Oswald R Simon

6-Shogaol reduced chronic inflammatory response in the knees of rats treated with complete Freund's adjuvant.

Background6-Shogaol is one of the major compounds in the ginger rhizome that may contribute to its anti-inflammatory properties. Confirmation of this contribution was sought in this study in Sprague- Dawley rats (200–250 g) treated with a single injection (0.5 ml of 1 mg/ml) of a commercial preparation of complete Freunds Adjuvant (CFA) to induce monoarthritis in the right knee over a period of 28 days. During this development of arthritis, each rat received a daily oral dose of either peanut oil (0.2 ml-control) or 6-shogaol (6.2 mg/Kg in 0.2 ml peanut oil).ResultsWithin 2 days of CFA injection, the control group produced maximum edematous swelling of the knee that was sustained up to the end of the investigation period. But, in the 6-shogaol treated group, significantly lower magnitudes of unsustained swelling of the knees (from 5.1 ± 0.2 mm to 1.0 ± 0.2 mm, p < 0.002, n = 6) were produced during the investigation period. Unsustained swelling of the knees (from 3.2 ± 0.6 mm to 0.8 ± 1.1 mm, p < 0.00008, n = 6) was also produced after 3 days of treatment with indomethacin (2 mg/Kg/day) as a standard anti-inflammatory drug, but during the first 2 days of drug treatment swelling of the knees was significantly larger (11.6 ± 2.0 mm, p < 0.0002, n = 6) than either the controls or the 6-shogaol treated group of rats. This exaggerated effect in the early stage of indomethacin treatment was inhibited by montelukast, a cysteinyl leukotriene receptor antagonist. Also, 6-shogaol and indomethacin were most effective in reducing swelling of the knees on day 28 when the controls still had maximum swelling. The effect of 6-shogaol compared to the controls was associated with significantly lower concentration of soluble vascular cell adhesion molecule-1 (VCAM-1) in the blood and infiltration of leukocytes, including lymphocytes and monocytes/macrophages, into the synovial cavity of the knee. There was also preservation of the morphological integrity of the cartilage lining the femur compared to damage to this tissue in the peanut oil treated control group of rats.ConclusionFrom these results, it is concluded that 6-shogaol reduced the inflammatory response and protected the femoral cartilage from damage produced in a CFA monoarthritic model of the knee joint of rats.

Supplementation with Pumpkin Seed Oil improves Plasma Lipid Profile and Cardiovascular Outcomes of Female Non-ovariectomized and Ovariectomized Sprague-Dawley Rats

Pumpkin (Cucurbita species) seed oil (PSO) is a rich source of phytoestrogens and the aim of this study was to examine the effect of PSO supplementation on the total cholesterol (TC), low density lipoprotein cholesterol (LDL‐C), triglycerides, high density lipoprotein cholesterol (HDL‐C), systolic and diastolic blood pressure in non‐ovariectomized and ovariectomized Sprague‐Dawley rats. Female rats weighing 220–300 g were divided into non‐ovariectomized rats for supplementation with corn oil (control CO; n = 6) or PSO (control PSO; n = 5) and ovariectomized rats for supplementation with corn oil (OVX/CO; n = 6) or PSO (OVX/PSO; n = 5) for 5 days per week for 12 weeks (corn oil 40 mg/kg or PSO 40 mg/kg given orally). Systolic and diastolic blood pressures were measured weekly. Blood was collected at the end of the period for plasma lipid assays. Control PSO had lower TC, LDL–C, triglycerides and higher HDL‐C than the control CO. The OVX/CO had higher TC, LDL–C, triglycerides and lower HDL‐C than the control CO and these changes were prevented in the OVX/PSO rats. PSO supplementation also resulted in lower systolic and diastolic blood pressures in both non‐ovariectomized and ovariectomized rats. It is concluded that PSO supplementation can prevent changes in plasma lipids and blood pressure associated with inadequate oestrogen availability. Copyright

The past and present use of plants for medicines

Evidence of the use of plants for medicinal purposes dates as far back as 60 000 years ago (1) in both western and eastern cultures; in both developed and undeveloped countries. For example, the pharmacopoeia of Emperor Shen Nung of China, around 2730–3000 BC, describes the medicinal use of plants such as Hemp, Aconite, Opium. The Egyptian Pharmacopoeia of Ebers Papyrus, written about 1500 BC, documents the medicinal use of plant extracts such as the poppy of Opium and oil of Castor beans (2, 3). Some of the plants commonly used today, such as peppermint (Mentha piperita), poppy (Papaver somniferum), mugwort (Artemisia vulgaris), sage (Horminum pyrenaicum), rosemary (Hyssopus officinalis), rue (Ruta graveolens) and verbena (Verbena officinalis) are well documented in the “Materia medica” of the great physician Hippocrates (about 460–370 BC) and in the several manuscripts written (around 160 AD) by Galen, a surgeon from Asia Minor. In early civilizations, illness was usually believed to be due to divine punishment. The Aztecs Indian of South America, for example, believed that particular diseases were linked to specific gods; thus their god Tlaloc was associated with diseases caused by water, such as oedema (4). Similarly, Greek physicians, such as Theoprastus, were generally followers of Asclepius, the god of Medicine. Thus the use of plants for healing became strongly associated with the gods. With the fall of the Roman Empire and the advancement of Christianity in western cultures, the use of plants for healing was discouraged. Ironically, although early Christians also saw disease and illness as divine (heaven-sent) punishment, they believed it could only be cured through repentance and prayer, not through the use of medicinal plants. Additionally, as Christianity only recognizes the power of one God, the strong association of many gods and plant medicines led to the value of plant medicines becoming clouded in myths. By the 1500s AD, the use of plants as medicine in western society became further mystified by the “Doctrine of Signatures”. Supporters of the doctrine believed that the physical attributes of plants were indications of their medicinal value. Thus, the holes in the leaves of St John’s wort (Hypericum perforatum) signified

The effect of phytic acid on the levels of blood glucose and some enzymes of carbohydrate and lipid metabolism.

In this study, six groups of rats were fed as follows: Groups 1 and 2 were fed formulated diets supplemented with zinc or without zinc respectively. Groups 3 and 4 were fed formulated diets supplemented with zinc plus phytic acid extracted from sweet potato (Ipomea batatas) or commercial phytic acid respectively. Groups 5 and 6 were fed formulated diets supplemented with phytic acid extract from sweet potato or commercial phytic acid respectively. The animals were fed for three weeks and then sacrificed The activities of key enzymes of carbohydrate and lipid metabolism as well as transaminases in the liver were determined. Blood glucose level was also assessed. Phytic acid extract consumption from sweet potato and commercial phytic acid plus zinc supplement lowered blood glucose levels. There was no significant change in the activity of 6-phosphogluconate dehydrogenase among the groups. Similarly, phytic acid supplementation showed no significant decrease in the activity of pyruvate kinase compared to the group fed formulated diets. There was a significant increase in the activity of glucose-6-phosphate dehydrogenase in the groups fed phytic extract from sweet potato compared to the other groups. The activities of malic enzyme and ATP-citrate lyase in this study were not significantly altered among the groups. There is a lowering of blood glucose levels which is desirable for diabetics who consume sweet potato diets. The changes in some of the hepatic metabolic enzymes are geared towards compensating for the decreased glycolytic responses.

Hypoglycemia and faecal minerals in rats fed phytate

In this study, phytic acid was extracted from Jamaican sweet potato, which has been reported to contain a high phytic acid to zinc ratio and fed to Wistar rats for three weeks. Animals were then sacrificed and blood glucose, intestinal amylase activity and faecal minerals were determined. Blood glucose levels in all the groups fed phytic acid extract from sweet potato or commercial phytic acid were reduced compared to their controls. This lowering was more pronounced in the groups fed phytic acid extract from sweet potato or commercial phytic acid plus zinc supplement. Faecal zinc was significantly higher in the groups fed phytic acid extract from sweet potato compared to the controls in weeks 1 and 2. Supplementation of the diets with phytic acid extract from sweet potato or commercial phytic acid resulted in an increase in the faecal output of iron except for the group that was fed commercial phytic acid plus zinc. Overall, the supplementation of the rat diet with phytic acid extract from sweet potato resulted in a general increase in the output of these faecal minerals.

Isolation of a muscarinic alkaloid with ocular hypotensive action from Trophis racemosa

A muscarinic alkaloid with a quaternary nitrogen was isolated from Trophis racemosa. Aqueous solutions (0.5%–2%) of the chloride salt of the alkaloid produced dose‐dependent reductions of intra‐ocular pressure ranging from 6.6 ± 0.7 mmHg to 15.7 ± 0.3 mmHg, (p < 0.001, n = 5) in dogs. Atropine (0.1 mL of a 1% solution) and pirenzepine at a non selective antagonist dose (0.1 mL of 0.5% solution) for M1 and M3 receptors blocked the reduction of intra‐ocular pressure, but alpha‐adrenoceptor blockade with phenoxybenzamine (0.1 mL of a 1% solution) did not block the reduction of intra‐ocular pressure. On the isolated guinea‐pig ileum and trachea, the alkaloid produced contractions which were inhibited by atropine (6 × 10−7M or 0.4 µg/mL) and by pirenzepine at a non‐selective antagonist dose (3.1 × 10−6M or 1.3 µg/mL) for M1 and M3 receptors. But neither selective blockade of M2 receptors with gallamine (1.7 × 10−6M or 1.5 µg/mL) nor selective blockade of M1 receptors with pirenzepine (7 × 10−9M or 3 ng/mL) inhibited the alkaloid‐induced contractions. There was also no inhibition of the alkaloid‐induced contractions in the presence of ganglionic nicotinic receptor blockade with pentolinium (5.6 × 10−7M or 0.3 µg/mL) and hexamethonium (1.7 × 10−6M or 0.6 µg/mL), but nicotine‐induced contractions were inhibited by these ganglionic blockers. These results suggest that a muscarinic alkaloid from Trophis racemosa produced ocular hypotension via M3 receptor stimulation in dogs. Copyright

Renal and Hepatic Function in Hypercholesterolemic Rats Fed Jamaican Bitter Yam (Dioscorea polygonoides)

ABSTRACT Background: We reported that Jamaican bitter yam (Dioscorea polygonoides) has antilipemic potential in rats; however there is limited data on the toxicological profile of the yam. We therefore investigated the effects of bitter yam consumption for 6 or 12 weeks on renal and hepatic function in rats fed a high (4%) cholesterol diet. Methods: Twenty four rats were divided into six groups (n = 4); three of which were used for each investigation (6 or 12 weeks). One group was administered 4% cholesterol diet, while the yam group had the cholesterol diet supplemented with 5% bitter yam. The control group was fed standard rat chow. Liver and kidney function tests were performed on serum, liver and kidney. Histological studies were conducted on liver samples. Acute toxicity tests were performed in rats and mice administered a single high dose of bitter yam (10 g/kg). Results: Activities of liver and kidney AST and ALT differed (p ≤ .02) between control rats and those fed cholesterol with bitter yam for 12 weeks. Albumin to globulin ratio was reduced (p = .03) in rats fed cholesterol with bitter yam for 6 weeks as compared to the control group. Serum urea concentration was higher (p < .05) in rats fed bitter yam as compared to normal chow for 6 weeks. The cholesterol diet caused extensive fat deposition in liver cells; however this was inhibited by co-administration of bitter yam. Conclusion: Long-term administration of Jamaican bitter yam may induce slight changes in renal and hepatic functions.

An alkaloidal extract (ALKS1) from Trophis racemosa lowers intraocular pressure in dogs

A 1.0% solution of ALKS1, an alkaloidal extract obtained from Trophis racemosa, produced a significant fall in intraocular pressure in the dogs eye (p <0.001). The fall was antagonized by atropine (p <0.0025), suggesting ALKS1 is acting through a muscarinic mode of action. Further purifcation of the extract is required to determine the actual compound producing this effect on the eye.

Demonstration of antihistamine properties with AST-1: a bioactive extract from garden slugs (Diplosolenodes occidentalis)

Parched and ground whole garden slugs are claimed in rural Jamaican folklore practices to have useful effects in the treatment of bronchial asthma. Since this claim may be associated with respiratory dysfunction due to histamine from allergic sensitization, the authors investigated the effects of a semi-pure alcoholic extract (AST-1) on histamine-induced contraction of the guinea pig in vitro tracheal muscle preparation and cutaneous allergic responses in ovalbumin sensitized guinea pigs. Chemical analysis of AST-1 by column chromatography and thin layer chromatography indicated two compounds in the composition, but the molecular structures were not determined Pharmacological evaluation of AST-1 produced a concentration-dependent inhibition of histamine-induced contraction of the guinea pig tracheal muscle preparation. AST-1 also inhibited contraction of the tracheal muscle produced by selective H1 receptor stimulation with HTMT dimaleate. H2 receptors were not involved, as indicated by the absence of contraction with dimaprit hydrochloride, a selective H2 agonist. Also, in ovalbumin sensitized guinea pigs, AST-1 and diphenhydramine, a selective H1 antagonist, inhibited the cutaneous responses due to intradermal injection of histamine and ovalbumin. These results suggest that AST-1 has H1 anti-histamine properties which can inhibit histamine-induced tracheobronchial muscle contraction and cutaneous responses due to allergy.

Choline Supplementation Facilitates Short-term Memory Consolidation into Intermediate Long-term Memory of Young Sprague-Dawley Rats

Choline is important for the synthesis of acetylcholine, an integral neurotransmitter involved in memory formation. In order to investigate the effect of choline supplementation on memory consolidation, the study utilized a T-maze to facilitate passive avoidance learning and memory in young female Sprague-Dawley rats. Rats were placed in two groups; choline-supplemented that received choline chloride daily for two weeks, and control that received vehicle daily for two weeks. Rats were evaluated to determine their ability to avoid an aversive electric foot-shock (0.1 mA at 60V) when they characteristically entered the preferred dark area (DA) of the T-maze. Both groups of rats showed preference, without significant difference, for entry into DA of the T-maze. However, fifteen minutes after passive avoidance both choline supplemented and control rats avoided entry into DA. This display of DA avoidance 15 minutes after training, suggests that both groups of rats had acquired short-term memory of the aversive stimulus. However, when the test was repeated 24 hours after training, the control group did not avoid entry into DA, whereas the choline-supplemented group either avoided entry or entered after a significantly longer latency period (p < 0.01). These results suggest that supplementation with choline facilitated the consolidation of short-term memory of the avoidance learning into intermediate long-term memory in young rats.