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PubMed2005

Anti-ulcer activity of ethanol extract of Terminaliapallida Brandis. in Swiss albino rats.

Ethanol extract of Terminalia pallida Brandis. (EETP) was evaluated for its anti-ulcer activity against various models of ulcers, such as drug-induced ulcers, histamine-induced ulcers and ethanol-induced ulcers in Swiss albino rats. The EETP at the doses of 250 and 500 mg/kg per os (p.o.) exhibited significant protection against ulcers produced by indomethacin, histamine and the effect was comparable to that of the reference drug famotidine (30 mg/kg b.w) orally. The extract also afforded significant protection against ethanol-induced gastric ulceration. Meanwhile, EETP significantly lowered the elevated lipid peroxide level (thiobarbituric acid reactive substances (TBARS)) and restored the altered glutathione level in ethanol-induced gastric ulceration. The present investigation revealed that the EETP exhibited significant anti-ulcer activity by enhancing antioxidant potential of the gastric mucosa, thereby reducing mucosal damage.

Animals↗
PubMed2003

Antimicrobial activity of pentacyclic triterpenes isolated from African Combretaceae.

Four pentacyclic tritepenes were isolated from Combretum imberbe Engl. & Diels, of which two are novel glycosidic derivatives of 1alpha,3beta,23-trihydroxyolean-12-en-29-oic acid (hydroxyimberbic acid). Terminalia stuhlmannii Engl. & Diels stem bark yielded two glycosides of hydroxyimberbic acid, one of which is reported for the first time. The structures of the isolated compounds were elucidated by spectroscopic methods. Several of the compounds had antibacterial activity, imberbic acid showing particularly potent activity against Mycobacterium fortuitum and Staphylococcus aureus.

Anti-Bacterial Agents↗
PubMed2002

The in vitro antimutagenic activity of Triphala--an Indian herbal drug.

A study to evaluate an antimutagenic potential of water, chloroform and acetone extracts of Triphala has been made in an Ames histidine reversion assay using TA98 and TA100 tester strains of Salmonella typhimurium against the direct-acting mutagens, 4-nitro-o-phenylenediamine (NPD) and sodium azide, and the indirect-acting promutagen, 2-aminofluorene (2AF), in the presence of phenobarbitone-induced rat hepatic S9. A combination drug 'Triphala' - a composite mixture of Terminalia bellerica, T. chebula and Emblica officinalis, has been used in traditional system of medicine for the treatment of many malaises, such as heart ailments and hepatic diseases. The drug was sequentially extracted with water, acetone and chloroform at room temperature. The study revealed that water extract was ineffective in reducing the revertants induced by the mutagens. The results with chloroform and acetone extracts showed inhibition of mutagenicity induced by both direct and S9-dependent mutagens. A significant inhibition of 98.7% was observed with acetone extract against the revertants induced by S9-dependent mutagen, 2AF, in co-incubation mode of treatment. Various spectroscopic techniques, namely 1H-NMR, normal 13C-NMR, distortionless enhancement by polarization transfer (DEPT-90 and DEPT-135), UV and IR, are under way to identify the polyphenolic compounds from an acetone extract.

Acetone↗
PubMed2003

Complex formation of sericoside with hydrophilic cyclodextrins: improvement of solubility and skin penetration in topical emulsion based formulations.

The main objective of this study was to devise novel methods for improving the solubility of the anti-inflammatory triterpenoid sericoside, the main component of Terminalia sericea extract, thus enabling its incorporation into topical formulations. Sericoside was stabilized by complex formation with hydrophilic derivatives of beta- and gamma-cyclodextrins in a molar ratio of 1.0:1.1. The complex of extract and cyclodextrin was equilibrated in water at 25 degrees C for approximately 24 h. The dehydrated complexes of T. sericea extract and cyclodextrin were characterized by differential scanning calorimetry, thermogravimetry analysis and X-ray diffraction. Complex formation with beta-cyclodextrin as well as gamma-cyclodextrin derivatives was detectable using these three analytical tools; however, only complexes with gamma-cyclodextrin derivatives showed stability upon storage after incorporation into topical o/w or w/o formulations. Furthermore, a T. sericea extract/gamma-cyclodextrin complex incorporated in an o/w formulation resulted in a 2.6-fold higher percutaneous penetration of sericoside in in vitro excised pig skin as compared to pure T. sericea extract. For the first time, the virtually insoluble anti-inflammatory active sericoside was incorporated into a topical emulsion based formulation in a stable manner, resulting in efficient skin penetration.

Administration, Topical↗
PubMed2004

Casuarinin protects cultured MDCK cells from hydrogen peroxide-induced oxidative stress and DNA oxidative damage.

Casuarinin has been shown to be an antioxidant in acellular experiments. This study was designed to assess the ability of casuarinin, extracted from Terminalia arjuna, to protect cultured Madin-Darby canine kidney (MDCK) cells against H2O2-mediated oxidative stress. A comparison with trolox, a hydrosoluble vitamin E analogue was performed. MDCK cells were pretreated with casuarinin or trolox for 1 h, then exposed to H2O2. After incubation with 0.8 mM H2O2 for 1 h, casuarinin caused a decrease in intracellular peroxide production as shown by dichlorofluorescein (DCF) fluorescence in a concentration-dependent manner. After 3 h exposure to 8 mM H2O2, the percentage of intracellular glutathione (GSH)-negative cells was reduced in the casuarinin-treated group. Addition of 32mM H2O2 to MDCK cells for 3 h induced an increase in the percentage of cells containing 8-oxoguanine but the level of such cells declined in casuarinin-treated cells. These results show that casuarinin is more effective against H2O2-induced oxidative damage than trolox. The data suggest that casuarinin attenuates H2O2-induced oxidative stress, decreases DNA oxidative damage and prevents the depletion of intracellular GSH in MDCK cells.

Animals↗
PubMed2004

New endophytic isolates of Muscodor albus, a volatile-antibiotic-producing fungus.

Muscodor albus, an endophytic fungus originally isolated from Cinnamomum zeylanicum, produces a mixture of volatile organic compounds (VOCs) in culture and its spectrum of antimicrobial activity is broad. Using the original isolate of M. albus as a selection tool, it has been possible to find other culturally and biochemically unique wild-type isolates of this organism existing as endophytes in a variety of other plant species, including Grevillea pterifolia (fern-leafed grevillea), Kennedia nigriscans (snake vine) and Terminalia prostrata (nanka bakarra) growing in the northern reaches of the Northern Territory of Australia. Interestingly, none of the new isolates had a culture morphology that was identical to the original isolate, nevertheless each possessed hyphal characteristics that resembled that isolate. Furthermore, their ITS-5.8S rDNA sequences were 96-99 % identical to that of M. albus and the isolates were considered M. albus on the basis of the DNA sequence data. However, the VOCs produced by these new isolates greatly differed in quality from the original strain by virtue of the production of naphthalene, naphthalene, 1,1'-oxybis-, and one or more other compounds. In bioassays with a range of test micro-organisms, including fungi and bacteria, each isolate possessed biological activity but the range of activity was great. Artificial mixtures of some of the VOCs mimicked the effects of the VOCs of the fungus. The value of these observations to the biology and practical uses of M. albus in agriculture and other applications is discussed.

Anti-Bacterial Agents↗
PubMed2004

Anti-inflammatory properties of BHUx, a polyherbal formulation to prevent atherosclerosis.

BHUx is a polyherbal formulation consisting of water-soluble fractions of five medicinal plants (Commiphora mukul, Terminalia arjuna, Boswellia serrata, Semecarpus anacardium and Strychnos nux vomica). The present study was undertaken to evaluate its antioxidant and antiinflammatory effects. BHUx, standardized by HPLC fingerprinting and filtered through 0.2 microm filter paper, was employed for different studies under in vivo and in vitro conditions. Under in vivo conditions, BHUx significantly reduced inflammation in the carrageenan-induced rat paw oedema model of inflammation, suggesting its anti-inflammatory properties. In order to test the mechanism of action of BHUx, further in vitro studies were undertaken on cumene-hydroperoxide-induced lipid peroxidation (CHP) in liver homogenate, LPS-induced NO production in peritoneal macrophages and on key enzymes of arachidonic acid cascade, involved in the mediation of inflammation. Under the conditions, BHUx showed concentration-dependent inhibition of CHP-induced lipid peroxidation in liver homogenate, suggesting its antioxidant properties. Similarly the potent anti-inflammatory effects of BHUx are evident by (a) preferential inhibition of COX-2 (IC50 for COX-2 = 80 microg/ml and IC50 for COX-1 = 169 microg/ml), (b) low ratios in the IC50 values of COX-2/COX-1 (0.47), (c) decreased production of NO in LPS-induced peritoneal macrophages and (d) inhibition of 5-LOX (IC50 = 795 microg/ml). BHUx also showed a preference for inhibiting 15-lipoxygenase (IC50 = 44 microg/ml), a key enzyme implicated in LDL oxidation. These studies suggest that BHUx is acting mainly at three levels, i.e., as a potent natural antioxidant, by reduction of key inflammatory mediators of arachidonic acid cascade and by preventing 15-LOX-mediated LDL oxidations, to prevent atherosclerosis.

Analgesics↗
PubMed2005

Screening of crude extracts of six medicinal plants used in South-West Nigerian unorthodox medicine for anti-methicillin resistant Staphylococcus aureus activity.

BACKGROUND: Six Nigerian medicinal plants Terminalia avicennioides, Phylantus discoideus, Bridella ferruginea, Ageratum conyzoides, Ocimum gratissimum and Acalypha wilkesiana used by traditional medical practitioners for the treatment of several ailments of microbial and non-microbial origins were investigated for in vitro anti-methicillin Resistant Staphylococcus aureus (MRSA) activity. METHODS: Fresh plant materials were collected from the users. Water and ethanol extracts of the shredded plants were obtained by standard methods. The Bacterial cultures used were strains of MRSA isolated from patients. MRSA was determined by the reference broth microdilution methods using the established National Committee for Clinical Laboratory Standards break points. Staphylococcus aureus NCIB 8588 was used as a standard strain. Susceptibility testing and phytochemical screening of the plant extracts were performed by standard procedures. Controls were maintained for each test batch. RESULTS: Both water and ethanol extracts of T. avicennioides, P. discoideus, O. gratissimum, and A. wilkesiana were effective on MRSA. The Minimum Inhibition Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the ethanol extracts of these plants range from 18.2 to 24.0 mcg/ml and 30.4 to 37.0 mcg/ml respectively. In contrast, MIC range of 30.6 to 43.0 mcg/ml and 55.4 to 71.0 mcg/ml were recorded for ethanol and water extracts of B. ferruginea, and A. conyzoides respectively. Higher MBC values were obtained for the two plants. These concentrations were too high to be considered active in this study. All the four active plants contained at least trace amount of anthraquinones. CONCLUSION: Our results offer a scientific basis for the traditional use of water and ethanol extracts of A. wilkesiana, O. gratissimum, T. avicennioides and P. discoideus against MRSA-associated diseases. However, B. ferruginea and A. conyzoides were ineffective in vitro in this study; we therefore suggest the immediate stoppage of their traditional use against MRSA-associated diseases in Lagos, Nigeria.

Ageratum↗
PubMed1998

Modern drug development from traditional medicinal plants using radioligand receptor-binding assays.

Traditional medicinal plants in various countries, particularly in India have been used for centuries for various ailments; however, there has been little scientific effort to validate these anecdotal uses mentioned in the literature. A number of these traditionally used plant extracts and various "Ayurvedic medicines" that are highly valued in Ayurveda, the traditional system of medicine in India for antiaging, memory-enhancing, nerve tonic, anxiolytic, anti-inflammatory and immunopotentiation, have been screened using National Institutes of Mental Health (NIMH) Synthetic Screening Program for scientific validation and the development of new leads of psychotherapeutic compounds using Radioligand Receptor Binding Assays (RRA). Crude methanolic extracts of plants are screened using approximately 40 different in vitro RRA (primarily from rat brain homogenates) and 6 enzyme assays including acetylcholine esterase, choline acetyltransferase, and monoamine oxidase (MAO), A and B. The total crude extracts of many of these plants showed potent selectivity to various receptors, especially gamma-Amino Butyric Acid (GABA(A)), N-Methyl-D-Aspartic Acid (NMDA), and MAO receptors, which are presumed to be involved in mental disorders. The focus was on plants showing the highest displacement of GABA, cholecystokinin (CCK), NMDA, MAO, and benzodiazopines. Bioassay guided fractionation of the most active extracts resulted in pure compounds which retained the original activity of the crude extract validating the folkloric use. A bioactivity-guided fractionation of Terminalia bellerica fruit extract led to the isolation of several pure compounds which retained the original activity of the crude extract for CCK and GABA receptors, with the exception of compound B3EA-6, which exhibited high affinity for Neurokinin receptor (Substance K approximately NK-1). The absolute structure of B3EA-6 has been established by x-ray crystallography.

Animals↗
PubMed1999

Adaptogenic properties of six rasayana herbs used in Ayurvedic medicine.

Plants from all over the world such as Eleutherococcus senticosus, Panax ginseng, Raponticum carthamoides, Rhodiola rosea, Withania somnifera and Ocimum sanctum have been extensively evaluated for their adaptogenic potential. However, none of them has been successfully introduced as an adaptogen in the clinic. This paper discusses some of the problems in evaluation of adaptogens which have precluded their inclusion as clinically useful drugs. We further discuss our results with six rasayana plants from Ayurveda, which were studied for their adaptogenic potential. The whole, aqueous, standardized extracts of selected plants (Tinospora cordifolia, Asparagus racemosus, Emblica officinalis, Withania somnifera, Piper longum and Terminalia chebula) were administered orally to experimental animals, in a dose extrapolated from the human dose, following which they were exposed to a variety of biological, physical and chemical stressors. These plants were found to offer protection against these stressors, as judged by using markers of stress responses and objective parameters for stress manifestations. Using a model of cisplatin induced alterations in gastrointestinal motility, the ability of these plants to exert a normalizing effect, irrespective of direction of pathological change was tested. All the plants reversed the effects of cisplatin on gastric emptying, while Tinospora cordifolia and Asparagus racemosus also normalized cisplatin induced intestinal hypermotility. Tinospora cordifolia was also tested for its ability to modulate the changes occurring in the phagocytic activity of peritoneal macrophages after exposure of rats to either carbon tetrachloride or horse serum. It was found to normalize the phagocytic function irrespective to the direction of change, complying to the definition of an adaptogen. All the plant drugs were found to be safe in both acute and subacute toxicity studies. Studies on the mechanisms of action of the plants revealed that they all produced immunostimulation. The protection offered by Tinospora cordifolia against stress induced gastric mucosal damage was lost if macrophage activity was blocked. Emblica officinalis strengthened the defence mechanisms against free radical damage induced during stress. The effect of Emblica officinalis appeared to depend on the ability of target tissues to synthesize prostaglandins. Recent data obtained with Tinospora cordifolia suggest that it may induce genotypic adaptation, further opening the arena for more research and experimentation.

Adaptation, Physiological↗
PubMed1999

Antibacterial activities of extracts from Nigerian chewing sticks.

Ten aqueous extracts from wooden chewing sticks widely used in Nigeria for teeth cleaning were studied for antibacterial activities against 25 different bacteria using an agar diffusion assay. The extracts from five sticks, namely Garcinia kola, Anogeissus leiocarpus, Terminalia glaucescens, Sorindeia warneckei and Vitex doniana, exhibited strong activities against a wide spectrum of bacteria including medically and dentally relevant bacteria. Notably, these five chewing stick extracts showed potent activities against methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, and multidrug-resistant Burkholderia cepacia and Pseudomonas aeruginosa. Extracts from Vernonia amygdalina, Fagara zanthoxyloides and Massularia acuminata also showed activities against bacteria significant to periodontal disease. Methanol extracts prepared from G. kola, A. leiocarpus and V. doniana were further fractionated by solvent extraction. Results showed that the antibacterial activities were distributed into different fractions suggesting that the sticks contain different active antibacterial principles. In conclusion, the results showed that most of the Nigerian chewing sticks do contain antibacterial activities which may contribute to the reported anticaries effect of chewing sticks. These sticks may be sources for new lead antibacterial agents for therapeutic or preventive applications.

Anti-Bacterial Agents↗
PubMed2005

Suppression of the onset and progression of collagen-induced arthritis by chebulagic acid screened from a natural product library.

OBJECTIVE: Chebulagic acid (CHE) from the immature seeds of Terminalia chebula was identified from a natural product library as a potent suppressor of T cell activity. This study examined the effectiveness of CHE against the onset and progression of collagen-induced arthritis (CIA) in mice. METHODS: Arthritis was induced in DBA/1J mice by subcutaneous immunization with bovine type II collagen on days 0 and 21. CHE was administered intraperitoneally for 3 weeks, either as prophylaxis (10 or 20 mg/kg) before disease onset or as therapy (20 mg/kg) after disease onset. Clinical scores, serum antibody levels, and cytokines were measured, and flow cytometric analysis and real-time reverse transcription-polymerase chain reaction were performed to evaluate the knee joints of mice with CIA. RESULTS: In both the prophylactic and therapeutic CHE dosing models, all clinical scores, serum levels of total and anticollagen IgG, and levels of interleukin-10 (IL-10) and IL-6 were reduced, while serum levels of transforming growth factor beta (TGFbeta) were markedly elevated. The number of granulocytes was reduced, but the proportion of CD4+,CD25+ T cells was greater in the knee joints of CHE-treated CIA mice. Expression of Foxp3 and TGFbeta messenger RNA was also augmented significantly in the knee joints of CHE-treated CIA mice in the therapeutic dosing model. CONCLUSION: CHE significantly suppressed the onset and progression of CIA in mice. Immune suppression via the induction of TGFbeta and CD4+,CD25+ T cells may represent a new strategy in the development of therapies for managing rheumatoid arthritis and other inflammatory diseases.

Animals↗
PubMed1982

Further studies of the engrailed phenotype in Drosophila.

Although most mutations at the engrailed locus of Drosophila cause embryonic death when homozygous, they are viable in clones of cells. We describe the phenotype of such clones in the eye-antenna, proboscis, humerus, wing, legs, and terminalia. When in anterior compartments the clones are normal, but in most posterior compartments they are abnormal and fail to respect the anteroposterior compartment boundary. We find that the yield of engrailed-lethal clones in posterior compartments is often significantly lower than expected, indicating that these clones are lost during development. Mutant clones are abnormal in the analia and rare in the humerus, suggesting that both structures are of posterior provenance. These results support the hypothesis that the engrailed+ gene is required exclusively in cells of posterior compartments to specify their characteristic cell affinities and pattern.

Animal Population Groups↗
PubMed2003

Screening South Indian medicinal plants for antifungal activity against cutaneous pathogens.

In this study, twenty-eight South Indian medicinal plants were screened for their anti-fungal activity against six species of fungi (Trichophyton mentagrophytes, T. rubrum, T. soudanense, Candida albicans, Torulopsis glabrata, and C. krusei). Three plant species extracts, Celastrus paniculatus, Eriodendron anfractuosum and Ficus glomerata showed inhibitory activity. An aqueous extract of galls of Terminalia chebula showed inhibitory effects on three dermatophytes (Trichophyton spp.) and three yeasts (Candida spp.). Seeds extract of T. chebula inhibited only the growth of T. glabrata. An aqueous extract of T. chebula showed inhibitory effects higher than those measured in ethanol extracts. It is therefore suggested that tannins are plausible candidates for the anti-dermatophytic effects of T. chebula. Chebulinic acid, a known tannin of T. chebula was tested and found not inhibitory, thus a search for the active compound is needed.

Antifungal Agents↗
PubMed2001

Antioxidant and hepatoprotective effects of punicalagin and punicalin on acetaminophen-induced liver damage in rats.

Punicalagin and punicalin were isolated from the leaves of Terminalia catappa L., a Combretaceous plant distributed throughout tropical and subtropical beaches, which is used for the treatment of dermatitis and hepatitis. Our previous studies showed that both of these compounds exert antioxidative activity. In this study, the antihepatotoxic activity of punicalagin and punicalin on acetaminophen-induced toxicity in the rat liver was evaluated. After evaluating the changes of several biochemical functions in serum, the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were increased by acetaminophen administration and reduced by punicalagin and punicalin. Histological changes around the hepatic central vein and oxidative damage induced by acetaminophen were also recovered by both compounds. The data show that both punicalagin and punicalin exert antihepatotoxic activity, but treatment with larger doses enhanced liver damage. These results suggest that even if punicalagin and punicalin have antioxidant activity at small doses, treatment with larger doses will possibly induce some cell toxicities.

Acetaminophen↗
PubMed2001

Evaluation of Ophthacare eye drops--a herbal formulation in the management of various ophthalmic disorders.

An open prospective multicentre clinical trial was conducted in patients suffering from various ophthalmic disorders namely, conjunctivitis, conjunctival xerosis (dry eye), acute dacryocystitis, degenerative conditions (pterygium or pinguecula) and postoperative cataract patients with a herbal eye drop preparation (Ophthacare) containing basic principles of different herbs which have been conventionally used in the Ayurvedic system of medicine since time immemorial. These include Carum copticum, Terminalia belirica, Emblica officinalis, Curcuma longa, Ocimum sanctum, Cinnamomum camphora, Rosa damascena and meldespumapum. These herbs reportedly possess antiinfective and antiinflammatory properties. The present study was undertaken to elucidate the role of this herbal product in a variety of eye ailments. Side effects, if any, were noted during the study. An improvement was observed with the treatment of the herbal eye drop treatment in most cases. There were no side effects observed during the course of the study and the eye drop was well tolerated by the patients. The herbal eye drop Ophthacare has a useful role in a variety of infective, inflammatory and degenerative ophthalmic disorders.

Adult↗
PubMed2001

Antiradical and antilipoperoxidative effects of some plant extracts used by Sri Lankan traditional medical practitioners for cardioprotection.

Reactive oxygen species (ROS) are implicated in many pathogenic processes including the cardiovascular system. Detoxification of ROS by antioxidants (AO) therefore affords protection against such diseases. There is a growing body of evidence suggesting that antioxidants contribute to cardioprotection. Therefore, nine plants that are components of Ayurvedic formulations used for the therapy of cardiovascular diseases were investigated to determine whether antioxidant activity is one of the mechanisms by which these plants exert cardioprotection. Initially aqueous freeze dried extracts of the plants were prepared and the antioxidant activity was measured (a) in vitro, by DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging and deoxyribose damage protection assays, and (b) in vivo, by effects on lipid peroxidation. Terminalia arjuna showed significant DPPH radical scavenging activity with EC(50) 8.3 +/- 0.3 microg/mL (similar to L-ascorbic acid). The potency of this activity was much lower in Cassia fistula (EC(50) = 59.0 +/- 2.7 microg/mL). The other seven extracts demonstrated no such activity in the concentration range tested. In the deoxyribose damage protection assay, T. arjuna> demonstrated no significant effect in the concentration range 0-20 microg/mL, but above -20 microg/mL concentration (20-125 microg/mL), a pro-oxidant activity was observed (although markedly less than demonstrated by L-ascorbic acid). A similar trend was observed with Vitex negundo. In contrast, C. fistula afforded a 30% protection against such damage at 125 microg/mL concentration. Other plant extracts did not show any activity in this assay. At a dose of 90 mg/kg (single dose) T. arjuna, cardiac lipid peroxidation in male Wistar rats was reduced by 38.8% +/- 2.6% (p<0.05) whereas the reduction was only 11.6% +/- 3.5% in the case of C. fistula even at a dose of 120 mg/kg. Of all the plants tested, T. arjuna demonstrated the highest antioxidant activity. Overall results show that only some plants used in the therapy of cardiovascular disease exert their beneficial effects via antioxidant activity.

Animals↗
PubMed2002

More woody plants? The status of bush encroachment in Botswana's grazing areas.

Foci points, which are currently intensified by increased anthropogenic activities, have resulted in vegetation changes in the cattle-dominated grazing areas of Botswana. Bush encroachment species--for instance Acacia tortilis, A. erubescens, A. mellifera, Dichrostachys cinerea, Grewia flava, and Terminalia sericea--are increasing in cover and density around foci points (e.g. water points and kraals) at the expense of the grass cover. A number of factors have the effect of encouraging the germination and survival of bush encroachment species. The practice of cattle husbandry and continual shifting of foci points within grazing areas have resulted in the spread of the distribution of bush encroachment species across the country. This is evidenced by the potential extent of 37,000 km2 (6.4% of Botswana) of darkened and near infrared (NIR) reflective bush encroached areas in 1994. This paper suggests that specific management strategies should be adopted to help overcome the bush encroachment problem, which is causing a significant reduction in the extent of Botswana's high quality rangeland. These strategies may vary from the enforced reduction of grazing intensity in areas identified as being heavily bush encroached to the selective management of opportunistic (communal) grazing in better quality predominantly grassland areas. Further work is however required to update this analysis and especially to consider trends since 1994-1995. While some work on the extent of woody cover and the further causes of bush encroachment is being undertaken under the SAFARI2000 project, more research is needed in specific areas to pinpoint causes and responses to the bush encroachment problem.

Agriculture↗