oksiklorida, sintetizirana je serija novih derivata 2-[3-(4-bromfenil)propan-3-on]-5-(supstituiranih fenil)-1,3,4-oksadiazola (4a-n) s ciljem da se dobiju spojevi s boljim protuupalnim i analgetskim, a manjim elcerogenim djelovanjem. Struktura sintetiziranih spojeva potvrđena je IR, 1H NMR i masenom spektroskopijom. Ispitano je protuupalno, analgetsko, ulcerogeno i antibakterijsko djelovanje spojeva 4a-n. Antibakterijsko djelovanje izraženo je kao minimalna inhibitorna koncentracija (MIC). Nekoliko spojeva imalo je značajno protuupalno i analgetsko djelovanje, nekoliko prilično antibakterijsko djelovanje, a svi su imali vrlo slabo ulcerogeno djelovanje. Rezultati ukazuju da ciklizacija karboksilne skupine u spoju 3 u 1,3,4-oksadiazol dovodi do povećanja protuupalnog i analgetskog, a do smanjenja ulcerogenog djelovanja.

Benzimidazole clubbed with triazolo-thiadiazoles and triazolo-thiadiazines: New anticancer agents

Two series of Benzimidazole clubbed with triazolo-thiadiazoles (5a-q, 5r, 5s and 5x-a(1)) and triazolo-thiadiazines (5t-w) were synthesized with an aim to produce promising anticancer agents. In vitro anticancer activities of synthesized compounds were investigated at the National Cancer Institute (NCI) against NCI 60 cell line panel; results showed good to remarkable broad-spectrum anticancer activity. Among them, the compound 5h (NCS: 760452, 1-(1H-benzo [d] imidazol-2-yl)-3-(6-(2,4-dichlorophenyl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-3-yl) propan-1-one) exhibited significant growth inhibition with GI50 values ranging from 0.20 to 2.58 μM and found superior selectivity for the leukemia cell lines and further screened at 10-fold dilutions of five different concentrations (0.01, 0.1, 1, 10 and 100 μM). The 5h may possibly be used as lead compound for developing new anticancer agents.

Synthesis of benzimidazoles bearing oxadiazole nucleus as anticancer agents

Starting from 4-(1H-benzo[d]imidazol-2-yl)-4-oxobutanehydrazide (1), twenty new 1-(1H-benzo[d]imidazol-2-yl)-3-(1,3,4-oxadiazol-5-substituted derivatives-2-yl)propan-1-ones (1b-A(7)(-)(26)) were synthesized under microwave irradiation in good yields. Further, compound 1b-A(7) was reacted with different secondary amines under microwave irradiation to produce five novel 1-(1H-benzo[d]imidazol-2-yl)-3-(5-(methyl substituted)-1,3,4-oxadiazol-2-yl)propan-1-ones (1b-A(7a)(-)(e)). The title compounds were screened for their in vitro anticancer activity at National Cancer Institute (NCI), USA; at a single dose (10 μM) in NCI 60 cell line panel and results showed significant to good anticancer activity. One compound, 1b-A(18) (NSC: 759205), 1-(1H-benzo[d]imidazol-2-yl)-3-(5-(2,4-dichlorophenyl)-1,3,4-oxadiazol-2-yl)propan-1-one, emerged as lead compound; it was selected for five-dose level screening and found to have significant growth inhibition activity.

Fenbufen based 3-[5-(substituted aryl)-1,3,4-oxadiazol-2-yl]-1-(biphenyl-4-yl)propan-1-ones as safer antiinflammatory and analgesic agents

The synthesis of a series of 3-[5-(substituted aryl)-1,3,4-oxadiazol-2-yl]-1-(biphenyl-4-yl)propan-1-ones derived from 4-oxo-4-(biphenyl-4-yl)butanoic acid (fenbufen) is described. The structures of these compounds were supported by IR, (1)H NMR, mass spectrometric data and elemental analysis. These compounds were tested for their antiinflammatory, analgesic, ulcerogenic and lipid peroxidation actions. A few compounds were found to have very good antiinflammatory activity in carrageenan induced rat paw edema test, while a fair number of compounds showed significant analgesic activity in acetic acid induced writhing test. The newly synthesized compounds showed very low ulcerogenic action with reduced malondialdehyde (MDA) content, which is one of the byproducts of lipid peroxidation. In vitro COX-1 and COX-2 isozyme inhibition studies were also performed on some of the selected compounds. Compound 4i and 4h were found to be more selective towards COX-2 as indicated by COX-2 selectivity index of 36.06 and 29.05 (COX-2 IC(50)=1.5 microM and 1.8 microM) respectively.

Benzimidazole bearing oxadiazole and triazolo-thiadiazoles nucleus: Design and synthesis as anticancer agents

Two new series of benzimidazole bearing oxadiazole[1-(1H-benzo[d]imidazol-2-yl)-3-(5-substituted-1,3,4-oxadiazol-2-yl)propan-1-ones (4a-l)] and triazolo-thiadiazoles[1-(1H-benzo[d]imidazol-2-yl)-3-(6-(substituted)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-3-yl)propan-1-one (7a-e)] have been synthesized successfully from 4-(1H-benzo[d]imidazol-2-yl)-4-oxobutanehydrazide (3) with an aim to produce promising anticancer agents. In vitro anticancer activities of synthesized compounds were screened at the National Cancer Institute (NCI), USA, according to their applied protocol against full NCI 60 human cell lines panel; results showed good to remarkable anticancer activity. Among them, compound (4j, NCS: 761980) exhibited significant growth inhibition and further screened at 10-fold dilutions of five different concentrations (0.01, 0.1, 1, 10 and 100 μM) with GI(50) values ranging from 0.49 to 48.0 μM and found superior for the non-small cell lung cancer cell lines like HOP-92 (GI(50) 0.49, TGI 19.9,LC(50) >100 and Log(10)GI(50) -6.30, Log(10)TGI -4.70, Log(10)LC(50) >-4.00).

Triazole incorporated pyridazinones as a new class of antihypertensive agents: Design, synthesis and in vivo screening

A number of 6-(substituted phenyl)-2-(4-substituted phenyl-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)-4,5-dihydropyridazin-3(2H)-one derivatives were designed and synthesized by a sequence of reactions starting from respective aryl hydrocarbons. The final compounds (4a-4u) were evaluated for antihypertensive activities by non-invasive method using Tail Cuff method. The compounds 4e, 4i and 4k showed appreciable antihypertensive activity comparable with that of standard hydralazine and propranolol.

Synthesis and pharmacological evaluation of 2(3H)-furanones and 2(3H)-pyrrolones, combining analgesic and anti-inflammatory properties with reduced gastrointestinal toxicity and lipid peroxidation

A series of 3-arylidene-5-(4-chloro-phenyl)-2(3H)-furanones (2-13) and their nitrogen analogues 1-benzylpyrrolones (14-18) were synthesized. The compounds were evaluated for their anti-inflammatory, analgesic, ulcerogenic and lipid peroxidation actions. Some of the newly synthesized compounds showed good anti-inflammatory and analgesic activities with low GI toxicity and reduced lipid peroxidation. The biological activity was found to improve upon replacement of oxygen of furanone ring with benzylamine moiety i.e. 1-benzylpyrrolones. Similarly, compounds containing halogen group(s), compounds 15 and 17, showed higher degree of anti-inflammatory activity and their activity was comparable to that of the standard. These compounds showed interesting profile of analgesic activity in acetic acid induced writhing test (peripheral effect) and in the hot-plate test (central effect). The compounds were also tested for their ulcerogenic and lipid peroxidation action and showed superior GI safety profile along with reduction in lipid peroxidation as compared to that of the standard.

Analytical methods for the detection of undeclared synthetic drugs in traditional herbal medicines as adulterants.

Traditional herbal medicines (THMs) are gaining popularity worldwide as an alternative approach to prescription drugs for many reasons including a general perception that they are safe. But recently there have been number of reported studies that reveal adulteration of THMs with undeclared synthetic drugs, which may potentially cause serious toxic adverse effects. This paper reviews the various classes of synthetic drugs that were found to be adulterated in THMs worldwide. The main focus is to highlight newer analytical tools used to detect adulteration. Due to the advancement in hyphenated techniques like liquid chromatography tandem mass spectrometry (LC-MS/MS), gas chromatography-tandem mass spectrometry (GC-MS/MS) and other conventional tools, it has become possible to detect synthetic drugs and their structural analogues as adulterants even if they are present in small quantities. This review also gives an overview of health-related risks after consuming such spurious products and challenges for future perspectives to control such type of malpractices.