The gastric antiulcer effects of the leaves of the neem tree

Medicinal Plants with Prospective Benefits in the Management of Peptic Ulcer Diseases in Ghana

Background

The growth or multiplication of harmful microorganisms in addition to harmful human activities has led to many disorders in humans. Consequently, there is a search for medications to treat these disorders. Interestingly, medicines of plant origin are known to be among the most attractive sources of new drugs and have shown promising results in the treatment of various diseases including peptic ulcers. This review, therefore, is aimed at obtaining knowledge on some Ghanaian ethnomedicinal plants used to treat peptic ulcers, their folkloric uses, their phytochemicals, and their antiulcer and related pharmacological activities as well as finding areas for prospective studies.

Methods

Published peer-reviewed articles on ethnomedicinal plants used for the management of peptic ulcers in Ghana from 1967 to 2020 were sourced and used for the study.

Results

In this review, 13 plants were identified which belong to 10 different families including Sapindaceae, Apocynaceae, and Bignoniaceae. The parts most often used for most preparations were the leaves (53%), followed by stem bark and roots (both having the same percentage of use of 17.6%), the whole plant (5.9%), and the rhizomes (5.9%). Azadirachta indica was the only plant that had undergone some patient studies in addition to animal studies. Conclusion. A discussion of various antiulcer activity studies using ulcer models carried out on selected medicinal plants used for the management of peptic ulcer disease in addition to brief information on their folkloric uses and their phytochemical and other pharmacological properties is presented. These medicinal plants may be used in developing herbal products for the management of peptic ulcer disease.

Harnessing the Phytotherapeutic Treasure Troves of the Ancient Medicinal Plant Azadirachta indica (Neem) and Associated Endophytic Microorganisms

Azadirachta indica, commonly known as neem, is an evergreen tree of the tropics and sub-tropics native to the Indian subcontinent with demonstrated ethnomedicinal value and importance in agriculture as well as in the pharmaceutical industry. This ancient medicinal tree, often called the "wonder tree", is regarded as a chemical factory of diverse and complex compounds with a plethora of structural scaffolds that is very difficult to mimic by chemical synthesis. Such multifaceted chemical diversity leads to a fantastic repertoire of functional traits, encompassing a wide variety of biological activity and unique modes of action against specific and generalist pathogens and pests. Until now, more than 400 compounds have been isolated from different parts of neem including important bioactive secondary metabolites such as azadirachtin, nimbidin, nimbin, nimbolide, gedunin, and many more. In addition to its insecticidal property, the plant is also known for antimicrobial, antimalarial, antiviral, anti-inflammatory, analgesic, antipyretic, hypoglycaemic, antiulcer, antifertility, anticarcinogenic, hepatoprotective, antioxidant, anxiolytic, molluscicidal, acaricidal, and antifilarial properties. Notwithstanding the chemical and biological virtuosity of neem, it has also been extensively explored for associated microorganisms, especially a class of mutualists called endophytic microorganisms (or endophytes). More than 30 compounds, including neem "mimetic" compounds, have been reported from endophytes harbored in the neem trees in different ecological niches. In this review, we provide an informative and in-depth overview of the topic that can serve as a point of reference for an understanding of the functions and applications of a medicinal plant such as neem, including associated endophytes, within the overall theme of phytopathology. Our review further exemplifies the already-noted current surge of interest in plant and microbial natural products for implications both within the ecological and clinical settings, for a more secure and sustainable future.

Comparative Evaluation of Antiulcer Activity of Ficus religiosa (Stem Bark) Extracts Prepared by Different Methods of Extraction

Background:

The stem bark of Ficus religiosa L. (Family-Moraceae) is traditionally used to treat gonorrhea, diarrhea, dysentery, leucorrhea, menorrhagia, vaginal and other urogenical disorders, ulcers and gastrohelcosis.

Objective:

The study was aimed at comparing antiulcer activity (ethanol induced gastric ulcer) for stem bark extracts of Ficus religiosa Linn. prepared by different extraction methods viz. soxhlet, ultrasonication and microwave assisted extraction.

Methods:

The powdered drug material was extracted by soxhlet (time 48 hours., temperature 60°C and solvent 60% ethanol), Ultrasonic (90 min., 50°C and acetone as solvent)and Microwave (3 min., 60°C and acetone as solvent) assisted extraction method. The acute toxicity study was carried out in adult female albino rats by “fix dose” method of OECD guideline no. 420 for selection of doses. Antiulcerogenic effect of prepared extracts (200mg/kg) was evaluated by ethanol induced ulcer method using omeprazole (40 mg/kg) as standard drug and absolute alcohol 99.5% as necrotizing agent.

Result and Conclusion:

Acute toxicity study did not show any significant toxicity signs and extracts were said to be practically non-toxic at tested dose level of 2000 mg/kg, b.w. The best antiulcer activity was shown by the hydroalcoholic extract prepared by soxhlet extraction method. Administration of ethanol produced significant ulcer index (41.00 ± 1.75) in the control group. Standard drug omeprazole (40 mg/kg) produced percentage protection of 70.31%. Among all three extracts, Ulcer index is significantly (p<0.001) protected by hydroalcoholic extract (Soxhlet Extraction Method) with percentage protection 52.02%.

Effect of Azadirachta indica Crude Bark Extracts Concentrations against Gram-Positive and Gram-Negative Bacterial Pathogens

Background

Today's pharmaceutical markets are crowded with antibacterial agents, yet their toxicities and resistance are always contentious. Azadirachta indica is used in India as an age-old treatment for diverse medical conditions. This study was put forth to analyze the antibacterial action of A. indica bark extract on different bacterial pathogens.

Materials and Methods

A. indica bark extract was prepared using Soxhlet extraction method. The bark extract of A. indica was screened for antibacterial activity by agar well diffusion assay technique against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, and Proteus mirabilis. Ciprofloxacin (5 µg per disc) was used as positive control. All assays were carried out under strict aseptic precautions. All the concentrations included were duplicated, and the results obtained were the average of two independent experiments. Broth microdilution method was used to study the minimum inhibitory concentration of the bark extract of A. indica.

Results

A. indica bark extract has shown antibacterial activity against all concentrations of bark extract, whereas antibacterial activity against S. aureus was observed at higher concentration of >500 µg/mL. The bark extract of A. indica showed zone of clearance against E. faecalis, P. aeruginosa, and P. mirabilis at all concentrations. Zone of inhibition was observed in higher concentrations against S. aureus.

Conclusion

This study has shown that A. indica bark extract has a potent antibacterial property against S. aureus, E. faecalis, P. aeruginosa, and P. mirabilis. Further isolation of bioactive compounds may lead to a new scope in the treatment of bacterial infections.

Gastroprotective Effects of Lion's Mane Mushroom Hericium erinaceus (Bull.:Fr.) Pers. (Aphyllophoromycetideae) Extract against Ethanol-Induced Ulcer in Rats

Hericium erinaceus is a famous tonic in oriental medicine. The gastroprotective effects of aqueous extract of H. erinaceus against ethanol-induced ulcers in Sprague Dawley rats were investigated. The possible involvements of lipid peroxidation, superoxide dismutase, and catalase were also investigated. Acute toxicity study was performed. The effects of aqueous extract of H. erinaceus on the ulcer areas, ulcer inhibition, gastric wall mucus, gross and histological gastric lesions, antioxidant levels, and malondialdehyde (MDA) contents were evaluated in ethanol-induced ulcer in vivo. In acute toxicity study, a high dose of 5 g/kg did not manifest any toxicological signs in rats. The extract promoted ulcer protection as ascertained by a significant reduction of the ulcer area. Furthermore, it exhibited a significant protection activity against gastric mucosal injury by preventing the depletion of antioxidant enzymes. The level of MDA was also limited in rat stomach tissues when compared with the ulcer control group. Immunohistochemistry showed upregulation of HSP70 protein and downregulation of BAX protein in rats pretreated with the extract. The aqueous extract of H. erinaceus protected gastric mucosa in our in vivo model. It is speculated that the bioactive compounds present in the extract may play a major role in gastroprotective activity.

New claims in folk veterinary medicines from Uttar Pradesh, India

BACKGROUND

In remote areas, folk medicines play a significant role in livestock health care management. The aims of this study were to document folk veterinary medicines of the Uttar Pradesh region and identify promising species for pharmacological studies.

METHODS

Fieldwork was conducted over a period of two years in Uttar Pradesh, utilizing the "transect walk" method of participatory rural appraisal (PRA). The data were analyzed through the following techniques: use-value, relative frequency of citation and informant consensus factor (Fic).

RESULTS

This research details the use of 83 medicinal plants used to treat 36 livestock ailments. A total of 91 new medicinal claims were discovered. The ailments are categorized into 11 ailment categories based on certain group of ailments (symptoms/similarities, etc). The Fic values indicate that there was a high degree of consensus among informants regarding how to treat burns, coughs, colds and fevers. The most useful medicinal species, ranked according to their perceived usefulness were: Linum usitatissimum, Saccharum officinarum, Brassica napus, Acacia nilotica, Alocasia macrorrhizos, and Calotropis gigantea. For certain medicinal uses, Ferula asafoetida, Linum usitatissimum, Pandanus tectorius, Brassica juncea, Brassica napus, Madhuca longifolia, Alocasia macrorrhizos and Tagetes erecta were also frequently cited for cures with a Fic value of over 3.00. In remedy preparations, the leaves were the most frequently used plant part (22 instances) and most of the preparations were in the form of crushed plant parts, leaves or otherwise. Herbs were the most frequently used source of medicine (43), followed by trees (21) and shrubs (17%).

CONCLUSIONS

Those plants which received high relative frequency citation (Fic) values may prove useful for pharmacological studies in new drug development projects, especially Ferula asafoetida (used for flatulence), Linum usitatissimum (a galactagogue), Pandanus tectorius (used for estrus regulation/preparation for breeding), Brassica juncea (to cure infections of the tail), Brassica napus (also to cure infections of the tail), Madhuca longifolia (to cure maggots in the hoof), Alocasia macrorrhizos (for estrus regulation) and Tagetes erecta (for otitis).

Antiulcerogenic activities of the extracts and isolated flavonoids of Euphorbia cuneata Vahl

The total alcohol extracts of Euphorbia cuneata Vahl.(Euphorbiaceae) were screened for antiulcerogenic activity using an ethanol-induced ulcer model at doses of 125, 250 and 500 mg/kg. The extracts possessed antiulcerogenic activity in a dose-dependent manner. Four flavonoidal compounds were isolated and identified as naringenin, aromadendrin, apigenin and 4'-O-methoxy-luteolin-7-O-rhamnoglucoside, each demonstrating antiulcerogenic activity with curative ratios ranging from 75.78% to 88.23%. In addition, the alcohol extracts and isolated compounds were shown to scavenge the 1,1-diphenyl,2-picrylhydrazyl radical by different ratio, with the most effective being 4'-O-methoxy-luteolin-7-O-rhamnoglucoside (91.14%). The antioxidant activity of the alcohol extracts and the isolated compounds may explain the antiulcerogenic properties. No side effects were observed on either liver or kidney functions.

Acute toxicity and gastroprotective effect of the Schiff base ligand ¹H-indole-3-ethylene-5-nitrosalicylaldimine and its nickel (II) complex on ethanol induced gastric lesions in rats

The present study was performed to evaluate the gastroprotective activity of Schiff base ligand derived from the condensation reaction of tryptamine (an indole derivative) and 5-nitrosalicylaldehyde (TNS) and its nickel (II) complex against ethanol-induced gastric ulcer in rats. The compounds were orally administered with low (30 mg/kg) and high (60 mg/kg) doses to ulcer-induced Sprague-Dawley rats. Macroscopically, the ulcer control group exhibited severe mucosal injury, whereas pre-treatment with either cimetidine or TNS and its nickel (II) complex each resulted in significant protection against gastric mucosal injury. Flattening of gastric mucosal folds was also observed in rats pretreated with TNS and its nickel complex. Histological studies of the gastric wall of ulcer control group revealed severe damage of gastric mucosa, along with edema and leucocytes infiltration of the submucosal layer compared to rats pre-treated with either cimetidine or TNS and its nickel (II) compound, where there was marked gastric protection along with reduction of edema and leucocytes infiltration of the submucosal layer. Acute toxicity study done on mice with a higher dose of 5 g/kg of TNS and its nickel (II) complex did not manifest any toxicological signs. Research finding suggest that TNS and its nickel (II) complex could be considered as effective gastroprotective compounds.

Cytoprotective effect of benzyl N'-(5-chloro-indol-3-yl-methylidene)-hydrazinecarbodithioate against ethanol-induced gastric mucosal injury in rats

Indolic compounds have attracted a lot of attention due to their interesting biological properties. The present study was performed to evaluate the subacute toxicity and anti-ulcer activity of BClHC against ethanol-induced gastric ulcers. Experimental animal groups were orally pre-treated with different doses of BClHC (50, 100, 200 and 400 mg/kg) in 10% Tween 20 solution (vehicle). Blank and ulcer control groups were pre-treated with vehicle. The positive group was orally pretreated with 20 mg/kg omeprazole. After one hour, all groups received absolute ethanol (5 mL/kg) to generate gastric mucosal injury except the blank control group which was administered the vehicle solution. After an additional hour, all rats were sacrificed, and the ulcer areas of the gastric walls determined. Grossly, the ulcer control group exhibited severe mucosal injury, whereas pre-treatment with either derivative or omeprazole resulted in significant protection of gastric mucosal injury. Flattening of gastric mucosal folds was also observed in rats pretreated with BClHC. Histological studies of the gastric wall of ulcer control group revealed severe damage of gastric mucosa, along with edema and leucocytes infiltration of the submucosal layer compared to rats pre-treated with either BClHC or omeprazole where there were marked gastric protection along with reduction or absence of edema and leucocytes infiltration of the submucosal layer. Subacute toxicity study with a higher dose of derivative (5 g/kg) did not manifest any toxicological signs in rats. In conclusions, the present finding suggests that benzyl N'-(5-chloroindol-3-ylmethylidene)hydrazinecarbodithioate promotes ulcer protection as ascertained by the comparative decreases in ulcer areas, reduction of edema and leucocytes infiltration of the submucosal layer.

Pharmacological mechanisms underlying gastroprotective activities of the fractions obtained from Polygonum minus in Sprague Dawley rats

The leaves of Polygonum minus were fractionated using an eluting solvent to evaluate the pharmacological mechanisms underlying the anti-ulcerogenic activity of P. minus. Different P. minus fractions were obtained and evaluated for their ulcer preventing capabilities using the ethanol induction method. In this study, Sprague Dawley rats weighing 150–200 g were used. Different parameters were estimated to identify the active fraction underlying the mechanism of the gastroprotective action of P. minus: the gastric mucus barrier, as well as superoxide dismutase, total hexosamine, and prostaglandin synthesis. Amongst the five fractions from the ethanolic extract of P. minus, the ethyl acetate:methanol 1:1 v/v fraction (F2) significantly (p < 0.005) exhibited better inhibition of ulcer lesions in a dose-dependent manner. In addition, rats pre-treated with F2 showed a significant elevation in superoxide dismutase (SOD), hexosamine and PGE2 levels in the stomach wall mucosa in a dose-dependent matter. Based on these results, the ethyl acetate:methanol 1:1 v/v fraction was considered to be the best fraction for mucous protection in the ethanol induction model. The mechanisms underlying this protection were attributed to the synthesis of antioxidants and PGE2.

Regenerative Potential of Aqueous Extract of Neem Azadirachta indica on the Stomach and Ileum Following Ethanol-induced Mucosa Lesion in Adult Wistar Rats

Background

The aim of this study was to examine whether neem Azadirachta indica possesses regenerative potential on the stomach and ileum at 500 mg/kg dose given every 12 hours after mucosa lesion was brought by the administration of 1 ml of 50% ethanol for 21 consecutive days in adult Wistar rats.

Methods

Adult male Wistar rats used in the study were divided into 3 groups: group A received oral normal saline and served as control; group B received 1.0 ml of 50% ethanol orally every 12 hours; and group C received neem extract (500 mg/kg) orally 12 hours after ethanol (50%, 1.0 ml) administration to verify its regenerative potential. The experiment lasted for 21 days after which the animals were sacrificed following chloroform inhalation and the stomach and ileum excised and processed for histological and morphometric examinations.

Results

Ethanol treated rats showed marked gross mucosal lesions in the stomach and ileum. Ulcerated mucosa with marked apoptotic bodies and destruction of glandular elements were evident in the animals (group B). Neem extract administered 12 hours after the ethanol administration showed regenerative potential against ethanol-induced mucosal damage. This was characterized by mild restoration of the ulcerated mucosa epithelium and reorganization of the cyto-architechtural outline in group C.

Conclusions

Our investigation suggests that neem extract has a regenerative potential and may be adopted in the management of gastrointestinal disorders such as ulcer.

The use of neem for controlling gastric hyperacidity and ulcer

H(2)-receptor blockers and proton pump inhibitors are now used extensively to control gastric and duodenal ulcer, inflammation and pain, but these drugs have limitations and are not always affordable. The development of novel nontoxic antiulcer drugs, including from medicinal plants, is therefore desirable, and Azadirachta indica A. Juss, commonly known as Neem, is known to have potent gastroprotective and antiulcer effects. This review deals with the pharmacological and biochemical studies carried out regarding the antiulcer activities of Neem extracts and their mechanism of action, including the inhibition of acid secretion. A comparison with ranitidine and omeprazole in some animal models has been included and clinical studies, where available, have also been incorporated, along with a safety evaluation. Neem bark extract has the potential for the development of novel medicines for the therapeutic control of gastric hyperacidity and ulcer.

Cytoprotective effects ofBergenia ciliata Sternb, extract on gastric ulcer in rats

Bergenia ciliata is used for the treatment of stomach disorders in the folk medicine of some areas of South East Asia. This study was designed to evaluate its gastroprotective effects on ethanol/HCl, indomethacin and pylorus ligation-induced gastric ulcers in rats. Doses of 15, 30 and 60 mg/kg b/w of the aqueous and methanol extracts of the rhizome were administered 1 h after ulcerogenic treatment. The animals were killed 3 h later, their stomachs removed and the mean area of ulcer lesion was determined. The weight of mucus and gastric acidity were also measured. The aqueous extract decreased the ulcer lesion (p < 0.05) in all models to a greater extent than the methanol extract, but at the higher doses the effect was reduced. In addition, the antiulcer activity appears to be mediated via cytoprotective effects conferred by enhancement of the mucosal barrier, rather than by prevention of gastric acid secretion or the lowering of pH and acidity.

Antimutagenic effect of neem leaves extract in freshwater fish, Channa punctatus evaluated by cytogenetic tests

Neem (Azadirachta indica), an indigenous plant commonly grown in India and its sub-continent is a multipurpose plant well known for its insecticidal and biomedical properties, however, its antimutagenic effects in vertebrate organisms are lacking. The present work is therefore, focused on possible antimutagenic potential of ethanolic extract of neem leaves evaluated on the clastogenicity induced by Pentachlorophenol (PCP) and 2, 4-dichlorophenoxyacetic acid (2,4-D) in freshwater fish, Channa punctatus used as a vertebrate model, by cytogenetic endpoints: chromosome aberration (CA) and micronucleus (MN) test. In the first set of experiment, fish were exposed by medium treatment to a single treatment of each chemical (PCP, 0.6 ppm; 2,4-D, 75 ppm; neem extract, 3 ppm) along with the controls. The chromosome preparations were made after processing kidney cells and micronucleus slides were prepared from peripheral blood at multiple duration (48, 72 and 96 h). PCP and 2,4-D when used alone, induced significant CA and MN in a time dependent manner. Neem extract did not show genotoxic potential in both assays. The maximum frequency of CA were recorded as 18.58% and 15.17%, while frequency of MN reached to 8.08% and 4.62% by PCP and 2,4-D respectively, after 96 h exposure. In the second set of experiment, three concentrations of neem extract (1, 2 and 3 ppm) were run simultaneously with the same concentration of PCP (0.6 ppm) and 2,4-D (75 ppm) for antimutagenicity estimates. In mixed treatment, neem extract significantly reduced the frequency of CA and MN. The reduction in the frequency of CA ranged from 40-75% and 45.4-83.3% and similar values for MN were 40.2-75.3% and 44.1-65.8% for PCP and 2,4-D respectively. Although the reductions were significant but not dependent on concentration and time intervals employed. Results suggested that under present experimental conditions, neem extract exhibit strong antimutagenic activity in this fish model, which could further contribute to study its benefit in humans.

Neem (Azadirachta indica) leaf mediated immune activation causes prophylactic growth inhibition of murine Ehrlich carcinoma and B16 melanoma

Conditional growth inhibition of murine Ehrlich carcinoma (EC) and B16 melanoma (B16Mel) was observed, following treatment of mice (Swiss and C57BL/6) with aqueous extract of neem (Azadirachta indica) (1 unit/mice/week for 4 weeks) either before or after inoculation of 1 x 10(6) tumor cells. Tumor inoculation after weekly injections for 4 weeks with neem leaf preparation (NLP) induced significant reduction of tumor growth (both EC and B16Mel) and increased survivability of mice. On the other hand, NLP treatment after tumor inoculation demonstrated no tumor growth inhibition in the NLP treated group in comparison to the PBS treated control. No direct cytotoxic effect of NLP towards EC and B16Mel tumor cells was observed in vitro. The spleen cells of NLP treated mice when mixed with inoculum of B16Mel tumor cells and injected into a group of mice, tumor growth was found to be significantly reduced and survivability of the tumor hosts increased remarkably in comparison to mice inoculated with tumor along with normal spleen cells. Concanavalin A (ConA) induced proliferation of lymphocytes from NLP treated mice was significantly higher than the lymphocytes of untreated mice. In in vitro, NLP by itself had no proliferative effects on lymphocytes but it co-stimulated ConA induced mitogenesis. NLP induced lymphocytosis as evidenced by increased lymphocyte count in blood as well as spleen. Flow cytometric evidence suggested that increase in CD4+ and CD8+ T cells accounted for lymphocytosis. The conditional tumor growth retardation, observed in mice treated with NLP before tumor inoculation, may be regulated by NLP mediated immune activation, having prominent role in the cellular immune function of the tumor host.

Protective effects of ethanolic neem leaf extract on N-methyl-N'-nitro-N-nitrosoguanidine-induced genotoxicity and oxidative stress in mice

We evaluated the effects of pretreatment with ethanolic neem leaf extract on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced genotoxicity and oxidative stress in male Swiss albino mice. The frequency of micronuclei (MN), concentrations of lipid peroxides and the status of the antioxidants, reduced glutathione (GSH), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) were used as intermediate biomarkers of chemoprotection. Animals were divided into four groups of five animals each. Animals in group 1 were given MNNG (40 mg/kg body weight) by intragastric intubation. Animals in group 2 received intragastric administration of ethanolic neem leaf extract at a concentration of 200 mg/kg body weight for 5 days followed by MNNG 1.5 h after the final feeding. Group 3 animals received ethanolic neem leaf extract alone for five days. Group 4 received the same volume of normal saline and served as control. The animals were sacrificed by cervical dislocation 27 h after the carcinogen exposure. In MNNG-treated mice, enhanced lipid peroxidation with compromised antioxidant defences in the stomach, liver and erythrocytes was accompanied by increase in bone marrow micronuclei. Pretreatment with ethanolic neem leaf extract significantly reduced MNNG-induced micronuclei and lipid peroxides and enhanced GSH-dependent antioxidant activities. The results of the present study demonstrate that ethanolic neem leaf extract exerts protective effects against MNNG-induced genotoxicity and oxidative stress by augmenting host antioxidant defence mechanisms.

Safety evaluation of neem (Azadirachta indica) derived pesticides

The neem tree, Azadirachta indica, provides many useful compounds that are used as pesticides and could be applied to protect stored seeds against insects. However in addition to possible beneficial health effects, such as blood sugar lowering properties, anti-parasitic, anti-inflammatory, anti-ulcer and hepatoprotective effects, also toxic effects are described. In this study we present a review of the toxicological data from human and animal studies with oral administration of different neem-based preparations. The non-aqueous extracts appear to be the most toxic neem-based products, with an estimated safe dose (ESD) of 0.002 and 12.5 microg/kg bw/day. Less toxic are the unprocessed materials seed oil and the aqueous extracts (ESD 0.26 and 0.3 mg/kg bw/day, 2 microl/kg bw/day respectively). Most of the pure compounds show a relatively low toxicity (ESD azadirachtin 15 mg/kg bw/day). For all preparations, reversible effect on reproduction of both male and female mammals seem to be the most important toxic effects upon sub-acute or chronic exposure. From the available data, safety assessments for the various neem-derived preparations were made and the outcomes are compared to the ingestion of residues on food treated with neem preparations as insecticides. This leads to the conclusion that, if applied with care, use of neem derived pesticides as an insecticide should not be discouraged.

Gastroprotective effect of Neem (Azadirachta indica) bark extract: possible involvement of H(+)-K(+)-ATPase inhibition and scavenging of hydroxyl radical

The antisecretory and antiulcer effects of aqueous extract of Neem (Azadirachta indica) bark have been studied along with its mechanism of action, standardisation and safety evaluation. The extract can dose dependently inhibit pylorus-ligation and drug (mercaptomethylimidazole)-induced acid secretion with ED(50) value of 2.7 and 2 mg Kg(-1) b.w. respectively. It is highly potent in dose-dependently blocking gastric ulcer induced by restraint-cold stress and indomethacin with ED(50) value of 1.5 and 1.25 mg Kg(-1) b.w. respectively. When compared, bark extract is equipotent to ranitidine but more potent than omeprazole in inhibiting pylorus-ligation induced acid secretion. In a stress ulcer model, it is more effective than ranitidine but almost equipotent to omeprazole. Bark extract inhibits H(+)-K(+)-ATPase activity in vitro in a concentration dependent manner similar to omeprazole. It offers gastroprotection against stress ulcer by significantly preventing adhered mucus and endogenous glutathione depletion. It prevents oxidative damage of the gastric mucosa by significantly blocking lipid peroxidation and by scavenging the endogenous hydroxyl radical ((z.rad;)OH)-the major causative factor for ulcer. The (z.rad;)OH-mediated oxidative damage of human gastric mucosal DNA is also protected by the extract in vitro. Bark extract is more effective than melatonin, vitamin E, desferrioxamine and alpha-phenyl N-tert butylnitrone, the known antioxidants having antiulcer effect. Standardisation of the bioactive extract by high pressure liquid chromatography indicates that peak 1 of the chromatogram coincides with the major bioactive compound, a phenolic glycoside, isolated from the extract. The pharmacological effects of the bark extract are attributed to a phenolic glycoside which is apparently homogeneous by HPLC and which represents 10% of the raw bark extract. A single dose of 1g of raw extract per kg b.w. (mice) given in one day and application of 0.6g raw extract per kg b.w. per day by oral route over 15 days to a cumulative dose of 9g per kg was well tolerated and was below the LD(50). It is also well tolerated by rats with no significant adverse effect. It is concluded that Neem bark extract has therapeutic potential for the control of gastric hyperacidity and ulcer.

The plant kingdom as a source of anti-ulcer remedies

Phytogenic agents have traditionally been used by herbalists and indigenous healers for the prevention and treatment of peptic ulcer. This article reviews the anti-acid/anti-peptic, gastro-protective and/or anti-ulcer properties of the most commonly employed herbal medicines and their identified active constituents. Botanical compounds with anti-ulcer activity include flavonoids (i.e. quercetin, naringin, silymarin, anthocyanosides, sophoradin derivatives) saponins (i.e. from Panax japonicus and Kochia scoparia), tannins (i.e. from Linderae umbellatae), gums and mucilages (i.e. gum guar and myrrh). Among herbal drugs, liquorice, aloe gel and capsicum (chilli) have been used extensively and their clinical efficacy documented. Also, ethnomedical systems employ several plant extracts for the treatment of peptic ulcer. Despite progress in conventional chemistry and pharmacology in producing effective drugs, the plant kingdom might provide a useful source of new anti-ulcer compounds for development as pharmaceutical entities or, alternatively, as simple dietary adjuncts to existing therapies.

Pharmacological screening of the anti-ulcerogenic effects of some Jordanian medicinal plants in rats

Ethanolic extracts of 18 medicinal plants traditionally used in Jordan for the treatment of gastric ulcers were evaluated for their possible anti-ulcer activity. Among the tested plants, 12 extracts lowered the severity of ethanol-induced gastric damage in rats with curative ratios ranging from 62.9 to 99.5%. The most active extract was that of Quercus coccifera, with a curative ratio of 99.5%.

Effects of Anchusa strigosa root aqueous extract on gastric ethanol-induced ulcer in laboratory animals

Anchusa strigosa Banks et Sol (Boraginaceae) root extracts (ASRE) were prepared by soaking the dry material in boiling water. The clear soluble extract was dried and found to be 0.238 g/g dry roots. A gastric ulcer was induced in fastened animals by oral ingestion of ethanol. Administration of 0.080 g of ASRE prior to ethanol ingestion protected the stomach of the rat from ulcer formation. The ulcer index values, expressed as a percentage of total stomach surface area affected by the ulcer, were lowered from 34.0+/-4.0 to 6.0+/-0.7 and 32.5+/-9.4 to 2.2+/-1.4 by the morphometric and the planimetric methods, respectively. Treatment of the induced ulcer in guinea pigs was achieved by oral administration of ASRE at the therapeutic dose of extract of 0.286 g/kg body weight/day for 24 days. The intraperitoneal LD50 of ASRE in mice was 0.080 g extract/kg body weight. Replacing water intake by ASRE at 75 ml of variable extract concentrations of 2.865, 3.57 and 4.284 g/l per animal per day for 90 days showed no histopathological changes in all organs of the rat. However, a clear depression effect on the central nervous system and anemia were observed particularly with extract of 3.57 g/l or more.

Limonoids from Azadirachta excelsa

Activity-directed fractionation of a stem extract of Azadirachta excelsa using KB (human oral epidermoid carcinoma) cells led to the isolation of four meliacin-type limonoids. Two of these constituents were novel, namely, 2,3-dihydronimbolide and 3-deoxymethylnimbidate, and these were purified along with the known compounds, nimbolide and 28-deoxonimbolide. The structures of the new compounds were determined by spectroscopic methods. Nimbolide and 28-deoxonimbolide were broadly cytotoxic when evaluated against a panel of human cancer cell lines, while the two novel compounds were inactive in this regard. The defection of nimbolide and 28-deoxonimbolide as cytotoxic constituents was facilitated by an electrospray LC/MS dereplication procedure.

Evaluation of the gastroprotective effect of Laurus nobilis seeds on ethanol induced gastric ulcer in rats

The possible antiulcerogenic activity of Laurus nobilis seeds was tested on experimentally (ethanol) induced gastric ulcer in rats. The results indicated antiulcerogenic activity for 20 and 40% aqueous extracts as well as for the oily fraction of these seeds. In acute toxicity studies, the aqueous extract was found safe with LD50 compared to oil LD50 0.33 ml/kg body weight.

Minor and trace elemental determination in the Indian herbal and other medicinal preparations

Medicinal plants described in the Indian "Ayurvedic" literature viz. Tulsi (Ocimum sanctum), Gulvel (Tinospora cardifolia), bitter Neem (Azadirachta indica), Kanher (Nerium Andicum), Vekhand (Acorus calamus), and Peacock's feather (ash) were analyzed for minor and trace elements by instrumental neutron activation analysis. The samples and the standards from the National Institute of Standards and Technology, USA and IAEA, Vienna were irradiated for 5 min, 1 h, 5 h, and 10 h with thermal neutrons at a flux of 10(12)-10(13) n cm-2 s-1 in APSARA and CIRUS reactor at BARC, Bombay. High resolution gamma ray spectrometry was performed using a 45 cm3 HPGe detector and a 4096 MCA system. Concentrations of 13 elements were determined. Zinc, manganese, and sodium were significantly higher in Tulsi leaves while zinc is higher in Neem leaves. Peacock's feathers were found to be rich in manganese, iron, copper, and zinc. A high concentration of mercury was also found in the peacock's feather ash. The therapeutic significance in restoring ionic balance is discussed.