Safety and Efficacy of Medicinal Plants Used to Manufacture Herbal Products with Regulatory Approval in Uganda: A Cross-Sectional Study

Abstract

Introduction. The Uganda National Drug Authority requires phytochemical screening, freedom from microbial contamination, and evidence of safety and efficacy of the constituent plants to register herbal products. Since Uganda has no pharmacopeia, safety, efficacy, and plant processing information are not readily available. We documented the plant materials used to manufacture products in Uganda and established evidence of their safety and efficacy and availability of monographs. Methods. The NDA register of herbal products was reviewed, and a product list was extracted. The herbal products were purchased from local pharmacies, and their labels were studied to identify plant ingredients and drug use. Literature was reviewed to document evidence of the safety and efficacy of the plant materials concerning manufacturer’s claims. Also, the WHO and available African Pharmacopeia were searched to establish the availability of the plant monographs. Results. Of the 84 NDA-registered local products, only 18 were obtained from the market; 82% were indicated for respiratory tract disorders. Thirty-three plant materials were listed with Eucalyptus globulus Labill, being the commonest. Several in vitro and in vivo studies demonstrate efficacy, thus supporting the use of the selected plant species for empirical treatment as stated on the product label. While most plants were safe, some species such as Albizia coriaria Oliv. had dose-dependent toxicities that cannot be predicted in combinations. The WHO, African Pharmacopoeia, and West African Herbal Pharmacopoeia had only 16 plant monographs of the 33 plants of interest. Nevertheless, Aloe vera (L.) Burm.f., Azadirachta indica A.Juss., Zingiber officinale Roscoe, and Allium sativum L. monographs were published by all three pharmacopoeias. Conclusions. Preclinical evidence of safety and efficacy exists in the literature for most of the plants used to manufacture registered herbal products in Uganda. More specific bioassays and clinical trials are required for the products to provide conclusive evidence of safety and toxicity. Monographs are urgently needed for the Ugandan plants.

Cytotoxicity of Medicinal Plant Species Used by Traditional Healers in Treating People Suffering From HIV/AIDS in Uganda

“…contains a toxic compound, 4-methoxypyridoxine that is a vitamin B6 antagonist ( Botha and Penrith, 2008 ). A. coriaria and W. ugandensis are widely used in traditional herbal preparations as well as commercial herbal preparations in Uganda ( Anywar et al, 2020a ; Kaggwa et al, 2022 ).…”

Application of the Herbal chemical Marker Ranking System (Herb MaRS) to standardization of herbal pharmaceutical raw materials-a case study

“…This work aimed at establishing chemical markers for the seven most commonly used plant species in the manufacture of herbal medicinal products in Uganda, as established in our previous study (6). The study established that Eucalyptus globulus oil was by far the most used material, (in 50% of the products studied); Aloe barbadensis and Albizia coriaria were the second most commonly used, while, Mangifera indica, Warburgia ugandensis, Azadirachta indica and Zingiber officinalis tied in third place (figure 3) We considered these seven most used species and reviewed literature to identify the most suitable markers for their quality control.…”

“…Aloe vera is used as the gel, latex or the whole leaf extract. The whole leaf and latex products are used to treat constipation and to "cleanse" the GIT, and to treat wounds (6). The main active ingredients are anthraquinone glycosides notably Aloin (barbaloin A and B) and aloe emodin (31) (Figure 5).…”

“…The dried stembark or is used as the drug; the commercial products are used for managing symptoms of respiratory tract disorders (whooping cough, catarrh, sore throat, congestion from asthma bronchitis, fever, sinusitis) (6). A few pharmacologically active compounds have been elucidated mainly the triterpenoids lupeol, lupenone, betulinic acid and betulin (115, 116) (Figure 7), with scores 8, 6, 8, 8 respectively.…”

“…The seed oil, leaves and stembark are used as the drug: the products are used to manage respiratory tract disorders (Cough, flu, sore throat, sinusitis), gastrointestinal disorders (gastric ulcers, flatulence, constipation) and as lip balms (dry, cracked, and painful lips) (6). The most important compounds are the tetranortriterpenes (72) including azadirachtin, nimbin, nimbidin, nimbolide and mahmoodin (Figure 9).…”